THE LIBRARY OF THE UNIVERSITY OF CALIFORNIA LOS ANGELES LABYRINTH PAPERS BY GEORGE W. MACKENZIE, M. D. PHILADELPHIA, PA. THIS COLLECTION OF 1'Al'KKS IS DEDICATKD To MY FRIEND AND TBACHBR, PROFESSOR GUSTAV ALEXANDER. tiiomedieaJ Library wv 1113 VORWORT. Es bereitet mir eine grosse Genugthuung, dem vorliegenden \Yerke meines Freundes und langjahrigen Schiilers Dr. George \\". Mackenzie einige Worte vorausschicken zu diirfen. Durch die Forschungsergebnisse der letzten Jahre hat die Klinik der Labyrintherkrankungen eine vollkommene Umgestaltung und ungeahnte Bereicherung erfahren. Die modernen Untersuchungsme- thoden des Ohrlabyrintbes setzen uns instand Erkrankungsformen und Erkrankungsgrade des Labyrinthes zu diagnoszieren, die in friiherer Zeit \vegen der Geringfiigigkeit der Initialsymptome oft lange unent- deckt geblieben sind. Auch die Bebandlung der Labyrintherkrankungen hat eine neue Gestaltung erfahren; es gilt diese sowohl fur die leichteren Formen nnd die conservative Behandlung als auch fiir die operative Behand- lung der sclnveren und komplizierlen Formen der Labyrintheiterung. Dr. George W. Mackenzie hat unter meiner Leitung mehrere Jahre sein ganzes Konne-n und Studium der Frage der Labyrinthkrankheiten gewidmet. Ich habe im Laufe dieser Zeit nicht bloss erkannt, dass er das \\issenschaftliche Material vollstandig beherrscht, sondern dass er auch in vorzuglicher \\"eise imstande ist, Andere in die klinische Un- tcrsuchungs- and Behandlungs rethoden einzufiihren und zu unter- richten. Dr. George \Y. Mackenzie scheint daher in besonderer Form berufen und vorziiglich befahigt, ein Buch iiber die Klinik der Labyrinthkrank- heiten zu verfassen. Das Ziel. das er sich bei der Abfassung des Buches gesteckt hat, hat er vollstandig und in vorzuglicher Weise errcicht. Mas Buch \\ird ebenso sehr dem Otologen. als auch dem Chirurgen, Xervenarzt. Tnternisten und Paediater ein willkommener Behelf sein. DR. GUSTAV ALRXAXDI.K. a. o. Professor an der A'. A'. Wiener Universitat Vorst and der Ohrenabteile d. Algetnein Wein. CONTENTS PAGES. Introductory Remarks 4 Diagnosis and Treatment of Labyrinth Suppuration 5 Labyrinth Suppuration Two Cases 13 Labyrinth Suppuration Differential Diagnosis 33 Differentiation of Labyrinth Suppuration from Cerebellar Abscess 46 Differentiation of Labyrinth Suppuration from Affections of the Eighth Nerve 62 Prognosis and Treatment of Labyrinth Suppuration 77 Physiology and Pathology of the Non-Acoustic or So-Called Static Laby- rinth Aanatomy 95 Nystagmus 1 16 Turning and After-Turning Nystagmus 130 Caloric Nystagmus 150 Galvanic Nystagmus 161 Urticulus and Sacculus : 174 Vertigo !88 Labyrinth Fistula .200 Report and Discussion of Labyyrinth Fistula . 210 INTRODUCTORY REMARKS. At the request of many friends in the profession, who have lookea with favor upon my writings on the Labyrinth, I consent to the publica- tion of the collection in this volume. In June, 1908, when presenting my first paper on the subject of Labyrinth Suppuration, there was no intention of writing so exten- sively upon the Labyrinth ; however, requests for others came in such rapid succession that it was not long before I realized that I was fairly launched in compiling a series of papers. The papers herein contained were witten for various Societies and Journals between June, 1908, and February, 1911. Each of these papers practically comprises a chapter. The effort was to make each paper complete in itself and still make the various papers dove-tail into each other, and in the end to make the series com- plete by covering every phase of the subject of the Labyrinth and its diseases. In a few instances, repetitions appear ; however, where they have occurred the writer had thought them of sufficient importance to war- rant the repetition. I wish to take this opportunity of thanking my friend and teacher, Professor Adam Politzer, with whom I studied and worked as aspirant assistant in the general hospital of Vienna; and no less to Professor Gustav Alexander, with whom I studied and worked as aspirant assist- ant in the Polyclinic of Vienna. With the latter I spent two most profitable years, receiving valuable suggestions and encouragement. THE DIAGNOSIS AND TREATMENT OF LABYRINTH SUP- PURATION. OUR knowledge of labyrinth suppuration, developed during the last few years, has revolutionized the science of otology. At the present time no one can pretend to practice otology who is not thoroughly familiar with this subject. An understanding of labyrinth suppuration presupposes : 1. A knowledge of the anatomy of the inner ear and the relative positions of the semicircular canals in the skull. 2. A knowledge of the physiology, especially of the nonacoustic labyrinth, as determined by Ewald, Breuer, Crum-Brown. Mach, Kreidl. Alexander. Kub<>. I'.arany. Stein. Krotoscheiner and others. Upon the more recently gained knowledge of the physiology of the nonacoustic labyrinth, exact examination methods have been developed which make possible an exact diagnosis in practically every case of labyrinth suppuration. The time allowed will not permit me to discuss in detail the physi- ology of the labyrinth ; however, for practical purposes, enough of the physiology will be brought out while discussing the diagnosis an;! the methods of examination used. The symptoms and signs of acute laby- rinth suppuration are briefly as follows : 1. Deafness of sudden onset. 2. Vertigo with nausea and vomiting. 3. Spontaneous rotatory nystagmus toward the sound side. 4. Disturbances of equilibrium. 5. Negative caloric reaction. 6. Diminished or negative reaction to turning. 7. Diminished or negative reaction to Galvanism. We shall now discuss separately the above symptoms and signs in the order given. i. Deafness of sudden onset. Deafness is a constant symptom of acute labyrinth suppuration which differentiates it from other forms of labyrinthitis diffuse serous labyrinthitis and circumscribed labyrinthitis. In the suppura- tive form of labyrinthitis the deafness is complete and permanent, while S TREATMENT OF LABYIU.\TH SUPPURATION. in the other forms there are remains of hearing ami the ultimate prog- nosis to hearing is good. Since no one would care to remove a labyrinth where there are re- mains of hearing, nor on the other hand neglect to operate a suppurat- ing labyrinth where the mortality without operation is above 70 per cent., the determination of deafness becomes a question of vital import- ance to the patient'^ hearing in the one instance and to the patient's life in the other. Prior to the introduction of the new, small (a^ fork of Bezold, the only errors made in the diagnosis of labyrinth suppuration arose from the uncertainty in the determination of deafness in a case where all other signs and symptoms were positive. At that time the best method for recognizing onesided deafness was the 2 and 3 meter speaking- tube. I have examined cases of unilateral deafness with the speaking tube when it seemed impossible for the patient to hear from the good ear, which was completely closed with a moistened finger, and yet they were able to repeat whispered words. Experimentally I have examined cases where the labyrinth had been removed, and the patient was ap- parently able to hear whispered words from that side through the tube. The only explanation is that the sound must have been trans- mitted to the well ear. To avoid all possibility of transmission of sounds to the well ear, Bezold designed the new small (a t ) fork, which has the advantage of being heard very distinctly when held close to the ear and of not being heard at all at a distance of 7 or 8 inches (the width of the skull or the distance necessary to be traversed in order to be heard by the other ear). I have examined a number of cases of one-sided deafness, using both methods (the tube and the small a, fork) and the fork has invariably ^iven more satisfactory re- sults than the 3 meter tube. Beside these methods, the other functional hearing tests (Rhine, Schwabach, Weber and the continuous chain of forks) will be an aid in diagnosing one-sided deafness. 2. Vertigo with nausea and vomiting. In acute labyrinth suppuration the vertigo is very intense and in- variably associated with nausea and vomiting. The vertigo is most pronounced at the onset of the process but gradually diminishes after three days; however, brief attacks of vertigo may be produced by rapid movements of the head for several weeks afterward. This LABYRIXTIl I'.irilKS. g vertigo is characteristic and known as vestibular vertigo ; it must be differentiated from ocular and central vertigo. Vestibular vertigo is characterized by certain subjective phenomena. The patient feels that the room and surrounding objects are moving about him in a circle around his axis of vision. The direction of this movement in a case of left labyrinth suppuration is the same as that made by the hands of a clock, and when the eyes are closed the patient has the sensation of falling to the right. In case of a right labyrinth suppuration the sen- sations are reversed. Yestibular vert'igo combined with sudden deafness speaks for some destructive process of the labyrinth, and when found in the course of chronic suppuration of the middle ear speaks for acute labyrinth sup- puration. For a further description of vestibular vertigo and its differentiation from the other types, see Panse's Work on Schwindel, 1902. 3. Spontaneous rotatory nystagmus toward the sound side. This symptom is constantly present, and like the vertigo it is most pronounced upon the first day and gradually diminishes during the fol- lowing three or four we?ks. when it practically ceases. In exceptional cases it may be observed months afterward. The vestibular nystagmus is due to the overbalance of impulses from the normal side (Normal Tonus}. This normal tonus can be better understood when we produce artificially a condition similar to that found in labyrinth destruction. This experiment can be made upon normal people by applying the anode to one side (say the right side) ; this produces an anelectrotonus of the right side, suppressing the normal tonus. At the same time the normal tonus from the opposite or left side pr<>< luces an overbalance of vestibular impulses from the left side and thereby a nystagmus to the left. Spontaneous nystag- mus associated with labyrinth suppuration is most pronounced when the patient looks toward his well side (the side of his nystagmus) ; however, during the first few days it may be observed in all positions of the eyeball. 4. Disturbances of equilibrium. These may be divided into two separate forms: the early and the late. The early is more marked and is so intense as to amount to a loss of equilibrium, which compels the patient to seek a recumbent position. ,o TKl-.lT.Mi-.\T 01- LABYRINTH SUPPURATION. The tendency ,.f the patient is to fall towards the diseased side. This tendency is increased when the eyes are closed. Falling to the diseased side may be termed "Reaction falling" an associated phenomenon of nystagmus. The explanation of this phenomenon is as follows: In a case of right labyrinth suppuration the patient has rotatory nystagmus to the left, accompanied by the subjective sensation of falling to the left. In his attempt to correct this subjective sensation of falling to the left, he overcorrects and actually falls to the right (toward the diseased side). The late form of disturbance of equilibrium is not accepted by some authors, including Barany ; however I hold that there is a late form, as do also Alexander. Kreidl. Stein. Krotoscheiner, Frey and Ham- merschlag. Recently I conducted a series of experiments upon a num- ber of cases, of late one-sided labyrinth destruction and deaf-mutes c "Klinische Untersuchungen iiber die labyrinthaeren Gleichgewicht- nmgen u. s. w." Arch. f. Ohren. Bd. 78, 1909. I found that, without exception, every case of late one-sided laby- rinth destruction showed positive signs of disturbance in equilibrium by the following tests: Khomberg. the gait (forward, backward and to the sides, with open and closed eyes), standing on one foot, hop- ping forward and backward upon one foot, elevation on the Alexander Stein goniometer with the face forward, backward and to the two sides, with open and closed eyes. 5. Negative caloric reaction. This examination method belongs to Barany (see his book on Phy- siologic und I\itliolo^ic lies jio^cngdiigs .Ipparat). 1908. Before the time of llarany, Breuer and others had experimentally produced vertigo in man and nystagmus of the head in animals, by the use of cold water syringed into the external canal; however, it remained for Barany t tir>t adopt these reactions for clinical purposes. The normal ear syringed with water colder than the body tempera- ture, produces a rotatory nystagmus to the opposite side, lasting for a few minutes ; whereas water warmer than the body tem- perature produces the opposite effect rotatory nystagmus to the same side. These caloric reactions are explained by Barany as due to cur- rents set up in the endolymph in the same manner as all other cur- LABYRIXTH PAPERS. u rents are produced in vessels containing fluid, when the temperature of any part of the fluid is changed. One thing characteristic of the caloric reaction, worth mentioning here, is that the nystagmus may be changed in character and direction by changes in position of the head. As an illustration : If we syringe the right ear with cold water with the head in an upright position a rotatory nystagmus to the left is produced ; now if we turn the head 90 to the left so that the head rests upon the left shoulder, the rotatory nystagmus to the left changes to a horizontal nystagmus to the right. The caloric test is the most certain qualitative test of the nonacoustic labyrinth, and when negative speaks for destruction of function in the semicircular canals (a most valuable diagnostic sign of labyrinth sup- puration). This method of examination is inapplicable in cases of ob- struction of the external canal (atresia, stricture, severe otitis ex- terna, furunculosus and large polyps), also in very acute inflammation with small perforations. In such cases it is well to be able to rely upon other methods of examination yet to be described. 6. Diminished or negative reaction to turning. This is an important sign found in labyrinth suppuration. The turn- ing test is made with the patient sitting on a revolving stool, fitted with a handle which the examiner uses to turn the patient. Normally, turning to the right with the head in the upright position produces a horizontal nystagmus to the right during turning and a horizontal nystagmus to the left upon stopping. If the head is inclined forward 90 a rotatory nystagmus to the right is produced during turning and to the left after turning. This latter nystagmus is called the "After turning" or "After nystagmus." If the head is inclined to the right 90 (that is the right side of the face upon the right shoulder) a vertical nystagmus upwards is pro- duced during turning to the right and vertically downwards after turning. If the position of the head is changed 180 to any of the above posi- tions, the opposite nystagmi are produced. Inclination of the head 45 in either of the lateral positions produces oblique nystagmi. In short, it is possible to produce nystagmus in any desired direction by change of position of the head. It is even possible to produce mixed forms ; 12 TREATMENT OP LABYRINTH SCI'PL'KATIOX. as an illustration: Upon bending the head backward 45 we get a horizontal nystagmus to one side combined with a rotatory nystagmus to the opposite side. For practical purposes, however we may limit our examinations to the horizontal and rotatory nystagmi. Normally the horizontal "after-nystagmus" lasts from 15 to 30 seconds after 10 turnings ; the rotatory a trifle longer : however, the duration of the horizontal after-nystagmus may be prolonged by the use of opaque spectacles or by having the patient look at a distant ob- ject to avoid convergence of the eyes which inhibits the nystagmus. If, in a case of suspected right sided labyrinth suppuration the re- action to the right side is negative or of but a few seconds duration, while the reaction to the left side is 15 seconds or more, then the diag- nosis is assured. 7. Diminished or negative reaction to galvanism. Prior to six months ago the galvanic reaction of the labyrinth was a much neglected subject, owing to the crude and inaccurate methods v used. Since then I devised a simple method of examination (Klin- ische Studit-n uber die Functions prufung des Labyrinthes mittlest de^ galvanischen Stromes. Archiv. fur Ohrenheilkunde. Bd. 77 1908), the examination is made with one pole in the hand and the second pole applied to the region of the ear, just in front of and above the tragus. The current is applied, gradually increasing until nysla^- mus is apparent and the strength of current necessary to produce the reaction noted in milliamperes. A record is made of the kathodal and anodal reaction of the two sides. Normally 4 ma. with kathode to the right ear produces rotatory nystagmus to the right, and 4 ma. anode to the right ear produces rotatory nystagmus to the left, and vice versa for the left ear. In a case of right sided labyrinth suppuration the kathode to the right ear fails to produce a reaction with as much as 8 ma. or more, while kathode to the left ear produces a reaction with less than 4 ma. In a similar nianm-r we obtain the reactions with the anode (the right ear does not react). In a similar manner we obtain the reaction with the anode (the right ear does not react). A further examination of the opening and closing nystagmus of the two sides is as follows : LABYRINTH PAPERS. 13 Right labyrinth acutely destroyed. *R. Ear K. O. X. > K. C. N. A. C. N. > A. O. N. L. Ear K. C. N. > K. O. N. A. O. N. > A. C. N. The above reactions apply to the earlier stages of acute labyrinth suppuration ; however, after secondary degeneration of the nerve has taken place it is impossible to obtain either kathodal or anodal reactions from the diseased side. In closing the subject of diagnosis, I wish to emphasize that sudden deafness in the course of middle ear suppuration, together with spon- taneous rotatory nystagmus to the sound side and vertigo, speak for labyrinth suppuration ; but in addition, when the nonacoustic labyrinth of that side is nonreactive to the above mentioned tests, then the diag- nosis of labyrinth suppuration is certain. TREATMENT. There is but one treatment for acute labyrinth suppuration ; that is immediate radical operation combined with vhe labyrinth operation, for the following reasons : i. Labyrinth suppuration is frequently associated with intracranial complications; the more frequent of which complications are menin- gitis and cerebellar abscess. 2. The prognosis in nonoperated cases is bad ; the mortality being over 70 per cent, whereas the mortality from labyrinth operation is less than 8 per cent. \Yhile the mortality is high in the nonoperative cases, it is still higher in those cases where the radical operation is done and the labyrinth operation left undone than in those cases where no operation is done at all. In other words it is safer to leave a case of labyrinth suppuration to itself than to attempt any half way measures. OPERATION. The operation consists, first, in the regular Kuester-Bergmann radi- cal; second, the laying free of the dura of the middle and posterior fossae and removing the bridge of bone between them ; third, removal *K. O. N. = Kathodal Opening Nystagmus; K. C. N. = Kathodal Closing Nys- tagmus; A. O. N. = Anode Opening Nystagmus; A. C. N. = Anode Closing Nys- tagmus; ^> = greater than. I4 TRI-.lTMl-XT OF L.\HYR1\TI1 SUPPURATION. of the semicircular canals from behind and the free opening of the cochlea and vestibule in front, allowing the facial nerve to remain in- tact. The dura is exposed for a double purpose : i. To allow room for the labyrinth operation and 2. To permit inspection of the membranes, since many of these cases have more or less meningitis as a complication. The question of labyrinth suppuration is a very important one and almost too large for a single paper ; my effort has been to cover as briefly as possible the entire subject. LABYRINTH SUPPURATION TWO CASES.* THIS paper is intended to supplement a former paper upon "Diagnosis and Treatment of Labyrinth Suppuration." The object is to report in full and discuss two cases of typi- cal labyrinth suppuration. It is the opinion of the writer that a thor- ( .ugh report of one or at most two cases is worth more practically than a less thorough report of a greater number of cases. The two cases here reported are selected from a series of twenty as the more classical cases of labyrinth suppuration. Copied from the records the cases are as follows : Case I. Franz G., 24 yrs. old, laborer. Diagnosis. Otitis Media Suppurativa Chronica Sinistra et Choles- teatoma et Labyrinthitis Suppurativa Acuta et Meningo-Enceph- alitis Serosa. History. Left ear has been discharging since early childhood. The patient could not recall exactly when or how it began. The discharge has not been continuous, often ceasing for months at a time. He had never been treated for the ear until ten days before admission. The left ear has been discharging continuously for the last seven weeks; during this time the patient complained of greater impairment of hear- ing in that ear and diffused headache, slight stiffness in the back of the neck and great weakness. Prior to this (seven weeks ago) the patient had never had vertigo, but at that time was taken with a very se- vere attack, which lasted several days. With the vertigo, he had the sensation as though he was being turned and complained of darkness before hi> eyes, he also vomited repeatedly with great nausea and he was compelled to lie down, which gave him slight relief. Upon questioning he had had no chill, and in his own words said he had had little or no fever. The patient came on account of discharge from and impairment of hearing in the left ear, intense headache, stiffness in the back of his neck and prostration. *The tuo cases here reported are taken from Prof. Alexander's clinic, of Vienna, with his permission. The examinations and records were made by the author when acting as Aspirant Assistant to Professor Alexander, but operated l.v him. i6 L.lBYh'IXTII SUPPURATION TWO CASES. Present Condition. Patient well nourished and muscular, sallow Complexion and his facial expression suggests pain and apathy. Otoscopic Examination Left Ear. Moderate amount of thick, grayish yellow, very fetid, purulent secretion in the external canal. Slight bulging of the superior wall of the canal; a mass of polyps about half the size of a pea hanging down from the attic-antrum region, which obstructed the view of the tympanic cavity, but it did not interfere with the introduction of the Hartmann canula for the purpose of washing out its contents, The mastoid process slightly sensitive t<> pressure. The entire left side of the head is more sensitive tn pressure and percussion than the right side. Right Ear. Membrane slightly cloudy, otherwise normal. Microscopic Examination of the more solid particles of the secretion obtained by syringing out the tympanic cavity of the left ear shows normal epidermis cells, epidermis cells in stages of degeneration, pus cells, fat crystals, cholestcarin crystals, active cocci and bacilli and debris. Ophthalmoscopic Examination showed marked choking of both discs (3 diopters). Functional Examination. Righ ,ir B< S t >ne 12 M. -f 12 M. + 12 M. -f Right Normal, + Conversation voice, Whisper voice, Acoumeter, . \}/2 meters. A Ad conchum. Ad conchum. Left ir Be >lir * M- i . Very short. . . Schwabach, . . . . Rhine" Normal, Normal, Normal, ... c,, . . ... a,, Not heard. . Not heard. + . Watch on bone, . . . SPONTANEOUS NYSTAGMUS. Marked rotatory nystagmus to the right when looking to the right. Vrrv -light rotatory n v^tai'.inti- tothe right when looking -traight Slight horizontal ny>tagmus to the left when looking to the left. LABYRINTH PAPERS. 17 DISTURBANCE OF EQUILIBRIUM. Rhomberg positive. Hopping very uncertain and patient falls. Gait forward and backward with closed eyes very broad, uncertain and slow. GONIOMETER. Eyes Open. Eyes Closed. 26 degrees, . . . Face forward, ... 20 degree^. 30 degrees, . . . Face backward, . . 22 degrees. 30 degrees, . . . Face to right side, . . 15 degrees. 30 degrees, . . . Face to left side, . . 15 degrees. CALORIC NYSTAGMUS. After three minutes' syringing of left ear with cold water the character of the spontaneous nystagmus was not changed (negative reaction). Horizontal after-nvstagmus to 1 ( Horizontal after-nystagmus to lAifWD.TrTBia right, 1 8 seconds. AFTER-IURN- | left, 9 seconds. Rotatory after-nystagmus to ,' ] Rotatory after-nystagmus to right, 15 seconds. left, 7 seconds. Kathode, 3 ma. nystagmus to 1 G\LV\N T IC ^ Kathode, 7 ma., no reaction. right increased. I NYSTAGMUS ^ Anode, 3 ma., rotatory nys- Anode, 7 ma., no reaction. stagmus to right increased. Negative, . COMPRESSION AND ASPIRATION NYSTAGMUS, . Negative. THREE-METER HEARING TUBE. { Conversation voice, 50 per cent, failures. I Whisper voice, all failures. Patient's temperature was 37 C., pulse 68. Operation by Prof. Gr. Alexander. Typical retro-auricular incision through soft tissues to bone. Laying free of the mastoid. Chiseling open the mastoid and antrum. The bone was sclerotic. The antrum and tympanic cavities were found rilled with cholesteatoma masses, which were curetted out, together with many granulations. The radical operation after Kuester-Bergmann was carried out. Inspection of the horizontal semicircular canal showed a dirty, gray colored eroded area and a fistula (2 mm. broad and 5 mm. long). Two parallel horizontal incisions through the skin and soft tissues were made backward, 4 cm. long, from the upper and lower ends of the first incision. The mastoid process was totally removed and the posterior and middle skull fossae freely exposed. Inspection of the sinus showed it to be normal. There 2 ,8 LAHYRIXTH SUPPURATION TWO CASES. were no granulations on the dura. The semicircular canals were then removed from behind, the horizontal being left till last. Opening of the vestibule and accidentally the facial nerve was slightly exposed. The facial canal was eroded in part by the cholesteatoma. Chiseling open of the promontory. The entire labyrinth was softened. By incising the dura of the posterior and middle fossa a small amount of cloudy cerebrospinal fluid flowed out and the brain substance prolapsed through the incision. The dural incision was dressed with a quantity of indoform gauze. Plastic was made after Pause. Wound dressing and bandage. Lumbar puncture was then made, 15 cc. of cloudy fluid collected iri three separate test tubes for further examination. The flow of fluid came with force indicating great pressure. Immediately after the operation a slight facial paralysis in all branches of the 7th nerve was observed. The character of the nystag- mus remained unchanged. The temperature 8 P. M. of the same day was 39 C. Patient was restless and an injection of morphine was given. First day after operation there was no change in the facial paralysis. Less headache than before the operation. Temperature 37 C, pulse 68. Patient was able to sit up in bed and said he felt good. Second day after operation, no headache, no vertigo, nystagmus un- changed. Patient had slept well and restful. Temperature 37.3 C and pulse 68. Third day after operation, the patient felt generally good except for a slight frontal headache. Temperature 36.6 C, pulse 74. A purgative was given. Fourth day. First change of outer dressings. Fifth day. Patient slightly weak, otherwise the patient said he felt perfectly well. Sixth day. Second change of dressings. Wound showed healthy granulations. For the next seven days the patient walked about the room at will and was free from symptoms. n the fourteenth day after the operation a thorough functional examination of the nonacoustic labyrinth was made and the results found to correspond exactly with the findings before the opera- tion. L.tKYRIXTH PAl'liRS. 19 Fifteenth day, under local anesthesia with Schleich's solution, the retro-auricular wound was closed with secondary sutures excepting the lo\ver tip for i l / 2 cm. Patient was discharged from the hospital with the advice to report every other day for further treatment. One month after the operation the patient felt entirely well and had gained in weight. Retro-auricular wound entirely healed. Facial paralysis unchanged. Six weeks after the operation the patient was free from all symp- toms. Slight return of function of the Jth nerve. The nonacoustic labyrinth examination gave same results as before. There was still ^ome slight mucoid secretion in the bottom of the canal. The patient was discharged and sent to his home, to be further treated by the local physician. Case II. Antonia K., 40 yrs. old, housekeeper. Diagnosis. Otitis Media Suppurativa Sinistra et Labyrinthitis Sup- purativa et Meningitis Serosa. History. As a child began with discharge from the left ear, ex- actly as to how it began could not be ascertained. The discharge was intermittent, the longest intermission being five years. Between the second and twelfth years of age the patient suffered from tubercular glands in the neck and axilla. Also had repeated attacks of inflamma- tion of the eyes (which proved to be keratitis eczematosa). Fifteen years ago the patient was operated for a left sided retro-auricular ab- scess ("Wild's incision), after which the discharge ceased for five years. Six weeks before admisison to the hospital the patient had a heavy attack of vertigo, which lasted four or five days, during which time she vomited almost continuously and suffered greatly from nausea. She suffered greatly from thirst and thought she had fever, but every- thing she drank was vomited almost immediately. The patient was obliged to remain quietly in bed and every movement aggravated the vertigo. With the vertigo the patient complained of the sensation of the room and everything in it turning about her. Since then the vertigo has been gradually diminishing. Two weeks after this attack she went out of doors for the first time, had a slight chill and when she returned to the house she noticed that her face was crooked (facial palsy). Upon admission the patient complained of discharge and pains in left ear, impairment of hearing, slight vertigo when making quick movements, frontal headache especially on the left side and be- canse of this last symptom the patient sought the hospital. 20 LAHYRi\Tii sL'rri'RATio\Tii'o CASES. Present Condition. Rather stout and well nourished woman. Scars in the neck from previous glandular involvement. Both eyes showed maculae corneae, but the fundi were negative. Otoscopic Examination: Left Ear. Moderate amount of brown, very fetid, purulent secre- tion, external canal slightly narrowed. Large polyps hanging down from the attic-antrum region which make it impossible to see the tympanitic cavity. The mastoid process is slightly sensitive to press- ure, the periosteum thickened and adherent to the bone. There is an old, one cm. long, vertical scar behind the left auricle representing the Wild's incision which had been performed several years before. Right Ear normal. Microscopic Examination of secretion from left ear showed a few normal and degenerated epidermis cells, many pus cells, movable cocci and bacilli, a few fat crystals and debris; but no cholesterin crystals. Functional Examination. Right dr Bone I2 M - 4 12 M. -f- 12 M. + Conversation voice, Whispered voice, . Acoumeter, . . 2 meters. \ Ad conchum. Ad conchum. Left ir Bone Right Normal, + - Weber. Schwabach, Rhine, Very short. Normal, Normal, Normal, ... C T . . - ... i tl c, Not heard. Not heard. Very short. ,/' + Watch on bone, . . . SPONTANEOUvS NYSTAGMUS. Marked rotatory nystagmus to the right when looking to the right. Slight rotatory nystagmu-. to the right with opaque glasses when looking straight ahead. Slightly rotatory combined with horizontal nystagmus to the left when looking to the left. DISTURBANCE OF EQUILIBRIUM. Rhomberg positive but slight. Gait forward and backward with closed eyes somewhat broad and very uncertain. Patient tends to fall laterally, l>ut not to either side particularly. Hopping impossible. LABYRINTH PAPERS. 21 GONIOMETER. Eyes Open. Eyes Closed. 24 degrees, . . . Face forward, ... 7 degrees. 22 degrees, . . . Face backward, ... 7 degrees. 23 degrees, . . . Face to right side, . . 3^2 degrees. 23 degrees, . . . Face to left side, . . 3 degrees. CALORIC NYSTAGMUS. Negative. Horizontal after-nystaginus to 1 \ F TER TURN* ^ Horizontal after-nystagmus to right, 30 seconds. I " IXG NvSTM ."_ left, 9 seconds. Rotatory after-nystagmus to Mrs. Rotatory after-nystagmus to right, 14 seconds. [ left, 3 seconds. Kathode, 2 ma., nystagmus to 1 f Kathode, 12 ma., nystagmus right increased. ! GALVANIC to i e ft. Anode, 12 ma., nystagmus to i NYSTAGMUS. j Anode, 7 ma., nystagmus to left. j [ - ight. COMPRESSION AND ASPIRATION NYSTAGMUS. Negative THREE-METER HEARING TUBE. { Conversation voice, 70 per cent, failures. I Whispered voice, all failures. Operation by Prof. G. Alexander. Typical 6 cm. long retro-auricular incision to the bone. Exposure of the mastoid in front of and behind the incision. Separation of the membranous canal from the posterior, superior and inferior bony canal. Opening of the mastoid and antrum. I'pon opening the antrum pus flowed freely. Removal of the posterior bony canal with bone forceps, carrying out of the radical operation after Kuester-Bergmann. The middle ear spaces were thoroughly curetted of granulations and pus. Curettement of the Eustachian tube. Laying free the dura of the posterior and middle fossae and the sinus wall. A granulation the size of a pea was found on the sinus wall. A fistula was uncovered, which led to the lower part of the superior semicir- cular canal from behind, opening of vestibule, opening of the promon- tory in front of the facial canal so that a bent probe passed through from behind the facial canal could be seen anteriorly. Clear liquid oozed through the anterior opening. Free incision of the dura of both fossae through which edematous brain substance prolapsed. Plastic after Panse. Abundant dressings of iodoform gauze were applied over the dural incisions, over, this sterile gauze and bandage. Several attempts at lumbar puncture were unsuccessful, owing probably to excessive amount of adipose tissue in this region. Evening of the same day the patient complained of some headache, i2 LABYRINTH SITI'I' RATIOS TWO CASES. slight verti-o and had v unite 1 two >r three times. Temperature 36.8" C, pulse 100. First day after the operation the patient complained of headache, partial facial paralysis of all branches, slight evidence of amnestic aphasia and patient also complained of being confused. Second day : Headache same as yesterday ; patient had ceased vomiting. Writing test showed that she omitted letters in words and she complained of being forgetful. Examination of fundi again nega- tive. Outer bandage was slightly loosened. Third day: Patient still complained of headache and could not sleep. Dressings were changed, showing a moderate amount of fetid secretion. Fourth day: Headache is less, facial paralysis less. Eye grounds again examined and found negative. Patient felt fairly well. Fifth day : Headache and paralysis better. Temperature and pulse normal. Second change of dressings and wound showed normal re- action. Seventh day: Third dressing; patient felt so well that she was al- lowed to leave the hospital to report every other day for further treatment. . End of fourth week. Patient felt well, was doing her regular housework. At this time a thorough functional examination was made which gave the same results as before the operation (see above). End of two months the patient was discharged cured. DISCUSSION OF THE CASES. The taking of the history is very important, especially in cases of labyrinth suppuration. In taking the history I have adopted a plan first suggested by Alexander, i. e., i. When did the suppuration of the middle ear begin? 2. How did it begin? Suddenly, with pain, with fever, how long did these acute symptoms last before the discharge began or did it begin gradually without acute symptoms? 3- Has the discharge been continuous or periodic? 4- Has the ear been treated ? 5- Of what does the patient complain? Discharge, impairment of hearing, subjective noises, vertigo and its character, fever, headache, and questioning for further symptoms according to what may have sug- gested itself up t<> this time. ' 6. Finally a very brief summary of symptoms most complained of by the patient. This can be best accomplished by putting to the pa- tient the question for what do you come ? LABYRIXTH PAPERS. 23 Observing the histories of the cases reported the reader will notice that this method of history taking has been adhered to. \Ye shall now discuss the histories of these cases. (a) Both cases began in early childhood; which shows that they were chronic suppurations of the middle ear. (b) The character of the onset was not ascertainable, since the pa- tients could not recall it, and no known cause in either case. (c) The discharge was periodic in both cases. This should prove to us the importance of keeping under observation all cases of ap- parently healed chronic middle ear suppuration for a long time after cessation of discharges from the ear; furthermore, the verbal report of the patient "that he has no further discharge from the ear" should not be accepted, since in many cases the discharge may be so slight as to escape the notice of the patient. (d) In both cases the treatment had been more or less neglected. In one case there had been no treatment until ten days before admission to the hospital. In the other case only partial and improper treatment, in- cluding a Wild's incision performed several years before ; a treatment long abandoned and condemned by the best operators. (e) Both complained of the following symptoms: Otorrhoea, mark- 'ecl impairment of hearing.* vertigo, slight fever (?) and headache. Neither case complained of subjective noises. Relative to this symptom : I have never found subjective noises in a case of labyrinth suppuration as some of the American writers have claimed ; however, subjective noises may be present occasionally just before the onset, but never after the actual development of the labyrinth suppuration, and indeed there seems to be no logical reason why there should be sub- jective noises in a case of suppurative panotitis any more than there should be subjective sensations of light in a case of suppurative panophthalmitis ; however, this is only a minor point which plays no important part in the diagnosis. As to the vertigo, it was slight at the time of the examination but had been very intense several weeks previous, lasting several days and gradually diminishing. The memory of the vertigo was vivid enough in both instances for the patients to describe it accurately. One patient described it as a sensation of apparent turning of the sur- rounding objects ; the other, a sensation of apparent turning of him- self.t Both patients had marked nausea and vomiting as accom- panying symptoms, and were compelled to lie down in order to feel *Actual deafness is rarely complained of in any case having from good to per- fect hearing in the remaining ear. The determination of complete deafness must be decided by the functional tests. fThe patient who experienced the sensation of surrounding objects turning was more observing and less neurotic than the patient who experienced only the sen- sation of being turned himself. Darkness before the eyes is a late symptom of vertigo found especially in neurotic people. L.IRYRIXTH SUPPURATION TWO CASES. secure from falling and to diminish the intensity of the vertigo. Not- withstanding the fact that the patients described their sensations some- what differently, the description of one is as characteristic as that of the other for vestibular vertigo (Drehschwindel of the German authors). Vesiibnlar vertigo then is our first cardinal symptom of labyrinth suppuration, elicited from the history of these cases. Fever was difficult to determine and if it had been present must have been very slight, since the one patient who believed she had fever decided so from the thirst she suffered. Thirst is a factor in de- termining fever only with the laity and in this case was due more to the excessive vomiting than to anything else. The other patient was inclined to the belief that he had had no fever. Headache was pronounced in both cases. I have come to regard headache, though not a cardinal symptom, yet one of importance in the differential diagnosis between suppurative and serous labyrinthitis. The reason is very apparent; since in the serous labyrinthitis the membranes of the brain are found to be normal while in the suppura- tive form I have frequently found in early cases serous meningitis. These two cases were no exception to this rule. In addition, Case I. complained of apathy and stiffness behind the neck. Case II. com- plained of a crooked face with inability to close the left eye, indi- cating 7th nerve palsy. Summary of the history in both cases showed in common : Chronic middle ear suppuration of unknown origin, intermittent discharge from the ear. neglected treatment, impaired hearing, typical vestibular vertigo and symptoms of headache indicating some form of meningitis or meningo-encephalitis. From the histories alone I was able to make a provisional diagnosis of labyrinth suppuration, fixing the date of the attack, and that secondary meningitis was present at the time. Otoscopic findings. Both cases presented a moderate amount of dirty looking, fetid, purulent discharge from the left ear. The fetidity of the discharge in these cases was not so important as in other cases where the ear had been recently treated. (Persistent fetidity of the discharge after thorough and repeated cleanings should lead one to suspect choles- teatoma). The external bony canal was narrowed in both cases, indicating recent mastoiditis. Mastoiditis in these cases was more coincidental than characteristic for labyrinth complications since I have founil as many cases free from mastoiditis as with it. Polyps were found in both cases hanging downward from the attic- antrum region into the mesotympamim which prevented a thorough inspection of the tympanic cavity. I did not remove these polyps in order to make a more thorough inspection of the tympanic cavity for LABYRINTH PAPERS. 25 the following reason : It is a safe rule never to do a minor intra- tympanic operation (polyp extraction or ossiculectomy) ivhen a radical operation is otherwise indicated. Tenderness over the mastoid was more or less present in both cases and in one case the periosteum was thickened. Microscopic examination of the syringed out tympanic secretion, examined in the natural state with a % objective, showed epidermis, pus cells, movable micro-organisms, debris, and in addition Case I showed the typical cholestearin crystals, indicating cholesteatoma, which was later corroborated at the operation. For a more detailed description of cholesteatoma and methods of diagnosis, the reader is referred to a paper upon "Cholesteatoma" by the, writer, Monatsch. f. Ohren., 1908. Zur klinischen Diagnostik des !\ I ittelohrcholesteatoms. Eye ground was normal in Case II, and choked discs found in both yes in Case I. Excepting for the ear and head conditions the general condition of the patients was fair. Functional examination of the ears showed both acoustic and non- acoustic functions to be negative in the diseased (left) ear of both patients. Conversational voice was heard from i l / 2 to 2 meters upon the left side and whispered voice and acumeter ad conchum (less than 20 cm.). This amount of hearing from the left side does not prove that the patients actually heard with the left ear. Bezold, Politzer, and recently Alexander, Barany and others have shown, in cases of one sided deafness, that exclusion of the normal ear by the ordinary means Of stopping up the canal with a wet finger or with paraffine is insuf- ficient. Repeated experiments with cases of absolute one sided deaf- ness (cases where the labyrinth of that side had been removed) show apparent hearing of from I to 6 meters distance for conversational voice. It was therefore necessary to try other methods, the 3 meter speaking tube recommended by Politzer and Bezold's new small z.^ fork, manufactured by Edelman. The telephone method and the new method of Barany were not tried. 'When the speaking tube shows more than 50 % failures to conversa- tional voice and 100 % failures to whispered voice, the Politzer school accepts such cases as those of complete deafness. I have, however, greater faith in the Bezold small a t fork. I make the examination by striking the fork a moderate blow with a rubber-covered hammer so that the fork can be heard distinctly at / or 8 inches, the width of the skull, but no further. When the fork thus struck is held I inch from the normal ear it can be heard very intensely. I have found this method of examination the best for producing loud tones when held close to the ear and at the same time excluding all possibility of hearing from the opposite ear. I can recommend this fork as the best asset an otologist can have for making functional hearing tests for one sided deafness. -6 l..UiYKI\TH SUPPURATIONTWO CASES. The low Q was not heard, and the high c 4 was heard but very much shortened. These high tone forks are always unreliable tests for one sided deafness since they can be heard at very long distances and have great power of penetration. The remaining tests negative Rhine, with the middle C with no air conduction and very much shortened bone conduction ; Weber to the better ear ;* Schwabach very short ; negative watch on bone are the same results as obtained in every case I have examined. From the above functional test findings we must conclude that both patients were absolutely deaf on the left side ; this, therefore, makes a second positive sign or symptom of labyrinth suppuration Absolute deafness. i:\.\MIXAT[ON OF THE NONACOUSTIC l.AI'.Y KI NTH. Both cases showed pronounced spontaneous rotatory nystagmus to the sound (right) side upon the patients looking to the right; less marked horizontal and mixed horizontal and rotatory nystagmus to the left si seconds for rotatory and 35 seconds for the horizontal. A diminution to 12 seconds for either horizontal or ro- H Fic.4 P, patient; A, assistant who runs the switch, C, and reads the milliamperage from the milliamperemeter M; E, examiner; H, head mirror to illuminate the eye; e and e', electrodes. The wall plate should show a reversing switch to change the polarity without changing the electrodes. tatory after-nystagmus is an indication of destroyed function upon that side, and according to some a diminution to 15 seconds is suffi- cient for a diagnosis. I am more conservative, however, since I found two cases one with 14 seconds and one with 13 seconds' dura- tion where the labyrinths were still in function. In the cases before us the longest duration for the after-nystagmus LABYRINTH PAPERS. 33. to the diseased side was 9 seconds in one of the cases for the horizontal nystagmus with the opaque spectacles. Such low figures are never found in a reacting labyrinth, and with even lower figures for the rotatory after-nystagmus clinches the fact that the nonacoustic laby- rinths upon the diseased side were destroyed. Thus, the sixth symp- tom or sign of labyrinth suppuration present in these cases Diminish- ed after-nystagmus to the diseased side. 3. The Galvanic reaction in both cases shows a characteristic diminu- tion of irritability upon the diseased side. Normally from 4 to 6 ma. applied with a small ball electrode i cm. in diameter just in front of and above the tragus (see Fig. 4) will produce a nystagmus (with vertigo) to the side of the kathode when the kathode is used, and to the opposite side when the anode is used. A reaction with less than 4 ma, with the kathode indicates over-irritability of that side or destruction of the opposite side. A reaction which requires more than 8 ma. in- dicates loss of function in the static labyrinth of that side or over-irri- tability of the opposite side. The question which would naturally suggest itself to the average- reader is Why should we conclude that there is destruction in the labyrinth when we can obtain a positive reaction with 8 ma. with the kathode to the diseased side? The answer is that in such cases the positive reaction is obtained from the nerve and not from the end organ in the semicircular canals. The Galvanic reaction is so large a subject that a thorough dis- cussion of it would take up too much space for this paper. I shall therefore reserve for another paper upon "Differential Diagnosis" a thorough discussion of the Galvanic reaction, where it plays a more- important role. In brief, the characteristic reaction for labyrinth destruction of not too long standing is : Left Ear (labyrinth suppuration). Kathode, 8 to 10 ma., no re- action or slightly positive rotatory nystagmus to left side. Anode, 2 ma., rotatory nystagmus to right side. Right Ear (normal). Kathode, 2 ma., rotatory nystagmus to right side. Anode, 8 ma., no reaction or slightly positive rotatory nystag- mus to the left side. Again, if the kathodal reaction to the diseased side requires more than twice the number of milliamperes as that to the normal side we may conclude that there is loss of function upon the diseased side. The Galvanic reaction in the cases presented is characteristic for the labyrinth suppuration ; hence our last positive symptom or sign of labyrinth suppuration Diminished or negative Galvanic reaction upon the diseased side. The operation, the subsequent treatment and results require no special discussion and are sufficiently clear to speak for themselves. 3 34 LABYRINTH SUPPURAT1OX TWO CASES. SUMMARY. I. All symptoms and signs were positive for the diagnosis of laby- rinth suppuration. II. Symptoms and signs were present sufficiently characteristic to warrant a diagnosis of meningitis and exposure and examination of the membranes at the time of operation. III. The operations consisted of the radical Kuester-Bergmann plus thorough opening of the labyrinth and the operation for serous menin- gitis recommended by Koerner and Alexander. IV. With the exception of facial palsy, which is rapidly improving, both cases experienced early improvement of meningeal symptoms .after operation and ultimately were discharged cured. LABYRINTH SUPPURATION DIFFERENTIAL DIAGNOSIS, WHILE the otologists are paying increased attention to the subject of labyrinth suppuration it is well that we pay even greater attention to the subject of differential diag- nosis, for with the advances made in its surgical treatment there is the danger that some of us. in our enthusiasm to operate, may sacrifice unnecessarily labyrinths of patients (presenting the history of chronic suppuration and the symptoms of vertigo, nystagmus and disturbance of equilibrium ) who would otherwise recover spontaneously. It is an appreciation of these dangers which prompts the writer in the presentation of this paper upon Differential Diagnosis. Of all the cases presenting the above history and symptoms only a relatively small per cent, are suffering from labyrinth suppuration. We shall consider only those affections of the labyrinth secondary to acute or chronic middle ear suppuration which, by reason of the symp- toms of impaired hearing, vertigo, nystagmus and disturbance of equilibrium, may be confounded with labyrinth suppuration. They may be divided into : I. Affections of the membranous labyrinth : I i. Diffuse hyperemia. .A. Diffuse (^ suppuration). C i. Circumscribed irritative lesion of the mem- branous labvrinth. n. Circumscribed { ~. .. . , . . , .. 2. Circumscribed destructive lesion of the mem- j branous labyrinth. II. Affections of the bony labyrinth (erosions, caries, necrosis. fistuke, etc.). III. Affections of the perilabyrinthine spaces (perilabyrinthitis with resulting sequestration of a part or the entire labyrinth. I, A. i. DIFFUSE HYPEREMIA OF THE LABYRINTH may be met with un the course of acute or chronic middle ear suppuration. The opinion , 2. Diffuse serous labyrinthitis. "] 3. Diffuse suppurative labyrinthitis (labyrinth 36 DIFFERENTIAL DIAGNOSIS. of some authors is that every acute middle ear inflammation is attended with more or less hyperemia of the labyrinth, while others believe that the labyrinth symptoms are due rather to the pressure of confined se- cretion upon the windows; it would seem that both views are in a measure correct. In support of the first view we know of cases of acute infections of the ear where the greater force of the infection has been felt in the labyrinth (especially infection from streptococcus mucosa) with resulting labyrinth suppuration and meningitis, whereas the mid- dle ear affection remained so mild that it did not lead to even perfora- tion of the membrane ; while on the other hand, in support of the second view, there are cases of severe acute otitis media with asso- ciated labyrinthine symptoms which are promptly relieved by para- centesis of the membrane. Aside from the cases of panotitis which terminate fatally within a few days after the onset of acute otitis media, the opinion of the writer is that every acute middle ear inflammation is accompanied by more or less congestion of the labyrinth ; its intensity varying in proportion to the virulence of the infecting micro-organism. Hyperemia of the labyrinth may occur too in the course of chronic middle ear suppuration, especially during periods of acute exacerba- tions. The cause in this instance is not exactly known. It is probably due to toxins generated by the infection in the middle ear which find their way into the labyrinth. Hyperemia and the symptoms of hyperemia may begin suddenly like those of labyrinth suppuration, in spite of which and the fact that they have several symptoms in common, the two processes are very unlike ; for in hyperemia we have an irritative process with increased re- actibility; while in suppuration we have a destructive process with negative reactibility. A comparison of the two processes shows the following : HYPEREMIA OF THE LABYRINTH. SUPPURATION OF THE LABYRINTH I. Impairment of hearing in- i. Absolute deafness. creased. 2. Tinnitis. 2. No tinnitis. 3. Moderate vertigo, aggravated 3. Intense vertigo, but con- in recumbent position. stantly diminishing and re- lieved in recumbent position. LABYRINTH PAPERS. 37 4. Spontaneous nystagmus to 4. In acute stage nystagmus to both sides, but more marked to the well side only ; later stages the the diseased side. it may be to both sides, but always more marked to the Lcell side. 5. Irritability of the labyrinth 5. Irritability of the labyrinth increased. negative. 6. Disturbance of equilibrium not 6. Disturbance of equilibrium so pronounced as in suppuration very pronounced in the acute of the labyrinth. stage ; present, though mod- erate, in the last stage. 7. Ultimate recovery of acoustic 7. Permanent loss of acoustic and static functions. and static functions. The increased reactibility of the labyrinth in hyperemia is determined by the turning and galvanic test (quantitative tests). Since the caloric test can be only positive or negative, it becomes purely a qualitative test, and can not be used as a quantitative one. The increased reactibility of the labyrinth is manifested by an in- crease in the duration of the after-nystagmus to the diseased side; for example if the right labyrinth is over irritable we have an after- nystagmus to the right lasting from 40 to 100 seconds or more, while the after-nystagmus to the left remains about the normal figures, say from 18 to 35 seconds. It may also happen in cases where one laby- rinth is very markedly pathologically irritated, that the after-nystagmus to the well side is also relatively increased. The galvanic reaction in case of hyperemia, say of the right labyrinth, shows that the right labyrinth with kathode to the right ear responds to irritation with less milliamperage than the opposite (well) ear. In addition to the above signs I have frequently found in cases of hyper- emia of the labyrinth associated with acute middle ear inflammation, a marked compression and aspiration nystagmus, a symptom never found in suppuration of the labyrinth. This compression and aspiration nystagmus in acute cases may be found before perforation, or after when the perforation is very small. I believe it is due to the hydraulic pressure of the secretion in the middle ear upon the windows being greater than the pneumatic pressure when the middle ear is in the normal state. Furthermore, in the acute in- flammatory conditions the pressure of the secretion, by reason of the 3 8 DIFFERENTIAL DIAGNOSIS. closure of the Eustachian tube by inflammatory swelling, is confined more to the walls of the tympanic cavity, while in the normal state the pressure is not so confined to the middle ear but escapes appreciably through the patulous Eustachian tube. The differential diagnosis of serous from suppurative labyrinthitis. may be quite difficult. I, A, 2. SEROUS LABYRINTHITIS. Serous Labyrinthitis is a serous inflammation of the membranous- labyrinth produced by the presence of toxins, while suppurative laby- rinthitis is due to the infecting micro-organisms themselves. In serous labyrinthitis we have a serous or a mildly serofibrinous exudate into the labyrinth, which later may become partially or completely resorbed with corresponding restoration of function. In suppurative labyrinth- itis we have a violent inflammation of the labyrinth with the formation of pus, resulting in total and permanent destruction of the membranous labyrinth with loss of function. The prognosis in serous labyrinthitis is generally favorable ; the re- sult being a partial or complete restoration of function : notwithstanding this, a serous labyrinthitis is often the precursor of a suppurative laby- rinthitis, a fact we should reckon with in considering the treatment. At their height the two processes are very similar, the symptoms and signs are perhaps not quite so pronounced in the serous as in the sup- purative form. A sign of importance in differential diagnosis which I have noted is the headache, of meningeal type, present in suppurative labyrinthitis, which is absent in the serous. This headache is due to irritation or serous inflammation of the meninges, termed by some few writers as meningismus, but accepted by most as a serous meningitis. This head- ache appears very early, often obscured somewhat at the beginning by the intense vertigo. Aside from the headache and the difference in the courses of the two processes we have nothing else to aid us in the differential diagnosis. These facts can be best illustrated by the com- parison of the two tables below, showing the symptoms and the course of the two processes : LABYRINTH PAPERS. 39 DIFFUSE SUPPURATIVE LABYRINTHITIS. STAGES I II Ill IV V Normal con- dition before labyrinth in- volvement. Prodrom al or irritative Qnset of stage; may j last from few g^ weeks to sev- eral years. From several days to sev- eral weeks after onset. End stage; destruction of functions. Hearing. + + But diminished. Tinnitus + Periodic. Vertigo. + In attacks + Intense + Only during rapid move- ment of head. Spontaneous Nystagmus. To both sides; more marked to diseased side Intense to well side only. Both sides ; more intense to well side. Irritability of the static labyrinth. Normal + and in- creased. DIFFUSE SEROUS LABYRINTHITIS. STAGES I II Ill IV V Normal con- dition before labyrinth in- volvement. Prodromal or irritative stage. Onset of serous laby- rinthitis. Stage of improve- ment. Recovery Hearing. + _!_ But diminished. + But diminished. + DIFFERENTIAL DIAGNOSIS. DIFFUSE SEROUS LABYRINTHITIS. (Continued.) STAGES I II III IV V Tinnitus. + Periodic. + Vertigo. + In attacks. + Intense + Only by rapid move- ment of the head. Spontaneous Nystagmus. To both sides; more marked to diseased side Intense to well side only. To both sides; more marked to diseased side Irritability of the static labyrinth. Normal. + and increased + with caloric test. Normal or nearly so. The above tables represent fairly accurately the course of these two processes. I have presented stage I as the normal condition ; stage II the stage of iritation and of prodromes. Although both serous and suppurative labyrinthitis have a sudden onset, they are preceded 'by a longer or shorter period of irritation with attacks of vertigo and nystag- mus to the well side. Ill is the stage of attack with sudden onset, ac- companied by deafness, intense vertigo and nystagmus to the well side and negative reaction of the static labyrinth. These stages are more or less sharply defined, and up to and including stage III the two conditions are clinically alike with the exception of headache in the suppurative form, already mentioned above. After stage III the two processes begin to differ and eventually in stage V we have the end stage of suppuration, complete loss of acoustic and static functions, while stage V of serous labyrinthitis records the normal findings or those existent before the attack, as in stage I. The differentiation of these two forms of labyrinthitis is quite difficult until stage III has passed, and where there is doubt it may be well to wait a few days or a week after the onset before deciding upon the treatment. If there is much headache or other signs of meningeal ir- LABYRINTH PAPERS. 41 ritation, we may safely consider the case as one of suppurative laby- rinthitis. On the other hand, if headache or signs of meningeal irrita- tion are absent, it is not at all dangerous to wait, even though it be a case of suppurative labyrinthitis. In considering the .differentiation, a fact worth bearing in mind is that the suppurative labyrinthitis is much more frequent than the serous. Although serous labyrinthitis may be the precursor of the sup- purative form, every attack of the suppurative labyrinthitis need not be preceded by an attack of serous labyrinthitis. I, B. CIRCUMSCRIBED LABYRINTHITIS. Circumscribed labyrinthitis, secondary to middle ear suppuration, oc- curs with the bony labyrinth intact and too when not intact. When intact we have either a metastatic or toxic condition from extension of the infection or the toxins of infection by way of the lymph vessels or by a thrombotic condition of the mucous membrane of the middle ear extending through the vascular system of the bone into the labyrinth. (Macewen, Infectioes Erkranknng u. s. w., Wiesbaden, 1898.) More often circumscribed labyrinthitis occurs when the labyrinth capsule is not intact; that is to say, when there is some destructive process (caries, necrosis, osteoporosis or pressure atrophy, etc.) of the labyrinth cap- sule, due to cholesteatoma or tuberculosis; the latter condition espe- cially in the first few years of life. The most frequent site is the prominence of the horizontal semicircular canal ; the next mo N st fre- quent site is the oval window ; less frequent, the promontory ; how- ever, any part of the external wall may be involved. These latter pro- cesses lead to an opening in the capsule which permits the entrance and growth of granulations into the labyrinth and finally in some cases to destruction of the entire membranous labyrinth. These are the more frequent conditions, besides which we have empyema of the saccus enclolymphaticus, described by Koerner and others. We will not enter into a discussion of the pathology of these various lesions, concerning which the reader is referred to the works of Koemer, Hinsberg, Freytag, Heine, Neumann, Alexander, Ruttin and others. We shall discuss rather the symptomatology and diagnosis. We may conveniently divide the circumscribed lesions of the laby- rinth, according to their location, into those involving the cochlea and those involving the nonacoustic labyrinth according to the symptoms and reactibility of the part involved, into the irritative and destructive. 4 _> DIFFERENTIAL DIAGNOSIS. Irritative circumscribed lesions may, under 'favorable treatment, re- main circumscribed or may (rarely) entirely disappear; however, when neglected the irritative processes usually becomes a circumscribed destructive or diffuse destructive process of the labyrinth. From the above it is readily seen that we may, therefore, have : i. Circumscribed irritative lesion of the cochlea. ii. Circumscribed destructive lesion of the cochlea. in. Circumscribed irritative lesion of the nonacoustic labyrinth (vestibule or semicircular canals). iv. Circumscribed destructive lesion of the nonacoustic labyrinth (vestibule or semicircular canals). It should not be a difficult task to differentiate these four conditions from each other and from labyrinth suppuration. I, B, i. CIRCUMSCRIBED IRRITATIVE LESION OF THE COCHLEA may show most or all of the following characteristics : By Otoscopic examination : (a) Polyps or granulations on the promontory, or exposed bone as determined by the use of the probe, with or without associated choles- teatoma. Clinically : (b) Tinnitis. (c) Marked impairment of hearing for all tones if the entire cochlea is involved, or more especially the high tones if the lower cochlear whorl alone is involved. (d) Bone conduction shortened (characteristic for all internal ear conditions). (e) Very positive Gelle; that is to say, with compression of air in the external canal the bone conduction is shortened very much out of proportion to the normal (a condition opposite to that found in otosclerosis). (f) Rarely scotoma, elicited by examination with Bezold's continu- ous chain of forks. (g) Absence of symptoms from the vestibular apparatus with quite normal reactions to the caloric, turning and galvanic tests. I, B, ii. CIRCUMSCRIBED DESTRUCTIVE LESIONS OF THE COCHLEA show by otoscopic examination : (a) Same as in condition I, in addition perhaps roughened bone,, small sequestra or fistula in the region of the promontory. LABYRINTH PAPERS. 43 Clinically : (b) Absolute deafness for some or all tones, depending upon the extent of the lesion. (c) Bone conduction very much shortened. (d) Gelle, /. c., compression and aspiration produces no effect upon the already very short bone conduction. (e) Xo symptoms or signs from the vestibular apparatus. I, B, in. CIRCUMSCRIBED IRRITATIVE LESION OF THE NONACOUSTIC LABYRINTH. As previously stated the favorite location of this lesion is the horizontal semicircular canal or the region of the oval window. The otoscopic examination may reveal polyps or granulations, with or without involvement of the bone in the antrum or attic-antrum region. Clinically the symptoms are : (a) Vestibular vertigo with its accompanying phenomena, nausea and vomiting, depending upon the intensity of the vertigo. (b) Spontaneous nystagmus toward the diseased side. Horizontal if the horizontal semicircular canal is the seat of the irritation ; rotatory, if the region of the oval window is the seat of the irritation. The m stagmus is pronounced during the attacks of vertigo but evident also- between attacks. (c) Increased reaction of the nonacoustic labyrinth, especially to turning and galvanism. The after-nystagmus to the diseased side may last from 35 to 100 seconds, while the after-nystagmus to the well side remains approximately normal or but slightly increased, 20 to 25 seconds. The galvanic reaction shows nystagmus to the diseased side, when (he kathode is to the diseased ear, with a much weaker current than is required to produce a nystagmus to the well side when the kathode is applied to the well ear. In making the galvanic test it is well to have the patient look straight ahead, since in this position the spontaneous nystagmus, which may be present when the patient looks to the sides, is perceptibly diminished. In exceptional cases only does the nystag- mus persist when the patient looks straight ahead. The caloric reaction test is purely a qualitative test and has no value in determining the degree of irritability of the labyritnh in any caKON Side JACN>AON side t ACN K O N Side ( A C N and A O N negative Side \ A C N < A O N In considering the differential diagnosis of labyrinth suppuration from neuritis, the history and the otoscopic findings afford us great aid. In labyrinth suppuration we have the positive history and otoscopic findings of middle ear suppuration, while in neuritis these are negative excepting in the rarest cases, where middle ear suppura- tion may be coincidently present. On the contrary, in the case of neuritis we are generally able to obtain a history pointing to one of the previously mentioned causes (infectious, constitutional or toxic). In case of neuritis complete involvement of all branches of the eighth nerve is the exception rather than the rule. It frequently happens that the cochlear branch is more involved than the vestibular branch, and vice versa. In neuritis it frequently happens that the involvement of the eighth nerve is but one of the manifestations of a polyneuritis ; in which cases we are often able to detect pareses, (though often but slight), of one or more of the other cranial nerves. In case of neuritis the affection is frequently bilateral, as elsewhere pointed out. The bilateral form occurs especially frequently from toxic LABYRINTH PAPERS. 77 causes. A bilateral aeffction points decidedly to neuritis rather than to labyrinth suppuration. From the foregoing we see that the greatest difficulty to be met with in the differential diagnosis occurs in the case of unilateral isolated complete neuritis of the eighth nerve with complete loss of both acoustic and static functions ; fortunately, these are the rarest cases we meet, and in these cases the Galvanic reactions (see above) should determine the diagnosis. In closing the subject, let us summarize briefly the more important differential symptoms and signs of these two processes. LABYRINTH SUPPURATION. I Positive history of middle ear suppuration, together with the history of previous attacks of vertigo from labyrinth hy- peraemia or labyrmthitis serosa. 2 Otoscopic findings character- istic for middle ear suppura- tion (secretion, perforation, polyps, cholesteatoma, etc.). 3 Tinnitus and noises negative. subjective 4 Deafness is absolute. NEURITIS OF EIGHTH NERVE. I Negative history of -middle ear suppuration ; but on the contrary history of infectious disease, or some toxic poison- ing (quinine, salicylates, al- cohol, tobacco, etc.) ; or ex- posure to cold and moisture. 2 Otoscopic findings negative except in cases of herpes zoster involving the membrana tympani (see above), but in these cases we are usually able to detect the herpes blebs elsewhere in the region of the external ear and frequently on the auricle. 3 Tinnitus and subjective noises usually positive, and they last for indefinite periods of time from few hours to several weeks; in rare cases, followed by atrophy, even longer. 4 Deafness may be absolute or partial, and the type of this deafness is characteristic of that found in diseases of the perceiving apparatus. 78 DIFFERENTIATION FROM AFFECTIONS OF EIGHTH NERl'E. LAP.VRINTH SUPPURATION" Coil- ti nued. 5 Intense vertigo lasting from three to five days, less pro- nounced for a few weeks long- er during rapid movements of the head. 6 Equilibrium disturbances of the so-called vestibular type. 7 Spontaneous rotatory nystag- mus to the sound side. 8 Negative caloric irritability of the static labyrinth. 9 Shortened duration of the after-nystagmus to the dis- eased side. 10 Galvanic reactions in recent cases only show the following average findings : Kathode, 7 ma., rot. Right nys> to r. Side Anode, 3 ma., rot. nys. to 1. Kathode, 3 ma., rot. Left n . vs - to 1- Side Anode, 7 ma., rot. nys. to r. II Paresis of other cranial nerves the exception, and then only the seventh nerve. 12 Unilateral involvement. 13 Permanent loss of both acoustic and static functions. NEURITIS OF EIGHTH NERVE. Continued. 5 Intense vertigo lasting as a rule longer than in the case of labyrinth suppuration. 6 Same as in labyrinth sup- puration. 7 Same as in labyrinth sup- puration. 8 Same as in labyrinth sup- puration. 9 Same as in labyrinth sup- puration. 10 Galvanic reactions show the following average findings : Kathode, 18 ma., no re- Right action. Side Anode, 18 ma., no re- action. Kathode. 3 ma., rot. Left nys. to 1. Side Anode, 18 ma., no re- action. II Paresis of other cranial nerves, more frequently the II, V, VII, XII ; however, any of the others may be involved. 12 Frequently bilateral involve- ment. 13 In the majority of cases the prognosis is favorable with ultimate recovery of both acoustic and static functions. PROGNOSIS AND TREATMENT OF LABYRINTH SUPPURATION GREATER attention has been paid to the operative treatment of labyrinthine infections than to their diagnosis and differentia- tions. Originally the determination of the operative proced- ure upon the labyrinth was decided by the findings at the time of the radical mastoid operation. This form of practice mighf. have done well enough for the past but not for the present. Since the adoption of exact examination methods the normal physi- ologic functions of the labyrinth have been ascertained and at present we are able to determine, from variations in or by absence of these functions, pathologic conditions of the labyrinth. As a result, the best operators are adopting the plan of determining the exact condition of the labyrinth before performing any operation upon the ear. It must not be forgotten that the best results are obtained not by the ability to operate alone but by the combination of this ability with a knowledge of the diagnosis ; I might go further and say that the prog- nosis and treatment are entirely dependent upon the diagnosis. The primary object of many operators has been to perform the labyrinth operations without a sufficient knowledge of the diagnosis and indications. This condition has been fruitful however in bringing about at least one result, namely, the perfection of the operations and a high development of surgical technique. Many excellent papers have been written upon the surgical treatment of labyrinthine infections, including the recent one by Richards, of New York (Laryngoscope, Oct., 1907), and the still more recent one by Albert Jansen (Annals of Otol., Rhin. and Laryng., June, 1908), however both authors in their respective papers show a lack of knowl- edge of the diagnosis and indications for treatment. Had they given mdre attention to the subject of diagnosis and the methods of examina- tion, or had they familiarized themselves with the work of Barany (Phys. und Path, des Bogc-ng. . \ppar. beim Menchen), these men would have made fewer misstatements concerning the diagnosis, prog- nosis and indications for treatment. Is it any wonder that Jansen's postoperative mortality (Annals of O., R. and L., 1908, page 367), 25 per cent., should have been so high 8o PROGNOSIS AND T RE ATM EXT. as compared with Hinsberg's, 4 per cent, (furnished by Freytag, Z. f. O., Bd. 51, page 341)? The explanation is that Hinsberg under- stood the diagnosis and operated when operation was indicated, while Jansen, who did not understand the diagnosis as well, operated hit or miss style, with the result that many labyrinths were sacrificed and lives risked if not lost that might have been saved by more conservative treatment. After having carefully read Jansen's paper upon the "Treatment of Infective Labyrinthitis/' I wish to protest forcibly against his mis- statements concerning the diagnosis and indications for operation, be- cause of the great danger of misleading some fortunately not all of the American otologists who may be inclined to accept his statements as authoritative. Had Jansen familiarized himself more with what Barany and N^u- mann had done, rather than attempt to take from them the credit they deserve, he certainly would have known more about the diagnosis of labyrinthitis and the indications for operation than he manifested in his jumble of misstatements. On the other hand, Jansen deserves great credit for having inaugurated and helped to perfect the labyrinth operations. In considering the prognosis and treatment of labyrinth suppuration it will be necessary at the same time to consider the prognosis and treatment of the other pathologic conditions of the labyrinth. These conditions will be considered separately. I. Hyperemia of the. Labyrinth. Passive hyperemia will not be considered here since it does not occur as a result of acute or chronic middle ear suppuration ; while on the other hand, active hyper- emia does (see former paper upon differential diagnosis). The prognosis in active hyperemia of acute middle ear inflammation or suppuration is generally favorable, the hyperemia terminating in resolution. In exceptionally rare cases the hyperemia is but the initial stage of suppuration ; in this latter instance the prognosis is generally unfavorable to the functions and to life, death occurring in from one to a few days from a suppurative meningitis due as a rule to very virulent streptococcic infection. The treatment of hyperemia of the labyrinth with acute middle ear inflammation should be the prompt evacuation of the middle ear by a free paracentesis or the enlargement of a too small perforation, the application of drainage gauze into the external canal and moist heat, LABYRINTH PAPERS. 8r absolute rest in bed and the administration of the indicated remedy. In the event of a serious turn in those rare cases mentioned with begin- ning meningeal symptoms the labyrinth operation should be performed early. The prognosis in the hyperemia of chronic middle ear inflammation is even more favorable than in those cases occurring with acute middle ear inflammation. Since here we have generally a perforation of the tympanic membrane of considerable size we are denied the opportunity of making or enlarging the perforation. In these cases there is usually an acute exacerbation of the chronic middle ear suppuration or reten- tion of secretion in one of the accessory cavities with adhesive bands, polyps or cholesteatoma. The treatment should be directed toward the cause ; in the event of ?,n acute exascerbation of the chronic middle ear suppuration con- servative treatment with rest in bed is generally sufficient. In the case of retention with polyps or cholesteatoma, these alone would give an indication for the radical operation, but not during the attack if it can be postponed for fear of precipitating an actual inflammation of the labyrinth ; in these cases it would be better to operate between the at- tacks. In rare cases the hyperemia, as in the case of hyperemia of acute inflammation of the middle ear, might be the preliminary stage of a labyrinthitis, in which event the case must be treated accordingly. II. Acute Diffuse Serous Labyrinthitis. Since the differential diagnosis of this condition from labyrinth suppuration is somewhat difficult ; and furthermore since no exact statistics have been made, we are unable to say what per cent, of serous labyrinthitis recovers spontaneously and what per cent, terminates either in acute labyrinth suppuration or chronic labyrinthitis with new formed con- nective tissue and destroyed end organs. Fortunately however the prognosis in many of the cases, under proper treatment, is favorable both to function and to life. The treatment during the attack should be both conservative and expectant; it is especially in these cases that waiting is profitable. There has been a tendency to commit one of two errors ; either to do the radical mastoid operation immediately, with the result that the serous labyrinthitis develops into a suppurative labyrinthitis, or to operate the case as one of suppurative labyrinthitis with the result of permanent destruction of the functions. It would be far better after having first determined the diagnosis of serous labyrinthitis (see paper on 6 82 PROGNOSIS AND TREATMENT. differential diagnosis) to put the patient to bed, insert drainage gauze into the canal, one end of which is introduced into the middle ear cavity, changing the gauze as often as necessary, and administer the indicated internal remedy. Such treatment will in the majority of cases result in recovery. It is a mistake to attempt any manipulation or instrumentation of the middle ear during an attack of serous labyrinthitis. In order to prevent a recurrence or a subsequent attack of suppurative labyrinthitis we should immediately, after the attack of serous labyrinthitis has passed over, perform the radical mastoid operation and eliminate all infecting foci within the middle ear spaces. III. Circumscribed Irritative Lesion of the Labyrinth. The prognosis in this condition is even more favorable under proper treatment than that of serous labyrinthitis, and the same remarks concerning the prognosis and treatment of diffuse serous laby- rinthitis apply to this condition. IV. Circumscribed Destructive Lesion of the Labyrinth. Since circumscribed destructive lesions of the mem- branous labyrinth are usually combined with similar changes of the bony labyrinth (labyrinth capsule) we shall speak of them together. Circumscribed destructive lesions of the membranous labyrinth are usually in the form of suppurations or granulations with surrounding zones of inflammatory reaction limiting the destructive pathologic changes to the circumscribed area. Later, in the surrounding zone of inflammation, adhesions are formed which serve as a barrier to the spreading of the infection. The changes in the labyrinth capsule are in the form of fistulae, erosions, caries and necrosis. The prognosis is dependent upon the location. When the lesion is in the region of the semicircular canals (more often horizontal) the prog- nosis is more favorable than when in the region of the oval window or promontory, since in the former instance the canals being narrow, lumened tubes the adhesions can better shut off the infection from spreading than in the case of the vestibule or cochlea, where the laby- rinth opens into wider spaces. The prognosis too is dependent upon the treatment. The circum- scribed destructive lesions of the labyrinth are usually slower processes than the diffuse serous or suppurative forms, as a result we have more time to consider our cases and the form of treatment to be applied In LABYRINTH PAPERS. {; 3 the event of neglect of treatment there is the constant danger of slow or rapid progress of the circumscribed destructive process with the result eventually of an acute diffuse suppurative labyrinthitis. Realizing the dangers of a circumscribed destructive lesion, we should institute our treatment as soon as the diagnosis is determined. The treatment consists of the radical mastoid operation and the ex- posure of the lateral labyrinth wall to full inspection. We should then eliminate, as thoroly as possible, all cholesteatomatous masses, granula- tions, necrotic bone, etc., using every precaution not to stir up the condi- tion in the labyrinth for fear of breaking the adhesions, which may have formed, and thus favor an extension of the suppuration. This can be more readily accomplished in the case of a circumscribed destructive lesion of the horizontal semicircular canal than in a case of lesion about the oval or round windows or the promontory. In the latter cases (circumscribed destructive lesion about the windows or promontory) the danger of the conservative operation is too great, besides since the hearing is almost if not entirely destroyed we have not the same in- centive to try the conservative operation. In these cases one of the more radical labyrinth operations should be performed. V. Perilabyrinthitis with partial or complete sequestration of the labyrinth capsule. The prognosis depends ( i ) upon the extent and acuteness of the pro- cess; (2) upon the nature of the predisposing cause (tuberculosis, diabetes, syphilis, scarlatina, etc) ; (3) upon the treatment, the prompt- ness with which we get at it and the thoroness of the operation. In all cases with complete sequestration of the labyrinth capsule there is facial paralysis. On the other hand, in case's of partial sequestration, especially when limited to the cochlea, the facial canal may escape in- volvement. In some cases the entire labyrinth has been thrown off piece by piece thru the external canal without any untoward result ; in other cases operative interference may be necessary. The prognosis to the func- tions is bad, but to* life generally good. There is less tendency to intra- cranial complications in perilabyrinthitis than in labyrinth suppuration ; however, complications do occur in exceptional cases, but in these the predisposing cause plays a role. In the cases of complete sequestra- tion facial paralysis is complete and permanent, the only hope for future function lies in the performance of one of the nerve anastomo- ses operations. 84 PROGNOSIS A\'D TREAT M EXT. The treatment should be at first prophylactic. In other words, all cases of mastoiditis in the course of acute or chronic middle ear sup- puration should be operated promptly, following up the pus until normal tissue is reached. If this were done in every case, especially those showing early involvement of the facial nerve, there would be fewer cases of labyrinth sequestration. The simple mastoid operation in acute cases and the radical Kuester-Bergmann mastoid operation in chronic cases, including the removal of the mastoid tip, if done and done early will be sufficient to limit most cases of perilabyrinthitis. In the cases well advanced, after sequestration has taken place, the above mentioned operations are insufficient. In this event we must perform in addition to the mastoid operation an operation for the removal of the sequestered part or whole of the labyrinth, which will be found ly- ing imbedded loosely in a dark granular mass of debris and pus, from which it can be removed easily with the anatomical forceps. This should be followed by thoro curettement of all diseased tissue. Aside from the operative treatment it is well to direct sanitary and internal treatment toward the predisposing causes, to aid the after healing, which tends to be very slow in these cases. VI. Suppurative Labyrinthitis (labyrinth suppura- tion). The prognosis in this condition would seem to vary with the skill of the diagnostician. It is almost impossible to compute the mor- tality, since in one clinic all cases of labyrinth infections are grouped together in one class, while in a second clinic the diagnoses are so loosely made that the figures become unreliable. For instance Jansen in his statistics includes cases which are positively not those of laby- rinth suppuration, as does also Herzog. Herzog (Labyrintheiterung und Gehor, 1907) reports three cases (Nos. 3, 4, 5) among a total of seven in which the labyrinth suppuration was double-sided. Altho double-sided labyrinth suppuration is possible, that so high a per- centage of such cases occurring in one man's experience seems highly improbable, especially when we recall the fact that such authorities as Hinsberg, Alexander, Neumann and Barany have failed to locate a single case during the last five years. All authors agree, however, that the prognosis is generally unfavor- able in untreated acute labyrinth suppuration, and much worse in cases maltreated; from which we may safely conclude that it is safer to leave the case to itself than to treat it improperly. In the first place the prognosis for both acoustic and static functions LABYRINTH PAPERS. 85 is invariably unfavorable; next the prognosis to life is rather un- favorable in the untreated cases, the infection finding its way into the brain (i) thru the internal auditory canal, resulting in a circum- scribed or diffuse serous or suppurative meningitis; (2) thru the aque- ductus cochleae, resulting in a circumscribed or diffuse serous or sup- purative leptomeningitis ; (3) thru the aqueductus vestibuli, resulting either in an interdural (saccus empyema), deep extradural, subdural or cerebellar abscess. Altho the above results are the rule, exceptions do exist ; in these exceptional cases two or more conditions may occur coin- cidentally thru two separate routes of invasion ; for instance, from an acute infection of an old cholesteatoma simultaneous infection of the middle and posterior cranial fossae with labyrinth suppuration may take place. In simple labyrinth suppuration the intra-cranial infection rarely takes place thru any but the preformed ways, for the reason that the infection tends to follow the line of least resistance. The cases which terminate favorably are those where the suppura- tion limits itself to the labyrinth ; the process of limitation of the sup- puration taking place as a result of closure of the orifices of communi- cation to the brain (internal auditory canal, aqueductus cochleae and aqueductus vestibuli) thru a serofibrinous inflammation, produced probably by the toxins of the infection and not the infection itself in a manner similar to the limitation of suppuration to the bulbus in case of panophthalmitis. This favorable result occurs in both instances (sup- purative panotitis and suppurative panophthalmitis), especially when treatment has been expectant and conservative with absolute rest in bed and as little local interference as possible combined with the indicated internal remedy. The indications for the labyrinth operation are not prompted by the labyrinth suppuration alone, but too by the meningeal irritation or in- flammation and the primary middle ear suppuration. Since it is dangerous to perform a radical operation in cases of laby- rinth suppuration without at the same time opening or removing a sufficient part of the labyrinth for the purpose of drainage, we are com- pelled to do the complete operation. There are cases of very late laby- rinth suppuration which have spent themselves within the labyrinth where a radical operation alone may be sufficient. However, I agree with Barany that such a procedure is rather dangerous, for the reason that we can never tell positively just how securely the suppurative pro- cess is shut in the labyrinth by the connective tissue adhesions about the 86 PROGNOSIS AXD TREATMENT. orifices, and if the adhesions are at all insecure the traumatism of the operation will rupture them with the result of a rapidly developing diffuse suppurative labyrinthitis. The prognosis after the labyrinth operation is quite favorable, the mortality being from 4 per cent. (Hinsberg) to 25 per cent. (Janscn). The mortality in the Politzer and the Alexander clinics corresponds roughly with that of Hinsberg's. The treatment of labyrinth suppuration may be conservative or radi- cal. The conservative treatment is indicated first in those cases where in spite of the continuance of the symptoms and signs of lost acoustic and static functions, the headache, slight fever, the slight choking of the discs or overfilling of veins, gradually diminish ; or in those late cases where from the lack of headache and fever and with normal fundus findings we have reason to believe that the diseased condition Ins be- come limited to the labyrinth. When we have decided upon the conservative treatment it is best to put the patient to bed, use simple drainage gauze, and give the indicat- ed internal remedy. It will be surprising what excellent results may be obtained in selected cases by such simple treatment. Personally how- ever I am somewhat too timid to rely upon this treatment ; knowing that a subsequent radical must be performed and the dangers it will invite, and furthermore believing that the labyrinth suppuration indicates a severe form of middle ear suppuration which may later give rise to other intracranial complications (sinus phlebitis, meningitis, extradural, cerebellar or temporal lobe abscess) I prefer to rely upon the radical treatment. The radical treatment of labyrinth suppuration consists first in the performance of the Kuester-Bergmann radical operation, including complete evacuation of the mastoid process and removal of the tip. Good illumination is a prerequisite, best accomplished by the use of an Alexander electric head mirror (obtainable from Meyrowitz, of New York). From this step we have a choice of three methods for per- forming the operation upon the labyrinth ; namely, the original method of Jansen, the method of Hinsberg and the method of Neumann. JANSEN'S TYMPANIC OR SEMICIRCULAR CANAL METHOD. Jansen has employed this first method since 1893. He begins by re- moving the upper wall of the anterior crus of the horizontal semicircu- LABYRINTH PAPERS. 87 lar canal, allowing the lower wall to remain for the double purpose of serving as a protection against injury to the facial canal and for sub- sequent orientation. This trick is practiced also by Neumann, and both men claim the credit for having originated the idea. The pos- terior crus of the horizontal canal is then removed in its entirety. He next removes the bone below and backward from this part of the hori- zontal canal, taking care to avoid the facial canal. He then opens the posterior wall of the vestibule between the ampullar and smooth ends of the horizontal canal. To accomplish this with the least danger of injury to neighboring parts the chisel should be applied with the con- cavity externally when chiseling from the posterior crus into the vesti- bule and vice versa when chiseling from the anterior crus medianward, at the same time taking care to avoid the facial canal. He varies his method somewhat according to the pathologic changes found at the time of operation (the presence or absence of fistula). After opening the posterior wall of the vestibule the anterior wall is sought. In determining the location of the anterior wall Jansen does not depend entirely upon the anterior crus of the horizontal canal but also upon the location of the oval window which he determines by the use of the bent probe introduced into the cavity of the vestibule. Jansen feels that the exposure of the anterior wall is imperative in those cases of narrowing of the vestibule with new formation of bone. After determining the exact location of the lateral wall of the vestibule by thoro sounding with the probe within the cavity of the vestibule, he then removes it with great care with either a narrow chisel or burr. He prefers the use of the chisel when he wishes to ascertain a knowl- edge of the vestibule contents, otherwise he prefers the use of the burr. He advises the use of the burr too especially to preserve the facial canal and the inferior wall of the anterior crus of the horizontal canal. He advises us of the importance of reaching the deepest point in the vesti- bule, laying bare its floor. He next enlarges the cavity of the vestibule downward by exposing the lower orifice of the inferior semicircular canal and enlarges it backward by exposing the common orifice of the vertical canals. He advises the use of the burr in enlarging the cavity backward. He finally exposes the ampulla of the superior semicircular canal. Rarely does he follow up all of the canals. He cautions against too vigorous enlargement of the oval window backward on account of the danger of narrowing the bridge of bone containing the facial nerve to the extent that necrosis may follow. 88 PROGNOSIS AXD TREATMENT. Jansen claims that this operation is the safest and fraught with the least danger to life. He does not consider the operation upon the cochlea as always necessary ; however, when he does deem it necessary he recommends the following method : OPERATION UPON THE COCHLEA. Jansen has modified his former method of complete removal of the cochlea to that of removal of the promontory and the exposure of the lower cochlear whorl only, at the same time avoiding injury to the modiolus. He has avoided injury to the modiolus since having lost at least one case by such injury with a probe. On the other hand, when the cochlea is transformed into a sequestrum lying in a bed of granula- tions and pus he effects its removal with the gouge. THE HINSBERG METHOD. The first step in this method is to perform the complete radical opera- tion, including the removal of the posterior wall of the external canal downward to the level of the floor of the canal and the shaving down of the facial spur as far as possible without injury to the nerve, thus permitting the best possible inspection of the region of the oval window, the facial canal and the prominence of the horizontal semicircular canal. He next seeks the oval window. If the stapes is still there he removes it, then with the very small bone forceps of Bourquet introduced into the oval window he proceeds to remove the lateral vestibular wall to the round window and at the same time opens the lower cochlear whorl ; he then lays the bone forceps aside and proceeds to remove the promon- tory anteriorly using the chisel, which he prefers to the burr since he can keep a clearer field, the burr producing too much bone dust and thereby obscures the field. He, like Jansen, is very careful not to work backward toward the facial. Hinsberg then introduces a bent probe, or better, the Bourquet facial nerve protector, into the enlarged opening, carrying it backward and slightly upward behind the facial until its tip reaches the anterior crus of the horizontal canal, which he then proceeds to remove with the Bourquet forceps. He completes his operation according to the findings, by opening or not the remaining canals. Hinsberg like Jansen deviates from his routine course in case of fistula. In the event of previously long standing facial paralysis with cholesteatomatous invasion of the labyrinth, where oftimes the facial LABYRINTH PAPERS. 89 canal has been eroded and the nerve more or less destroyed, he does not spare the facial canal but proceeds directly to remove it, trusting to a subsequent facial nerve anastomosis rather than to the dangers invited by a less radical procedure. THE NEUMANN ENDOCRANIAL METHOD, Is a modified and improved endocranial method of Jansen which he (Jansen) claims to have performed as early as 1895, m cases of deep extradural abscess. Jansen has since abandoned this method more or less because, as he claims, it is a more difficult and dangerous procedure than his socalled "tympanic method." The operation as Neumann performs it consists first in performing the most complete radical operation, including a thoro shaving down of the facial spur, thoro removal of the inner mastoid wall and also the mastoid tip, free exposure of the posterior and middle skull fossae. For this method of radical operation Neumann claims the advantages, first, of thoro inspection of the neighboring vital structures (middle and pos- terior fossoe) for any pathologic changes that may have clinically escaped our attention ; second, of permitting the greatest possible roc-u for the performance of the subsequent labyrinth operation ; third, of more prompt healing after the operation, since the dura of both the middle and posterior fossa tends to prolapse somewhat into the wound cavity, thereby lessening its size. The second part of the operation consists in complete removal of the semicircular canals, free opening of the vestibule and cochlea. This part of the operation is begun by removing the posterior wall of the pyramid with the chisel from behind, the posterior vertical canal is re- moved and the common orifice of the two vertical canals, then the pos- terior crus of the horizontal canal. The removal of the posterior wall of the pyramid is continued to the internal auditory canal. The danger of opening the subdural space (as Jansen fears) at the entrance of the ductus endolymphaticus is very slight indeed, sine? the saccus endo- lymphaticus lies between two layers of the dura (interdural space) and not below the dura. The anterior crus of the horizontal canal is left till later. The bone in the solid angle between the three canals is attacked next to gain an entrance into the posterior part of the vestibule, this is accomplished by using the smallest chisels (Alexander, number 6 or 7). After opening the vestibule at this point the opening is enlarged very carefully, often by using the chisel as a plane, removing the bone in thin 90 PROGNOSIS AND TREATMENT. layers. The lateral vestibular wall is then thoroly removed and next the promontory, permitting the freest possible opening of the cochlea. At this stage a probe introduced into the anterior opening behind the facial canal should present itself thru the posterior opening. The bridge of bone containing the facial canal is well preserved and to aid in its preservation as much of the anterior crus of the horizontal canal as pos- sible is allowed to remain until the final step. The final step consists in removing the entire upper wall of the horizontal "canal to the ampulla. Neumann usually includes in his operation the removal of the lateral wall of the internal auditory canal. He does not fear to the same extent the dangers of injury to the facial canal, the carotid, the internal audi- tory canal and the bulbus jugularis as does Jansen, and I believe, too, that these dangers are over estimated and are really of less importance than the thoro removal of the diseased parts. COMPARISON OF THE OPERATIONS. The Jansen "tympanic" method has the following disadvantages : 1. If, as Jansen himself cautions against, the dura is accidentally exposed or injured at the time of the operation, the injury is so fine as to be invisible and escapes our notice ; this makes the danger of com- plications following vastly greater than where the dura is well exposed or a larger incision of the dura has been made. The dangers of small invisible injuries to the dura have been pointed out long since by Koerner and Alexander. 2. In the event of slight or beginning intracranial complications (extradural granulations or abscess, serous meningitis, etc.) which may have escaped clinical diagnosis we are unable to inspect the parts at the time of operation. 3. In the event of intracranial complications following the labyrinth operation, they are much more difficult to get at, because of the pres- ence of the extra bone and tissue we are compelled to remove, which would not exist had the endocranial method of operation been originally performed. 4. When the cochlea, which is always involved in acute diffuse labyrinth suppuration, is left unopened, as Jansen frequently does, the danger of a meningitis is quite as great as tho he had performed no operation at all. This undoubtedly accounts for his exceedingly high post operative mortality (25 per cent). Since advantages imply a comparison of one with another, I fail to LABYRINTH PAPERS. 91 see any advantage of the Jansen operation over that of the Neumann modified endocranial method, or even the Hinsberg operation. Disadvantages of the Hinsberg operation are much the same as those given for the Jansen ; they are briefly : 1. Too little room to work, as in the Jansen tympanic method. ' 2. The bone forceps of Bourquet used to enlarge the oval window are apt to slip and injure the facial behind, or by using too much press- ure the tip of the forceps may injure the carotid in front. At best the forceps are less under our control, obscure our field more and are gen- erally clumsier than either the chisel or the burr. 3. Since Hinsberg's operation is a "tympanic" method like that of Jansen's, it is subject to the same general disadvantage (see above). Hinsberg's method has at least one pronounced advantage over that of Jansen's in that Hinsberg includes the opening of both vestibule and the cochlea ; hence his much lower post operative mortality (4 per cent, in 69 cases Heine, Oper. am Ohr., page 118) than Jansen's (25 per cent). The Neumann method has no disadvantage compared with the Jan- sen or Hinsberg methods ; on the other hand, it has many advantages fewer however over the Hinsberg than over the Jansen method ; they are: 1. The advantage of the greatest possible exposure of the field of operation to the view of the operator, with an opportunity of inspecting the dura of both fossae and the sinus. 2. The advantage of the greatest possible room for the manipula- tion of instruments in the performance of the operation. 3. The advantage of increased accessibility to intracranial structures in the event of postoperative complication. 4. Quicker afterhealing than after either the Hinsberg or Jansen operation. The advantages and disadvantages of the three methods of operating can be told furthermore mathematically by a comparison of the figures of the postoperative mortality. Out of 100 cases Jansen's postoper- ative mortality is 25 per cent. Out of 70 cases Hinsberg's mortality about 4 per cent. Out of the not yet computed number of cases operated since 1906 in the Politzer and Urbantschitsch clinic after the Neumann method a mortality of o per cent. One case, however, ended fatally as a result of an intercurrent attack of facial erysipelas (Barany, Phys. u. Path, des Bog. Ap., 1907, page 49). 9 2 PROGNOSIS AND TREATMENT. It is claimed that figures do not lie, nor do they ; but at the same time I will not go so far as to say that these differences in mortality were due entirely to the differences in the methods of operation employed but also to the difference in the ability of these men to make the diagno- sis and select their cases from the indications. In closing the subject I still insist that the ability to operate is of secondary importance to our ability to diagnose, and I would trust myself with labyrinthine infection in the hands of a diagnostician be- fore I would the operator, providing the one knew nothing of the sub- ject of the other. DRESSINGS AND AFTER-TREATMENT. At the completion of the labyrinth operation the wound cavity should be thoroly cleansed and washed out. In doing this some operators use hydrogen dioxide, others a weak formaldehyde solution ( l / 2 to i per cent.), and still others use both solutions, the hydrogen dioxid first fol- lowed by formalin; each of these solutions to remain in the wound cavity for a very brief period. The danger of hydrogen dioxid spread- ing the infection to neighboring parts is less feared today than form- erly, and most surgeons doubt its possibility altogether. \Yhether the one or the other or both of these solutions have been used, they should be followed by copious quantities of sterile water. After thoro cleansing of the wound cavity, as above described, a careful inspection should be made of the neighboring parts, especially of the sinus and dura, for other complications. Normally the sinus should present a smooth, somewhat glistening surface, blue in color and normally distended. The dura should pre- sent a smooth glistening surface, of a pearly, faintly bluish white color; it should be very loosely adherent to the inner surface of the bone, from which it can be readily separated by a suitable instrument (dura pro- ector) ; furthermore there should be neither bulging nor prolapse of the dura. Any deviation from the above appearances of sinus or dura indicates some pathologic condition. Granulations on the sinus are recognized by the red or brownish discoloration with unevenness of the surface and the tendency to bleed. Occasionally there may be free pus found in association with these granulations, when the condition is spoken of as a perisinus abscess. These granulations, or perisinus abscess, may or may not be associated with sinus phlebitis and thrombosis but more often they are not. The LABYRINTH PAPERS. 93 treatment consists of the thoro removal, preferably by bone forceps, of all overlying bone until normal sinus wall is reached, so that at the completion of our efforts the granulations or abscess should be com- pletely surrounded by a zone of healthy tissue. The subject of sinus thrombosis is so immense that the writer will not even attempt a brief outline of the subject at this time, but will refer those interested to the text books ; to Koerner's work "Erkrank des Hirns der Hirnhaute und cler Blutleiter" or to a recent paper by Alexander, translated by Dr. Geo. Davis, of New York (Archives of Otology, 1908). Extradural granulations are recognized by the same general appear- ances as when found upon the sinus wall. These may also be asso- ciated with free pus, when we recognize the condition as an extradural abscess. In every case of extradural abscess a careful inspection should be made for the purpose of determining the presence of a communicating fistula leading to a brain abscess. Where no fistula is found we should treat the extradural granulations or abscess after the manner of treat- ment for the same condition of the sinus described above. If on the other hand the presence of fistula has been determined it should be en- larged and the deeper brain abscess opened and drained. For this purpose the writer advises the use of a freshly sterilized, double edged,- graduated brain knife. Puncture needles are to be condemned as too dangerous and unreliable instruments to be used in the brain or sinus. Bulging or prolapse of the dura thru the openings which have been made in the skull fossa indicates, in a general way, an increase of intra- cranial pressure. A moderate degree of circumscribed bulging with discoloration of the dura (usually dark) indicates subdural abscess. The treatment consists of free opening of the abscess with a freshly sterilized knife. A moderate degree of prolapse of the dura indicates more frequently a serous leptomeningitis or meningoencephalitis, less frequently a brain abscess. The degree of prolapse in brain abscess is variable, depending upon the size and the stage of advancement of the abscess. In all suspected cases of brain abscess free paracentesis with the previously mentioned brain knife should be made, and it is surpris- ing how frequently our suspicions will be verified. In all cases of pro- lapse, even of moderate degree, the dura should be freely incised, at least one large incision for the posterior and a second one for the middle fossa. In case of serous meningitis or meningoencephalitis the brain 94 PROGNOSIS A.\D TREATMENT. substance prolapses thru the dural incision. If the prolapse is very marked and the convolutions flattened to any extent a further puncture of the lateral ventricle of that side is indicated. A marked degree of prolapse indicates suppurative meningitis. In these cases the symptomatology will have aided us considerably in our diagnosis. Here the same incision as in the case of serous meningitis is indicated, together with puncture of the ventricle and lumbar punct- ure. When making the dural incisions a milky or purulent fluid escapes. With suppurative meningitis the prolapse of brain substance thru the dural incision acts more or less as a plug, interfering with the drainage of pus from the surrounding areas ; for this reason some have attempted, with more or less success, the making of counter openings in the skull and dura at distant points. In suppurative meningitis when not too far advanced this operative treatment has been fairly satisfactory and more is to be hoped for in the future. DRESSINGS. The materials required for the dressings are the same whether the operation for labyrinth suppuration alone has been performed or whether a more complex operation to include the treatment of some of the other complications. The only difference in these cases is in the manner of applying the dressings. The materials needed are (a) freshly sterilized moist iodoform gauze, prepared in narrow strips (i to i l / 2 inches wide) and of convenient lengths for handling. As a substitute for the iodoform gauze some operators have been using iodoform docht (the German for wick) pre- pared in small bundles of ten or a dozen strands each, the bundles held loosely correspond in size to the thickness of an infant's finger. For the wicks the advantages are claimed that they are easier to introduce, es- pecially into small openings, are more readily removed and with less discomfort to the patient than iodoform gauze since a strand or two may be removed at a time if so desired. (b) Additional strips of iodoform gauze, about 2 inches wide and of considerable length, but folded. (c) Plain gauze, folded into 4 inch squares, of four or five thick- nesses. (d) Gauze bandage. (e) Starch bandage or adhesive strips. LABYRINTH PAPERS. 95 In case of labyrinth suppuration without other complications, the dressings are applied according to the following: After ligating the vessels and suturing the plastic flap or flaps, we introduce the moist freshly sterilized iodoform gauze or wick, first into the very bottom of the wound cavity, and then fill up the cavity partially. A second piece of the same material is then introduced into the cavity thru the external meatus ; this second piece should be packed in tightly against the plastic flap in its new position. The entire cavity of the wound is then filled up to the level of the surface with the remnants of the posterior piece if the quantity is sufficient, or a third piece may be used for the pur- pose. Most operators prefer a fairly tight packing for the first dress- ing. Over the moist iodoform gauze or wick a few strips of the wider iodoform gauze is applied, and over this the plain gauze, using 8 or 10 squares. The first 4 or 5 plain gauzes should be unfolded and laid on loosely thus moulding the dressings better, they also tend to stick or adhere less when we come to remove them. Over all is applied a 2 inch gauze bandage (personally the writer prefers the Koerner method of bandaging), and finally a starch bandage or adhesive plaster is used to hold all in place. It is never advisable to sew up the wound, partially or competely, after the labyrinth operation or where the cranial cavity has been opened. Secondary closure of the retroauricular opening may be done after a few weeks. The only variation in the dressing of those cases associated with other complications is in the application of the dressings. In these cases care should be exercised to see that the moist iodoform gauze or wick is applied directly to the granulations or into the openings made in the dura in cases of meningitis or into the abscess cavity in cases of brain abscess. After the operation the patient should be put to bed and kept there until the temperature reaches normal and the patient feels comfortable. Internal medication will be decided by the symptoms as they may arise. The dressings need not be touched for from 6 to 10 days if the case does satisfactorily. After a few days a rise of temperature, pain or saturation of the dressings may call for a change of dressing. A rise of temperature may indicate some acute infectious fever, ton- silitis, facial erysipelas or simple autointoxication from constipation or the extension of intracranial infection. Slight pain may indicate nothing. More intense pain may indicate a 96 PROGNOSIS AXD TREATMENT. too tightly applied bandage or the spreading of infection; especially meningitis when the pain is associated with cerebral vomiting, choked disc, diminution in the pulse rate, etc. Early saturation of the dressings with bloody colored watery fluid indicates escape of cerebrospinal fluid. All of these conditions indicate early partial or complete redressing of the wound. On the other hand, if every thing goes along smoothly the first redressing may be made on or about the sixth day. At this time we should remove all that can be removed readily. In case the iodoform gauze immediately next the wound surface adheres firmly it is best not to remove it but to allow the adhering part to remain until the next redressing. Providing the wound shows healthy granulations the first redressings should be made considerably looser than the pri- mary dressing. Redressings should be made every day or two, according to the behavior of the wound and the amount of secretion. The greater the amount and the more purulent its character the oftener the redressing should be made. In labyrinth suppuration healing takes place about as promptly or more promptly than after one of the radical operations ; furthermore, after the third or fourth redressing less care need be exercised than in the case of the radical mastoid where the conservation of hearing De- comes a factor in the after-treatment. After the labyrinth operation the rapid filling up of the wound cavity with granulations resulting in obliteration of the middle ear spaces is not contraindicated as in other cases of ordinary chronic middle ear suppuration. The secondary sutures for closure of the retroauricular opening may be performed after two or three weeks or when all acute symptoms have disappeared. Final healing takes place in from two to three months, when the patient may be discharged. PHYSIOLOGY AND PATHOLOGY OF THE NON-ACOUSTIC OR, SO-CALLED, STATIC LABYRINTH THE ANATOMY. FOR the thorough understanding of the physiology of any part of the body one must have at least a fair knowledge of the anatomy (gross and microscopic) of that part, together with some knowledge of its relation to other parts. These facts are es- pecially true with regard to the labyrinth, and for this reason the author will devote the entire first paper to this part of the subject. It is not intended that this paper should be a complete work upon the anatomy of the ear ; on the contrary, only as much of the anatomy will be con- sidered as is absolutely necessary for the understanding of the physi- ology and pathology and the reactions of the labyrinth under normal and pathologic conditions to be described in subsequent papers. OSSEOUS LABYRINTH OR LABYRINTH CAPSULE. The osseous labyrinth is formed of compact, densely lamellated bone, quite complex in shape as its name would indicate and located within the pyramid of the temporal bone. It is surrounded, with the exception of parts of its lateral surface, with diploetic or pneumatic bone. When of pneumatic bone, the cells form part of the mastoid cells, are lined with mucous membrane and are in direct communication with the mas- toid antrum. The character of the bone surrounding the osseous labyrinth is im- portant, less from the physiologic than from the pathologic standpoint. The danger of labyrinth sequestration from an attack of mastoiditis is increased directly in proportion to the pneumatic and inversely to the diploetic character of the surrounding perilabyrinthine bone. The osseous labyrinth is composed of three essential parts : ( I ) The cochlea; (2) The vestibule; (3) The three Semicircular Canals. The osseous cochlea is a hollow tube, wound 2.^/2 times about a conical shaped axis called the modiolus. The largest diameter of the tube is at the base and it tapers gradually toward and terminates in a blind end on the summit of the modiolus, known as the cupula cochleae. The cochlear tube is partly divided into two parts by a spiral shaped 7 98 \0.\'-.-lCOL'STIC OR STATIC LABYRINTH. process of bone, called the lamina spiralis ossea, which projects from the modiolus and runs its entire length, terminating in a sickel shaped lip at the apex, called the hnmulus. The lamina spiralis ossea incompletely separates the cochlea into a lower semicircular shaped tube, known as scala tympani, and an upper one, known as the scala vestibuli. The separation of the two scalar is completed by the lamina spiralis mem- branacea (of the membranous labyrinth) excepting at the apex where the two scalae communicate around the tip of the hamulus ; this space of communication is known as the helicotrema. The scala vestibuli opens at the lower end into the cavity of the vestibule. The scala tympani ends somewhat beyond the fenestra rotunda. The fenestra rotunda is closed by the membrana secunda. The modiolus is composed of spongeous bone and contains a fairly large spiral shaped canal which also terminates in a blind end at the apex. This canal accommodates the ganglion spirale cochleae. Another smaller spiral shaped canal within the modiolus accommodates the artery, ramus cochleae a branch from the arteria auditive intense, and its subdivisions. The accompanying veins run in a separate canal. The base of the modiolus presents inwardly at a slight angle to the internal auditory foramen. f In the scala tympani of the lowest whorl of the osseous cochlea just anterior to the fenestra cochlea is a small opening, the apertura interna canaliculi cochleae, for the transmission of the perilymphatic duct (ductus perilymphaticus). The osseous cochlea contains the pars inferior labyrinthi, which com- prises the hearing organ. u The vestibulum is that part of the osseous labyrinth which is more or less sack shaped, lying between the cochlea anteriorly and the semi- circular canals posteriorly, taking up much less space than either. On its upper and outer surface are two rounded prominences which lie just next to each other with a wedge shaped depression or incision be- tween them ; the anterior prominence is known as the recessus spheri- cus, a better name would be prominentia sphericus ; the posterior is known as the recessus ellipticus. The depression between the two prominences is known as the crista vestibuli. As the names imply, the recessi and crista are strictly speaking correct only when viewed from the inner aspect. The recessus sphericus accommodates the sacculus and the recessus ellipticus the utriculus of the membranous labyrinth, LABYRIXTH PAPERS. > and the depression on the outer surface corresponds with the crista be- tween these two recesses. On the external surface of the vestibule, a short distance below the two prominences above mentioned, is a kidney shaped window, the fenestra vestibuli, the long axis of which is somewhat oblique from above and forward to below and backward ; the concavity corresponds to the hilus of the kidney, is downward and forward. This window is closed by the stapes plate (basis stapedis). There is no anterior sur- face of the vestibule but that part corresponding to it opens into the lower cochlear whorl, so that the vestibule appears somewhat as a mo-e or less rounded body resting upon but too large to fit into a cornucopia. The anterior inferior part of the vestibule is represented by that part of the lowest cochlear whorl which is covered by the secondary mem- brane and slightly overlaps the floor of the vestibule ; the part just pos- terior to this represents the floor of the vesubule. Posteriorly the semicircular canals open into the vestibule through five openings ; the three ampullar ends of the three canals, one separate smooth end for the external and one common smooth end for the two vertical canals. From the median or inner side the prominences representing the recessus sphericus and ellipticus can be seen above, the common crus of the two vertical canals posteriorly, the ampullar end of the inferior semicircular canal inferiorly and a very narrow space in the center of all three in which a foramen the apertura externa aqueductus vesti- buli is located which allows for the transmission of the ductus endo- lymphaticus. The semicircular canals are three in number: (a) the External, Hori- zontal or Lateral; (b) the Superior or superior vertical; (c) the Pos- terior, Inferior, Inferior Vertical. These canals are more or less cylind- rical shaped tubes bent in the form of semicircles or a trifle more than a semicircle, they are of almost uniform transverse dimensions, except- ing at one end where each canal terminates in a somewhat spherical shaped swelling called the ampulla. Each canal therefore has two ends, the ampullar and the nonampullar or smooth end. The ampullae of the three canals all open directly into the vestibule. The smooth end, crus simplex of the horizontal canal does likewise, but the smooth ends of the two vertical canals open into a common tube, the crus commune, and it in turn into the vestibule. ioo NON-ACOUSTIC OR STATIC LABYRINTH. The locations of the ampullae are more or less important. The am- pulla of the horizontal canal is located at the anterior end of the crus ampullare just behind the facial canal, which separates it from the oval window on the lateral aspect of the vestibule ; the ampulla of the superior canal is immediately above the ampulla of the horizontal semi- circular canal on the upper posterior aspect of the lateral wall of the vestibule. The ampulla of the inferior semicircular canal is located just posteriorly and medianward to the inferior wall of the vestibule. The nonampullar or smooth end of the horizontal semicircular canal opens into the vestibule at its posterior part. The common orifice of the vertical canals opens into the vestibule at its posterior median part The description of the facial canal and its course will not be given in this paper since it does not belong strictly to the subject. That part of the osseous labyrinth which is exposed laterally forms the greater part of the inner wall of the middle ear, and is recognized from the tympanic side as the prominence of the horizontal semicir- cular canal (prominentia canalis semicircularis lateralis), part of the lateral vestibular wall and the promontorium corresponding to the superior, posterior and lateral part of the cochlea. This exposure of the lateral wall of the labyrinth is of clinical im- portance in the making of the caloric test, as we shall learn later, and of pathologic importance since it offers especially vulnerable points for the infection of the labyrinth from middle ear suppuration. In addition to the exposed parts just mentioned, we have two win- dows of the labyrinth exposed laterally, the fenestra vestibuli or ovalis and fenestra cochleae or rotunda, which normally are sealed up, the former with the basis stapedis, the latter with the membrana secunda. These closed windows are of physiologic importance to the function of hearing, but under the destructive influence of middle ear suppuration they may become open gates for the spread of infection to the labyrinth. The basis stapedis separates the tympanic cavity on the external side from the perilymphatic space in the vestibule on the median side. The membrana secunda separates the tympanic cavity on the external side from the perilymphatic space at the bottom of the scala tympani on the median side. The fenestra vestibuli and the fenestra cochleae are both located at Figure i. A mould of the right osseous labyrinth (lateral view) after Spalt- eholz. I Canalis semicircularis superior. 2 Ampulla ossea superior. 3 Recessus ellipticus. 4 Recessus sphericus. 5 Cupula cochleae. 6 Middle cochlear whorl. 7 Upper cochlear whorl. 8 Lower cochlear whorl. 9 Location of crista vestibuli. 10 Fenestra cochleae, n Fenestra vestibuli. 12 Ampulla ossea posterior. 13 Canalis semicircularis posterior. 14 Crus simplex. 15 Crus ampullare. 16 Ampulla ossea lateralis. 17 Crus commune. Figure 2. Median wall of the right tympanic cavity of the adult human after Spalteholz (enlarged 5 diameters). I Boundary between antrum tympanicum and recessus epitympanicus. 2 Tegmen tympani. 3 Paries tegmentalis. 4 Prominentia canalis facialis. 5 Tendo M. stapedii. 6 Plica stapedis. 7 Processus cochleariformis. 8 M. ten- sor tympani. 9 Stapes. 10 Paries labyrinthicus. n Septum canalis mus- culotubarii. 12 Ostium tympanicum tubae. 13 Pars ossea tubse. 14 Paries carotious. 15 Plexus tympanicus (Jacobsoni) im sulcus promontorii. 16 Cell- ulae tympanicae. 17 Paries jugularis. 18 Promontorium. 19 Fossula fenestrae cochleae. 20 Subiculum promontorii. 21 Paries mastoideus. 22 Sinus tympani. 23 Eminentia pyramidalis. 24 Sinus posterior. 25 Fossa incudis. 26 Prominentia canalis semicircularis lateralis. 27 Recessus epitympanicus. 28 Antrum tympanicum. LABYRINTH PAPERS. 103 the bottom of bony niches (see Fig. II). These niches serve normally as a protection against direct injury ; on the other hand, during an at- tack of middle ear suppuration they serve as reservoirs for the reten- tion of pus and as beds for granulations. Thus these niches while Figure 3. The right temporal bone viewed from the posterior median and slightly inferior aspect. I Meatus acusticus internus. 2 Superior petrosal groove. 3 Aqueductus cochleae. 4 Aqueductus vestibuli. 5 Groove for the lateral sinus. 6 Pro- cessus styloideus. 7 Inner surface of the squamous portion. diminishing the vulnerability of the labyrinth to traumatism increase it to infection. The labyrinth capsule is perforated cranialwards by its three fora- minae, two of which are represented on the posterior median surface of the temporal bone by the meatus acusticus internus and the aqueductus vestibuli; and the third, aqueductus cochleae, is directly below the meatus acusticus internus. 104 NOX-ACOUSTIC OR STATIC LABYRINTH. The meatus acusticus interims perforates the posterior median sur- face of the petrous bone at about one-third the distance from the tip in an oblique direction outward and slightly backward, so that the angle Figure 4. Fimdus meatus auditor!! intern! of the right temporal bone of a child after Schwalbe. I Crista falciformis. 2 Spiral crista corresponding to the spiral turnings of the cochlea and defining the tractus spiralis foraminulentus. 3 Canalis N. facialis opening for nervus facialis. 4 Area cribrosa superior for the passage of the branches of vestibular nerve which go to the macula sacculi. 5 Area cribrosa media for the passage of branches of vestibular nerve which go to macula utri- culi. 6 Foramen singulare for the N. ampullaris posterior. 7 Tractus spiralis foraminulentus for the passage of the branches of the ramus cochlea. 8 Fora- men centrale cochleae. between the canal and the surface of the bone directly posterior to the canal is quite acute (25). At the depth of about 6 mm. from the posterior lip of the meatus in a plane almost at right angles to the di LABYRINTH PAPERS. 105 rection of the canal or, in other words, in the sagittal plane, the canal is partially obstructed by a perforated plate of bone. Through the perforations pass the VII (Facial) and the branches of the VIII (Acoustic) nerves. These perforations are illustrated in Fig. IV. The aqueductus vestibuli viewed from below is a slit-like foramen on the posterior median surface of the petrous bone, about i l / 2 cm. external to and slightly below the level of the meatus. Immediately below it is a small, more or less rounded, depression for the accom- modation of the saccus endolymphaticus. The aqueductus cochleae is another slit-like foramen on the lower edge of the posterior median surface of the pyramid, immediately be- low the meatus acusticus internus ; it serves for the exit of the ductus perilymphaticus from the scala tympani of the lower cochlear whorl previously mentioned. MEMBRANOUS LABYRINTH. The membranous labyrinth takes more or less the form of the os- seous labyrinth with the exception of two sacs, the sacculus and utri- culus, located within the cavity of the vestibulum (see Figs. V, VI and VII). The membranous labyrinth is composed of four essential parts: (i) The Ductus Cochlearis, a membranous tube within the osseous cochlea, taking the same spiral turns and ending in a blind end at the apex (csecum cupulare) ; (2) The Sacculus, a more or less pear shaped sac resting in the recessus sphericus of the vestibule; (3) The Utriculus, an irregularly ovoid shaped sac resting in the recessus ellipticus of the vestibule : (4) The three Semicircular Canals, corresponding and loose- ly adherent to the osseous canals. At one end of each of these semi- circular canals as they enter the utriculus, is a dilatation known as the ampulla. The membranous is much smaller than the osseous labyrinth ; it con- tains a fluid known as the endolymph. Surrounding the membranous labyrinth is the perilymphatic space containing the perilymph. The ductus cochlearis has two blind ends, the upper caec.jm cupulare, already mentioned and a lower one projecting into the cavity of the vestibule and known as the cjecum vestibulare (see Figs. VI and VII). Very close to the latter is a small duct (ductus reuniens) leading from the ductus cochlearis to the sacculus. More about the ductus cochlearis need not be said in this paper since it does io6 \OX-ACOUSTIC OR STATIC LABYRINTH. not bear upon the subject of the physiology and pathology of the non- acoustic labyrinth. The sacculus is a sac somewhat smaller in size than the utriculus and communicates with the ductus cochlearis through the ductus reuniens and indirectly with the utriculus through the ductus utriculosaccularis, which empties into the ductus endolymphaticus a short distance after the ductus endolymphaticus leaves the sacculus. Surrounding the sacculus is the perilymphatic space of the vestibule containing the peri- lymph. The sacculus contains an important end organ for the perception of the static function, known as the macula acustica sacculi, which re- ceives its nerve supply from the nervus saccularis, a branch of the nervus vestibuli. The utriculus is located somewhat posterior and superior to the sacculus. It has six openings, one for the short ductus utriculo-sac- cularis, which empties into the ductus endolymphaticus, and five for the three semicircular canals; three of these receive the ampullar ends of the three canals, one the nonampullar end of the external semicir- cular canal, and one the crus commune, which represents the blending into one of the two smooth ends of the vertical canals. The utriculus, like the sacculus, contains an end organ for the percep- tion of the static function, known as the macula acustica utriculi and receives a corresponding branch (nervus utriculi) from the vestibular nerve. The three membranous canals are much smaller, but correspond in form to the osseous canals; they are: (a) the ductus semicircularis lateralis, (b) superior, and (c) posterior. The spindle shaped ampullae of the three canals are known respect- ively as the ampulla membranacea lateralis, superior and posterior. Each ampulla contains an end organ for the perception of motion ac- celeration in curved lines; of this we shall speak further when we come to the physiology. These three end organs are located on a sort of spine running transversely to the canal within the ampulla on the more distant side (see Fig. IX). The membranous canals contain endolymph which is capable of mo- tion in two directions from the canal to the utriculus, and vice versa. Surrounding the membranous canal is a space containing deli- cate fibrous threads, which hold the membranous canal more or less fixed to the more distant side of the osseous canals. This space is known as the spatium perilymphaticus and contain? the perilymph. Figure 5. Right membranous labyrinth of an adult partly laid free (from the lateral side) enlarged 5 diameters after Spalteholz. I N. ampullaris superior. 2 N. ampullaris lateralis. 3 N. utricularis. 4 Scala vestibuli. 5 Caecum cupulare. 6 Helicotrema. / Hamulus ossis lac- rimalis. 8 Ductus cochlearis. 9 Macula acustica sacculi with N. saccularis. 10 Ductus reuniens. n Canalis caroticus. 12 Ductus cochlearis. 13 Cut surface of the bone. 14 Ductus semicircularis posterior. 15 Ampulla mem- branacea posterior. 16 Caecum vestibulare. 17 Sacculus. 18 'Utriculus. 19 Macula acustica utriculi. 20 Ampulla membranacea lateralis. 21 Ductus semi- circularis lateralis. 22 Ampulla membranacea superior. 23 Ductus semicir- cularis superior. 24 Canalis semicircularis superior. Figure 6. Right membranous labyrinth of an adult laid bare, viewed from the median and posterior side, enlarged 5 diameters after Spalteholz I Utriculus. 2 N. ampullaris superior. 3 Ampulla membranacea superior. 4 Ductus semicircularis superior. 5 Ampulla membranacea lateralis. 6 Ductus semicircularis lateralis. 7 Crus commune. 8 Ductus semicircularis posterior. 9 Ductus reunien,s. 10 Ampulla membranacea posterior. II Sac- culus. 12 N. ampullaris posterior. 13 N. saccularis. 14 Ganglion vesti- bulare. 15 N. vestibularis. 16 N. acusticus. 17 N. cochlearis. 18 Ductus cochlearis. 19 Superior branch of the vestibularis. LABYRINTH PAPERS. 109 MICROSCOPIC ANATOMY. In considering the microscopic anatomy of the nonacoustic labyrinth, the cochlea and its membranous contents are naturally excluded. The nonacoustic labyrinth contains two types of nerve endings: (a) two of the one type located in the sacculus and utriculus are known as the macula acustica sacculi and the macula acustica utriculi ; (b) three l-'igure 7. Schematic representation of the osseous and membranous labyrinths, enlarged 5 diameters after Spalteholz. I Ductus atriculosaccularis. 2 Ampulla membranacea superior. 3 Ductus endolymphaticus. 4 Saccus endolymphaticus. 5 Dura mater encephali. 6 Bone. 7 Caecum cupulare. 8 Helicotrema. 9 Ductus cochlearis. 10 Scala vestibuli. ii Scala tympani. 12 Sacculus. 13 Ductus reuniens. 14 Spatium perilymph- aticum of the vestibule. 15 Ductus perilymphaticus. 16 Fenestra cochleae. 17 Cavum tympani. 18 Caecum vestibulare. 19 Fenestra vestibuli. 20 Ampulla membranacea posterior. 21 Canalis semicircularis posterior. 22 Ductus semi- circularis posterior. 23 Utriculus. 24 Canalis semicircularis superior. 25 Ductus semicircularis superior. of another type located in the three ampullae membranaceae which are known as the cristae ampullari. It is these two maculae and three cristae which particularly interest us, and for this reason we shall describe their microscopic anatomy no XOX-.ICOL'STIC OR STATIC LABYRINTH. somewhat in detail. A description of one macula will answer for both, as will also a description of one crista answer for the remaining two. The macula acustica utriculi is located w'thin the cavity of the utriculus. According to Retzius (das Gehororgan der VVirbeltiere, II., p. 333) the long axis is from above, in front and inward, to behind, below and outward, and the shorter diameter at right angles to this and somewhat horizontal. The long axis of the macula acustica sacculi, according to the same author, lies on the median wall and is al- Figure 8. Cut through the macula acustica recessus utriculi of the human, magnified 130 diameter after Schwalbe. i Neuro-epithelium of the macula acustica ; a, nuclear zone ; b, zone free of nuclei ; upon the surface, ciliae. 2 Cuboid cells at the border of the macula. 3 Perilymphatic net work of connective tissue trabeculse. 4 The same but more compact. 5 The basement membrane. 6 Nerve bundles cut transversely. most vertical, or more exactly from above and inward to below and outward, and its shorter diameter is at right angles to this direction. The maculae receive the terminal nerve filaments of the nervi utriculi and sacculi, branches of the vestibular nerve. Each macula is com- posed of a layer of two distinct kind of cells (a) neuro-epithelial cells; (b) supporting cells. The neuro-epithelial cells are the actual perceiving cells (special sense cells) and contain short hairs or cilia of uniform length extending into the cavity of the sacculus and utriculus. The supporting cells are the alternate ones between the perceiving cells ; they contain no cilia and have no known function but are supposed to support, and the writer would add to insulate, the perceiving cells. LABYRINTH PAPERS. in On the surface of the cells or the cilia of the cell rest somewhat loosely the socalled otoliths, small crystalline bodies which are held more or less together and to the surface by a mucilaginous substance which prevents them from becoming separated or detached from the surface through change of position of the head, when for instance the surface of the macula is above and the otoliths below. The macula and otoliths are nothing more than a more complex and higher de- veloped aural vesical or otocyst with the otoliths found in the craw fishes Figure 9. Longitudinal cut through the ampulla after Hensen (schematic). I Semicircular canal communication. 2 Utriculus communication. 3 The epithelia of the ampullar roof. 4 Neuro-epithelia of the crista ampuliaris or acustica. 5 The long cilia of the neuro-epithelia. 6 N. ampuliaris. 7 Con- nective tissue of the crista. which Kreicll has demonstrated to be the static organ by the iron filings and magnet experiment. Crista ampuliaris. There are three cristae; one for each mem- branous ampulla. They are located on the far side of the ampullae on the summit of the prominences which project into and narrow the lumen of the ampullae. These prominences are really ridges which ap- pear triangular-shaped when viewed from the side and more or less crescent shaped when viewed lengthwise of the canal ; in other words, Figure 10. Transverse cut through the medula oblongata showing the origin of the nervus acusticus, the Deiter's and the triangular nuclei. (From the Mikroskopisch-topographischer Atlas des menschlichen Zentralnervensystems after Marburg.) Stra Striae acusticae. VIII av Pars vestibularis radicis spinalis acustici. Nmv Nucleus vestibularis magnocellularis. Tnc Tractus nucleo-cerebellaris. TVIII Tuberculum acusticum. VIIIc Ramus cochlearis asustici. NVIIIac Nucleus acustici acessorius. VIII Nervus acusticus. Crst Corpus restiforme. Flp Fasciculus longitudinalis dorsalis. RG Area glossopharyngei. NIX Nucleus glossopharyngei dorsalis. m Fasciculus longitudinalis dorsalis. Nft Nucleus eminentiae teretis. Np XII Nucleus praepositus hypoglossi. pt Fibrae pretrigeminales. Trs Tractus rubrospinalis. Tst Tractus spinotectalis et thalamicus. Tscv Tractus spinocerebellaris ventralis. cH Fasciculus tegmeti Centralis. NarcP Nucleus arcuatus pyramidum. Py Pyramis. faev Fibrae arcuatae externas ventrales. Na Nucleus ambiguus. F c V Fasciculi comitantes trigemini. IX Nervus glossopharyngeus. Va Radix spinalis trigemini. Sgl Substantia gelatinosa trigemini. fai Fibrae arcuatae interns. Fco Fibrae cere- bello olivares. No Nucleus olivaris inferior. Oae Paroliva dorsalis. Lm Lem- niscus dorsalis. Sra Substantia reticularis alba. Sri Substantia reticularis lateralis. Nci Nucleus centralis inferior. Ra Raphe. Fprd Fasciculi predorsalis. rt Fibrae retrotrigeminales. it Fibrae arciformes intertrigeminales. Fig. ir. Longitudinal cut through the medulla oblongata corpora quadrigemina and thala- mus opticus, showing Deiter's Nucleus, the eye muscle, nuclei and the posterior longitudinal bundle. (From the Mikroskopisch-topographischer Atlas des menschlichen Zentralnerven- systems after Marburg) . E W Nucleus paryicellularis oculomotorii. Nllhn Nucleus oculomotorii medialis. Nllll Nucleus oculomotorii lateralis. VIIIv Ramus vestibularis acustici. T Vlll Tuberculum acusticum. Nvt Nucleus abducens. Flp Fasciculus longitudinalis dorsalis. Vlll e Ramus cochlearis acustici. Vlll a Radix spinalis acustici. Ci Capsula interna. Nc Nucleus caudatus. St. "Stria cornea. Ndm Nucleus dorsalis magnus thalami. Tt Taenia thalami. Pu Putamen. Nl Nucleus lateralis thalami. Nm Nucleus medialis thalami. Narc Nucleus arcuatus thalami. Nl Corpus Luyisii. Cgm Corpus geniculatum mediale. Cgl Corpus geni- culatum laterale. IM Meditullium lateralle. Vlll Ventriculus tertius. Lmm Lamina medul- laris lateralis. frtf Fasciculus retroflexus. Ntg Nucleus riber tegmenti. H. Fasciculus triangularis Helweg. Nlve Nucleus lateralis externus thalami. Brqp Brachium corporis quadrigemini posterioris. Ncop Nucleus commissurae posterioris. Ndr. Nucleus dorsalis raphes. Brcj Brachium conjunctivum. LI Lemniscus lateralis. NL1 Nucleus lemnisci lateralis. dl H Fasciculus tegmenti dorsolateralis. Lm Lemniscus medialis. N Vm Nucleus motorius trigemini. V Nervtts trigemini. N Vs Nucleus sensibilis trigemini. Va Radix spinalis trigemini. Crst Corpus restiforme. NXII Nucleus hypoglossi. Ncu Nucleus funiculi cuneati. Ng Nucleus funiculi gracilis. Fnc Fasciculus cuneatus. m Fasciculus longitudinalis dorsalis. Sgl Substantia gelatinosa trigemini. VLL Nervus facialis. LX Nervtis glossopharyngeus. NX Nucleus vagi dorsalis. LXa Radix spinalis glossopharyngei. BPo Brachium pontis. ii 4 \OX-ACOUSTIC OR STATIC LABYRINTH. the long axis of the ridge is at right angles to the long axis of the canal. The ridge is built up of a fan-like separation of the ampullar nerve fila- ments plus connective and vascular tissues. The nerve filaments ter- minate in the special sense end-organ (crista ampullaris). The crista?, like the maculae, are composed of ciliated neuro-epithelial and supporting cells. The ciliated cells are the real special sense or perceiving cells. These differ from those of the maculae in that they carry much longer cilia. The supporting cells of the cristse no doubt perform a similar func- tion to the supporting cells of the maculae. The cilia are held more or less together, or so to speak matted to- gether, by a mucilaginous substance in such manner that their distal tips come close together, much like a paint brush after dipping in oil, and looks not unlike it. On the summit of the cilia is an accumulation of the mucilaginous or gelatinous substance which is known as the cupula terminalis. The cilia are more or less flexible and capable of inclination in two directions toward and away from the utriculus in the long axis of the canals. Because of the matting together of the cilia they all move in one or the other direction as a single mass. All of these five end organs receive their nerve supply from branches of the vestibular nerve, the course of which according to Obersteiner and Marburg is as follows: the peripheral fibers are interrupted and terminate in the bipolar ganglion cells (ganglion vestibulare or Scarpa's ganglion). From this ganglion originate central fibers which unite into a thick trunk and form the median acusticus root (vesti- bular). This root of VIII N. enters the medulla oblongata at the level of the olive, just medianward of the nucleus accessorius. The fibers then pass in a median dorsal direction between the corpus resti forme and the spinal trigeminus root to the nucleus vestibularis triangularis and the nucleus vestibularis magnocellularis. The latter nucleus com- prising Deiter's and Bechterew's nuclei. (Figs. 10 and n.) The nucleus triangularis and the nucleus magnocellularis lie on the floor of the fourth ventricle ; the nucleus triangularis somewhat more medianward and nearer the floor of the ventricle than the nucleus magnocellularis. From the triangularis nucleus go ascending and descending fibers. From the nucleus magnocellularis go both crossed and uncrossed, ascending and descending fibers. The ascending fibers form the pos- terior longitudinal bundle fasiculus longitudinalis dorsalis of Schulz, LABYRINTH PAPERS. 115 and are in direct communication with the nuclei of the VI, IV and III nerves. It is this part of the so-called Deiter's system which has to do with vestibular reflex nystagmus. Descending fibers from the nucleus magnocellularis go to the motor cells of the anterior horns of the spinal cord, and they play a part in the co-ordination of the trunk and leg muscles. Furthermore from the nuclei vestibuli magnocellularis et triangularis go fibers by the tractus nucleocerebellaris to the cerebellum. These fibers terminate in the nuclei tecti of the same and opposite side, and ac- cording to some authors to the cortex of the cerebellum. RELATIVE POSITIONS OF THE SEMICIRCULAR CANALS. The writer considers the relative position of the semicircular canals to the skull and to each other a subject of some importance, since quite a number of men (beginners) with whom he has spoken concerning the labyrinth have had the erroneous impression that the lateral or hori- zontal canals lie in the horizontal, the superior canal in the frontal and the posterior in the sagittal planes of the skull, and these same men are prone to associate horizontal nystagmus with the horizontal canals, rotatory nystagmus with the superior canals and vertical nystagmus with the posterior canals. For this and other reasons he feels it neces- sary to describe and illustrate the realtive positions of the canals. In the erect position of the head the external canals lie practically in the horizontal plane : furthermore, the planes of the two sides are one and the same. If the lateral canals of the two sides were united they would make a complete circle, the two smooth ends meeting and blending posteriorly and the two ampullae coming together anteriorly. The two superior canals lie in vertical planes, but unlike the external canals, they are neither in the same nor parallel planes; but on the contrary, the planes of the canals of the two sides are at right angles to each other, the planes meeting in the median line posteriorly at the point P, at the posterior margin of the foramen magnum. Again, when the canals of the two sides are united we do not have the arrangement (blending of the smooth ends and meeting of the ampullar ends) as in the case of the external canals. The two posterior canals lie in vertical planes at right angles to each other, meeting at the point A Fig. 12 in the median line in the region of the sella tursica. Again, if these canals were united we would not have the same arrangements as in the case of the external canals. ii6 NON-ACOUSTIC OR STATIC LABYRINTH. When considering the two superior or two posterior canals together there is a lack of congruity or association which we find existing in the case of the two external canals. On the other hand, if we consider the superior canal of one side with the posterior canal of the opposite Figure 12. Half schematic representation of the two labyrinths showing the relative positions of the semicircular canals to the skull and to each other. N 7th and 8th nerves as they enter the internal auditory foramen. C Coch- lea. F Geniculate ganglion of the facial nerve. E External semicircular canal. The dashed line i-i illustrates the vertical plane of the left superior semicircular canal. The dashed line 2-2, the vertical plane of the right posterior semicircular canal. The dotted line 3-3 represents the vertical plane of the left posterior semicircular canal. The dotted line 4-4 represents the vertical plane of the right superior semicircular canal. A The point of meeting of the vertical planes of the posterior semicircular canals of the two sides. P The point of meeting of the vertical planes of the superior semicircular canals of the two sides. side, their association as found in the external canals is established. In other words, they lie in parallel planes, and if the canals are brought together they would form a circle with the smooth ends coming to- gether and blending, while the two ampullae would meet at a point 180 from the smooth ends. Thus we see that the six canals of the two sides are correllated and designed after a definite plan. PHYSIOLOGY AND PATHOLOGY OF THE NONACOUSTIC OR, SO-CALLED, STATIC LABYRINTH. NYSTAGMUS. BEFORE considering that special form of nystagmus which may be produced physiologically by irritation of the nonacoustic labyrinth or pathologically by irritative or destructive changes in the same, let us briefly consider the subject of nystagmus in general Nystagmus is an involuntary to and fro movement of the eyes, sub- ject in some instances to more or less voluntary inhibition. According to the plane in which the movements take place we have horizontal, rotatory, vertical or oblique nystagmus ; or any combina- tion of these. According to the comparative rapidity of the two move- ments (to and fro) we have the oscillatory and rhythmic forms of nystagmus. In the case of oscillatory also known as undulatory nystagmus the two component eye movements or excursions are performed with equal rapidity, just as in the case of the pendulum of a clock, the oscil- lation to one side is performed with precisely the same rapidity as the oscillation to the opposite side. For this reason we cannot speak of oscillatory nystagmus taking place in any definite direction. We may speak of a horizontal oscillatory nystagmus, but it would be nonsense to speak of a horizontal oscillatory nystagmus to the right or to the left. In the case of rhythmic nystagmus the two component eye move- ments are performed with unequal rapidity; in other words, the eye movements are jerky or spasmodic in one direction and slow in the opposite; for this reason we may consistently speak of horizontal rhythmic nystagmus to the right or left. Authors have agreed to specify the direction of rhythmic nystagmus according to the direction of the rapid movement; thus horizontal nystagmus to the right is understood to be rhythmic and not oscillatory, from the fact that a definite direction is specified ; the plane of the movements is horizontal and the direction of the quicker movements is to the right. For the sake of convenience the plane and direction of rhythmic nystagmus may be indicated by appropriate signs, as follows : n8 NON-ACOUSTIC OR STATIC LABYRINTH. \ N L. Horizontal nystagmus to the patient's left. R. Horizontal nystagmus to the patient's right. L. Rotatory nystagmus to the patient's left. R. Rotatory nystagmus to the patient's right. U. Vertical nystagmus upward. D. Vertical nystagmus downward. U. L. Oblique nystagmus upward and to the patient's left. D. R. Oblique nystagmus downward and to the patient's right. D. L. Oblique nystagmus downward and to the patient's left. U. R. Oblique nystagmus upward and to the patient's right The directions indicated by the arrows above correspond to the directions of the eye movements as seen by the observer looking directly at the patient, from in front. These signs are the author's, modified after Barany, and have been adopted and used by Alexander and his staff in the ear department of the Polyclinic in Vienna. It is well at this time to differentiate still further the oscillatory and rhythmic forms of nystagmus, including a review of the points already mentioned. OSCILLATORY NYSTAGMUS. I May take place in any plane. 2 The two opposite movements occur with equal rapidity. 3 We cannot speak of a definite direction of this nystag- mus. 4 Cannot be produced experi- mentally. RHYTHMIC NYSTAGMUS. I May likewise take place in any plane. 2 The two opposite movements occur with unequal rapid- ity. 3 We may speak of a definite direction, corresponding to the direction of the rapid movement. 4 May be produced experi- mentally by active or pass- ive rotations, by caloric, mechanical or galvanic ir- ritation of the ear laby- rinth (vestibular) ; or by the looking out of a mov- ing train, looking at a waterfall, etc. (optical.) LABYRINTH PAPERS. 1 19 5 Is not accompanied with vertigo. 6 Is ahvays of pathologic sig- nificance. 7 The intensity can be volun- tarily inhibited, and in some cases even to the ex- tent of bringing about temporary cessation. The inhibition of the nystag- mus is in direct proportion to the inhibition of the at- tempt at central visual fix- ation. 8 Oscillatory nystagmus is practically a permanent pathologic condition, and tends in some cases to in- crease. 9 Oscillatory nystagmus, in some cases, has been ob- served to take on a some- what rhythmic character during attempts at fixa- tion in extreme lateral po- sitions. 5 Is generally accompanied with vertigo, at least when the nystagmus first occurs. 6 Is not always of pathologic significance, since it may be produced physiologic- ally by attempts at volun- tary fixation of the gaze in any extreme direction. Be- sides, most optical forms (see above) are generally physiologic. 7 The intensity of the nystag- mus can be inhibited only by the patient looking in the opposite direction to his nystagmus. A pronounced nystagmus to the right when looking to the right cannot be inhibited so long as the patient continues to look in that direction. 8 Rhythmic nystagmus is gen- erally a transient condi- tion, and tends rather to dimmish and may even cease in some cases. 9 On the contrary, rhythmic nystagmus cannot be made to take on an oscillatory character. Nystagmus is almost always bilateral. In exceptional cases we find it unilateral ; in other exceptional cases, tho the nystagmus is bilateral and synchronous, the length of the nystagmic excursions are unequal in the two eyes. In this connection the writer will cite three cases illustrating these variations. 120 NO\' -ACOUSTIC OR STATIC LABYRINTH. CASE I. A woman about 50 years of age, with both labyrinths normal, was examined upon the revolving stool. After ten complete turns to the left with the head in the upright position, instead of mani- festing a bilateral horizontal after-nystagmus to the right as the vast majority of cases do she manifested a horizontal after-nystagmus to the right of the right eye only, the left eye remaining stationary. The same results were obtained when turned in the opposite direction, ;. r., after-nystagmus to the left of the left eye only, the right eye remaining stationary. With the caloric test the same character of reactions was obtained, namely, unilateral nystagmus and always of the eye of the side to which the nystagmus manifested itself. CASE II. A woman, aged 40, of low intelligence, after the turning test (as above described) manifested instead of nystagmus a deviation of one eye. For instance : Instead of manifesting a bilateral nystag- mus to the right by the various tests which produce nystagmus to the right, she manifested a deviation of the right eye to the left, in other words, a convergent strabismus of the type corresponding to paralysis of the right external rectus. The deviation endured for a length of time corresponding to a nystagmus reaction in the average normal individual. CASE III. A young man 21 years old, with diffuse corneal opacity in the right eye and slight microphthalmos of the same eye, manifests a pronounced spontaneous rhythmic nystagmus of the right eye to the left ; while the left normal eye manifests a barely perceptible nystag- mus synchronous with that of the right eye. ETIOLOGY OF OSCILLATORY NYSTAGMUS. Oscillatory nystagmus is usually, if not always, due to congenital or early acquired visual defects ; especially central visual defects. We therefore find it prone to occur in cases of centrally located opacities of the ocular media (central corneal macula, etc.) and in cases of fundus disease where the lesion involves the region of the macula lutea, more especially when these conditions have occurred before or about the age at which a child learns to fix the eyes for central vision. In other words, the more central the visual defect and the earlier in life it occurs, the more likely the child is to develop oscillatory nystagmus. While the above conditions favor most the de- velopment of oscillatory nystagmus, we find cases developing later in life. We also find rare cases of congenital oscillatory nystagmus oc- curring in individuals where every method of examination fails to reveal any pathologic condition of the eyes ; but on the other hand, they show at least some defect of central vision. The cause in these latter cases is unknown ; however, it is possible that at some future time they LABYRINTH PAPERS. 121 may be found to result from some congenital hemorrhage or other character of lesion in the tracts or centers corresponding to central macular vision. While oscillatory nystagmus results from congenital or early ac- quired visual defects, not every case of congenital or early acquired visual defect produces the oscillatory form of nystagmus, for we find cases where the resulting nystagmus is rhythmic in character. The writer has examined such cases for the purpose of determining the presence of other factors that might have caused the nystagmus to Be rhythmic instead of oscillatory in character, but with negative results. Concerning the exact causes in all cases of oscillatory nystagmus we have yet much to learn. Fortunately for the otologist, the causes of rhythmic nystagmus have been more definitely ascertained. ETIOLOGY OF RHYTHMIC NYSTAGMUS. Rhythmic nystagmus may be produced physiologically, pathologic- ally or experimentally. Physiologically, as already pointed out, by looking out of a moving car window at passing objects (horizontal nystagmus to the left when looking out of the right side of the car which is moving forward) ; by looking out of elevator car (vertical nystagmus upward when car is going up, and vertical nystagmus downward when car is going down). Again, these same nystagmi may be produced physiologically by one remaining stationary and observing moving objects waterfalls (verti- cal upward), moving carousal (horizontal to the right when the carousal is moving to the left past our field of vision, etc.). All of these represent physiological optical nystagmus. Rhythmic nystagmus may be produced physiologically also by active or passive rotation of the head in any plane. Barany has found that a single rotation will produce nystagmus in the plane of rotation and in the direction of rotation during the turning, even with the eyes closed. With the eyes open the nystagmus produced by rotation represents a combined optical and vestibular nystagmus; with the eyes closed it represents purely vestibular nystagmus. The nystagmus manifested by attempts at fixation of the eyes in ex- treme positions may in a sense be termed physiologic. For instance all normal individuals when looking to the extreme right or. left manifest rhythmic nystagmus to that particular side. This nystagmus is due to the extra strain put upon the abductors of one eye and the adductors of the other eye, and compares with the clonic contractions of other 122 NON-ACOUSTIC OR STATIC LABYRINTH. body muscles when any extra strain is put upon them. This nystagmus is dependent upon two contrary working factors : ( I ) the strong vol- untary cortical impulse to the muscles, and (2) the inherent weakness of the muscles to maintain the excessive muscular contraction. The contractions are intermittent, with the result that the individual mani- fests nystagmus. This form of nystagmus varies in different indi- viduals ; for instance, those with weak eye muscles and with strong power for voluntary cortical innervation will manifest a more marked nystagmus than those with stronger muscles and weaker power of innervation. It is characteristic for nystagmus of this type to manifest itself with equal intensity to both sides. The knowledge of all these facts is important and will save much confusion when we come to consider the observations of vestibular nystagmus. Rhythmic nystagmus may be produced pathologically by unilateral, irritative or destructive conditions of the labyrinth, the vestibular nerve, its nucleus in the medulla, the supranuclear tracts (posterior longitudi- nal bundle and tractus nucleo-cerebellaris) or of the cerebellum itself, which involve the sensory or centripetal impulses. Again, rhythmic nystagmus may be produced pathologically by irritative or destructive lesions of the supranuclear motor tract (including the posterior longi- tudinal bundle, which is really more motor than sensory), the cortico- nuclear, equivalent to the pyramidal tract, the motor nuclei, the motor nerves or the eye muscles themselves which involve the motor or centrifugal impulses. Besides the location, the nature of the lesions capable of producing nystagmus are numerous. These two^conditions (location and character of the lesion) taken together multiply the number of possible pathologic processes capable of producing rhythmic nystagmus, some of which may be cited, e. g.: any form of lesion of the labyrinth ; hyperemia, inflammation ; fist- ula ; traumatism, direct and indirect, involving the labyrinth capsule and including fracture at the base of the skull passing thru the pyramid ; hemorrhages into the labyrinth from chlorosis, pernicious anemia, from changes in atmospheric pressure in caisson workers, balloonists, etc. ; ischemia from embolism or partial obliteration of the arteria auditivae internae in arteriosclerosis and endarteritis ; toxemias from quinine, salicylates, etc. ; granulomatous infiltration of syphilis, tuberculosis and leukemia. Diseases of the vestibular nerve : neuritis ; tumor ; granulomatous LABYRIXTH PAPERS. 123 infiltration ; basal meningitis ; increased intracranial pressure in case of acute hydrocephalus, cerebral tumors and abscess. Diseases of the medulla oblongata involving the vestibular nuclei (triangularis and magnocellularis), including bulbar and pseudobulbar palsy, tumors, syphilis, tuberculosis, hemorrhage, multiple sclerosis ; toxic substances circulating in the blood stream (alcohol, nicotine, ex- cess of carbon dioxid, etc.). Diseases of the cerebellum : tumors, abscess, areas of multiple sclero- sis, etc. Diseases of the posterior longitudinal bundle : tumors, gummatous or tuberculous infiltrations on the floor of the fourth ventricle (above the striae acousticae) or the aqueductus silvii, multiple sclerotic plaques, etc. Diseases of the eye muscle nuclei: tumors, hemorrhages, degenera- tions, abscess, sclerosis, emboli, arteriosclerosis, etc. Diseases of the motor nerves of the eye muscles : neuritis from vari- ous causes (refrigeratory, postinfectious, toxic, luetic, etc.), tumors and granulomatous infiltrations, orbital fractures and intraorbital dis- ease which might impair the innervation or action of a particular muscle or set of muscles. The writer has merely mentioned some of the pathologic causes ; there are perhaps as many more, including the yet undiscovered, that may produce rhythmic nystagmus. It might be said in this conjunction that the nystagmus of cerebellar disease is not a real ataxia nor is it homologous to the ataxia mani- fested in the extremities or trunk, as might be believed, but is a true rhythmic nystagmus. Marburg and others, including the writer, be- lieve that the nystagmus of cerebellar disease is actually vestibular in type and originates from influences acting directly upon Deiter's nucleus, which lies in the immediate neighborhood of the lateral cere- bellar lobe. Experimentally optical nystagmus can be produced by the rota- tions of objects in various planes before the open eyes (experi- ments similar to those made by Mach) or by passive rotations of the individual in various planes about stationary surroundings. In this latter instance the resulting rotational nystagmus is produced by a combination of two irritations: (i) the passage of moving objects be- fore the open eyes (optical), and (2) motion of the endolymph in the semicircular canals (vestibular). The elimination of the vestibular element and the production of pure optical rotational nystagmus after 124 NON-ACOUSTIC OR STATIC LABYRINTH. the above method is possible only in those cases of deaf mutes which have complete destruction of both labyrinths or nerves. The elimination of the optical element and the production of pure vestibular rotational nystagmus is possible by the simple closure of the eyes during the rotations. In fact, this was one of the earlier methods of examination for rotational vestibular nystagmus, the determination of which was ac- complished, during the turning, by feeling of the eye movements with the fingers thru the closed lids. Experimentally, vestibular nystagmus can be produced in man by active and passive turnings, by caloric irritation of the labyrinth and by galvanic irritation of the labyrinth and nerve, or by mechanical irrita- tion as practiced first by Ewald and later by Dreyfuss. Sketch After Barany. Ewald, 1888 (Zur. Physiologic der Bgg. Tageblatt de 61 Ver- sammlung Deutscher Naturforscher u. Aerste in Koeln, von 18-23, Sept., 1888, s. 74-76), described for the first time his experiments upon pigeons made with his celebrated pneumatic hammer. This experi- ment was unique in the history of the subject and a description of his hammer and methods of applying it is well worth citing. Ewald first exposed and prepared the osseous external semicircular canal of a pigeon. He then drilled a small opening thro it several mm. posterior to the ampulla, at the same time avoiding injury to the mem- branous canal. Through this opening he inserted a filling material similar to that used by dentists, which when it becomes set acted as a plug interrupting completely the lumen of the membranous canal at this point (a). LABYRINTH PAPERS. 125 Xext he made a second small opening after the manner of the first midway between the first opening and the ampulla. At the second opening he adjusted an apparatus known as a pneumatic hammer. This hammer consists of a slender glass cylinder open at both ends, inside of which glides a piston with a small button on its distal end, which comes in contact with the membranous canal and serves to give it the hammer effect. Over the other end of the glass cylinder is fitted a rubber tube of convenient length and on the end of this again is fitted the rubber bag () Compression of the bag held in the hand, drives the piston inward against the membranous canal. Relaxation of pressure on the bag produces aspiration, causing the piston to be withdrawn to its pri- mary position. When the piston is driven inward by compression the displaced endolymph, since it cannot flow posteriorly on account ot the plug (a), must flow anteriorly toward the ampulla and utriculus in- dicated by the arrow. On the other hand, by aspiration the endo- lymph must flow in the opposite direction. Ewald, after this manner oi examination, found that compression, equivalent to movement of endolymph from the nonampullar toward the ampullar end, caused a slow movement of the eyes and head to the opposite side in the plane of the canal (horizontal) ; and that aspiration, equivalent to a move- ment of the endolymph from the ampullar toward the nonampullar end, caused a slow movement of the eyes and head to the same side. From this, Ewald was able to conclude that definite movements of the endolymph in the horizontal canal were responsible for definite re- flex movements of the head and eyes. Ewald after the same manner demonstrated the characteristic movements of the head and eyes cor- responding to definite endolymph movements in the remaining canals. The physiology of vestibular nystagmus produced by turning and the caloric irritation of the labyrinth differs from that produced by gal- vanism. Before discussing the physiology of nystagmus produced by these separate irritations, let us consider the physiology of vestibular nystagmus in general. PHYSIOLOGY OF THE TWO MOVEMENTS OF NYSTAGMUS. It is a well known and established fact that irritation of the semi- circular canals of one side will produce nystagmus to that side and that the inhibition of impulses from the semicircular canals of one side will produce nystagmus to the opposite side. Let it be understood early that nystagmus produced by either irritation or inhibition is not the actual vestibular reflex, but merely the evidence of the reflex. The 126 NON-ACOUSTIC OR STATIC LABYRINTH. actual reflex, from irritation, for instance, of the right semicircular canals, produces a deviation of the eyes to the left, while the quick, jerky movements of the eyes to the right (Einstellung of the German authors) is the result of a voluntary effort on the part of the individual to restore macular fixation of external objects which had been tm- porarily lost during the reflex deviation of the eyes. To better show the physiology of the two movements of nystagmus the writer will make use of an illustration from Barany's work upon the Phys. and Path, des Bgg. Appar. beim Menschen, page 53. See Fig. 14. There is an abundance of evidence to show that the conjugate devia- tion of the eyes (slow movement of the nystagmus) is the actual vestib- ular reflex, and that the rapid movements in the opposite direction arc purely voluntary, produced by cortical innervation. In the making of various animal experiments by sectioning of the canals, by sectioning of the acusticovestibular nerve, by mechanical (Ewald's pneumatic hammer experiment) or by galvanic irritations of the semicircular canals, it has been found that some animals show only the reflex deviation (correspondng to the slow movements of the nystagmus) to the opposite or nonirritated side, while others will show rhythmic nystagmus to the same dr irritated side. Again, the same animal will show by the same experiment at one time deviation and an- other time nystagmus. Frequently the nystagmus will be more pro- nounced immediately after the irritation or destruction, whereas later, as the animal tires, it will show only the deviation. Furthermore, it will be found that the lower the animal the weaker is the volition and the more likely it is to show only the reflex deviation ; while the higher the animal, the stronger is the volition and the more likely it is to show nystagmus. Again, if one experiments with a sufficient number of human sub- jects he will observe quite a difference in different individuals. It will be observed that the more intelligent people will show the more pro- nounced nystagmus ; while occasionally very young children or very stupid people of low intelligence will manifest deviation only. When making time experiments of after-turning nystagmus, in those cases manifesting deviation only it is important to time the duration of the deviation just as one would in another case time the duration of nystagmus. Fig. 14 illustrating horizontal nystagmus to the left produced by irritation of the left semicircular canal apparatus. L y j i ><>f .-- x i r -"' f in -** 1 1 ~^ c rf . 7*>4- *\q. :S .. J~ &:' >vr: A 1 r" J ^ n n V o' (m a, a 1 Nucleus Deiters, sinis, et dext. b, b 1 Nucleus nerv. abducens, sinist. et dext. c, c 1 Nucleus nerv. oculomotor, sinist. et dext. d, d 1 Oculus, smist. et dext, e, e 1 Muse. rect. extern, sinist. et dext, f, f 1 Muse. rect. intern, sinist. et dext. g, Shaltzelle (Monakow) = centre for the movement of the eyes to the left, h, Nervus vest, sinist. i, Vestibular tract ( ) crossing to the contralateral abducens nucleus, k, Vestibular tract ( ) crossing to the contralateral oculomotorius nucleus. 1, Vestibular inhibition tract ( ) to the homolateral oculomotorius nucleus. m, Vestibular inhibition tract (.... ) to the homolateral abducens nucleus, n, Gyrus angularis dextra (cortex), center for the voluntary movement of the eyes to the left, o, Cortical tract ( . . . .) to subcortical center (Monakow's) for the voluntary movements of the eyes to the left, p, Supranuclear tract ( . . . .) from the left subcortical center (Monakow's) to the homolateral oculomotorius nucleus, q, Supranucleur tract ( . . . .) from the left cortical voluntary center (Monakow's) to the homolateral abducens nucleus, r, A double sided lesion at r would produce paralysis of voluntary movements of the eyes, which at the same time would leave vestibular nystagmus undisturbed (pseudo- ophthalmoplegia of Wernicke). s, A double sided lesion at s would produce paralysis of voluntary movements of the eyes and make impossible the quicker voluntary movements of nystagmus, but would leave the slow vestibular reflex movement undisturbed (supra/mclear ophthalmoplegia of Barany). 128 XOX-ACOUST1C OR STATIC LABYRIXTH. A further illustration of the voluntary nature of the quick move- ment of the nystagmus is demonstrated by the fact that the nystagmus is least pronounced when the patient looks toward the side of the devia- tion and most pronounced when he looks toward the side of his nystagmus. An interesting and instructive case cited by Ilarany (Phys. u. Path, der Bgg. Appar. beim Menchen), also seen by the writer, practically settles the problem of the physiology of the two movements of nystag- mus. The case is as follows : A patient was referred from the neurological to the ear department of the general hospital in Vienna, suffering with complete paralysis of abduction and adduction. The patient could not voluntarily move the eyes to either side, because of a supranuclear lesion ; but upon rotation and caloric irritation of the semicircular canals the patient manifested a reflex conjugate deviation of the eyes to the side opposite the irrita- tion, without nystagmus. After turning there was conjugate deviation of the eyes to the same side without nystagmus. The writer might cite many other circumstances, including experiments made upon nar- cotized and comatose subjects, to prove the facts originally stated that the deviation of the eyes or its equivalent, the slow movement of the nystagmus, is the actual vestibular reflex, while the quick movement in the contrary direction is voluntarily produced. From what has been previously said, the intensity of the vestibular nystagmus depends upon two factors : ( I ) the intensity of the irritation of the semicircular canals in producing the reflex deviation of the eyes ; and (2) the intensity of the voluntary cortical innervation to re-estab- lish macular fixation of external objects. For these reasons the in- tensity of the nystagmus should be (exactly as we find it) most marked when looking in the direction away from the reflex deviation (toward the nystagmus), and least marked when looking in the direc- tion toward the reflex deviation (away from the nystagmus). ESTIMATION OF THE INTENSITY OF THE NYSTAGMUS. The intensity of the nystagmus is estimated by the length of excur- sions of the eyes and the frequency of these excursions. Thus a nystagmus of six mm. excursion is more intense than one of two mm. Again, a frequency of six excursions per second is more intense than one of two excursions. For the reason that the rapidity of the move- ments is easier to estimate than the length of the excursions the custom LABYRINTH PAPERS. 129 has been to judge the intensity by this factor; however, the amount of deviation of the eyes measured in degrees would be a more exact but a less practical method. HOW SHOULD OXE EXAMINE FOR NYSTAGMUS? The observation of nystagmus is quite important. Low degrees of rotatory nystagmus can be very easily overlooked by casual observa- tion of the eyes between the normal palpebral fissure, and the more so with ordinary illumination. The writer has described the methods of examination in a former paper upon "Labyrinth Suppuration ; Two Cases." The first requisite is good illumination, which can be obtained by the use of any ordinary head mirror. It is well to direct the illumination sufficiently obliquely (from the side) to avoid too great irritation of the macular region of the eye. This form of illumination serves another purpose, that of producing a bright reflex on the upper part of the sclera. That one may observe the eye movements to the best advant- age it is necessary to elevate the upper lid, preferably with the thumb of the left hand when examining the right eye or the thumb of the right hand when observing the left eye. Have the patient look at some distant object in the horizontal plane or slightly above it and directly in front of him. If nystagmus be present, the eye movements can be not- ed by change of relative position between the bright reflex produced by your concentrated light on the sclera and one of the nearby deep con- junctival or long ciliary vessels which run meridianally. It is also im- portant to look long enough, for in case of late labyrinth suppuration the nystagmus is oftimes so slight that the length of excursions is but one or two mm. at most, and the movements may repeat themselves at intervals of five or six seconds or even longer. The object of having the patient look at distant objects has been pointed out by Abels and quoted by the writer in former papers upon the subject. When looking at objects at close range the necessary convergence of the eyes calls for so strong a voluntary innervation of the muscles supplied by the oculomotori nuclei and nerves, that it inter- feres and inhibits considerably the vestibular reflex ; again, since the nystagmus is diminished in proportion to the convergence, the same patient with the same amount of irritation in the semicircular canals may at one time show more pronounced reaction than at subsequent times when the oculomotori were more strongly innervated. This may 9 130 NON-ACOUSTIC OR STATIC LABYRINTH. in a measure account for some of the wide discrepancies in Barariy's earlier figures, especially in his observations of after-turning uystagmus. For the same reason the observation of nystagmus by directing the pa- tient to look at the finger held to the sides is a less certain method than the observation of nystagmus after the manner described by the author. However, in some exceptional cases the examination after this coarser method (by having the patient to look to the side) may be permissible, especially in demonstration work before student bodies. TURNING AND AFTER-TURNING NYSTAGMUS. THUS far we have observed that vestibular nystagmus is rhythmic in character ; that it is designated horizontal, rota- tory, vertical, etc., according to the plane of its move- ments ; to the right, to the left, etc., according to the direction of the quicker excursion. \Ye have further observed that vestibular nystagmus can be produced by a one-sided destruction or irritation of certain end-organs in the semicircular canals, irritation of which may be produced mechanically (Ewald's experiments) by turning, by thermic changes and by galvanism. Of mechanical irritation we have already spoken in the last paper. In the present paper we shall discuss the subject of irritation by turn- ing and after-turning. Physiologically every act of turning, no matter how slight, is ac- companied by a definite amount of nystagmus ; for instance, when one turns the head but 20 degrees, the eyes make a double movement ; first a slow one, in the direction contrary to the head movement, followed promptly by a second quicker movement in the same direction. The slow movement is due to the vestibular reflex which permits a brief lingering of the visual fixation upon the object last seen, while the quick movement is due to a second fixation upon a fresh object. The quicker eye movement subtends an arc equal to that of the head movement. If instead of stopping at 20 degrees, the head is continued in rota- tion for a total of 360 degrees (thus completing the circle) it will be found that instead of a single slow and quick movement, as in the above instance, the eyes will have made a succession of such move- ments. In other words, the subj'ect will have manifested a rhythmic nystagmus in the direction of rotation. The total amount of the quick eye movements equals the total amount of rotation of the head. During each slow movement there is a visual impression together with a fixation of the field, which appears to be constantly passing and which the eyes follow in the direction con- trary to the rotation of the head. During the quicker movements there is neither visual impression nor fixation of the field, but a series of interruptions between succeeding visual impressions. In brief, I 3 2 TURXIXG AXD AFTER-TURX1XG XYSTAGMUS. rhythmic nystagmus is accompanied by a series of alternate visual im- pressions and interruptions of these impressions. Thus far we have spoken of the nystagmus produced by rotation of the head with the eyes open, the effects being quite similar but not identical to those produced by the rotation of the field about the sta- tionary subject, the difference being, in the case of rotation of the field about the stationary subject the production of rotational optical nystagmus, while in the case of rotation of the subject with open eyes about the stationary field, the production of combined rotational optical nystagmus and rotational vestibular nystagmus. In order to produce pure rotational or turning vestibular nystagmus it is necessary to make the turning with the eyes closed, whereby the optical factor is eliminated. The demonstration of turning vestibular nystagmus can be made by feeling the eye movements thru the closed lids with the finger tips ; an experiment made by Kreidl and others which can be repeated easily by anyone upon himself. To examine another person it would be neces- sary to have a revolving platform sufficiently large to accommodate both the subject and the observer. For practical purposes, however, this method has become obsolete. With every movement of the head, with closed eyes, there occurs the same movements of the eyes as when the eyes are open ; the physiology however differs as has been stated. This then leads us to a discussion of the PHYSIOLOGY OF PURE,VESTIBULAR NYSTAGMUS PRODUCED BY ROTATION. When the head is erect and the subject turned around the vertical axis with the eyes closed, there is a horizontal nystagmus in the direc- tion of turning which may be felt thru the closed lids ; the rapidity of this nystagmus is in proportion to the rapidity of the turning. If the turning is continued long enough, however, the nystagmus ceases. The nystagmus thus produced is known as turning vestibular nystagmus. If after more or less turning the subject is brought to a standstill, he exhibits an after-turning nystagmus directed to the opposite side to v:hich the turnings had been made; this is designated as an after- nystagmus (a term meaning the same and contracted from the more compound term of after-turning nystagmus). The explanation for turning and after-turning nystagmus offered by Breuer and generally accepted, is that of endolymph pressure against the cupola of the crista LABYRINTH PAPERS. 133 ampullaris which causes an inclination of the cilia, which in turn pro- duces the sensation of turning and the reflex nystagmus. For instance, in the case of turning with the head erect : at the beginning of turning, say to the right, the endolymph in the horizontal canals lags behind because of inertia, just as one standing in a car tends to fall backward when the car starts forward. This results in a relative movement of the endolymph in the horizontal canals in the opposite direction (to the left), which is equivalent to a movement of the endolymph in the right horizontal canal toward the ampulla with a corresponding in- clination of the cilia toward the utriculus, and a movement of the endo- lymph in the left horizontal canal toward the nonampullar end with an inclination of the cilia away from the utriculus. In both cases endolymph pressure in the righ^ canal toward the ampullar end and in the left canal away from the ampullar end nystagmus to the right is produced. These results correspond exactly with the results obtained by Ewald who produced mechanically these same endolymph pressures toward and away from the ampulla. Thus we see that no matte- how it may be produced endolymph motion in the horizontal canal toward the ampullar end causes hori- zontal nystagmus to the same side, A\~* .i^lymph motion away from the ampullar, i. c., toward the nom> npullar end causes horizontal ny-tagmus to the opposite side. See illustration, No. X. This movement of the endolymph in the opposite direction to the movement of the canal continues only so long as there is a c c e 1 e r a- t i o n of the turning motion. Let the turnings become of uniform velocity the'n the endolymph will sooner or later acquire the same veloc- ity as the canals themselves when there will cease to be any relative movement of the endolymph in the canals. At this moment the cilia ac- cording to Breuer and Barany begin to re-establish their normal posi- tion of rest that is a position vertical to their insertion base. This re- establishment to the primary position is brought about by the elasticity of the cilia and of the gelatinous substance which holds them together. This assumption of Breuer, supported by Barany, is based upon the fact that after turning has been continued uniformly for some length of time, the physiological reflex (nystagmus) ceases. After-turning nystagmus, according to the same authority, is ex- plained as follows: Taking the same case (subject turning to the right with head erect), at the moment of cessation of turning the canals cease also, but not so E.M A/,/? L.U FIG. 3 LABYRIXTH PAPERS. 135 Illustration X. Fig. I illustrates the quiescent state of the endolymph in the horizontal semicircular canals. E. C. L. H. represents the external crus of the left horizontal canal; E. C. R. H. the external crus of the right horizontal canal; C. A. the crista ampullaris ; C. C. A. the cilia of the crista ampullaris in a state of rest perpendicular to the base. L. U. relative position of the left utriculus; R. U. right utriculus ; L. E. left eye, and R. E. right eye ; both eyes looking straight ahead. Fig. 2 illustrates the influence of rotation of the head to the left : (a) Upon the cilia of the crista ampullaris in both right and left horizontal canals, and (b) upon the eyes to produce turning nystagmus to the left. The large arrow L. R. represents left rotation of the head. The arrow E. M. L. H. the direction of endolymph motion in the left horizontal canal, toward the ampulla producing an inclination of the cilia toward the left utriculus (L. U.). The arrow E. M. R. H. represents the direction of the endolymph motion in the right horizontal canal away from the ampulla, causing an inclination of the cilia away from the right utriculus (R. U.). The straight arrow N. L. represents the direction of the nystagmus to the left, produced by the inclination of the cilia in either or both canals. Fig. 3 illustrates the influence of cessation of head rotation to the left: (a) Upon the cilia of the crista ampullaris in both right and left horizontal semi- circular canals, (b) upon the eyes to produce after-turning nystagmus to the right. The arrow E. M. L. H. the direction of endolymph motion in the left horizontal canal away from the ampulla, producing inclination of the cilia away from the left utriculus (L. U.). The arrow E. M. R. H. the direction of the endolymph motion in the right horizontal canal toward the ampulla, producing inclination of the cilia toward the right utriculus (R. U.). The straight arrow N. R. represents the direction of the nystagmus to the right produced by the inclination of the cilia in either or both canals. i 3 6 TURNING AND AFTER-TURNING NYSTAGMUS. the endolymph, which continues to move in the same direction, just as onp standing in the car tends to move forward for a moment after the car comes to a stop. In consequence there is a relative movement of the endolymph in the right horizontal canal from the ampullar tow r ard the nonampullar end and with it a corresponding motion of the cupula together with inclination of the cilia a^'ay from the utriculus : and in the left horizontal canal a movement of the endolymph from the non- ampullar toward the ampullar end, with a corresponding motion of the cupula and inclination of the cilia toward the utriculus ; both of which produce an after-turning nystagmus to the left (in the direction contrary to the turning.) The rapidity of the after-turning nystagmus is more or less in proportion to the rapidity of turning which precedes it ; how- ever, the duration does not vary appreciably one way or the other. When the head is held in such a position that rotation occurs exactly in the plane of the horizontal canals, the maximum amount of endo- lymph motion occurs in these canals (both during a nd after rotation) ; in which case we have the most pronounced and the purest form of horizontal nystagmus. When the head is inclined away from this plane the amount of endolymph motion in these canals diminishes pro- portionately, while at the same time the endolymph motion begins to occur in the remaining canals and proportionately to the inclination. As a result, the nystagmus begins to lose its horizontal and assumes another character. If the head is inclined 90 forward or backward, so that the plane of the horizontal canals is at right angles to the plane of rotation, then no endolymph motion in the horizontal canals can occur. but instead endolymph motion in the two vertical canals of each side resulting in the purest form of rotatory nystagmus. The rotatory nystagmus has occurred as a result of the irritation of four vertical canals, two on each side. Altho Ewald, by careful research with his pneumatic hammer, had determined positively the effects of endolymph motions (both toward and away from the ampulla) in the case of each of the canals it be- comes quite a mathematic problem to figure out accurately in which canals the endolymph movement .occurs and the direction it oc- curs in the case of turning in the various planes (frontal, saggital. oblique, etc.). Fortunately, for practical purposes alone, it is not neces- sary to resort to mathematics, since we have other definite and much simpler laws, to guide us as to the plane and direction in which a nvstagmus should occur from turning. They are : LABYRINTH PAPERS. 137 I. Turning nystagmus occurs in the plane of rotation of the head. II. The direction of turning nystagmus is in the direction of rota- tion of the head. III. The plane of the after-nystagmus is the same as that of the turning nystagmus. IV. The direction of the after-turning nystagmus is opposite to that of the turning nystagmus. ILLUSTRATIONS. I. As previously stated, if the head is held erect, so that the hori- zontal canals lie approximately in the horizontal plane and the subject is turned about the vertical axis to the right (as the hands of a watch move) a rhythmic horizontal nystagmus to the right occurs during the turning and a rhythmic horizontal nystagmus to the left occurs after cessation of turning. II. If the head is inclined 90 forward so that a plane thru the corneal limbus lies in the horizontal plane and the subject is turned about the vertical axis to the right, a rhythmic rotatory nystagmus to the right occurs during turning to the right and a rhythmic rotatory nystagmus to the left occurs after, cessation. III. If the head is inclined 90 backward so that a plane thru the corneal limbus lies in the horizontal plane and the subject is turned to the right, a rotatory nystagmus to the left is produced during the turning and to the right after cessation. IV. If the head is inclined 90 to the right so that the vertical meridians of the eyes lie in the horizontal plane and the subject is turned to the right, a vertical nystagmus upward occurs during the turning and downward after turning. Y. If the head is inclined 45 forward (a position midway between horizontal and that of 90 forward) and the subject is turned to the right, a combination of horizontal and rotatory nystagmus to the right occurs during turning and to the left after turning. VI. If the head is inclined 45 backward (a position midway be- tween the horizontal and that of 90 backward) and the subject is turn- ed to the right, a combination of horizontal nystagmus to the right with rotatory nystagmus to the left occurs during the turning and a hori- zontal nystagmus to the left combined with rotatory nystagmus to the right after turning. YII. If the head is inclined 45 to the right and the subject is 138 TURXIXG AXD AFTER-TURXfXG XVSTAG.MUS. turned to the right, an oblique nystagmus upward and to the right oc- curs during turning and an oblique nystagmus downward and to the left after turning. From these seven illustrations it is an easy matter to reason out others. All of these forms of nystagmus are increased in intensity when looking to the side toward the direction of the nystagmus and diminish- ed when looking to the opposite side. Following the same law, the case of illustration VI (head inclined backward 45), resulting in after- nystagmus of combined horizontal to the left with rotatory to the right the horizontal character is more pronounced when looking to the left and the rotatory character more pronounced when looking to the right. Vestibular nystagmus is accompanied by other phenomena, both sub- jective and objective, which may be studied more accurately and to the best advantage when it has been produced by the turning method These are : I. Visual sensations. II. Subjective sensation of mo ti o n (turning, fall- ing, etc.). III. Reaction movements. (Equilibrium disturbance.) The first and second of these may be considered likewise the sub- jective sensations of vestibular vertigo. Let us take the case (in which by turning to the left with head inclined forward 90) a rotatory after-nystagmus to the right has been produced. The rotatory after-nystagmus to the right remains as such so long as the reaction lasts, no matter to which position the head may be changed ; however, a change of position of the head will change relatively the plane and direction the nystagmus makes to the erect body and to the external world. For instance, so long as the head is allowed to remain in the primary position, i. e., head inclined 90 forward to the erect body, so that the face looks toward the floor, the rotatory after-nystagmus to the right is occurring in the horizontal plane and is directed to the right. The quick movements of the eyes occur in the same plane and direction as move the hands of a watch lying upon a table with the face up. The nystagmus is taking place, in relation to the head, in the frontal plane : but in relation to the erect body and also to the external world in the horizontal plane. If the head of the subject, who remains sitting or standing vertically erect, is shifted to the erect position so that the face is LABYRINTH PAPERS. 139 directed straight ahead, the rotatory after-nystagmus to the right will be found to remain unchanged in relation to the head (frontal plane), but in the relation to the body and to the external world it will have changed from the horizontal (as in the former instance) to the frontal. If during the reaction the head is turned 90 to the right so that the eyes are directed horizontally over the right shoulder, the rotatory after-nystagmus to the right must occur in the sagittal plane of the body while the quick movement of the eyes will be directed backward. If during the reaction the head is turned 90 to the left so that the eyes are directed horizontally over the left shoulder, then the rotatory after-nystagmus to the right must occur in the sagittal plane of the body while the quick movements of the eyes will be directed forward. If during the reaction, the erect head is turned 90 backward so that the face is directed towards the zenith, then the rotatory after-nystag- mus to the right occurs in the horizontal plane and the quick move- ments are directed to the left (the same plane and direction as the hands of a watch move when its face is turned downward upon the table or the reverse of that which is made when the face of the subject is directed, downward, toward the floor). From the foregoing certain facts have been brought out which are common to every after-turning nystagmus and may be briefly stated as : (a) The plane and direction of after-turning nystagmus retains its same plane and direction relatively to the head as long as the reaction lasts, no matter how the position of the head may be changed. (b) The plane and direction of the after-turning nystagmus changes its plane and direction relatively to the body and to the ex- ternal surroundings with every change of position of the head. These facts must be reckoned wdth also in considering the three as- sociated phenomena of vestibular nystagmus. It will be found that change of position of the head influences not only the plane and direc- tion of the nystagmus in relation to the body and the external world, as already pointed out, but also the visual sensations, the subjective .ensation of motion and the objective (reaction movements) equilib- rium disturbance. I. VISUAL SENSATIONS. The visual sensations accompanying vestibular nystagmus are ex- pressed variously by different individuals. For instance in the case of rotatory nystagmus to the right, we may by inquiry elicit the following expressions : I 4 o TURNING AND AFTER-TURNING NYSTAGMUS. (a) The (visual) sensation of objects, rolling continuously to the right, i. c ., the outer world appears to be rotating about the visual axis to the right. (b) The sensation of external objects rolling to the right with periods of brief interruptions which find the objects back to their primary (normal) position from which they repeat the rolling. (c) The sensation of seeing the external world or room double; one stationary and in normal position while the second appears to be rolling to the right. (d) Some few subjects perceive no motion at all but simply see objects double. (e) Of those who experience the sensation of external objects mov- ing to the left, the writer doubts the accuracy of their observations. The sensation of objects rolling to the right, either continuously or, more accurately, interruptedly as experienced by the vast majority of people during rotatory nystagmus to the right is the normal sensation and can be easily explained. For instance, an involuntary movement of the eyeballs to one side is interpreted as the sensation of motion of ex- ternal objects to the opposite side; objects to the left are perceived upon the retina to the right of the macula, and conversely every retinal impression which falls upon the left side of the macula is projected to the right and perceived as an object upon the right In the case of very active nystagmus of long excursions, the quick movements may occur so quickly that retinal impressions are barely possible, but interruptions take place. The quick excursion, however, has brought the eyes back to their primary (normal) position from whence the slow movement begins to repeat itself and with it comes a repetition of the sensation of external objects rolling. Since retinal impressions are liable to take place during the slow excursion only, then it must follow according to the law of projection that external objects are perceived by the subject as moving in the direction contrary to the slow excursion, in other words, in the same direction as the nystagmus. For illustration see Fig. 2. In those cases where the subjects express themselves with having seen two rooms, one stationary and the other rolling, the sensations may be explained as follows: that seen as the stationary room in its normal position and relation is due to the rapid succession of retinal impressions obtained at the moment the eyes have leaped back to their primary position (Einstellung), which impressions linger sufficiently LABYRINTH PAPERS, MI long to produce, by their very rapidity, quite a continuous visual sensa- tion. The other or second impression, that of the rolling room, has already been explained. In the cases where the subjects experienced diplopia without the sensation of objects rolling was due, in the one case seen by the writer, to an actual convergent strabismus which lasted as long as the average after-nystagmus lasts. The eye of the side to which the after- FIG. 2. E represents the eyeball at rest just before the slow excursion begins. Object O produces a visual image at the macula M and the object is perceived in its normal position. E' represents the position of the eyeball at the end of the slow excursion to the left, as indicated by the arrow L, the image of object O upon the retina has moved to the left, as indicated by the arrow A to point I. Since retinal impressions at I (to the left of the macula) are referred to the right then the object O has apparently moved to the right, as indicated by the arrow R, to the point O'. nystagmus should occur was deviated inward. This patient therefore manifested the vestibular reflex (slow movement) only and that of the one eye. The subject having been unable to voluntarily bring the eye back to its primary position (Einstellung) until after the reflex had passed. Just as in the case of nystagmus so in the case of visual sensations i 4 -' TL'RMXG A\D AFTER-TURNING NYSTAGMUS. of external objects rolling, etc., the intensity is increased when looking toward the side to which the nystagmus is directed and diminished when looking toward the opposite side. Change of position of the head will change the plane and direction of apparent turning. Citation of a single case will be sufficient to illustrate the point. For instance, in the case of horizontal after-nystagmus to the right so long as the patient holds the head erect he experiences the sensation of surrounding objects rotating in the horizontal plane to the right. If the position of the head is so changed that it is inclined 90 to the right, i. e., the right side of the face resting upon the right shoulder with face directed forward, the horizontal nystagmus will then occur in the vertical sagittal plane of the body and the quick movement will be directed downward ; the visual sensation must therefore be that of objects falling vertically downward toward the floor. II. SUBJECTIVE SENSATION OF MOTION. The subject with an after-nystagmus experiences a sensation of motion in the plane and direction of his nystagmus which is increased when looking in the direction of the nystagmus and diminished when looking in the opposite direction. For instance, a patient with hori- zontal nystagmus to the right experiences a sensation of turning or rotation to the right. In case of rotatory nystagmus to the right the plane of the nystagmus is frontal, hence he suffers the sensation of falling laterally to the right. In the case of vertical nystagmus down- ward, the plane of the nystagmus is sagittal, hence the patient has the sensation of falling forward. These sensations are not entirely dependent upon the visual im- pressions, for they are present with the eyes closed as well as with the eyes open. Again the subjective sensation of motion endures as long as the after-nystagmus, and is felt by the subject whether he is stand- ing, sitting or lying down. The sensation of turning or falling when the eyes are open is de- pendent mostly upon the visual impressions that of objects turning or tumbling. As the room in which one is standing seems to turn in a given direction the subject will naturally feel as tho he is going with it. This same sensation of turning or tumbling is experienced by one with rhythmic nystagmus even when produced optically, as by Mach's rotating cylinder experiments, in the muscle paresis, etc. Visual im- LABYRINTH PAPERS. 143 pressions however do not explain the sensation of turning or falling experienced in vestibular nystagmus with the eyes closed. Barany (Phys. u. Path, des Bogeng.) who has studied the subject most carefully is undecided as to whether the falling sensation is due to an irritation conveyed directly to the cortex thru vestibular fibers, or whether the sensation arises thru the medium of the nystagmus. Ac- cording to Ewald (Physiolog. Untersuchungen ueber das Endorgan des N. Octavus), we are led to believe that the sensation of falling is due to an overbalance of muscle innervation of one side of the body produced by the vestibular reflex. There are certain facts which contradict the theory that these sensa- tions are the result of impulses which are conveyed to the cortex. Flourens (Comptes Rendus, Tome LII, p. 673-75) and others have found that animals whose cerebral hemispheres have been removed show the same reactions as before. Again, if cortical perception was entirely responsible for the falling sensations then the sensations should remain constantly the same in spite of change of position of the head, which is contrary to the facts as we find them. For similar reason we must deny Ewald's explanation of muscle tonus. If the muscular hyper- and hypotonus theory was correct then movements of the head should not influence the plane or direction which the sensation of turning or falling takes, or that of the actual reaction falling. For instance, a patient manifesting a rotatory nystagmus to the right because of destruction of the left semicircular canals or stimulation of the right semicircular canals, the hypertonus of one side and hypo- tonus of the opposite side should remain constantly the same in spite of any change of position of the head ; the subject should fall constantly to the one side. The fact however is that both the sensation and the reaction falling may be reversed in their directions by a change of position of the head of 180. From the facts as we find them it would seem that one explanation alone is left us, and that is: The sensation of falling and the objective falling is dependent not upon the cerebral hemispheres, but upon the cerebellum. The writer would attempt the following explanation : That the reflex slow movement of the eyes to the left in case of stimulation of the right semicircular canals occurs independently of the great brain, as 144 TURXIXG AXD AFTER-TURXIXG XYSTAGMUS. shown by Flourens's experiments. Furthermore, since we have come to accept the cerebellum as the central organ for the control of equi- librium and that the kinesthetic sense impulses are conveyed to the cerebellum from the deep muscles, joints, etc., from all parts of the body, may we not look upon the reflex contraction of certain eye muscles as producing similar kinesthetic sense impulses which are con- veyed likewise to the cerebellum? In brief, the opinion of the writer is that when by stimulation of the right horizontal semicircular canal the eyes deviate to the left, the involuntary reflex contraction of the left abductor and the right adductor causes a kinesthetic sensation of con- traction of these muscles which is conveyed to the cerebellum in the same manner as all other kinesthetic sensations are, and is interpreted in the cerebellum as the sensation of torsion of the body to the right which the cerebellum as the central organ for equilibrium attempts to correct by sending motor impulses to certain body muscles to produce the opposite torsion. However, since the sensation of torsion is only apparent and not real, the attempt to unwind the apparent body tor- sion produces an actual torsion in the opposite direction. III. REACTION MOVEMENTS (EQUILIBRIUM DISTURBANCE). The subject with an after-nystagmus will move or fall in the plane of his nystagmus but in the contrary direction. For instance, a subject with horizontal nystagmus to the right will tend to turn in the hori- zontal plane, that is make a torsion movement of the head and body to the left. In the case of rotatory nystagmus to the right the plane of the nystagmus is frontal, hence the subject will tend to fall laterally to the left. In the case of vertical nystagmus downward the plane of the nystagmus is vertical and the direction is downward, hence the sub- ject will tend to fall vertically backward. As pointed out elsewhere the plane and direction of an after-turning nystagmus remain the same, no matter how we may change the posi- tion of the head. A rotatory after-turning nystagmus to the right re- mains as such whether the head is kept forward, turned upward, back- ward or to either side; however, with a change of the head position comes a change in the plane and direction of the falling sensation and of the actual falling. A few cases may be cited to illustrate this point. For instance, in case of rotatory nystagmus to the right the subject has the subjective sensation of falling laterally to the right, because of which in his at- LABYRINTH PAPERS. 145 tempt to correct he really over corrects and actually falls laterally to the left. Xow if the subject's head is turned 90 to the left so that the face is directed to the left, his rotatory nystagmus to the right con- tinues as such, but it occurs in the sagittal plane of his body. As a re- sult the subject experiences the subjective sensation of falling forward, which his attempt to correct causes him to fall backward. If the head should be turned 90 to the right, so that the subject is looking horizontally to the right, the rotatory nystagmus is taking place in the sagittal plane and directed backward and downward, in which case the subject experiences the false subjective sensation of falling backward, which in his attempt to correct causes him to fall forward. If the head should be inclined forward 90 so that the subject looks down- ward, toward the floor, the rotatory nystagmus to the right occvrs in the horizontal plane; the subject experiences the false sensation of torsion to the right, which in his attempt to correct he actually tvrns around the vertical axis of his body (in the horizontal plane) to the left. In the case of horizontal nystagmus to the right with the head upright the subject naturally suffers the sensation of turning in the hori- zontal plane to the right, but actually turns to the left. If the lie-ul is inclined 90 forward so that the patient is looking toward the floor the horizontal nystagmus remains as such, but the nystagmus occurs in the frontal plane of the body, which is equivalent to a rotatory nystagmus to the left with head erect, the corresponding false sen..a- tion is that of falling to the left, which causes the patient to actually fall to the right. If the head is inclined 90 backward so that the sub- ject look? toward the zenith, the horizontal nystagmus remains the same, but the nystagmus occurs in the frontal plane of the body, equivalent to a rotatory nystagmus to the right with the head erect. !TI which case the patient experiences the false sensation of falling tc the right, which results in the subject actually falling to the left. So we might continue the number of illustrations. Barany teaches (Phys. u. Path, des Bogeng. Appar. beim Menscht'u. page, 14, third paragraph from the bottom) that the sensation of fall- ing is increased when the eyes are closed. This is probably so, for we find the subject has a greater tendency to fall with the eyes closed than when open. Beside the above typical phenomena which are constantly present in association with vestibular nystagmus, we find other symptoms more or less present. These are : 10 146 , TL'RXIXG AXD AFTER-TURXIXG XYSTAGML'S. IV. Nausea and vomiting, which occur most constantly in connec- tion with the rotatory form of nystagmus and least constantly in con- nection with the horizontal. V. Vasomotor changes. Flushing and pallor of the face, profuse sweating, etc. VI. Nervous and hysterical phenomena and epileptiform attacks are not uncommon in those so inclined. METHOD OF MAKING THE EXAMINATION. As a result of his thoro and painstaking experiments, Barany has de- veloped an accurate method for the determination of the reactions of the semicircular canals to turning. At the same time he has supplied us with data and figures of inestimable value in the differentiation of the normal from the abnormal. Before Barany began his researches, the best apparatus for the study of turning nystagmus was a large revolving platform upon which sat or stood both the subject and the experimenter. This apparatus was Cumbersome and costly. At that time the experimenters studied mostly the reactions (nystagmus) during the turnings. Later, as Barany found the reactions after turning were just as positive and even more accurate than during turning, he dis- carded the revolving platform, and used the less expensive and more available revolving stool, so that today the method as developed by Barany can be practiced by any one in his office and without the aid of an assistant. To make the examination, one needs a suitable revolving stool fitted with a bearing that does not permit elevation or depression when turning, and a metal or wooden bar fastened to the back and reaching above the patient's head to serve as a handle. An illustration of the one used by the writer may be seen in the paper upon "Labyrinth Suppuration Two Cases." Besides this, one needs a stop watch and a pair of opaque spectacles. The spectacles used by the writer are nothing more than a pair of dark glasses with adhesive plaster fast- ened to the external surface. The subject should be seated comfortably in the revolving stool with the feet just escaping the floor. It is well to have handles on the chair that the patient may hold on well and avoid toppling over. The ex- aminer stands in front of the chair with his feet and legs far enough from those of the subject to avoid collision. In one hand is held the LABYRINTH PAPERS. 147 stop watch, with the other hand reaching over the subject's head the top of the handle is grasped. The patient is instructed to hold fast for fear of losing his balance. The turnings should be made as nearly uni- form as possible, consuming about two seconds for a complete turn (360 degrees). Turning ten times (3,600 degrees) as a rule produces the maximum amount and duration of after-nystagmus, as determined by Barany and corroborated by others. When one wishes to examine for horizontal after-nystagmus to the right, naturally we must turn the subject to the left, i. e., as the hands of a watch move when lying upon the floor with the face down, and vice versa for horizontal after- nystagmus to the left. If one wishes to examine for rotatory after-turning nystagmus to the right, the head should be inclined 90 forward and the patient turned to the left ( as the hands of a watch move lying upon the floor with the face down), and vice versa for rotatory after-turning nystagmus to the left. After ten complete turnings the subject is brought to a sudden stop, when the examiner starts the watch and begins to observe the nystagmus. As soon as the nystagmus ceases, the watch is stopped. If the observations have been correct, the stop watch should record the exact duration of the after-nystagmus. It is well for beginners and of advantage to the expert, providing the patient can tolerate it and does not object, to make a second experiment to corroborate the first find- ings. It is needless to add, that all experiments and observations should be made in a well lighted room, and if necessary a head mirror should be used by the experimenter to better illuminate the subject's eye. Since both eyes move in unison, the observation of one eye is gen- erally sufficient to note the reactions to both the right and the left side. It is well, however, since exceptional cases of unilateral nystagmus do occur, to casually observe the fellow eye. The reaction of the semicircular canals to turning is in proportion to the duration of the after-nystagmus. The average duration of after- turning nystagmus is between twenty and twenty-two seconds for the horizontal without the use of the opaque spectacles, and between twenty-three and twenty-six seconds for the rotatory. With opaque spectacles fitted before the subject's eye the duration of the horizontal after-nystagmus is considerably lengthened and endures on an average from thirty-six to forty seconds. The examination of horizontal after-nystagmus with the opaque i 4 S TURXIXG AXD AFTER-TL'KXIXG XYSTAG.MVS. spectacles is to be preferred to that made without, since Abels has pointed out that convergence of the eyes inhibits the free play of the vestibular reflex. The writer has alluded to this subject before and will not go into further details now. Tho the figures given above rep- resent the average duration of rotatory and horizontal after-nystagmus Barany points out some wide variations that he has found in some of his experiments upon normal people. In his experiments upon 200 persons, some normal and others with ear affections but not complaining of vertigo, he found the average duration of horizontal after-nystagmus after ten turnings to the left forty-one seconds, and to the right thirty-nine seconds. These figures are somewhat high, but may be explained as due to the fact that many of those with ear affections may have suffered slight irritation of their labyrinths, which would tend to lengthen the dura- tion of the after-nystagmus. For the fear of confusing the nystagmus due to the reflex and that "spontaneous nystagmus" met with in most individuals, due to over strain of the extra ocular muscles during attempts to gaze in extreme directions, Barany constructed a special instrument which he calls i "Hilfinstrument zur Beobachtung des rotatorischen Nystagmus" to aid him in his observation of rotatory after-nystagmus ; illustration and description of which may be found on page 19 of his booklet. The writer has used this instrument at the request of Barany and discarded it again. Barany himself has discarded it also and brings it out only occasionally to show the students. I do not consider observations of after-turning nystagmus as thoroly accurate when the subject looks in any other direction than straight ahead. This point has been dwelt upon by me in former papers. I am led to this conclusion by repeated experiments made upon more than 400 subjects. Besides I find that my figures are more uniform and con- sistent than those of Barany, which I believe is due to the very fact that my observations have been made with the subjects looking straight ahead instead of to the side as Barany's have been made. I have never been able to find the extremely high figures even in cases of marked labyrinth irritation as Barany has in some of his normal cases (88 and 120 seconds). According to Barany the duration of the after-nystagmus diminishes slightly after fifty years of age ; which corresponds with the results ob- tained by the writer. LABYKIXTH PAPERS. 149 The duration of after-nystagmus varies according to the number of times the subject has been turned. It is proportionately less where the turnings are less than ten, i. e., the duration averages less for two turns than for five, and less for five than for ten turnings. Again a greater number of turns than ten seem to diminish rather than increase the duration of after-nystagmus. For instance, the average duration of after-turning nystagmus is less after twenty thar after ten turnings, and less after forty than after twenty. These data are important since they prompt us to adopt the method of Barany, i. e., to practice ten turning tests rather than more or less than ten. Normal subjects generally show about the same reaction (duration of after-nystagmus) when examined repeatedly upon different days. However, slight variations have been found by Barany which the writer believes is due rather to his method of examination having the subjects look laterally than to an actual variation in the semicircular canals' reactions. In Austria where people dance continuously to the right or the left, as the case may be, without reversing Barany found the physiological reactions vary somewhat to the t\Vo sides. For instance, with those who dance to the right, the duration of after-nystagmus to the right was found to be of slightly shorter duration than the after-nystagmus to the left. Rapid turnings produce a more rapid nystagmus both during and after turning, but the duration of the after-nystagmus does not vary from that produced by the slower turning. In some cases the duration was longer and in other cases shorter after slow turnings than after quicker turnings ; but on the whole they average up about the same. Barany refers to a form of nystagmus which he terms "nachnach nystagmus" (after-after-nystagmus). It occurs not infrequently in those who have been turned twenty or more times. In those cases the subject shows first a very pronounced after-nystagmus in the usual direction (contrary to the turnings), which ceases rather suddenly, followed by a small excursioned nystagmus in the opposite direction to the after-nystagmus (that is, in the direction of the turnings which produced it) ; this may last as long as sixty seconds. This form of nystagmus is more of scientific interest than of practical value. Since the semicrcular canals of one side are capable of producing nystagmus to either side it becomes a question of interest and import- ance to know just how much the after-nystagmus to one side is due to 150 TURXIXG AXD AFTER-TURNING XVSTAG.MUS. irritation of the semicircular canals of the same side and how much to irritation of the semicircular canals of the opposite side. (1) We have learned from Ewald's experiments that mechanical forcing of the endolymph toward the ampulla of the horizontal canal produces nystagmus to the same side ; while suction produces the oppo- site movement of the endolymph and with it the opposite nystagmus. (2) In a normal individual it is impossible, by turning, to produce endolymph motion of one side only. (3) In a normal case with an after-turning nystagmus of twenty- four seconds (the approximate normal) duration, it is apparent (from the foregoing) that irritation from the two sides is responsible for the after-nystagmus. (4) If the same patient should lose the labyrinth of one side from any cause it will be found that the after-nystagmus to the well side will have diminished from twenty-four to sixteen seconds (which repre- sents an average obtained from an examination of numerous cases) ; while the after-nystagmus to the diseased side will have diminished from twenty-four to approximately eight seconds. (5) It will be seen from the above figures that in a case of one- sided labyrinth destruction the after-nystagmus to the sound side is twice as long as the after-nystagmus to the diseased side. (6) The greatest common divisor of the above figures (8, 16, 24) is 8 from which we may simplify the solution of our problem as fol- lows : For instance, in a case of left-sided destruction (a) The duration of after-nystagmus to the right, representing irritation of the right side only, is sixteen seconds. (b) In the same case the duration of after-nystagmus to the left, representing irritation of the opposite side only, is eight seconds or just one-half the value of irritation of the right side. (c) In the normal case, both sides intact, the duration of the after- nystagmus to the left, representing irritation of the both sides, is twenty-four seconds or sixteen for the same side plus eight for the opposite side making the total of twenty-four seconds. These figures are not to be considered exact for all cases, for we find many variations but in the main they represent a fair average, demonstrating that after- turning nystagmus to one side is due to two irritations, two-thirds of which is produced by irritation of the semicircular canal of the same side and one-third by irritation of the semicircular canal of the op- postt side. CALORIC NYSTAGMUS. CALORIC Nystagmus is the name given to the rhythmic nys- tagmus which results from the application of heat or cold directly (thru a perforation in the tympanic membrane) or indirectly (in case of intact membrane) to that portion of the exter- nal labyrinth wall which forms the inner wall of the middle ear spaces. The phenomenon of vertigo after lavage of the middle ear spaces had been observed and reported by numerous authors. Quoting from Barany, pages 26 and 27 of his work "Phys. u. Path, des Bgg. Appar. beim Menschen" : "Smiegelow and Hensen in the year 1868 discov- ered, while experimenting upon the strength of resistance of the tym- panic membrane, that the influence of cold water in the external canal produced vertigo, nausea and vomiting, while water at the body tem- perature did not. Other authors have corroborated the fact that syr- inging the ear with too cold or too hot water produces vertigo (Cohn, Urbantschitsch)." "Baginsky, in the year 1881, made animal experiments, syringing the ears of rabbits with cold water. He found that it produced the same vertigo and nystagmus, but as soon as warm water was used the vertigo and nystagmus ceased. Baginsky then increased the pressure until the tympanic membrane and the membranes of the round and oval windows were ruptured and water rushed into the semi-circular canals and thence into the brain. Since the animals died of menin- gitis, Baginsky concluded that the nystagmus was not produced from the semi-circular canals but from the brain itself. He neglected to observe, however, whether with the use of the cold water these mem- branes were always destroyed." For three years prior to 1907, Barany investigated thoroly the sub- ject of caloric nystagmus, and thru his efforts have been established certain definite facts concerning the reactions of the ear labyrinth to heat and cold. Besides, he has given us a theory which satisfactorily explains all the phenomena of caloric nystagmus. Since his publica- tion (1907) nothing new has been added to this branch of the subject nor has Barany been compelled to retract a single statement. Con- cerning the theory advanced by Barany a few have ventured to dis- agree, but without avail. His theory stands today stronger than it did i 5 2 CALORIC NYSTAGMUS. before these authors attempted to disagree with him. The subject of caloric nystagmus is so linked with Barany's work that it is well nigh impossible to write upon this branch of the subject in anything like original style. The following are the reactions of the ear labyrinth to heat and cold as determined first by Barany and since corroborated by every inves- tigator. I, With the head erect, cold water (i. e. water below the body tem- perature) syringed into the right ear produces a rotatory nystamus to to the left or opposite side. II, With the head erect, hot water (i. e. water above the body tem- perature) syringed into the right ear produces a rotatory nystagmus to the right or same side. III, With the head inverted (i. e. vertex toward the floor) cold water syringed into the right ear produces rotatory nystagmus to the right or same side. IV, With the head inverted, hot water syringed into the right ear produces rotatory nystagmus to the left or opposite side. V, With the head inclined to the left so that a line uniting the two eyes stands vertically, cold water syringed into the right ear produces a horizontal nystagmus to the right or same side. VI, With the head inclined to the right, cold water syringed into the right ear produces a horizontal nystagmus to the left or opposite side. VII, With the head inclined to the left, warm water syringed into the right ear produces a horizontal nystagmus to the left or opposite side. VIII, With the head inclined to the right, warm water syringed into the right ear produces a horizontal nystagmus to the right or same side. The writer was the first to observe a mixed reaction from the use of cold water syringed into the ear, as follows : with the head inclined obliquely to the left, cold water syringed into the right ear will pro- duce a pronounced horizontal nystagmus to the right side combined with a moderate degree of rotatory nystagmus to the left. In order to obtain this reaction, it is not necessary to have the head held exactly at an angle of 45 to the left, for the horizontal feature will be mani- fested even with a much less inclination of the head. I cite this reac- tion for the purpose of avoiding confusion to anyone who may see it LABYRINTH PAPERS. 153 for the first time. It comes natural to one in syringing an ear to have the patient's head inclined somewhat away from the operator intro- ducing the canula, so the first evidence of a positive reaction may be a pronounced horizontal nystagmus to the same side. Change of posi- tion of the head to the erect causes the nystagmus to change to the typical rotatory character to the opposite side. That the horizontal element predominates in the case of the mixed nystagmus referred to is due probably to the fact that the horizontal semicircular canal is more exposed to the influences of temperature changes than the superior vertical canal. It has been observed that in the case of after-turning nystagmus, the plane and direction of the nystagmus when once begun remain unaltered by any subsequent change of position of the head. In the case of Caloric -Nystagmus the opposite condition holds true, viz. a subsequent change of position may alter either the plane or direc- tion or both plane and direction of the nystagmus. This characteristic is a distinctive feature of the Caloric Nystagmus. In the case of Galvanic Nystagmus, the polarity determines the direction and no change of position of the head will change either the character or the direction of the nystagmus. i THE THEORY OF BARANY. Briefly put, the theory of Barany is as follows : endolymph motion in the semicircular canals is produced by an increase in density of the fluid in that part of the canals exposed to cold, causing it to sink ; and by the diminution of the density of the fluid in that part of the canal exposed to heat, causing it to rise. Let the labyrinth be represented by a vessel filled with a fluid of even temperature (37 C.) upon the external surface of which is played a stream of cold water (Fig. i). The fluid immediately behind the exposed external wall is cooled, caus- ing it to sink to the deepest part of the vessel, while the uncooled water above moves downward to take its place. The result is a circulation or tendency to circulation of the fluid in the vessel. It is evident that hot water would produce the opposite effect to that produced by coM water. Altho the density of the endolymph increases when the temperature is reduced below 37 C. (body temperature), we see in fig. i that the arrow indicating the direction of the cooled endolymph next to the 154 CALORIC NYSTAGMUS. wall c is downward in both instances (A, vessel upright and B, vessel inverted), but in relation to the surfaces of the vessels the direc- tion in the case of B (vessel inverted) is the reverse of that in the case of A (vessel erect). /I. / \ ^ | 3fc / $ N f 1 d A * 37 c A \f Cold FIG. I. Schematic representation of the vestibular apparatus by a vessel filled with a fluid at a temperature of 37 C. (98.6 F.) ; after Barany. A. The direction of the fluid circulation when the wall c is cooled with a stream of cold water. The vessel is shown in the upright position. The surface (a) indicating the top and the surface (b) indicating the bottom of the vessel. B. The direction of fluid circulation when the wall c is cooled with a stream of cold water. The vessel is here indicated in the inverted position; the bot- tom (b) is above and the top (a) is below. In order to fix more closely in the mind the caloric reactions, the writer has made use of two other illustrations figures 2 and 3. In figure 2 is represented the right membranous labyrinth viewed LABYRIXTH PAPERS. 155 from the external surface with the head erect. In this position the external canal lies approximately in the horizontal plane, hence the application of heat or cold produces but little or no effect upon the endolymph contained within it. The superior canal, on the contrary, lies approximately in a vertical plane and the endolymph within it must necessarily be more subject to upward and downward movements from temperature changes than in the case of the external canal. FIG. 2. Schematic representation of the right membranous labyrinth viewed from the external surface with the subject in the erectposition. C, cochlea ; S, sacculus ; U, urticulus ; APC, ampulla of the posterior semicircular canal ; PSCC. posterior semicircular canal; ESCC, external semicircular canal; SE, saccus endolymphaticus ; AEC, ampulla of the external semicircular canal ; ASC, ampulla of the superior semicircular canal; H, highest point of the superior semicircular canal; SSCC, superior semicircular canal; CP, common portal of the superior and posterior semicircular canals. The dotted arrow indicates the direction of endolymph circulation during the application of cold. The full arrow indicates the direction of endolymph circulation during the appli- cation of heat. tion in this direction to the same effects produced by the mechanical A play of cold water upon the inner wall of the middle ear will cool the endolymph in the utriculus and the external crus of the superior canal. The cooled endolymph sinks in the direction indicated by the dotted arrow. We have but to compare the effect of endolymph mo- i 5 6 CALORIC NYSTAGMUS. experiments of Ewald or to those produced by turning to the left with head inclined 90 forward to determine the results. In all three cases inclination of the cilia of the crista ampullaris toward the utricu- lus is produced and with it a rotatory nystagmus in the opposite direction of the inclination (to left side). From what has already been said, it is evident that the application of heat produces the opposite endolymph motion, indicated by the full arrow, and with it a rotatory nystagmus in the same direction of the inclination (to the right side). ESCC FIG. 3. Schematic representation of the right membranous labyrinth viewed from below, the position it is in when the head is inclined to left 90 (left side of the face resting upon the left shoulder). C, cochlea; S, sacculus ; U, utriculus ; A PSC, ampulla of the posterior semicircular canal ; P S C C, posterior semicircular canal ; ESCC, external semicircular canal ; S S C C, superior semicircular canal ; H, most superior part of the external semicircular canal ; A E C, ampulla of the external semicircular canal ; A S C C, ampulla of the superior semicircular canal ; C. P., common portal of the superior and pos- terior semicircular canals. The dotted arrow indicates the direction of endo- lymph circulation during the application of cold. The full arrow indicates the direction of endolymph circulation during the application of heat. In figure 3 is represented the right membranous labyrinth in the position it occupies when the head is inclined laterally 90 to the left. The external surface is directed upward. In this position the external LABYRINTH PAPERS. 157 canal lies approximately in a vertical plane and for this reason particu- larly the application of heat or cold must produce the maximum amount of endolymph motion in this canal. There are other reasons too for this maximum of endolymph motion in the external canal rather than in the superior canal, which also lies in a vertical plane at right angles to the external canal ; ( i ) that the highest point in the external canal is higher than the highest point in the superior canal, and (2) it lies nearer to the point of application of the heat or cold than the superior canal. A play of cold water upon the inner wall of the middle ear will cool the endolymph in the utriculus and the exposed part of the exter- nal crus. The cooled endolymph must sink in the direction indicated by the dotted arrow. Again we have but to compare the effects of endolymph motion toward the ampulla and utriculus in the case of the external canal with those produced by Ewald's pneumatic hammer by compression or by turning to the right with the head erect in order to determine the results. All three produce inclination of the cilia of the crista ampullaris toward the utriculus and with it a horizontal nystagmus to the same side (right). If the play of cold water upon the labyrinth, with the head in this position, produces horizontal nystagmus to the same side then it follows that hot water must produce the opposite effect, viz. endo- lymph motion in the horizontal canal in the opposite direction indi- cated by the full arrow and with it a horizontal nystagmus to the oppostte side (left). Opposite effects to those enumerated are produced by change of position of the head 180. Furthermore, the direction and plane of the nystagmus may be definitely changed by altering the position of the head even after the reaction has once begun. This feature is characteristic alone for this form of irritation which was alluded to earlier in the paper and is one of sufficient importance to bear this reiteration. The caloric reaction of the labyrinth is positive when nystagmus results and negative when nystagmus does not result. We therefore find the reaction positive in normal labyrinths and all pathologic con- ditions which fall short of complete destruction. We find the reaction negative in complete destruction of the labyrinth and complete disa- bility of the nerve, be it temporary or permanent. But one thing it does not tell and that is the intensity of an existing pathologic process in the labyrinth when that process is other than a complete destruction. 1 58 CALORIC NYSTAGMUS. In other words, the caloric test, altho a perfectly satisfactory qualita- tive test, is in no way a quantitative one like the turning and galvanic tests. METHOD OF MAKING THE CALORIC TEST. The caloric test may be made with either water or air injected into the canal or better, when possible, directly into the tympanic cavity. Since water is capable of carrying a greater number of heat units to and from the parts than air or vapors, it is naturally better suited for the purpose. In fact, for a patient to react at all promptly to the caloric test with the use of air or vapors it would be necessary to have a suitable generator, the simplest of which would necessarily be quite complex in structure. I would hardly advise the use of ethyl chloride vapor since it is impossible to regulate the temperature satis- factorily and harm can be done. In fact I have never made a test with air or vapor nor have I seen or read of anyone else making any. The investigations of Barany, Alexander, Neumann, Ruttin and myself have all been made with water, which is quite simple to make and the most satisfactory. The selection of the temperature of the water to be used. Remem- bering that the temperature of the endolymph in the canals is about that of the body (between 98.6 and 100 F.), it is evident that in order to obtain a positive reaction from heat we must use water the temperature of which is at least 10 degrees higher. This temperature can be borne comfortably by the patient. An increase of 10 degrees more, however, is about the limit which the patient can tolerate. A difference of 20 degrees then is about the limit of high temperature for water to be used in making a caloric examination. This difference is sufficient to produce a caloric reaction under favorable circum- stances ; i. e., large perforation in the tympanic membrane, the absence of excessive granulations or cholesteatomatous masses, marked thick- ening of the mucous membrane, acute inflammation or acute exacerba- tion of a chronic inflammation or high fever. Alexander pointed out the importance of fever upon this reaction. A patient suffering from a chronic middle ear suppuration with a large perforation and without fever may react promptly today with water at the temperature of 118 F., but tomorrow with the patient suffering fever (104, 105 or 106), water of 118 may fail to produce a positive reaction while the labyrinth condition has remained unchanged. The use of hot water is not so trustworthy for testing the labyrinth- LABYRINTH PAPERS. 159 ine function as is the use of cold water. The cold water is by far the more satisfactory, and is used almost exclusively by all investigators, the reason being that a greater variation of temperature from the nor- mal (98.6 F.) may be applied without any discomfort to the patient. Water at the temperature of 68 can be comfortably borne by the patient ; besides, the density of the endolymph is considerably influenced by this difference (30) of temperature. Lower temperatures may however be employed and tolerated, but these lower temperatures are not necessary except in a small percentage of cases presenting certain obstacles : atresia of the canal, acute narrowing of its lumen, foreign bodies in the canal, tumors, intact membrane, small perforations, acute inflammation of the tympanic cavity, excessive amount of granulations or cholesteatomatous masses. The use of water in the ear is generally contra-indicated in cases of healed middle ear suppuration with remaining dry perforation. METHOD OF APPLYING THE TEST. Before beginning the test it is necessary to note the presence or ab- sence of spontaneous nystagmus, and when present its character, plane and direction. Ascertain too the positions of the eyeballs at which the spontaneous nystagmus is most and least pronounced. It is well to have one observer to direct the gaze of the patient and observe the reaction. The finger of the observer may be used for the purpose or a specially designed instrument of Barany known as the Hilfsinstru- ment, or, better still, have the patient look at a distant point (say a nail in the wall). A second operator applies the stream of water into the canal or better, where possible, directly into the tympanic cav- ity. The instrument used in the Politzer and Alexander clinics and by the writer, consists of a Politzer bag attached to a soft rubber tube about one foot long and on the distal end of this tube is fitted a Hart- man's attic canula. The safest and surest method of introducing the canula properly is with the aid of a speculum and head mirror. The introduction and holding of the speculum in place occupies one hand of the second operator and the introduction of the canula his other hand. Someone else (a third party) must elevate and squeeze the Politzer bag containing the water. Since this requires no especial skill, it may be done by a nurse or friend accompanying the patient. I have, however, occasionally managed without any assistant, but it is never so satisfactory as when you have one and better when you have two. 160 CALORIC NYSTAGMUS. It is especially desirable to have one trained assistant at least, to either observe the first signs of reaction (nystagmus) while you intro- duce the canula or vice versa. Since the caloric reaction is sometimes quite violent and unpleasant, it is well to note the reaction directly it is manifested and then be prepared to control it promptly. As soon as the reaction is sufficiently pronounced to be sure of its presence, imme- diately detach the balloon containing' the cold water and substitute for it one containing warm water. The play of warm water soon counter- acts the effects of the cold. This is the practice of the writer and one which he strongly recom- mends for the comfort of the patient. At this juncture I would further suggest that directly you have ob- served the cold water reaction (rotatory nystagmus to the opposite side) that you direct the patient to look to the side away from his nys- tagmus in order to diminish the intensity of the accompanying vertigo along with its tram of unpleasant sensations. In making the cold water test the first sign of reaction may be the gradual increasing of an existing spontaneous nystagmus, or it may be the beginning of a nystagmus which had not existed spontaneously. After withholding the cold water it will be seen that the nystagmus which began quite mildly at first increases in intensity until it reaches its maximum. This occurs frequently as late as 30 seconds after the discontinuance of the cold water. It is for this reason that I adopted early the plan referred to above, of counteracting the effects of cold water with the immediate use of warm water. The examination of the caloric irritability of the labyrinth may be con- ducted with the patient sitting up or lying down. It is generally more satisfactory to examine the patient while sitting up. The exami- nation of the patient while lying in bed is very unhandy, since a portable light is necessary for illumination and considerable care must be exer- cised to avoid getting the bed wet. These obstacles however can be more or less overcome or overlooked by an examiner who is bent upon his task. There are certain cases where the patient's physicial condition will not permit the test being made in the sitting posture. Take, for instance, a patient in a comatose or semicomatose condition; for this character of case the examination in bed will be found to be especially suited. Concerning the examination of these cases, we must not forget that a positive reaction in a comatose LABYRINTH PAPERS. 161 patient is manifested by a conjugate deviation of the eyes in the direction contrary to that of the nystagmus which the patient would have shown had he been normally conscious. There are some obstacles to the carrying out of the caloric test in some cases, among which may be mentioned : I, A completely occluded canal from (a) congenital atresia; (b) the presence of a large foreign body; (c) the presence of a large fur- uncle in the cartilaginous canal; (d) the presence of a periosteal or subperiosteal swelling in the osseous canal in cases of mastoid abscess ; (e) exostoses, tumors, etc. In these cases it is often impossible to bring the water near enough to the parts to produce effect. II, The presence of excessive granulations springing from the tympanic cavity, reaching well into the external canal, may prevent or hinder the entrance of water into the tympanic cavity. In other less pronounced cases the position of the polyps may hinder the water from reaching the inner wall of the middle ear and thus at least delay the reaction. It is well in these cases to use water of a lower tem- perature and for a longer period (3 to 5 minutes). Sometimes a pro- nounced reaction may be obtained after three or five minutes when a shorter length of time would have failed completely. III, Cholesteatoma, since it breaks up readily under the influence of a fairly continuous stream, seldom presents an obstacle sufficient to prevent a reaction ; but it frequently delays it. IV, Acutely inflamed tympanic cavity with a red swollen mem- brane either intact or with a small perforation delays the reaction con- siderably and an unpersistent examiner may after two minutes' trial either give up or decide that the labyrinth is nonreactive, whereas a second trial with colder water used over a longer period may succeed in bringing about a typically positive reaction. There is one caution that might be suggested to a beginner and that is to be careful in every case with a normal membrane. The writer saw two cases of middle ear suppuration produced by careless- ness on the part of students in the introduction of the canula. The complication was the result of direct rupture of the membrane by the canula together with the bad effects of the water which had found its way into the tympanic cavity. It is a well known fact that water introduced into the tympanic cavity through a traumatic rupture results practically always in suppuration of the middle ear. Such a mishap is of such importance that the writer feels justified in mentioning it. n GALVANIC NYSTAGMUS. ACCORDING to L. William Stern (Arch. f. Ohrenheilk., Band xxxix, pages 248-284) the first one to investigate the ef- fects of the galvanic current in producing vertigo was Ritter in 1803. The results of Ritters investigation were published in Hufe- land's/owrna/ /. prakt. Heilk., bd, xvn, 3 stueck, s. 34, under the title of "Ueber die Anwendung der Yoltaischen Saule." Nearly three- fourths of a century later, E. Hitzig, 1871, published the results of his experiments in an article entitled "Ueber die biem Galvanisiren des Kopfes entstehenden Stoerungen der Muskelinnervation und der Vor- steilungen von Verhalten in Raume" Reichert und Dubois' Arch., ?. 716-770. Hitzig was the first to observe that the application of gal- vanic electricity to the sides of the head caused vertigo, the subjective sensation of objects rolling to the side of the kathode, and that with the use of the stronger currents the subjects tended to fall towards the side of the anode. His observations were correct and have since been amply corroborated. He failed, however, to observe the asso- ciated nystagmus, which must have been present, to the side of the kathode. He explained the reaction as due to cerebral irritation ; falsi- fication of the muscle sense. E. Hitzig, 1874, wrote a second article entitled "Untersuchungen ueber das Gehirn" Berlin, which was a polemic against the Mach- Breuer theory ; pointing out that their theory did not explain galvanic vertigo. In this he was supported by Kny, 1887 ("Untersuchungen ueber den galvanischen Schwindel." Arch. f. Psyschiatrie, xvm, s. 637- 58), who claimed that galvanic vertigo was not dependent upon the semicircular canals. J. R. Ewald, 1890, "Die Abhaengigkeit des galvanischen Schwindels vom inneren Ohr" (Cent^alblatt f. d. Med. Wissenschaft, xxvni, s. 753- 755), found that pigeons with completely extirpated inner ears did not manifest galvanic vertigo. Both Hitzig and Ewald made' careful and accurate observations. Their conclusions were correct as far as they had gone, in spite of their apparent contradictions. The writer, in making extensive examinations with the galvanic cur- rent, has met with these same apparent contradictions and explained them in a subsequent part of this paper. LABYRINTH PAPERS. 163 J. Pollak "Ueber den galvanischen Schwindel bei Taubstummen" (Pflueger's Arch. LIV, s. 188-207, 1893) found that normal people show upon the application of the galvanic current to the head typical head and eye movements which are not present in about 30 per cent, of deaf mutes. He concluded that the cause of the reaction must be in the v^stibular apparatus. Alexander and Kreidl, "Ueber die Beziehungen der galvanischen Reaction zur angebornen und erworbenen Taubstummheit" (Arch f. die ges. Physiologic, bd. 89, seite 475-492, 1902), examined deaf mutes with the galvanic current. Their method was to apply the two elec- trodes to the opposite sides of the head, always using the kathode to the right ear and the anode to the left. They considered only the reaction movements of the subjects and did not make any observations of the nystagmus reaction. They noted the head movement by the opening and closing current of 30 milliamperes. The reaction was considered positive when by closing the current the head moved toward the anode and when by opening the current the head moved toward the kathode. Barany "Phys. u. Path, des Bogengang Appar. beim Menschen," Wein, 1907, page 34-36 gives a brief outline of the improved method for the examination of the galvanic nystagmus of each ear separately and cites Neumann's experiment of galvanization of the vmth nerve stump after operation ; however he concluded that the galvanic method of examination was of no practical value. Neumann's experiment, cited by Barany, was made in the Politzer Clinic, 1906. He found after an operation for the extirpation of the labyrinth, that the nerve stem reacted to the negative electrode when introduced into the wound cavity, which in a measure supports the previous claim of Hitzig and Kny ; that galvanic nystagmus can be pro- duced independently of the semicircular canals. Had Neumann tried the experiment several weeks or months later, he would not have found this reaction present because of the secondary degeneration of the nerve which follows extirpation of the labyrinth. Neumann's results then would have corroborated the results of Ewald's experiments upon pigeons and those of Pollak and my own upon a certain per cent, of deaf mutes. Alexander and MacKenzie "Functional examination of the organ of hearing in deaf mutes," translation from the German, Arch, of Oto\., vol. xxxvni. no. 6, 1908 examined deaf mutes, using the same ma- terial as was used by Pollak, Kreidl and Alexander. They found that :6 4 GALVANIC NYSTAGMUS. 22 out of 51 cases showed absolutely no reaction with 12 ma. ; a few of these might have shown a positive reaction with a stronger current. About this time (1908), the writer published the results of his ex- periments upon a variety of cases under the title, "Klinische Studien uber die Functionspruefung des Labyrinthes mittles des Galvanischen S'romes" (Arch. f. Ohrcnhcilk., bd. 77 and 78, 1908). The method employed by Alexander and MacKenzie was according to the method cited in this paper. There are two methods of producing galvanic vertigo and nystag- mus : ( i ) by the two electrodes applied to opposite sides of the head ; kathode to one side and anode to the opposite side. This was the first method employed. By this method a much weaker current is required to produce a reaction than by the second method to be described. The first method will produce a positive reaction in normal cases with a current strength of from 2 to 4 ma. The reaction consists of (a) rotatory nystagmus to the side of the kathode; (b) sensation of the room rolling to the side of the kathode (pointed out first by Hitzig) ; (c) sensation of falling in the sagittal plane to the side of the kathode; (d) actual falling takes place to the side of the anode (pointed out first by Hitzig). This falling Barany terms reaction falling and he claims it is produced by the nystagmus ; but Ewald claims it is due to hyper- tonus of the voluntary muscles of the side of the body corresponding to the kathode or to hypotonus of the side of the body corresponding to the anode. By this first method the two sides are irritated simultaneously (the 'one by the kathode, the other by the anode) and it is impossible to tell exactly in cases of pathologic imbalance, which side is pathologically under or over irritable. The untrustworthiness of this first method for the examination of each side separately gave rise to the second method, i. e., the applica- tion of one electrode to the region of one ear and the other to some distant part, preferably away from the head. Unfortunately the wider the separation of the electrodes the more the resistance is in- creased and naturally the stronger the current must be applied to pro- duce the same reaction. Barany found it necessary to use a current strength of from 10 to 20 ma. to produce a marked reaction by this second method. The writer, on the other hand, has been able to pro- duce distinctly visible reactions with a very much weaker strength of current from 4 to 8 ma. LABYRINTH PAPERS. 165 The writer considers the technique of considerable importance in making the galvanic reaction, and for this reason will describe briefly the method which he employs. The method has been described before in some of his writings ; however, to save the readers time in looking it up we shall review it here. W h a t is required ? A suitable wall plate with an accurate milliampere-meter, with the scale sufficiently large to be plainly seen. Two electrodes one large and flat, the other small (i cm. in diameter) and rounded, fitted into a handle with an interrupting adjustment, with cords of at least 2 meters length. The wall plate should be fitted too with a reversing switch to change the polarity. An assistant is necessary to control the various switches of the wall p!ate and observe the milliampere-meter. Good illumination, preferably from a head mirror to be worn by the observer. In using the head mirror it is necessary to have a light placed behind the subject's head. Care should be taken not to reflect the light too strongly into the eyes. I try as far as possible to direct the light slantwise on the eyeball and focus on the sclera above the cornea, so that a minimum amount of light enters the pupil. The subject should be seated comfortably in a chair close to the wall plate and should be told that the examination is not painful ; any anxiety the patient may have concerning the examination should be allayed. The operator should stand facing the subject, slightly to the left when examining the left side and slightly to the right when ex- amining the right side. This is done in order to allow the patient to look straight ahead over the observer's shoulder, at some distant point. Abel's opaque spectacles are not needed in this examination. In order to see the sclera above the cornea it is well to have the sub- ject's head inclined somewhat backward (15 to 20). It might be added that the reaction is not governed in the least by the position of the head. In other words, the character and the direction of the nystagmus are the same no matter to which position the head may be put. The subject should fix his gaze upon some small object on the opposite wall. As a preliminary, the observer should note carefully whether spon- 'aneous nystagmus is present or not, and if present its character, direc- tion and intensity. The observation of nystagmus should always be made with the upper lid passively elevated by the thumb of the ob- server, taking care not to touch the eyeball or lid edges. It must not 166 GALVANIC NYSTAGMUS. be forgotten that the eyeball, when too long exposed tends to become dry and this is uncomfortable to the patient. To avoid this, the writer frequently lowers the upper eyelid momentarily at regular intervals. It is always essential to have the parts where the electrodes are to be applied thoroly moistened with warm salt water (too much cannot be used) and also the sponges of the electrodes should be kept dripping wet with the same solution. It is my practice to place the large flat electrode in the right hand of the subject to be held there thruout the examination. I do not consider it necessary to change hands when examining the opposite ear ; I have never been able to note any differ- ence whatever between using the one hand and the other or whether the right hand was used when examining the same or the opposite ear. The handle of the second electrode is held in the right hand of the examiner when examining the left ear, the small, sponge, end is placed just in front of the tragus. The examiner's left hand rests upon the frontal region of the subject's head and with the thumb is free to move the upper lid of the left eye which is gently elevated to uncover a fair portion of the sclera above the cornea. The current is started by the assistant gradually increasing the strength until a reaction is observed, then I say to the assistant "reaction present to the left, or right" as the case may be and he notes the reading of the milliampere meter, call- ing it off to me, and tells me too if the direction of the nystagmus as I find it, corresponds with the polarity used. Up to this time I have not allowed myself to know the polarity, which is controlled by a switch in the hand of the assistant. This is done so that I may not be governed, in the least, in deciding the direction that the nystagmus should take; thereby helping to eliminate the socalled personal equation factor. Curiosity naturally prompts me to know afterwards, and I find myself looking at the instrument. This is done, too, to see that the assistant, should he be new at the work, has done his part correctly. So we proceed examining first one ear with both the anode and kathode, then the other ear, often repeating the examination on the same individual two or three times to be absolutely certain of our re- sult. After making this examination, occasionally coincident with it, an examination of the opening and closing nystagmus is made, using about the same strength of current or a little less than was required to cause the first reaction. In making the galvanic nystagmus examination, I frequently in- LABYRINTH PAPERS. 167 struct the patients to tell me of their subjective sensations, i. e., to which side they saw the room rolling or to which side they felt they were falling, remembering that both of these sensations are to the side cf the kathode or away from the anode and to the side corresponding to that of their nystagmus. The reaction may manifest itself in different ways according to cir- cumstances. The normal individual without spontaneous nystagmus, except in the extreme lateral position of the eyeballs, should show when looking straight ahead : (a) Rotatory rythmic nystagmus to the same side when the kathode is used with a current strength of from 4 to 8 ma. (b) Rotatory rythmic nystagmus to the opposite side when the anoc'e is used, and with a current strength equal to that required to produce the same degree of nystagmus to the same side when the kathod? is used. Normal people should show a perfect balance of reactions to the two sides and an equal balance between the kathode and anode ; for instance, if 4 ma. kathode to the left side produces rotatory nystagmus to the left side, then 4 ma. anode to the left side should produce the same de- gree of nystagmus to the (opposite) right side and 4 ma. kathode to the right side should produce the same degree of nystagmus to the right side. This is true of course only when the technique is perfect. Care- lessness in keeping the parts equally wet with salt solution or applying the electrodes to different places on the two sides (i. e., a favorable location on one side and an unfavorable location on the other) or mal- observation of the eye movements during the examination may lead to failure to recognize the accurate balance noted above. However, ex- perience and earnestness should soon teach one the importance of care- fulness. That normal people show no spontaneous nystagmus when looking straight ahead and that they should manifest nystagmus to the oppo- site side when the anode is used proves that there must be normally a definite amount of bilateral tension or tonus on the two sides. This is located in the nerves and, in a measure, their terminals in their end- organ (special sense epithelia in the ampullae of the semicircular canals). This same tonus is present in all nerves thruout the organ- ism. It may vary somewhat in degree in different individuals but is ever present in every healthy individual. In the case of the vestibular i68 GALVANIC NYSTAGMUS. nerve and its endorgan this tonus is capable of accurate measurement and is found to be somewhere between 4 and 8 ma. ; which is the in- tensity of current required to upset the balance between the two oppo- site or antagonistic nerves. In pathologic cases we find a variety of deviations from the normal reactions. The writer, after making careful observations with the galvanic current upon a great many normal and pathologic cases, was able by this method of examination to divide the pathologic cases into three primary groups, namely : I. Those with a pathologically over-irritable inner ear of one side. II. Those with a pathologically under-irritable inner ear (destroyed inner ear) of one side but with the nerve still irritable. The case examined by Neumann, where after extirpation of the labyrinth he found the nerve stem still reactive to the cathode, comes under this group. III. Those with negative irritability of both inner ear and nerve. The pigeons examined by Ewald after total extirpation of the semi- circular canals fall under this group. This same classification of pathologic conditions is possible in a measure also with the turning method of examination. Details of the individual cases examined by the writer may be found in a former paper by the writer ("Klinischen Studien ueber die Functionsprue- fung des Labyrinthes mittles des galvanischen Stromes" Archir f. Ohrenheilk., Bd. 78, 1909). There are other secondary groups, including the cases of double sided affections, etc., but to cite them all would only tend to confuse the beginner. Let us represent the normal reactions graphically, as follows : R. E. L. E. *K. 4 ma. Rot. R. K. 4 ma. Rot. L. A. 4 ma. Rot. L. A. 4 ma. Rot. R. "The numeral 4 is here used to show the strength of current because it is approximately normal and can be used to better advantage to show what is in- tended than the numeral 5 or some other odd figure. We could use quite as 'well the numeral 6. R. E. = right ear, L. E. = left ear, K. = kathode, A. = anode, Ma. = milliampere, Rot. L. = rotatory nystagmus to the patient's left, Rot. R. rotatory, nystagmus to the patient's right. LABYRINTH PAPERS. 169 If it takes 4 ma. with the anode to the right ear to suppress the nor- mal tonus sufficiently to permit the normal tonus of the left side to produce a rotatory nystagmus to the left, \ve may conclude that the strength of the normal tonus to the right side is equal to 4 ma. On the other hand, if 4 ma. with the kathode to the right ear is required to produce rotatory nystagmus to the right side, we may conclude that 4 ma. kathodal irritation to the right side plus the normal tonus of the right side is sufficient to overbalance the normal tonus of the left side. In either of the above instances it is readily seen that a difference of 4 ma. tension, whether it be taken from or added to the normal, will result in a sufficient overbalance to produce rotatory nystagmus to the side of the increase of tension or to the side opposite the diminution. I. A pathologic case with the history of right-sided middle ear suppuration and attacks of vertigo may present the following reac- tions : R. E. L. E. K. 2 ma. Rot. R. K. 6 ma. Rot. L. A. 6 ma. Rot. L. A. 2 ma. Rot. R. This case shows first a difference between the kathodal reactions of the two sides of 6 2 = 4 ma., which is just about enough to produce an overbalance and cause the subject to manifest a very slight spon- taneous nystagmus to the right side ; secondly, a difference between the kathodal and anodal reactions of the same side of 6 2 = 4 ma. ; thirdly, the kathodal reaction of one side just balances with the anodal reaction of the opposite side, which is just what we find in this group of cases. By comparing the figures in the second case with those in the first (normal) we can estimate the amount of pathologic irritability. If it takes normally 4 ma. with the kathode to the right ear to pro- duce an overbalance of impulses to the right side, then it follows, in pathologic case I. where but 2 ma. is required, that the difference between 4 ma. and 2 ma. or 2 ma. represents the amount of pathologic irritation of the right side. Furthermore, if it takes 4 ma. with the anode to the right side to suppress the normal tonus, then it follows in this same case where 6 ma. is required that the 2 additional ma. must be used to overcome that amount of pathologic irritation of the right side. In the patient just examined we may conclude that the amount of pathologic irritation of the right inner ear is equal to 2 ma. and represent the reactions algebraically as follows: i 7 o GALVANIC NYSTAGMUS. Right ear: R.. \.T.4 ma. + R.K.T. 2 ma. + R.P.T.2 ma.= R.T.T. 8 ma. R.T.T. 8 ma. -- L.N.T. 4 ma. == R.B.T. 4 ma. or surplus of 4 ma- tension to right side, which is sufficient to cause a rotatory nystagmus to the right side. R.X.T.4 ma. -f R.P.T.2 ma = R.T.T. 6 ma. R.T.T. 6 rna. R. A.T.6 ma. + L.N.T.4 ma. = L.B.T.4 ma. Since the 6 ma. with anode to the right side just neutralizes the -f- 6 ma. total tension on right side, there is left 4 ma. of normal tension on the left side to produce rotatory nystagmus to the left. Left ear : R.N.T.4ma. -f R.P.T.2 ma. = R.T.T. 6 ma. L.. \.T.4ma. + L.K.T.6ma. = L.T.T.io ma. L.T.T.ioma. R.T.T. 6 ma. = L.B.T.4 ma. The left total tension exceeds the right total tension by 4 ma., which is sufficient to cause rotatory nystagmus to the left side. R.N.T.4ma. + R.P.T.2 ma. = R.T.T. 6 ma. L.X.T.4 ma. L.A.T.2 ma. = L.T.T.2 ma. R.T.T. 6 ma. L.T.T.2 ma. = R. B. T.4 ma. which is sufficient to cause a reaction to the right side. II. A second case, with the history of chronic middle ear sup- puration of the right ear combined with complete deafness of the same ear and vertigo of recent date, associated with spontaneous rotatory nystagmus to the left side, may show the following reactions : R. E. L. E. K. 7 ma. Rot. R. K. i ma. Rot. L. A. i ma. Rot. L. A. 7 ma. Rot. R. Comparing these figures with the normal we find : *R.N.T. = normal tension of right side. R K.T. = kathodal tension to right side. R.P.T. = pathologic tension of right side. R.T.T. = total tension of right side. L.N.T. = normal tension of left side. R B.T. = balance of (tension to right side, or right side irritation exceeds that of left side by 4 ma. R.A.T. = anodal irritation, or minus tension of right side. L.K.T. = kathodal irritation or tension to left side. L.T.T. = total tension to left side. L.A.T. = anodal irritation or minus tension to left side. L.B.T. = balance of tension to left side. LABYRIXTH PAPERS. 171 (i), with the kathode to the right ear, that to obtain a reaction* a much stronger current is required ; in fact, 7 ma. 4 ma. = 3 ma., more than normal. (2), with the anode a proportionately weaker current is required (4 ma. i ma. = 3 ma.). (3), with the kathode to the left ear but i ma. current strength is required to produce a reaction (increase the nystagmus to the left), which is 3 ma. less than is required normally. (4), with the anode 3 ma. more than normal (4 ma.) is required. From these reactions it is evident that though the irritability of the right side is diminished, it is not entirely lost. Furthermore, that since the right inner ear has been destroyed (thiu labyrinth suppura- tion) this remaining irritability must He elsewhere than in the inner ear, no doubt in the nerve. Comparing the reactions of the left side with those of the right, we find the same reactions with the same figures but reversed polarity or with the same polarity but with reversed figures. In other words, 7 ma. kathode to the right side will produce the same reaction as 7 ma. anode to the left. Again, i ma. anode to the right side, will produce the same character and amount of reaction as i ma. kathode to the left ear. Again, if the kathodal reaction is i ma. and the anodal is 7 ma. on one side, the reaction on the opposite side would be kathodal 7 ma. and anodal i ma. The explanation of reactions may be found in the following equaT tions. Representing the amount of pathologic destruction in the right inner ear by 3 ma. Right ear: R.N.T.4 ma. tR.P.L.T.3 ma. +R.K.T.7 ma. = R.T.T.8 ma. R.T.T.8 ma. L.N.T.4 ma. = R.B.T.4 ma. which is just sufficient to cause a rotatory nystagmus to the right. *A reaction in this class would be indicated by a cessation of the spontane- ous nystagmus to the left or by a reversal oi the direction of the nystagmus. A reaction in the case of anode to the right ear would be indicated by a perceptible increase in the nystagmus to the left. It must not be forgotten that all of my observations have been made with the patient looking straight ahead and not to the sides as has been done by many of the other authors. fR.P.L.T. right pathologic loss of tonus or tension (loss of tonus from destruction of inner ear). , i 7 2 GALVANIC NYSTAGMUS. R.X.T.4ma. R.P.L.T.3 ma. R.A.T.* i ma. = R.T.T.o ma. L.X.T.4ina. R.T.T.oma. = L.B.T.4ma. which necessarily produces spontaneous nystagmus to the left. Left ear : R.N.T.4ma. R.P.L.T.3 ma. =R.T.T.i ma. L.X.T.4ma. + L.K.T.i ma. = L.T.T.5 ma. L.T.T.5 ma. R.T.T.i ma. = L.B.T.4 ma. which must produce a nystagmus to the left. R.X.T. 4 ma. R. P.L.T. 3 ma. == R.T.T. I ma. L-N.T. 4. ma. -- L.A.T. 7 ma. = L. T.T. -- 3 ma. R.T.T.i ma. L.T.T. 3ma. = R.B.T.4ma. which difference in tension is just sufficient to cause rotatory nystag- mus to the right side. III., a third case presenting the same history as the last but of much longer duration (where the attack of vertigo has probably antedated the examination two or three months) will show the fol- lowing reaction : R. E. L. E. K. 12 ma. or more, no reaction. tK. 2 or 3 ma. Rot. L. A. 12 ma^or more, no reaction. tA. 12 ma. or more, no reaction. Analysis of this reaction shows that the right inner ear and nerve cannot be made to react to a current strength of 12 Ma. and more from which it may be safely concluded that the vestibular nerve has undergone complete secondary degeneration. The normal tonus is still present in the left inner ear and nerve and it can be made to react to both the kathode and the anode ; however, by the most com- plete anelectrotonus of the left nerve a reaction to the right cannot be produced. In examining deaf mutes I found quite a number who did not react to 20 ma. and even 30 ma. Besides, these were not all cases due ex- clusively to early meningitis; for the great majority in whom no re- action was present were due to other causes. *R.A.T. = anodal tension, is always a negative one and must be represented with a minus sign in front of it. tA barely perceptible spontaneous nystagmus to the left of short excursions and wide interva's, is increased to that of longer excursions and closer intervals. tWith the anode the strongest currents cannot reverse the direction of the nystagmus, however they may cause a cessation of the very slight spontaneous nystagmus which is present and from this standpoint it might be said that a reaction is possible with a current strength of somewhat less than 12 Ma. LABYRIXTH PAPERS. 173 In a case where the one or the other side cannot be made to react, with either the kathode or anode, using the strongest currents we may safely conclude that it is one of primary or secondary destruction of the vestibular nerve. OPEXIXG AND CLOSING NYSTAGMUS. The examination of the opening and closing nystagmus is but one step further in the examination than that which has already been cited. The same apparatus is used as in the previous method of ex- amination. Ascertain by the previous method the least current strength required to produce a positive reaction where a positive reaction is possible. For instance, in a normal case with the patient reacting to 4 or 6 ma., the reactions should balance and may be recorded as follows : R. E. With 4 to 6 ma. L. E. *K.C.\. = K.O.X. K.C.X. : K.O.N. A.C.X. = . VO.X. A.C.N. = A.O.X The explanation of this reaction is as fol'ows : Kathodal closing nystagmus is the nystagmus which is caused by closing the current with the kathode applied to the ear ; it is rotatory in character and is directed towards the side of the kathode. With the use of the stronger currents the nystagmus is associated with the sensation of falling in the sagittal plane towards the kathode, while actual (re- action) falling occurs in the opposite direction, away from the kathode. This latter fact was pointed out long since by numerous writers, in- cluding Kreidl and Alexander. Kathodal opening nystagmus is the nystagmus which occurs for a few seconds after the breaking of the current. It is most intense at the moment the current is interrupted. It is rotatory and is directed towards the opposite side (away from the kathode). With the stronger currents it is associated with the sensation of falling in the sagittal plane away from the kathode, while actual falling occurs to- wards the kathode. *K C.N. = kathode closing nystagmus. K.O.N. = kathode opening nystagmus. A.C.N. = anode closing nystagmus. A O.N. = anode opening nystagmus. > = greater than. = less than. 174 GALVANIC NYSTAGMUS. Anodal closing nystagmus is the nystagmus which is produced by closing the current with the anode applied to the ear. It is rotatory in character and is directed towards the opposite side ; with the stronger currents it is associated with the sensation of falling in the sagittal plane towards the opposite side, while actual falling oc- curs towards the same side. Anodal opening nystagmus is the nystagmus which results from opening or breaking the current with the anode applied to the ears and lasts for a few seconds but is most intense at the instant of breaking the current. It is rotatory in character and is directed to- wards the same side. With the stronger currents it is associated with the sensation of falling in the sagittal plane towards the same side while the actual falling occurs towards the opposite side (away from the anode). In the first type of pathologic case recorded, that is with a path- ologically over-irritable right inner ear, we find the reaction to be : R. E. With 4 to 6 ma. L. E. K.CN. > K.O.N. K.C.N. < K.O.N. A.C.N. < A.O.N. A.C.N. > A.O.N. In the second type of case suffering with pathologically destroyed right inner ear but with intact nerve, we find the reaction to be : R. E. With 4 to 6 ma. L. E. K.C.N. < K.O.N. K.CN. > K.O.N. A.C.N. > A.O.N. A.C.N. < A.O.N. In the third type of case suffering with pathologically destroyed right inner ear combined with secondary degeneration of the vestibular nerve, we find the reaction to be : With current strength of 12 ma. or more. R. E. L. E. K.CN. and K.O.N. not present. K.CN. > K.O.N. A.C.N. and A.O.N. not present. A.C.N. < A.O.N. Strictly speaking there is no K.O.N. or A.C.N. upon the left side in this group of cases. The most that may be expected by opening the current with the kathode or closing it with the anode is the ces- sation of the existing nystagmus to the left side, which we may ac- cept as a positive galvanic reaction. The production of a nystagmus to the right side, however, in the case of destroyed vestibular nerve of the right side is impossible by any method of irritation of the destroyed nerve or inhibition of the opposite nerve. yr j V UTRICULUS AND SACCULUS. THE utriculus and sacculus are the two membranous sacs located within that part of the osseous labyrinth known as the vestibule. The utriculus is located just anteriorly to the semicircular canals and is in direct communication with them through five openings. 'The sacculus is located anteriorly to the utriculus and posteriorly to the ductus cochlearis and is in direct com- munication with the latter through the ductus reuniens. The utriculus and sacculus are in communication with each other through the ductus utriculo-saccularis. ) (The utriculus and sacculus each contain an endorgan known as a Nniacula acustica. composed of a group of ciliated neuro-epithelia with alternating supporting cells. The cilia of the neuro-epithelia are short. The maculse are somewhat elliptical in shape with the long axes running at right angles to each other. On the surface of each macula is a jelly-like mass in which is suspended small calcium carbonate crystals (otoliths or statoliths).") (These sacs are phylogenetically the oldest part of the ear labyrinths; the simplest form of which is that found in the Ctenophores~)(jelly fish) for which Yerworm, because of its function, suggested the name statocyst. That these sacs perform a function distinctly separate from that of the semicircular canals has been shown by the researches of Delage, Yerworm. Breuer. Mack, Engelman, Kreidl, Lee, Kubo and others. |\\s early as 1874 Mack 1 expressed the view that the sensation of angle accelerations (turnings) is mediated probably thru the three semicircular canals and that of progressive movements presumptively thru the sacculusj "Die Empfindungen der drei Winkelbeschleunig- ungen werder wahrscheinlich durch die Ampullennerven der drei Bogengaenge die Empfindungen der Progressivbewegungen muth- masslich durch den Sacculus vermittelt." Breuer 2 simultaneously expressed the same view and, too, he be- lieved that reflex contrarolling movements of the eyes, "reflectorischen Stellungsveraenderungen der bulbi," (observed also by Graefe 8 , Skrebitzky 4 and Xagel 5 ) which are manifested by changes of posi- tion of the head are produced reflexly from the ear labyrinth macula 176 UTRICULUS AND SACCULUS. acustica and the otolithic mass. To Breuer, these reflex contrarolling move rents of the eyes were an argument in favor of the supposed function of the macula acustica and otolithic mass as expressed by himself and Mach. We shall refer to Breuer again later. Carl Chun 6 , in 1880, experimented upon the ctenophores in the Gulf of Naples ; he held the opinion that the otocyst in the inverte- brates probably performed an equilibrium function. V Henry Sewall 7 experimented upon the ears of fishes (young sharks and skates) at the marine laboratory of the Johns Hopkins University at Beaufort, N. C, in 1881, and on the Chesapeake Bay in 1883.) He claimed theories essentially similar to Goltz, Crum-Brown and Breuer, that the endolymph within the membranous labyrinth presses with every new movement of the head with greater or less force upon the auditory nerve endings within definite ampullae of the canals and thus mechanically stimulates them.f He also attempted the removal of the otoliths from the \nesrrhl3^acs?^ In some cases he was able to pro- duce equilibrium disturbances, while in others he failed. J Although his experiments were ingenious, on the whole they led him rather to uncertainty than to any definite conclusions. W. James 8 , of Harvard University, in 1887, found that of 200 normal people who were subjected to turning but one only was free of vertigo, whereas of 517 deaf mutes subjected to the same turning, 1 86 had absolutely no vertigo. He learned further from many of these (186), that when they were under water they suffered an indescrib- able confusion and anxiety which was relieved only when the head came above the surface. Similar experiments subsequently conducted by others, and particularly Breuer, corroborated the observations of James. Nothing could be more conclusive to show that the ear con- tains an organ for orientation in space which, when lost, materially handicaps the subject. Furthermore that the eyes are capable in a ireasure of overcoming the loss of equilibrium which results from a complete destruction of the ears. Yves Delage 9 in 1886 conducted a series of interesting experi- ments upon cephalopods and crustaceans. Among other experiments he removed the otocysts from a crab and found that the animal was but slightly disturbed during the act of crawling, but during attempts at swimming the crab made all sorts of irregular movements. He then blindfolded the animal and found the disturbances still more pro- LABYRINTH PAPERS. 177 nounced ; whereas normal crabs blindfolded made the same regular move-rents but somewhat slower and more cautiously than when the eyes were not blindfolded. He repeated these experiments on other forms of crustaceans. The results of his experiments proved to him that the otocyst is an organ for orientation in space while the eyes and the antennae (feelers) are capable of correcting, in a measure, for such loss of orientation which results from the loss of the otocysts. The work of Delage prompted T. H. Engelmann 10 to publish an article wherein he cites his own observations made several years be- fore, upon the otoliths of the ctenophores. Engelmann held that the otolith and the sac which holds it perform a function of body equilib- rium "den allgemein als Otolithen bezeichneten, am aboralen Pol cles Ctenophorenkoerpers gelegenen Kalkkoerper fuer einen die Ert haltung des Koerpergleichgewichts vermittelunden Apparat." Max Yerworm's 11 experiments upon the ctenophores (euchris rrulticornis, bolina hydatina, beroea ovata) led him to conclude that the otolith and otocyst performed the function of equilibrium in these animals, endorsing the prior supposition of Engelmann. Because of their function he suggested the terms statolith and statocysts as more appropriate than otolith and otocyst. He experimented further with these animals to determine if possible whether these organs performed in addition an acoustic function. He failed, as did also Chun, to pro- duce any response to the loudest tones and noises. Jacques Loeb 12 experimented upon sharks (scyllium canicula and catalus) in the winter of 1890x91 at the Zoological Station at Naples, resecting certain parts of the brain (the cerebral hemispheres, the middle brain, the medulla oblongata in the region of the eighth nerve and the eighth nerve). He found as the result of section of the eighth nerve, forced movements of- the eyes to the destroyed side and the mem- bers (fins) to the opposite side, together with rolling movements and circus movements (around a ring) towards the operated side during attempts of the animals to make voluntary movements. Loeb in a separate article (Geotropismus bie Thieren) recites his ex- periments upon the inner ears of the sharks. When the otoliths of one side were removed, he found the animals deviated laterally down- ward to the operated side from 20 to 50. When the otoliths of both sides were removed the animals failed to retain the normal horizontal position of equilibrium even when they were so placed. These operated 12 178 UTRICULUS AND SACCULUS. animals furthermore failed to show the normal forced (reflex) move- ments of the eyes (contrarolling movements) manifested by changes of position. Kreidl 13 likewise observed this lack of balance in sharks with double side loss of otoliths ; he found that the sharks would as frequently swim or lie on their backs as they would take any other position. F. S. Lee 14 in 1893 conducted experiments mostly upon dog sharks galens cam's) and some five specimens of skates (raja erinacea). In his introduction he claims that "a complete theory of the socalled 'equilibrium' function of the internal ear ought to be competent to explain three classes of facts, viz., the equilibrium phenomena of the resting body, those of the body moving in a straight line, and those of the body moving in a curve. The first comprises the statical, the last two dynamical phenomena." He points out the fact that birds and fishes are naturally best adapted for study because these animals spend so much of their time in a fluid medium out of contact with a solid supporting surface. Lee noted compensatory eye and fin movements. He endorses Breuer's work and conclusions and sums up under the heading, "Equilibrium Function of the Ear." "ll. STATIC FUNCTIONS. "(a) Normal: Sensations of position of the body in space accom- panying corresponding positions of the eyes and fins ; varying according to nerve stimulated ( ?). "(b) Pathological: Abnormal sensation causing lack of orienta- tion and abnormal position of the eyes, fins and trunk ; varying accord- ing to the nerve thrown out of function. (Localization of statical func- tion in otolithic parts; stimulation continual.) Breuer 15 in 1891 in an hiteresting article on the subject of the functions of the otolithic apparatus, reviews the literature up to that time, and sets forth his own theories as to the subject. Quoting as ac- curately as I can from his resume: "RESUME, PAGE 268. "i. There exists positively specific sensations for the position of the head to the vertical and. for progressive (straight line) movements. "2. The topographic arrangement of the otolithic apparatus makes LABYRIXTH PAPERS. 179 it most probable that they, like the semicircular canals, have to do with the perception of local or spacial conditions. Their structure makes it probable that the gravitation of the otoliths is the producing irritant. "3. The Ausf allserscheinungen ( i. e., the phenomena resulting from the loss of function) in frogs and birds with destroyed labyrinths and of deaf mutes, proves that the labyrinth mediates the perception of position in space, which in the cases cited (deaf mutes) were com- pletely absent, when by immersing under water they who were form- erly orientated lost for the most part their sensations of gravitation. "4. Every position of the head corresponds in man to a definite combination of gravitations upon the four maculae. When we accept that gravitation of the otolithic plates drags on the cilia and excites nerve endings, producing an irritation which is conveyed to the center for the conception of position, then it appears that the sacs of the labyrinth are (collectively) an organ entirely adapted as one of special sense for the perception of our location in space." I might go on page after page reviewing the experiments and pub- lications of Kreidl 13 , Crum-Brown 16 , Bunting 17 , Bethe 18 , Rawitz", Lautenback 20 , Alexander and Kreidl 21 , Cyon". Panse 28 , Ach 2 *, Zoth 25 , Froelich 26 , and others, but instead I will proceed directly to a brief discussion of what may be considered the most important and conclusive work accomplished in this direction (the physiology of the vestibular sacs). I refer to that done by Ino Kubo 37 . The experimental research work of Kubo is the most exact and thoro of its kind. He spent the winter of 1905 and 1906 at the K. K. Zoological Station in Triest experimenting on living fish (scyllium canicula, acanthias vulgaris, mustelus laevis, rhombus maximus, pleuro- noctes platessa, raja clarata, torpedo marmorata and petromyzon marinus). 1. His experiments consisted of studying the eye movements during active and passive turnings of the animals. 2. Experiments upon the semicircular canals and the ampullae by (a) Thermic irritation. (b) Mechanical irritation. (c) Galvanic irritation. 3. He studied the deviations of the eyes when the animals were passively turned to different positions and made experiments on the otoliths of the vestibular sacs (utriculus, sacculus and legena). i8o UTRICULUS AND SACCULUS. It is that part of Kubo's research which dealt with a study of devia- tions of the eyes and experiments upon the sacs which interests us more especially at present. The exactness of Kubo's methods and the logic of his conclusions practically preclude any adverse discussion; I shall therefore briefly outline his work. For various reasons some of tKe fish were better adapted for one form of study than others and vice versa ; so that I shall recite the results obtained generally rather than those obtained in each individual fish. EVE POSITIONS (DEVIATIONS). When the fish was held in the position of long axis horizontally and with the belly down, the eyes assumed their normal position. When the fish was turned to the vertical position, head up, the eyes rolled downward and remained there as long as the fish was held in that position. When the fish was turned to the vertical position, head down, the eyes rolled upward and remained there as long as the fish was held in that position. When the fish was turned to the horizontal position with the belly up the eyes resumed the primary position as in the case of belly down. In the side position (with long axis horizontal) the eyes deviated in the vertical axis, so that the upper eye deviated downward and the under eye upward. To show that these deviations of the eyes were not dependent upon the semicircular canals Kubo then removed the membranous canals together with their ampullae, when he found that the identical devia- tions of the eyes occurred as in the first instance. He next removed the sacs of both sides, when he found the deviations ceased to occur. When the sacs of one side only were removed the deviation occurred, but not so pronounced as when both sides were intact. KUBO'S EXPERIMENTS ON OTOLITHS. i. He exposed the membranous sacs to full view and observed the gliding movements of the otoliths. When changing the position of the fish from the horizontal (belly down) to the vertical, head up, he was able to see plainly a gliding movement of the otoliths of the sacculus downward. In the side posi- tions the movement of the otoliths in the sacculus was slight but visible. LABYRINTH PAPERS. 181 Briefly, he found the otolithic mass to glide or gravitate in a direction corresponding to the movement of the eyes or contrary to the move- ment of the head. 2. Direct manipulation of the otoliths with small cotton protected probes. When the otolithic mass was pushed with the probe in definite direc- tions the eyes deviated in the corresponding directions. For instance, when the otoliths of utriculus (fish in the horizontal position, belly down) were gently shoved forward the eyes would deviate upward, the position corresponding to that which occurs when the head is turned downward and the otolith mass of the utriculus naturally gravitates forward. A-ain, when otoliths of the sacculus were gently shoved backward the eyes deviated downward ; the position corresponding to that which occurs when the head is turned upward. liriefly, every artificial movement of the otoliths produced reflex deviations of the eyes corresponding to those produced by the same natural movements of the otoliths which follow changes in position of the head. 3. Experiments after partial or total extirpation of the otoliths. After the removal of the otoliths of the sacculus the rotation of the eyes by the position head up was very indistinct, while the rotation of the eyes by the position head down was quite distinct ; from which he concluded that the rolling of the eyes in the position of the head down was due principally to the forward gliding of the otoliths in the utriculus. After the removal of the otoliths of the utriculus from one side the deviations of the eyes by the position head up and head down was very indistinct. After the removal of all otoliths from one side the deviations of the eyes by the position of the head up and head down occurs but slightly on the unoperated side only. In the side positions also only on the unoperated side. By turning the fish in the horizontal plane after total extirpation of the otoliths of one side there occurs no deviation bulbi horizontalis by turning towards the operated side, while turning toward the healthy side produces distinct deviation hulbi bilateralis and in this case the deviation is stronger in the eye corresponding to the unoperated side. 4. Electrical irritation of the nerve branches after the removal of the otoliths together u'ith the ampulla:. :82 UTRICULUS AND SACCULUS. As previously observed, one sees two groups of nerve fibres in the floor of the utriculus and one group in the sacculus. From the anterior group branches go to the macula utricularis and to the two ampullae (anterior and horizontal) and from the posterior group branches go to the macula saccularis and the ampullae of the posterior canal. Kubo observes that one cannot irritate the individual nerve fibers of each group ; however, he was able to, at least, irritate separately the three groups of fibers, the results of which follow : i. By electrical irritation of the nerve fiber group to the utriculus of one side, the nasal pole of both eyes turned upward corresponding to the position of the head down. By electrical irritation of group III (the group of fibers to the utriculus) the eyes of both sides deviated horizontally to the side oppo- site the irritation, corresponding to that which appears by turning of the head to the operated side. By electrical irritation of group III (the group of fibers of the sacculus) the nasal pole of both eyes deviated downward, correspond- ing to the position of head up. When the contents of the vestibulum were curetted entirely away and the remaining nerve stem was electrically irritated, the eyes rolled in the horizontal plane as in the case of rabbits and pigeons. CONCLUSION. Among other things Kubo observed that "also with fish every body position corresponds to an exact eye position and when the otoliths are removed or the entire vestibular apparatus is destroyed this re- lationship is lost." He then cites a list of authors who had since the time of Hunter 27 observed and studied these eye movements (con- trarolling) which occur as the result of inclinations of the head. He gives credit to Mack and Breuer as the first authors to point out separate functions for the semicircular canals and for the otolithic apparatus. "The single direct proof until now (of the functions of the otolithic apparatus) was Kreidl's iron filing experiments upon crabs." "Die Verschiebung oder Gleitung der Otoliten ist wenigstens bei Rochen und Acanthias vulgaris bei Lagewechsel des Korpers sicher zu konstatieren ; und die kuensiliche Verschiebung der Otoliten hat dieselbe Bulbusdrehung zur Folge wie der Lagewechsel des Koerpers wenigstens fuer die Lagen 'Kopf oben und Kopf unten.' Das ist LABYRINTH PAPERS. 183 ein neuerlicher Beweis class die Gleitung der Otoliten die Xervenend- igungen reizt, wie dies Breuer annimmt. Aus den Yersuchsresultaten geht hervor, dass der Zug odor die Spannung der Haarzellen durch die Gleitung der Otoliten als normaler Reiz zu betrachten ist. Je nach der Gleitrichtung muessen die verschiedenen Xervenendzweige gereizt werden, deren reflektorische Funktionen (oder Verbindungen) ungefaehr durch elektrische Reizung zu bestimmen sind ; Z. B. in der 'Lage Kopf unten' muss der Otolit des Utriculus nach vorn gleiten und diejenigen Xervenzweige reizen, die durch elektrische Reizung in der Bauchlage die Bulbi so zu drehen veranlassen. dass der nasale Bulbuspol nach oben geht ('I. Gruppe') ; diese Xervenzweige treten zur Macula utriculi in Beziehung. In der Lage 'Kopf oben' gleiten die beiden Otoliten des Sacculus und Utriculus kaudalwarts. allein der Otolit des Sacculus uebt den wirksamen Zug auf die Haarzellen der Macula sacculi aus, wie die kuenstliche Verschiebung des sac- cularen Otolits und die elektrische Reizung der Xervenzweige im Sacculus ('III. Gruppe') uebereinstimmend gezeigt haben. Fuer die Deviatio bulbi bilateralis horizontalis kommt die II. Gruppe in Betracht; es ist jedoch schwierig, in diesem Falle die horizontale Am- pulle auszuschalten, die selbst von der II. Gruppe die Nerven- endzweige aufnimmt. Die Bulbusstellungen in den Seitenlagen kcennten von der kombinierten Wirkung der beiden Otoliten (des Utriculus und Sacculus) herruehren. Die Macula lagenae entzieht sich bei Fischen dem Experiment ; bei der von Breuer festgestellten Tatsache, dass die drei Otoliten in den drei Dimensionen des Raumes orientirt sind, wird man anzunehmen das Recht haben, dass diese Apparate zur Wahrnemung der Kopf bz\v. Koerperlage dienen. Die Reizung der maculae durch die Gleit- ung der Otoliten ruft reflekttorisch die eigentuemlichen Bulbusstel- lungen hervor. \Yie Lee beschreibt, ist die Deviatio bulbi bilateralis horizontalis beim Drehen des Tierkoerpers in der Horizontalebene vergaenglich temporaer aber man hat kein Recht, deswegen nur dem horizontalen Bogengang (resp. seiner Ampulle) eine besondere dynamische Funk- tion (d.h. die Wahrnehmung der Kreisbewegung) zuzuschreiben ; denn meine Versuche haben gezeigt, dass bei Drehung des Tierkoer- pers in der Seitenlage oder in der lage 'Kopf oben' oder 'unten' eben falls Deviationen der Bulbi von verganglichen Xatur auftreten. Man wird annehmen muessen, dass beim Drehen die Bogengaenge 184 UTRICULUS AND SACCULUS. (mit ihren Ampullen) mit dem Otolitenapparate stets gemeinsam in Taetigkeit versetzt werden, vvobei die Bogengaenge fuer die \Yahr- nehmung der \\"inkelbeschleunigung und die Otolitenapparate fuer die \\ ahrnehmung der Lage (wahrscheinlich auch der geradlinigen Be- wegung) bestimmt sind. RESUME. Paragraphs i, 2, 3, 5 and 6 concern more the subject of eye move- ments associated with the physiology of the semicircular canals ; the remaining paragraphs given below pertain more to that of the sacs. 4. The positions of the eyes are definite for every body position, as in the case of rabbits. 7. The maximal deviation of the bulbus (especially in the side position) goes back considerably after a short time. 8. After the extirpation of the semicircular canals there still occurs these same altered eye positions (contrarolling) always according to the definite body positions. They diminish perceptibly after the re- moval of the otoliths of one side and disappear altogether after the complete removal of the otoliths of both sides. 9. The gliding movements of the otoliths are actually visible by change of position of the body in Rochen and Acanthias. Gliding of the otoliths artificially produced (while the animal is in the normal horizontal position with belly down) produces the same eye move- ments which occur from the natural gliding movements of the otoliths. 10. Each group of nerve endings in the vestibulum reacts, after the removal of the otoliths, to electric irritation with a definite eye move- ment. 11. The alterations of eye position with changes of body position are produced reflexly by a gliding movement of the otoliths (at least) from the macula utriculi and sacculi. Clinical observations of contrarolling movements of the eyes in man have been made by Barany 28 . He had a specially designed instrument constructed by Schwartz, of Vienna, for the accurate measurement of the normal contrarolling movements, which had been observed by many others (see above), and that these are perceptibly diminished in cases of one sided labyrinth destruction, however he has not written much upon the subject. It is to be hoped that he will sooner or later give us an extensive report of his investigations along this line. The writer 29 examined clinically the following character of cases LABYRINTH PAPERS. 185 (i) Those with one sided labyrinth destruction, (2) those with double sided labyrinth destruction (selected deaf mutes), and (3) those with labyrinth diseases showing an increased reactibility of the vestibular apparatus for the purpose of ascertaining to what degree equilibrium is dependent upon the semicircular canals and the vestibular sacs. Sim- ilar efforts had been previously attempted by Frey and Hammer- schlag 30 , Krotoscheiner 31 , Kummels 32 , Von Stein 33 , Pollack 34 , Kreidl 35 , Alexander and MacKenzie 30 , and others whose experiments had been made principally upon deaf mutes. The writer's own clinical examina- tions differ in some particulars from those attempted by previous in- vestigators. First of all patients showing the least evidence of hysteria, neuras- thenia, syphilitic cerebral or spinal affections, visual defects, natural clumsiness or poor intelligence were excluded from the list. (2) To ascertain these facts the history of the patient was most carefully taken, the vision determined, and in some cases the eyegrounds examined. The pupillary and deep reflexes were examined as also coordination. \Yhen we consider that equilibrium may be disturbed by a lesion of any one of the three peripheral sense organs of orientation (eyes, vestibular apparatus, kinesthetic sense organs, in the deep muscles, joints, etc.) or their centripetal tracts to their terminals in the brain, we appreciate how important it is. in making these clinical investigations, to include an examination of vision, pupillary and tendon reflexes. Furthermore, since the examinations to be made were rather ex- haustive, it was necessary to select intelligent patients, free from any acute ailments that might in any way tend to hasten fatigue. \-ain. it was necessary to examine the patients with one sided labyrinth destruction at a period sufficiently remote from the acute affection to avoid confusing the acute equilibrium disturbances with those which I have termed the late. The condition of the labyrinth was determined by the usual func- tional examination methods as practiced in Professor Alexander's clinic. I was doubly certain of most of the cases of one sided labyrinth destruction from the fact that they had previously undergone the opera- tion for its removal. The equilibrium was determined by the following tests : standing with feet together and eyes closed (Rhomberg), standing upon one foot then the other, gait forward, gait backward, hopping upon one foot forward and backward, all of these tests were made both with open 186 UTRICVLUS A\'D SACCULUS. and closed eyes. Elevation upon the Alexander-Stein goniometer \vith face toward the instrument, first with eyes open then with eyes closed, with face away from the instrument, with right side to- ward the instrument and with left side toward the instrument : all of which were made with eyes open and with eyes closed. To avoid slip- ping on the goniometer the patients were examined with bare feet, and the instrument was dusted with rosin. In some cases the examinations were repeated in order to be absolutely certain of the results. Many of the patients were examined repeatedly at wide intervals. The time re- quired in collecting and examining the material extended over a period of ten months. Without going into too many details, individuals with a one sided labyrinth destruction showed diminished ability to equilibrate, while those with double sided labyrinth destruction showed marked disturb- ance, in some cases amounting to an almost complete loss of equilib- rium when the eyes were closed. These disturbances were always more marked when the eyes were closed than when they were open. The equilibrium tests enumerated did not include rotational move- ments, so we must exclude the semicircular canals as a factor in these cases. No doubt these patients would have shown the same degree of equilibrium disturbances by rotational movement tests (determined previously by James and Breuer and others) as by the tests selected. Since the patients showed positive equilibrium disturbances, in- creased by closure of the eyes, and, furthermore, since every other possible factor had been eliminated we must conclude that the equilib- rium disturbance was due to a loss of some organ of equilibrium lo- cated in the inner ear. Finally, if the loss of equilibrium was due to destruction of some- thing within the inner ear and the tests employed were not rotational (thus excluding the semicircular canals), then it follows that the lost function must have been due to the destruction of the vestibular sacs. The writer in his work on labyrinthine equilibrium disturbances de- clared in favor of the Breuer theory, which in part declares the func- tions of the utriculus and sacculus to be that of perception of straight line (progressive) movements, allowing the functions of the semi- circular canals to be for the perception of turning movements. LABYRINTH PAPERS. 187 THE WRITER S CONCLUSIONS. The functions of the utriculus and sacculus are both static and dynamic. Static for the perception of position in space. Dynamic for the perception of straight line (progressive) move- ments in any direction, so long as the movement is increasing or dimin- ishing in velocity. BIBLIOGRAPHY. 1. Mach "Versuche ueber den Gleichgewichtssinn" 2 Mittheilung LXIX Bd. d. Wiener Akad. Sitzungber. 2. Breuer "Ueber die Function der Bogengaenge des Ohrlaby- rinthes" W. Med. Jahrbucher, 1874, page 42. 3. Graefe Archives f. Ophthal., Bd. i, 1855. 4. Skrebitzky Arch. f. Ophthal., Bd. 14, 1868. 5. Nagel Arch. f. Ophthal., Bd. 17, 1870. 6. Chun "Die Ctenophoren des Golfes von Neapel und der angren- zenden Meeres abschnitte" A monograph, published from the Zoolog- ical Station at Napels, Leipsig, 1880. 7. Henry Sewell "Experiments upon the ears of fishes with refer- ence to the function of equilibrium, Jour, of Physiology, Vol. IV., pages 339-349. 1883. 8. James "Sense of Dizziness in Deaf mutes," Jour, of Otology, October, 1887. 9. Delage "Sur une fonction nouvelle des otocystes comme- organes d'orientation locomotrice." Arch, de Zool. Experiment et generale, n ser. Tome 5, 1887. 10. Engelmann "Ueber die Function der Otolithen" Zoolog. Anzeigen Nr. 258, 1887. 11. Verworm "Gleichgewicht und Otolithenorgan" Pfluegers Arch, fur die ges. Physiologic, Bd. 50, seiten 423-472, 1891. 12. Loeb "Ueber den Antheil des Hoernnerven an dem nach Getierverletzung auftrettenden Zwangsbewegungen und Zwangsladen und assorziirten Stellungsaenderungen der Bulbi und Extremitaeten" Pfluegers Arch, fur Physiologic, seiten 66-183. Bd. 50, 1891. Loeb "Ueber Geotropismus bei Thieren Pfluegers Arch, fur Phys. Bd. 49, 1891. i88 L'TRICULUS AND SACCULUS. 13. Kreidl "\Yeitere Beitrage zur Physiologic des Ohrlabyrinthes Sitzungsber, der K. Akad. der Wissenschf., Wien. Bd. 51, 1892. Kreidl "Weitere Beitrage zur Phys.' des Ohrlabyrinthes" n Mitt- eilung Versuche an Krebsen Sitzungsber d. k. Akad. d. Wissenschf. \Yien. 1893. Bd. 102, Heft i. 14. Lee "A study of the sense of equilibrium in fishes i Jour, of Physiology, Vol. XV.. pages 311-348. i893-'94- 15. Breuer "Ueber die Function der Otolithen Apparate" Pfluegers Arch, fur Physiologic, Bd. 48, seiten 195-306. 1890- '91. 16. Crum-Ilrcnvn "On the sense of rotation and the anatomy physiol. of the semicircular canals of the internal ear" Jour, of Anatomy and Physiology, Vol. 8. 1874. 17. Bunting "Ueber die Bedeutung der Otolithenorgane fur die geotropischen Functionen von Astucus fluviatus" Pfluegers Arch. f. Phys., Bd. 54. 1893. 18. Bethe "Das Nervensysten von Carcinus Maenas" Arch. f. mikros. Anat., Bd. 50, 1897, and Bd. 51, 1898. "Die Locomotion des Haifisches (Scyllium) und ihre Beziehungen zu den einzelnen Gehiru- theilen und zum Labyrinth" Pfluegers Arch. Bd. 76. 1899. 19. Rawitz "Das Gehoerorgan der japanischen Tanzmause?" Arch. f. Anat. u. Phys. 1899. 20. Lautenbach "Zur Otolithenfrage" Pfluegers Arch. f. Phys. Bd. 77, 1899. 21. Alexander & Kreidl "Zur Physiologic des Labyrinthes der Tanzmaus" Pflueger's Arch. f. Phys., Bd. 82, 1900. 22. Cyon Ohrlabyrinth Raum sinn und Orientirung Pfluegers Arch. f. Phys., Bd. 82, 1900. 23. Panse "Das Gleichgewichts und Gehoerorgan der japanischen Tanzmause" Muenchner Med. Wochen. No. 13, 1901. 24. Ach "Ueber die otolithenfunction und den Labyrinthtonus" Pfluegers Arch. f. Phys., Bd. 86, 1901. 25. Zoth "Ein Beitrag zu den Beobachtungen und Versuchen an japanischen Tanzmauesen" Pfluegers Arch. f. Phys., Bd. 86, 1901. 26. Froelich "Studien ueber die Statocysten," i Mitteilung, "Ver- suche an Cephalopoden" Pfluegers Arch. f. Phys., Bd. 102, 1904. n Mitteilung, "Versuche an Krebsen" Pfluegers Arch. f. Phys., 1904. 27. Hunter "The use of the oblique muscles. Observations on certain parts of the animal economy'' London, n edition, 1792. LABYRINTH PAPERS. 189 28. Barany "Physiologic u. Pathologic des Bogen Appar beim menchen." A monograph, Deuticke., Wein, 1907. 29. MacKenzie "Klinische Untersuchungen ueber Labyrinthaeren Gleichgewichtsstoerungen mit besonderer Bereuchsichtigung der allge- meinen Pruefungsmethoden und des Goniometers" Arch. f. Ohren- heilk, Bd. 78, 1909. 30. Frey and Hammerschlag "Untersuchungen ueber den Dreh- schwindel der Taubstunvnen" Zeitsch. f. Ohrenheilk, 1904. 31. Krotoscheiner Zeit. f. Ohrenheilk, Bd. 51 and 52. 32. Kummels "Ueber infectioese Labyrinth Erkrangungen" Zeitschrift fur Klinische Mediz., Bd. 55, 1904. 33. Yon Stein "Ueber Gleichgewichtsstoerungen bie Ohrenleiden" Zeitschn. f. Ohren., Bd. 27, 1895. 34. Pollak "Ueber galvanischen Schwindel bei Taubstummen und seine Beziehungen zur Function des Ohrenlabyrinthes" Pfluegers Arch.. Bd. 54, 1893. 35. Kreidl "Beitraege zur Physiologic des Ohrlabyrintb.es auf Grund von Versuchen an Taubstummen" Arch. f. Ohrenheilk, Bd. 51, 1891. 36. Alexander and Mackenzie 'Tunctionspruefungen des Gehor- organes an Taubstummen" Monatschrift fuer Ohren., 1908, und Zeit- schrift fuer Ohren., 1908. 37. Kubo "Ueber die vom N. Acusticus ausgeloesten Augen- bewegungen." II Mitteilung, "Yersuche an Fischen" Arch. f. Phys., Bd. 115, 1906. VERTIGO. THE subject of vertigo has become one of importance, espe-> cially in view of the recent advances made in our knowledge of the physiology and pathology of the ear labyrinth. Although vertigo in conjunction with nystagmus and equilibrium disturbances has been referred to in every recent publication upon the labyrinth and diseases of the labyrinth, writers as a rule have not attempted to make clear to the minds of their readers exactly what is meant by the term. As a result, not only the laity but some physicians have but a vague conception of the symptom. I find this especially so when noting the history of the cases. Of all those who claim to have vertigo, upon close questioning I find that many have not. I am, therefore, prompted to write a paper upon this subject. WHAT IS VERTIGO? I agree, in substance, with Panse that vertigo in its broadest sense is that sensation of confusion which results from any false perception of one's relative position to space or motion in space. Normally one is aware of the fact whether he is standing vertically erect, inclined forward, backward or to either side, sitting or lying down ; whether he is moving in a straight line forward, backward or to either side, vertically upward or downward; whether he is moving in a circle in any of the three principal planes or resultant of these planes. Furthermore, one is aware of the fact whether surrounding objects are out of plumb, so to speak, inclined toward or away from him, to one or the other side. Finally one is able to determine whether ob- jects are stationary or in motion, and when in motion whether they are moving toward or away from him, to one or the other side, ver- tically upward or downward, in a circle in front of him etc. We are made conscious of these positions and motions, subjective or objective, through three different peripheral sense organs and their centripetal tracts, i. Thru the visual organ, the eyes, including their intrinsic and extrinsic muscles ; 2. Thru the equilibrium sense organs, the nonacoustic labyrinth; 3. Thru the kinesthetic sense organs; the deep muscles, joints, sensory nerve endings all over the LABYRINTH PAPERS. 191 body, which may, since their functions are identical, be classed as one organ. The normal, physiologic, correlation of these three centripetal im- pulses from the eyes, ears (nonacoustic labyrinth) and muscles and joints, and possibly the skin and viscera, enables one to maintain per- fect equilibrium of the body when at rest (static) and during motion (dynamic). According to Bechterew, quoted by Panse, the correlation of all these centripetal impulses takes place in the cerebellum. Any sudden falsification of sensation from one of these organs whether pro- duced experimentally or pathologically produces that unpleasant sen- sation of confusion known as vertigo and in proportion, equilibrium disturbances. However, a falsification of sensation from any one of these three sensory organs if continued will eventually be corrected by the remaining two. With this correction comes a relief of the vertigo. In other words, the contradictory or false sensation will be suppressed while the remaining virtual sensations will be accepted. These above conditions are true only in so far as they apply to cases of permanent and fixed falsification ; for instance : in cases of labyrinth suppuration, those of permanent eye muscle paralysis, etc. On the other hand, vertigo may recur in cases of variable falsification, for instance in cases of irritative lesions or in those cases of partial loss, followed by subsequent restitution of function. In cases of tem- porary eye muscle paresis when the affected muscle begins to func- tionate again we may find vertigo accompanied with nystagmus during attempts to roll the eye in the direction of the muscle's action; ob- served by Stewart (Deutsches Median. Zcitschr.. 1895, se i te 5 11 ) an( ^ others, including the writer. While vertigo is always accompanied by pronounced equilibrium dis- turbances the reverse is not true. At this writing I wish to deny the claim of some authors, quoted by the writer in one of his recent papers upon labyrinth suppuration, that vertigo is always associated with nystagmus. Although vertigo may disappear after a few days in cases of per- manent loss of function of one of these end organs and the equilibrium disturbances may become less pronounced, there still remains a slight degree of permanent equilibrium disturbance. This is theoretically, mathematically and practically so as shown by the writer in a recent 192 I'ERTIGO. paper upon the subject of equilibrium disturbances, entitled "Klinische Untersuchungen ueber die labyrintharen Gleichgewichtsstoerungen mit besonderer Berucksichtigung der allgemeinen Pruefungsmethoden und des Gonimeters" (Archiv. f. Ohrenhlk., band 78, Feb., 1909.) If three different sets of centripetal impulses are necessary for per- fect orientation and equilibration, it must follow that when one of these is lost, orientation and equilibration must be disturbed in proportion ; however, with the remaining two impulses one learns rapidly to orien- tate and equilibrate, quite sufficiently for ordinary purposes. In fact one may get along so well under favorable circumstances as to almost conceal the presence of his equilibrium disturbance ; but careful tests of such patients by Von Stein, Krotoscheiner, Kreidl, Alexander and Mackenzie have never failed to prove their presence. \Yhen a second of these centripetal impulses is lost, naturally orientation and equilibration are disturbed still further, and proportion- ately more than when the first impulse alone was lost. Sudden falsification of sensation from one of these three peripheral sense organs leads not only to vertigo, -as already stated, but also to pronounced equilibrium disturbance, nausea and vomiting, vasomotor changes flushing or more frequently pallor of the face profuse sweating, etc. The sensation and intensity of the vertigo differs in different cases according to which of the three special end organs or centripetal tracts is involved. In the case of vertigo resulting from experimental irritation of, or pathologic lesion in, the labyrinth or its centripetal tracts, the vertigo is always of the type called rotational ; that is to say, the patient suffers either the sensation as though external objects were in motion or else the sensation of subjective motion. Whether the sensation of motion is referred to external objects or to the patient himself, these motions are in circles in one of the three principal planes or resultant of these planes. Rotational vertigo is perhaps the most intense and unpleasant form and is always combined with nystagmus. While vertigo the result of affection of the labyrinth or its centri- petal tracts is always rotational in Character and is combined with nystagmus, it does not follow that every rotational vertigo combined with nystagmus must necessarily be produced by disease of the laby- LABYRINTH PAPERS. 193 rinth or its centripetal tracts; for on the contrary we find rotational vertigo and nystagmus in cases of vertigo produced by a lesion in the eye or, more exactly, in cases of eye muscle paresis during the stage of improvement (Panse). However, as a rule rotational vertigo indicates a lesion in the labyrinth its centripetal tracts or their ter- minals in the cerebellum. In the case of vertigo resulting from disease of the eye or eye mus- cles, excepting in the case above mentioned, the patient's sensation of vertigo is referred to external objects ; they seem too near or too distant, inclined toward or away from him to one or the other side, or the floor upon which the patient is standing is inclined in one of these directions, etc., and on account of which the patient is in danger of making false steps and movements. He misjudges the distances and directions of objects. This ocular form of vertigo is less intense as a rule than the vesti- bular form and is unassociated with nystagmus except in the case previously referred to. Ocular vertigo is characteristically ameliorated by closure of the eyes, whereas the former vestibular or rotational is uninfluenced. This is quite an important differential test for these two forms. In contrast with the ocular vertigo we have the vertigo due to falsi- fication of centripetal impulses from the muscles, joints, etc., (the so- called deep sensibility). In this form of vertigo, for we may call it so accepting the broad definition, the patient perceives the external world in its normal relations, but suffers the subjective sensation as though he himself was out of plumb with it. He feels as though he is tilted forward, backward, or to one or the other side, or else when making a movement he believes he has made it either too great or too slight; in other words, he is not properly informed of either the ex- tent or character of the movement, his perception of the movement (excepting when aided by the eyes) causes him to innervate too strong- ly or not strongly enough ; he makes incorrect movements believing he has made them correctly. In contrasting the kinesthetic form of vertigo with the ocular it may be said that while ocular vertigo is improved by closure of the eyes, the kinesthetic form is made worse and its accompanying phe- nomenon equilibrium disturbance, is decidedly aggravated. Let us consider next some of the more definite causes of and the sensations produced by these three separate forms of vertigo. 13 194 I'ERTIGO. I. Rotational or vestibular vertigo may be produced experimentally or pathologically. Experimentally by : (a) turning (as first practiced by Flourens) in a revolving chair. This should be done with the patient's eyes closed during the turning in order to obtain a pure vestibular form, otherwise a combination of vestibular and the ocular is produced. (b) caloric irritation of the nonacoustic labyrinth. (c) galvanism with opposite electrodes applied to opposite sides of the head or with one electrode applied to the region of the ear and the other applied to some other part of the body, say the hand. (d) mechanical irritation of the semicircular ca'nals after the mannei of Ewald's experiment. (e) sectioning one or both of the 8th nerve stems. (f) removal of a cerebellar hemisphere. These latter three expen- ments are not applicable to human subjects. Pathologically by : (a) any lesion in the nonacoustic labyrinth: including congestion, circumscribed irritative or destructive lesions, diffuse serous or sup- purative inflammations, toxemias, growths, etc. (b) any lesion in the vestibular nerve: nueritis, tumors, basal fract- ures, meningitis, etc. (c) any intracranial lesions involving the nuclei or tracts to the cerebellum or the cerebellum itself. In the case of vertigo produced by any of these causes, experimental or pathologic, the sensation of subjective or objective turning is pro- duced. The vertigo persists even with the eyes closed. With the eyes closed the sensation is that of subjective turning ; the patient feels as though he is being turned. With the eyes open the sensation is generally that of objective turning, the patient feels as though surrounding objects were turning. The direction and plane of the turning is dependent upon the direction and plane of the nystagmus which is constantly present in this form of vertigo. The equilibrium disturbance manifests itself by falling or turning in the opposite direction to and in the plane of the nystagmus. This falling results from the efforts of the patient to correct the sensation of apparent falling. Like the sensation of vertigo, the equilibrium disturbance is manifest even more with the eyes closed than when open. Again by the aid of touch and the deep muscle sense, the pa- LABYRINTH PAPERS. I Q5 tient is aided in maintaining equilibrium : which accounts for the fact that patients suffering with vestibular vertigo immediately grasp, for support, the nearest fixed object. II. Ocular vertigo may be produced experimentally or pathologi- cally. Experimentally by: (a) sudden disturbance of vision, especially when monocular; for instance by the placing of strong concave or convex spherical lenses before om or both eyes or the placing of a minus glass before one eye and a prus glass before the other. The convex glass, because ot the magnification, produces the sensation of nearness of objects while the indistinctness of the outlines and details produces the contradictory sensation of remoteness. The concave glass produces just the opposite contradiction of sensations. (b) the placing of plus or minus cylinders before the eyes producer distortion of objects, irregularity in angles, etc. ; for instance, right angles are made to appear too acute or too obtuse, dependent upon whether a plus or minus cylinder is used and the axis to which it may be turned. (c) sudden paralysis of accommodation with dilatation of the pupil produced by a mydriatic will cause vertigo, especially in those suffering from considerable latent hyperopia or hyperopic astigmia. The pa- tients complain usually of objects, especially the floor, being too near or distant, dependent upon the amount and axis of the manifest astigmia. (d) The placing before the eyes of prisms, whether strong enough to produce diplopia or not, will cause vertigo. The placing of prisms, bases in the same direction, produces slanting effects of external ob- jects and false impression of location. The placing of the bases in op- posite directions, if strong enough, produces diplopia with vertigo. On the other hand, the use of weaker prisms, insufficient to produce diplopia, produces a vertigo often more intense than that produced by the stronger prisms. \Yith the weaker prism producing vertigo, there is always associated nystagmus directed toward the apex of the prism. In the case of vertigo produced by prisms, the patient is con- fused most as to the direction of external objects. (e) Tenotomy or section of the nerve supply to one of the extrinsic muscles produces similar effects to that produced by prisms. (f) Pressure of the finger upon the one eyeball may so change the direction of the visual axis as to produce diplopia with vertigo, etc. 196 I'ERTIGO. (g) There is a form of vertigo combined with nystagmus, which we may conveniently term visual rotational vertigo and may be produced experimentally by gazing for a long time at moving objects water- falls, rapidly moving currents, carousal, windmills in motion or by Mack's rotating cylinder, etc. After looking for a long time at one of these moving objects and then looking away at stationary sur- roundings the patient suffers the sensation of a mild rotational vertigo, whereby the stationary objects appear to be moving in a contrary di- rection, and when this vertigo is pronounced it is accompanied by equilibrium disturbance characteristic of rotational vertigo. This ver- tigo is similar to the vertigo associated with the socalled after-turning nystagmus ; the character of the vertigo might suggest the presence of rhythmic nystagmus, but up to the present time the writer has been unable to demonstrate it. On the other hand an experiment practiced by the writer would sug- gest the absence of nystagmus. The experiment is made as follows: Seated on the rear end of a moving train (observation platform) one directs his view straight ahead at some distant receding point for about 30 to 40 seconds. This produces no nystagmus, but naturally the sensation- as though the field of vision was receding. Should the train come to a stop, or should one direct his gaze at some stationary object (within the car) the sensation of reversed motion is produced lasting for several seconds. This is an ocular form of after-motion vertigo, and is unassociated with nystagmus. This visual sensation of reversed motion is furthermore unassociated with any labyrinthine function from the fact that it can be produced only with the eyes open. Pathologically by : (a) Sudden irregular swelling of the lens, as sometimes found in incipient cataract, may cause polyopia with unpleasant vertigo. (b) Sudden blindness from a lesion in the perceiving apparatus, retina and optic nerve tho it causes a loss of the perspective sense seldom if ever produces unpleasant vertigo, from the fact that we have long since learned to accommodate ourselves to monocular vision. The nail driving experiment with one eye closed is familiar to you all. (c) Lesions especially in the short optic tracts to the ganglion genicula externa, corpora quadrigemina anterior and the pulvinar and perhaps too, in a measure, the long tracts to the visual centers in LABYRINTH PAPERS. 197 the occipitial lobe, produce not infrequently vertigo with equilibrium disturbances according to Bechterew (Deutsche Med. Zeitung, 1894, No. 46). These are produced in the former instance by disturbances more especially in the pupillary and accommodation reflex arc and in the latter instance by disturbance in visual perception. (d) Sudden paralysis of accommodation from a lesion in the ciliary muscle itself, nerve supply, ciliary ganglion, that part of the oculomotor nucleus which controls accommodation, produces the sensation of ver- tigo with equilibrium disturbance, similar to that produced by my- driatics. (e) Sudden paralysis of one or more of the extrinsic eye muscles from lesion in the muscle, nerve or nucleus, produces diplopia with vertigo. The sensation as well as the mechanism of vertigo produced by complete paralysis of one of the extrinsic eye muscles differs from that produced by slight paresis. In case of paralysis, the patient manifests real squint but no nystag- mus ; the patient suffers diplopia and a sensation of confusion (ver- tigo) as to the location of external objects, especially objects located to the side or direction of the muscle's action. For example : in case of paralysis of the right external rectus, the location of objects to the right are estimated to be farther to the right than they actually are. The reason is that since we have learned to estimate the location of objects by the amount of muscle innervation necessary to fix the ob- jects for central vision, any extra amount of innervation put forth in the attempt to fix them is interpreted by the patient as an extra amount of angle deviation of the object to the right. This is associated with a corresponding amount of secondary deviation of the fellow eye to the right. Such a patient in attempting to grasp an object lying to the right of him will invariably reach too far to the right. In brief, there is confusion as to the location of external objects. In the case of slight paresis, or in those cases of late paralysis where a restoration of function has begun in the affected muscle, the sensa- tion and mechanism of the vertigo is quite different. In these cases the patient may manifest but little or no squint, but instead will show rhythmic nystagmus, especially when looking in the direction of the muscle's action. The vertigo is present only when looking in the di- rection of the paretic muscle, is rotational in character and associated igs VERTIGO: with equilibrium disturbance corresponding to rotational vertigo. This trio of symptoms rhythmic nystagmus, vertigo and equilibrium dis- turbance may simulate closely the vestibular form ; the nystagmus of eye muscle paresis is more likely to be unilateral, and less intense than in the case of nystagmus of the vestibular form. Again, the vertigo of eye muscle paresis differs from that of the vestibular form in that the vertigo improves upon closure of the eyes ; whereas the vestibular form does not. III. Kinesthetic vertigo. That vertigo may be produced by falsi- fication of sensory impulses from the muscles, joints, etc., may seem to some far fetched ; nevertheless the fact is true if we accept the broad definition of the term offered in the early part of the paper. For instance : The vertigo resulting from paresis of the eye muscles is produced by two factors: (i) visual (diplopia) and (2) muscular (falsifica- tion of sensation of the affected muscle). The concomitant equilib- rium disturbances would indicate that the vertigo results more from the falsification of sensory impulses from the muscles than from the diplopia. The author has arrived at this conclusion from the results obtained by equilibrium tests made upon patients suffering from pa- ralytic squint. These patients were examined ( I ) with both eyes open ; (2) with the affected eye closed, and (3) with the well eye closed, the patients being directed to look in the direction of the action of the paralyzed muscle. With both eyes open, the gait and equilibrium were disturbed. With affected eye closed, the gait and equilibrium were quite normal. With the well eye closed, gait and equilibrium were disturbed and quite as markedly so as when both eyes were open. Kinesthetic vertigo may be produced experimentally or pathologi- cally. The production of experimental kinesthetic vertigo has been only partially successful, from the fact that the deep muscle and joint sensibilities are so widely distributed over the entire body as to make it quite impossible to irritate or anesthetize a sufficient proportion of them to produce marked vertigo and equilibrium disturbance. The results of experiments thus far made have been sufficiently successful however to warrant further experimentation after more improved methods. A few of these experiments may be mentioned : (a) Anesthesia of the soles of the feet produced artificially has re- LABYRINTH PAPERS. 199 suited in the subject manifesting positive Rhomberg sign and disturbed gait (Vierordt's experiment quoted by Bechterew. P finger's Arch. xxx, s. 517). (b) Experiments by Mach with the two feet placed air tight in two holes in a box resulted in the sensation as though the floor was ele- vated when aspiration of air from the box was made. (c) Further experiments by Mach with weights (vessels containing water) held in the hand or attached to the shoulders caused the sen- sation as though the arms or body were elevated when the load was re- moved. (d) Panse tells of an interesting experiment made by Mach, as fol- lows : two vessels so constructed as to permit a gradual emptying when filled with water, were adjusted to a cap arrangement fitted on the head ; this when set in horizontal rotation, produced, as the weight di- minished from loss of water, the subjective sensation of turning in the opposite direction. (e) Bechterew (Pfiuger's Arch, xxxiv) found that section of the posterior cerebellar peduncle caused animals to roll to the side operated. Kinesthetic vertigo with equilibrium disturbance may be produced pathologically by : (a) Acute polyneuritis, involving sensory nerves. (b) Diseases involving the posterior columns, Gall and Burdach or spinocerebellar tracts in the cord, tabes, Friedrich's disease, multiple sclerosis of the cord, hemorrhages and myelitis in the cord, etc. (c) Diseases in the corpus restiforme, interrupting the centripetal impulses. In all these and others not mentioned the equilibrium disturbance is a more pronounced symptom than the vertigo, and lasts permanently in cases of permanent destructive lesions. Furthermore, the equilib- rium disturbance from interruption of these impulses is even more pro- nounced than in the case of interruption of impulses from the eye while the vertigo is less pronounced. Vertigo is never complained of as being so unpleasant as in the case of interruption of impulses from the eye or ear. This is due to two circumstances: (i) That the disease which produce interruption of sensation from the muscle and joint sense endings is very rarely acute, except in the case of acute hemorrhagic lesions ; and (2) That these diseases are very rarely extensive enough at the onset. On the con- 2 oo I'ERTIGO. trary, they are usually gradual progressive conditions which permit the patient to become gradually accommodated to the changes. The vertigo and equilibrium disturbances, like those of vestibular origin, are exaggerated by closing the eyes. CENTRAL VERTIGO. Finally we come to a discussion of that large class of so-called cen- tral vertigoes. By central vertigo is not meant the vertigo which results from anatomic changes in the brain substance itself, which presents, accord- ing to the location of the lesion, the characteristic of one of the three definite types already referred to ; but on the contrary, by central ver- tigo is meant that form of vertigo which is due to circulatory dis- turbances in the brain or to toxic substances circulating in the blood current; and it presents a combination of the several characteristics of all three types. In other words, central vertigo differs from each of the three described types or primary forms in that the manifesta- tions in the primary forms are distinct and definite ; while in the cen- tral forms they are not. That central vertigo should present the combined features of all three primary forms, but less defined and distinct than any one of them is quite evident when we recall the etiology. In the primary forms we have a vertigo due to a well defined ex- aggeration or suppression of the normal impulses from one of the three peripheral orientation organs through an irritative or destructive lesion in these organs or their centripetal tracts, while in the central vertigo due to circulatory disturbances the exaggeration or suppression of im- pulses are more general and less pronounced ; for instance, in the case of congestion or anemia of the brain the whole brain suffers whereby all centers are more or less affected. Again, in the case of toxemia the toxic substance circulating in the blood current is never so selective in its action as to affect the centers for one of these impulses to the exclusion of the remaining two. However, exceptional cases do occur where the toxic substance may be sufficiently selective in its action as to affect certain centers more than others when the resulting vertigo may present the characteristics of one primary form more prominently than the other two. In such cases a differential diagnosis of the cen- tral vertigo from the primary forms, which 'it resembles, may be quite LABYRINTH PAPERS. 201 difficult. A similar condition may result in cases of arteriosclerosis or endarteritis where certain vessels may be more affected than others or where the blood vessels make a sharp turn, or in cases where vessels branch off from the main stem at a sharp angle. Central vertigo may be produced by the following familiar condi- tions : I. Cerebral congestion, active or passive, from any cause II. Cerebral anemia. Psychic or physical shock producing syn- cope. Insufficiency of the heart's action. Post-hemorrhagic anemia. General anemia, including chlorosis, pernicious anemia, etc. Change* in the blood vessels narrowing their lumen ; arteriosclerosis, endarter- itis, etc. III. Toxemias, acute or chronic. Acute: Tobacco, alcohol, carbon dioxide, ether, chloroform, ben- zine and the inhalation of other volatile toxic substances. Chronic : Tobacco, alcohol, lead, etc. Uremia, autointoxication. Toxemias associated with the acute infectious fevers, etc. All vertigoes are aggravated by change of body position, especially from lying down to standing up. This aggravation is more pronounced in the case of vertigo from cerebral anemia than in the case of vertigo from any other cause. This has been felt at some time in the experi- ence of most of us, especially after a depleting illness, which at the same time required us to remain in bed for some days or weeks. Concerning vertigo of gastric origin the writer is quite skeptical. It is true that the ingestion of certain toxic substances produces vomit- ing with vertigo, but in these cases the author believes that the vomit- ing is merely a symptom of the vertigo, and the toxic substances in- gested would produce vertigo at all events even though the patient did not reach a stage where vomiting resulted. If irritation of the pneu- mogastric was the cause of the vertigo then it must follow that all sub- stances which are capable of producing emesis should at the same time produce vertigo. Since this is not the case, but the reverse is true, then it follows that nausea and vomiting are the results and not the cause of the vertigo. LABYRINTH FISTULA. WHAT IS A LABYRINTH FISTULA? A LABYRINTH fistula consists of any loss of substance in the osseous labyrinth which permits an artificial path of communi- cation between its cavity and the middle ear space. They vary in size, shape and location; generally occur as single perforations, but may be found multiple. The most frequent locations of labyrinth fistula are / naturally the most exposed, and at the same time most vulnerable, points in the lateral labyrinth wall ; namely the prominence of the external semi- circular canal, the promontory, the oval and round windows ; however, no part of the osseous labyrinth is entirely exempt. Fistulse of the labyrinth have been found in the region of the external crus of th^ superior semicircular canal ; besides, cases have been reported of the inner labyrinthine wall (by Koerner, Jansen and Habermann) resulting from long standing deep extraclural abscess; while in cases of necrosis. the loss of substance in the labyrinth capsule may extend in almost any imaginable direction. ETIOLOGY AND PATHOLOGY. Since labyrinth fistula is a process secondary to middle ear suppura- tion and more especially that of the chronic form, we must, in seeking for the etiology of labyrinth fistula, seek for the etiology of the primary middle ear suppuration and especially for those causes which tend to produce chronicity of an already existing acute suppuration. I shall not take the time here to discuss all the predisposing and ac- tive causes of chronic middle ear suppuration, but proceed immediately to a brief discussion of the more direct causes which tend to produce fistiilae ; among these may be mentioned : (1) Cholesteatoma. This is pre-eminently the most frequent of the direct causes of labyrinth fistula. By its growth that part of the lateral bony labyrinth wall with which it comes in direct contact is gradually absorbed until a saucer shaped fistula results. (2) Adhesive bands between the meso- and epitympanic spaces or antrum leading to the formation of closed or nearly closed cavities LABYRINTH PAPERS. 203 which favor retention of secretion and pressure. The pressure of the confined secretion leads to a destruction of the bone through caries or necrosis or both combined. (3) Polyps and granulations. These may, by reason of their pres- ence, operate in a similar manner as do the adhesions to produce re- tention with pressure resulting in the destruction of the bone. Granu- lations in themselves are generally an evidence of deep seated bone in- volvement (osteitis) more often of the rarifying type. Granulations occur frequently in the depressions about the windows and lead event- ually to destruction of the periosteum, thrombi of the nutrient vessels of the underlying bony capsule with resulting caries and necrosis. (4) Local tuberculosis. This comprises a destructive form of chronic middle ear suppuration liable to result in fistula of the labyrinth by reason of infiltration of the periosteum with subsequent softening, detachment of the periosteum and devitalization of the bone. (5) Diabetes. This condition especially favors necrosis, seques- tra partial or complete of the labyrinth capsule being quite common. (6) Prolonged constitutional diseases which lower the vitality of the patient or impair the power of repair. (7) Finally, unhygienic surroundings, poor nourishment and neg- lect of proper treatment may be mentioned ; however, these last three belong more to the indirect or contributory causes. PATHOLOGY. The microscopic pathology of labyrinth fistula will not be discussed in this paper for the reason that ( i ) the microscopic pathology differs considerably in different cases, depending principally upon the cause; (2) a sufficient number of cases have not yet been studied to warrant a thorough discussion of it; (3) the intention of the writer is to dis- cuss rather the clinical pathology. According to the extent and depth of the destructive process which produced the fistula, we may find any one of the following conditions of the membranous labyrinth present : i, Normal and intact. 2, Circumscribed irritative process (conges- tion). 3, Circumscribed destructive process (circumscribed suppura- tion or granulations). 4, Diffuse destructive process (diffuse labyrinth suppuration). Chronic diffuse plastic or obstructive inflammation of the membranous labyrinth will not be considered because (i) of its rare association with fistula: (2) from the fact that it does not afford us a 204 LABYRINTH FISTULA. distinct clinicopathologic type; (3) its discussion here would lead to too much confusion in the grasping of the more frequent and funda- mental conditions. If one is able to comprehend these four fundamental conditions, he will be in a position to work out a clinical diagnosis of the rarer complex conditions. These four conditions may be considered the four stages of the same process which follow each other in the order above men- tioned. The transition from one stage to the next succeeding may take place rapidly or slowly, or there may be a prolonged or even permanent arrest of the process at any stage. This arrest is especially apt to take place during the third stage so that the fourth stage may never be reached. In some cases, especially where the circumscribed destructive lesion is located in the horizontal semicircular canal, the spontaneous arrest of the process in the third stage is very desirable, since the patient retains fair hearing. For this reason our efforts should be to treat such cases with this object in view. These four conditions of the membranous labyrinth, three of which are pathologic, associated with fistula give rise to four separate clinic- al pictures. The first three of these conditions we are able to diagnose and differentiate, but the fourth condition is really one of the forms of labyrinth suppuration which is impossible of differentiation from the other forms of labyrinth suppuration without fistula ; and from the standpoint of prognosis and treatment the presence or absence of a fistula plays no important role. In order to better understand the symptoms and signs of labyrinth fistula when we come to discuss them, it is well that we digress for the present and consider briefly Ewald's physiologic experiments upon the semicircular canals and Gelle's test of the acoustic function. Concerning Ewald's experiment you are referred to the paper on "Nystagmus." The clinical application of Ewald's experiment, but slightly modified, may be applied as an examination test for the diagnosis of fistula of the static labyrinth. Since in most cases we are unable by otoscopic examination to ac- tually see the fistula and apply compression and aspiration directly to the membranous labyrinth, we are compelled to do so indirectly by in- creasing and diminishing the atmospheric pressure in the tympanic cavity. This is accomplished by a simple device consisting of an olive LABYRINTH PAPERS. x - shapecl hard rubber tip fitted on the distal end of a soft rubber tube, the proximal end of which is attached to a Politzer balloon, a Gelle" balloon or any other suitable force and suction apparatus. The olive tip is introduced into the external auditory canal air tight and may be held in place by the patient ; the physician is thus free to manipulate the balloon with one hand and to elevate the upper eyelid with the thumb of the other hand. A positive fistula sign is manifested by a pronounced nystagmus in one direction when the compression of the balloon is made, and a less pronounced nystagmus in the opposite direction when aspiration is made. Again, both compression and as- piration nystagmus are accompanied by more or less marked vertigo. A negative fistula sign is manifested by the absence of these phe- nomena. The plane and direction of the compression and aspiration nystag- mus varies with the location of the fistula. A horizontal nystagmus to the same side by compression and the opposite side by aspiration is the most frequent and at the same time the most positive in- dication of fistula and that of the horizontal semicircular canal. A rotatory nystagmus to the opposite side by compression and to the same side by aspiration indicates generally but not always a fistula of the superior semicircular canal. At one time Neumann, and likewise the writer, believed that this nystagmus indicated a fistula of the er ternal vestibular wall or loss of the stapes plate, but subsequent events have not verified this supposition. A rotatory nystagmus to the same side by compression and to the opposite side by aspiration may indicate a fistula of the external vesti- bular wall or of the stapes plate, but not absolutely. In brief the most certain localizing compression and aspiration nystag- mus is in the case of the external semicircular canal. In all other cases of compression and aspiration nystagmus we can say, at most, that the signs indicate fistula of the static labyrinth capsule but the ex- act location in all cases, for the present at least, remains more or less an open question. The question arises : Is the so-called compression and aspiration nystagmus an infallible sign of fistula? The answer must be "no," from the fact that we find cases where the sign is negative in spite of the presence of fistula, and on the other hand we find cases where the 206 LABYRINTH FISTULA. sign is positive without the actual presence of a fistula. The reasons for these discrepancies have been pointed out by Alexander and La- salle, "Ueber den durch Luftdruckveranderungcn auslosbaren Xystag- rnus und das Fistelsymptom, \\'iener klin. Rundschen, 1908, and by the writer. The reasons are as follows : I Negative fistula sign with positive fistula may be found : (a) In cases of labyrinth destruction (suppuration) ; since the laby- rinth is nonreactive the sign must be negative. (b) In cases of obstruction from polyps, adhesions or large choles- teatoma plugging up the fistula, compression of the membranous laby- rinth is quite impossible. (c) In cases of large dilated Eustachian tubes, the air escapes thru the open tube and makes impossible any increase of atmospheric press- ure within the middle ear spaces. II Positive fistula sign with negative fistula may be found : (a) In cases of acute middle ear inflammation (frequently observed by the writer). The explanation offered is that of a combination of factors ; first, the Eustachian tube is closed by inflammatory swelling ; second, because of this closure the secretion is more confined to the middle ear and cannot escape thru the tube ; third, compression of the secretion acts as a hydraulic pressure which is necessarily greater than pneumatic pressure; fourth, the ligament surrounding the stapes is more mobile because of the presence of secretion than it normally is when there is no secretion in the middle ear space. (b) In case of chronic middle ear suppuration with loss of the ham- mer and incus (observation by Alexander). Notwithstanding the fallibility of the fistula sign, the presence of it, especially when marked, is strongly suggestive of labyrinth fistula. GELLE'S TEST. Gelle's test was originally intended as a test for the determination of ankylosis of the stapes in the oval window in cases of otosclerosis. The test is made with an apparatus similar to that used for the de- termination of compression and aspiration nystagmus (described above) with the exception that compression only is used. Normally compression of air in the external canal is communicated to the stapes, which is forced inward and held so by the pressure from the tympanic side. The effect of the forcible pressure inward of the LABYRINTH PAPERS. 207 stapes plate is to produce impairment of hearing of a type correspond- ing to disease of the perceiving apparatus ; namely, Rinne positive with shortened bone conduction. Weber lateralized to the opposite side, etc. This effect upon the normal ear is known as a positive Gelle sign. In cases of otosclerosis the compression of air in the canal produces no effect upon the hearing, since the stapes plate is ankylosed in the oval window. This negative effect is designated "negative Gelle sign." In cases of fistula or abnormally loose and movable stapes, instead of the normally moderate positive Gelle we find abnormally p r o- n o u n c e d positive Gelle sign, which we may term a fistula sign of the acoustic labyrinth. According to Politzer, in cases of pathologic con- dition of the membranous labyrinth the positive Gelle sign is likely to be more pronounced than in those cases with normal membranous laby- rinth. The principle of the Gelle test may be applied in one of two WHY-; First after inserting the olive tip air tight in the canal, apply the handle of a vibrating tuning fork (Politzer middle tone) to the ba^. \Yhen compressing the bag with the hand the pressure of air in the ear is increased and upon relaxation the pressure is diminished. With the normal ear the fork is heard less distinctly during compression than during relaxation : this is recognized as a normally positive Gelle. In the case of otosclerosis. where the foot plate of the stirrup is ankylosed in the oval window, the compression of air does not produce the same degree of diminution of hearing as the normal ; this is recognized as a negative Gelle. In the case of abnormally loose stapes or where a fistula exists in the region of the vestibule, the diminution of hearing is greater than normal : this is recognized as an abnormally positive Gelle. Secondlv Since compression of air in the ear presses the foot- plate of the stapes inward in the oval window an experimental inner ear disease is produced in normal individuals, therefore it follows that the vibrating fork held to the mastoid is heard less distinctly or not at all during the compression of air in the ear and heard again during relaxation. In the case of ankylosis of the foot-plate in the oval window the diminution of bone conduction is less evident than normal, and in the case of abnormally 1< >< L - stapes plate or in case of fistula this diminu- tion of bone conduction is more evident than normal. 208 LABYRIXTH FISTULA. By a comparison with a sufficient number of normal cases one learns to recognize the difference between the normally positive Gelle and the abnormally positive as found in fistula of the acoustic labyrinth. SYMPTOMS AND SIGN'S OF LABYRINTH FISTULA. I With normal and intact membranous labyrinth. 1. By otoscopic examination evidence of middle ear suppuration, i. e., partial or complete destruction of the tympanic membrane, dis- charge, etc. 2. Impairment of hearing of the type belonging to disease of the conducting apparatus : Weber to diseased side, lengthened bone con- duction, negative Rinne, etc. : 3. Absence of acoustic and static labyrinth symptoms including tin- nitus, vertigo, nystagmus and equilibrium disturbances 4. Normal reactions of static labyrinth to turning, caloric and gal- vanic irritations. 5. Positive fistula sign. (a) If the fistula is located in the region of the static labyrinth, we find marked compression and aspiration nystagmus associated with vertigo (making due allowance for the exceptions already mentioned). (b) If the fistula is located in the region of the acoustic labyrinth we find a very positive Gelle sign. In some rare cases with a single fistula located in the region of the vestibule we find a combination of these two fistula signs. II Labyrinth fistula with circumscribed irritative process of the membranous labyrinth. According to the location of the fistula there may be present one of two distinct and separate pictures ; they are : (A) In case of fistula of the acoustic labyrinth with irritative pro- cess of corresponding part of the membranous labyrinth : 1. By otoscopic examination evidence of middle ear suppuration as in other cases of labyrinth fistula. 2. Impairment of hearing of the type belonging to disease of the conducting apparatus with a slight element belonging to disease of the perceiving apparatus. 3. Tinnitus corresponding in pitch to the location in the cochlea which is involved. 4. Absence of static labyrinth symptoms ; vertigo, nystagmus, equi- librium disturbance. LABYRINTH PAPERS. 209 5. Reaction of the static labyrinth normal. 6. Very positive Gelle symptom. In other words, by compression abnormally marked diminution of hearing, especially thru the bone. (B) In case of fistula of the static labyrinth with irritative process ot the corresponding part of the membranous labyrinth we find : 1. By otoscopic examination, evidence of middle ear suppuration as in other cases. 2. Impairment of hearing of the type belonging to disease of the conducting apparatus. 3. Absence of acoustic labyrinth symptoms, or more concisely speak- ing, there is no tinnitus. 4. Positive static labyrinth symptoms : (a) Vertigo pronounced or slight, depending upon the degree and extent of the process and characteristically aggravated by rapid move- ments of the head, no matter whether they are made actively by the patient or passively by the surgeon. (b) Nystagmus, rotatory, horizontal or mixed, to the diseased side. The nystagmus may be constant or intermittent and like the vertigo can be excited by the surgeon making rapid passive movements of the patient's head. (c) Equilibrium disturbances which have been amply described in the series of papers upon labyrinth suppuration and elsewhere and can be easily determined by Stein's, Alexander's and Mackenzie's tests.* 5. Reactions of static labyrinth increased upon the diseased side to turning and to the caloric and galvanic irritations. 6. Positive fistula sign; that is, marked compression and aspiration nystagmus. Ill Labyrinth fistula with circumscribed destructive process in the membranous labyrinth, like the former condition, may present one of two distinct clinical pictures according to the location of the fistula. They are : (A) In case of fistula of the acoustic labyrinth with destructive pro- cess of the corresponding part of the membranous labyrinth, the symp- toms and signs are: 1. By otoscopic examination, evidence of middle ear suppuration as before. 2. General impairment of hearing of the type belonging to disease of the conduction apparatus, together with absolute deafness for certain 2io LABYRINTH FISTULA. tones corresponding to the area of destruction. In other words single or multiple scotoma. This latter circumscribed deafness is of the type belonging to affections of the perceiving apparatus. These may be best ascertained by the use of Bezold's continuous chain of forks. 3. Tinnitus is present during the active stage since there is a zone of irritation surrounding the area of destruction. In a very late stage tinnitus may be absent. 4. Absence of static labyrinth symptoms. 5. Static labyrinth reacts normally to the usual examination methods. 6. Gelle's sign may be positive or negative, depending upon the size of the fistula and the extent and character of the destruction. In those cases where it is possible to produce compression of the endo- or perilymph beyond the areas of the destructive process, the Gelle sign would be proportionately positive ; on the other hand, in those cases where extensive granulations or organized exudate within the labyrinth prevent the possibility of compression of the endo- and perilymph beyond the area of the destructive process, the Gelle sign must be negative. (B) In cases of fistula of the static labyrinth with destructive pro- cess of the corresponding part of the membranous labyrinth, the symp- toms and signs are : 1. By otoscopic examination, evidence of middle ear suppuration as before. 2. Impairment of hearing of the type belonging to disease of the conducting apparatus. 3. Absence of tinnitus. 4. Positive static labyrinth symptoms: (a) vertigo is always pres- ent in acute cases, absent in late cases. The vertigo is aggravated by rapid head movements ; (b) nystagmus, rotatory, horizontal or mixed, it the unaffected side. The nystagmus is more constant, but rapidly diminishes in intensity and may eventually disappear ; (c) equilibrium disturbances are pronounced in early stages and but slight in late stages. *Klinische Untersuchungen ueber die Labyrinthaeren Gleichgewichtsstoerungen mit besonderer Bereuck der allegemeiner Pruefungsmethoden und des Gonio- meters. Arch. f. Ohrcnh. Bd. 78, 1009. LABYRINTH PAPERS. 211 5. Reactions of static labyrinth partially or completely lost upon the affected side, dependent upon the extent of the area of destruction. 6. Fistula sign, that is, compression and aspiration nystagmus, ab- sent. IV Labyrinth fistula with diffuse destructive process of the laby- rinth. The symptoms and signs in this condition are the same as those of labyrinth suppuration, and briefly are : 1. Otoscopic examination shows evidence of middle ear suppura- tion. 2. Complete loss of hearing. 3. Absence of tinnitus. 4. Positive static labyrinth symptoms vertigo, nystagmus and equilibrium disturbance (see former papers upon labyrinth suppura- tion). 5. Negative reactions from the static labyrinth of the affected side. 6. Fistula sign negative. PROGNOSIS AND TREATMENT. The prognosis and treatment is too large a subject to take up at the present time, besides the subject has already been considered more or less in a former paper upon the Prognosis and Treatment of Labyrinth Suppuration. REPORT AND DISCUSSION OF A CASE OF LABYRINTH FISTULA. WHEN comparing the history, findings and ultimate results of the present case with other similar cases of labyrinth fistula, treated after the same manner, the writer finds so much similarity that he could just as well have selected any one of the other cases. THE CASE.* NameR. W. Age 27 years. Occupation Clerk. Diagnosis (made prior to and substantiated at the time of opera- tion) Otitis Media Suppurativa Chronica Sinistra et Cholesteatoma et Fistula Labyrinthi (external semicircular canal). Treatment Mastoid operation after the Zaufall method, removal of the cholesteatoma and plastic after Panse. History Discharge from the left ear since third year of life. Pa- tient is unable to recall how the discharge first began or whether it was preceded by any other disease. From the third year until two years ago the discharge continued without interruption. Two months ago (June, 1907) the left ear started to discharge again. Two weeks ago the patient experienced dizziness for the first time. Every move- ment of the body and walking brings on an attack of dizziness which prompts the patient to seek a quiet position of the body, when the dizziness becomes less intense or disappears altogether. With dizziness the patient experiences a sensation of turning and swaying. When questioned, he disclaims any sensation of movement of external objects. The patient has been treated by a physician prior to his admission to the hospital. He comes for treatment on account of dizziness, impairment of hearing and profuse discharge from the left ear. *I am indebted to Professor Alexander, of the Vienna Polyclinic Hospital, for the opportunity allowed me to study this along with the other similar cases. It was my privilege, while acting as Zimmerarzt under him, to examine, study and write up the cases before operation, to take part in the operations and to look after the after-treatment. LABYRINTH PAPERS. OTOSCOPIC FINDINGS. Right ear normal. Left Ear Profuse and very offensive, dirty gray colored, purulent discharge which when wiped away shows the external canal to be nor- mal. Complete destruction of the tympanic membrane. Remnant of the hammer handle still present. Large polyp behind the short process of the hammer. Granulations in the hypotympanum which bleed read- ily. Typical cholesteatoma visible. Mastoid process not sensitive and periosteum not thickened. FUNCTIONAL EXAM I NATION. 1 Right Left 12 meters, 4 Conv. voice . . i mete. 12 meters, f Whisp. voice . . . Ad. conchr 12 meters, 4 Acumeter . . . Ad. conch Weber > . . . To the left Normal . . . Schwabach . . . . Shortened 4. . Rinne" . . Normal . c,. Shortened Normal . .C 4 , . . Shortened / 4- Watch on mastoid i t 4 s SPONTANEOUS NYSTAGMUS. Slight nystagmus to the right when looking to the extreme right and to the left when looking to the extreme left; but to neither side more marked than to the other. CALORIC NYSTAGMUS. By syringing the left ear with cold water with the head in the erect position the patient exhibits rotatory nystagmus to the right. GALVANIC NYSTAGMUS. Was not examined for at this sitting. TURNING NYSTAGMUS. After ten turnings to the left (3600) with head inclined forward 2i 4 A CASE OF LABYRINTH FISTULA. 90 the patient manifests a bilateral rotatory nystagmus to the right, when looking straight ahead, for a period of 20 seconds. After ten turnings to the right (3600) with head inclined forward 90 the patient manifests bilateral rotatory nystagmus to the left, last- ing for a period of 20 seconds. EQUILIBRIUM. At the time of this examination (August 26, 1907) there was no evidence of equilibrium disturbances by the usual tests, including that made on the Alexander-Stein goniometer. Three days later (August 29) after an accident which occurred during the local treatment, to be described later, the patient showed positive signs of equilibrium disturbances by all tests as follows: Rhomberg positive, gait forward and backward broad and uncertain hopping on one foot quite impossible. The Alexander-Stein gonio meter test showed quite evident disturbances, as follows : With eyes closed and face forward the patient tends to topple ovei with an elevation of 14, with face backward 11, with face to tht right 9 and with face to the left 10. For reasons stated below the author on this same date made tht test for labyrinth fistula ; as a result, compression and aspiration nystagmus or the so-called fistula symptom was found to be positive. Upon applying compression of air in the external canal of the left ear the patient manifests a pronounced horizontal nystagmus to the left and upon applying suction, a pronounced horizontal nystagmus to the right. The compression nystagmus to the left is somewhat more pronounced than the aspiration nystagmus to the right. The examination for compression and aspiration nystagmus was not generally made prior to this time, but has been quite universally since. This case appeared at a time when aurists were beginning to recognize the importance of the symptom. OPERATION. The case was operated by Professor Alexander, August 29th, 1907, under general narcosis with Billroth's mixture; operation lasting 25 minutes. Operation as follows : Typical retro-auricular incision from 4 to 5 cm. long. Laying free of the mastoid process. Chiseling open the same to the antrum which was filled with a cholesteatomatous mass. Removal of the cholesteatoma and curettement of the matrix. Thoro LABYRINTH PAPERS. 215 removal of all granulations in the middle ear spaces. On the promi- nence of the external semicircular canal a 3mm. long oval shaped, fistula was found. The dura of the posterior fossa was exposed for an area about the size of a 5 cent piece. The operation was completed after the method of Zauf all ; plastic after Panse ; wound dressing with iodoform gauze and bandage. August 29th. Evening of same day. Patient vomited considerably, pronounced vertigo. August 3Oth. Patient vomited often, has pronounced vertigo, rotatory nystagmus to the right when looking straight ahead. August 31. Patient feels generally better, has not vomited. Vertigo has become less severe. Rotatory nystagmus to the right when look- ing straight ahead, but less pronounced than yesterday. September ist. No vertigo. Rotatory nystagmus to the right. September 2d. No vertigo. Rotatory nystagmus to the right. September 3d. No vertigo. Rotatory nystagmus to the right. Slight facial palsy on left side involving all branches of the 7th nerve. September 5th. Change of dressings. No vertigo. Rotatory nystagmus to the right present, but diminishing in intensity. Facial palsy more pronounced, patient can barely whistle and raises the left angle of his mouth poorly. Can close left eye but incompletely. September Qth. Change of dressings. No vertigo. Rotatory nystagmus to the right less pronounced. Facial palsy unchanged. Pa- tient feels the slightest degree of vertigo when walking. Was dis- charged from the hospital and made an ambulatory patient to report for further treatment and observation. September loth. Change of dressings. Vertigo is only present when making quick movements. Rotatory nystagmus to the right. Facial palsy unchanged. Examination of left ear with 3 meter speaking tube whispered words heard without failure. September I2th. Change of dressings. Facial palsy less distinct. Patient can close left eye. Rotatory nystagmus to the right continues. Speaking tube-whispered words heard without failure. September i/th. Change of dressings. Facial palsy about the same as last examination. Rotatory nystagmus to the right. When cold water is syringed into left ear the nystagmus is unaffected (not in- creased). September i8th. Change of dressings. Retro-auricular wound much smaller. Facial palsy unchanged since last examination. Cold 2l6 A CASE OF LABYRINTH FISTULA. water in left ear produces no alteration of the very slight degree of rotatory nystagmus to the right. After ten turnings to the left with head inclined forward, pronounced rotatory nystagmus to the right lasting twenty seconds. After ten turnings to the right with head inclined forward, rotatory nystagmus to the left lasting ten seconds. Speaking tube, whispered voice heard without failure. September 29th. Redressing. Facial palsy improved. Spontaneous rotatory nystagmus to the right when looking to the right. No nystag- mus to the right or left when looking to the left. Same reactions to turning as on the i8th. Speaking tube, whispered voice heard with- out failure. October loth. Facial palsy decidedly better, other findings about the same as last examination. Wound closed and all discharge from left ear has ceased. Patient was told to report at wider intervals. A complete functional re-examination was made December loth which gave the following results : DECEMBER IOTH, 1907. Right Left 12 meters, -j- Conv. voice .... 2% meters 12 meters, -(- Whisp voice . . . . y$ meter 12 meters, -f Acumeter o Weber .... Not lateralized Slightly short, Schwabach . . . Very short -f Riling - Normal . . . . C 1 , o Normal ... c 4 , o Normal .... A, . . . . . o + Watch on mastoid SPONTANEOUS NYSTAGMUS. When looking to the right, bilateral rotatory rhythmic nystagmus to the right. Also less marked rotatory nystagmus to the right when looking straight ahead. Xo nystagmus to the left when looking to the left. LABYRINTH PAPERS. 217 CALORIC NYSTAGMUS. Negative, i. e., syringing the left ear with large quantities of cold water does not increase the existing spontaneous nystagmus to the right. AFTER-TURNING NYSTAGMUS. After ten turnings to the left After ten turnings to the with head erect and with opaque right with head erect and with glasses before the eyes, hori- opaque glasses before the eyes, zontal nystagmus to the right horizontal nystagmus to the left lasting 35 seconds. lasting 12 seconds. After ten turnings to the left After ten turnings to the with head inclined forward, ro- right with head inclined for- tatory nystagmus to the right ward, rotatory nystagmus to the lasting 19 seconds. left lasting n seconds. GALVANIC NYSTAGMUS. Kathode 4 ma. rotatory Kathode 10 ma. no effect, nystagmus to right increased. Anode 4 ma., rotatory nystag- Anode 10 ma. no effect. mus to right increased (?). THREE METER SPEAKING TUBE. Conversational voice without failure. COMPRESSION AND ASPIRATION NYSTAGMUS. Negative. EQUILIBRIUM. Positive evidence of equilibrium disturbances as shown by positive Rhomberg. Wide and uncertain gait both forward and backward, also side stepping and hopping on one foot less certain than normal. 2i8 A CASE OF LABYRINTH FISTULA. ON THE GONIOMETER. With open eyes: With closed eyes: Face forward 26. Face forward 14. Face backward 23. Face backward 11. Face to right 19. Face to right 10. Face to left 18. Face to left 9. Patellar reflexes normal as are also other deep reflexes. Vision normal, pupils react promptly to light, accommodation and convergence. Patient's intelligence normal. DISCUSSION OF THE CASE. The history is that of a chronic middle ear suppuration. The fact that the discharge was intermittent suggests a cholesteatoma. The history of dizziness with the subjective sensation of_ turning aggra- vated by active movements, ameliorated by keeping quiet, in the course of chronic middle ear discharge should direct our attention imme- diately to the inner ear. The dizziness, ^however, does not tell us the exact character of the lesion within the inner ear, for it may be due to one of several clinical conditions, an irritative lesion, circumscribed or general, or a de- structive lesion, circumscribed or general. The Otoscopic Findings. The offensive discharge in spite of the treatment, which he had prior to admission to the hospital, suggests a cholesteatoma. The complete destruction of the membrane may sug- gest either chronicity or marked virulence of the original infection. It more often points to the latter for in those cases of suppuration following scarlet fever we frequently find complete destruction of the membrane early. Again complete destruction of the membrane is a most favorable condition for the development of a cholesteatoma, which by the way was present too in this case (see paper by author "Zur Clinischen Diagnostik des Mittelohrchlesteatome," Monatsshr fur ohrenheilk, 1908). A part of the cholesteatoma was visible by otoscopic examination, presenting a glistening, pearly white, smooth surface. The granulations, bleeding readily, suggest bone involvement and they are apt to be found in conjunction with cholesteatoma. Functional Examination. The right ear showed normal hearing function. The rooms in the hospital were not ideal for determining LABYRINTH PAPERS. 219 hearing distances, so the figures are lower than they would otherwise have been. The left ear showed the hearing to be greatly reduced. Lateraliza- tion of the tuning fork to the left points to middle ear affection ; but since the bone conduction on the left mastoid was shortened we have a finding which points to inner ear affection. The Rinne was nega- tive, which, when combined with shortened bone conduction, indicates middle ear disease with secondary inner ear involvement. That C x was shortened points to middle ear disease. That c 4 was shortened points to inner ear disease. Watch on mastoid was heard on the normal side but not on the affected side, which fact points to disease of the inner ear of the af- fected side. That the spontaneous, rhythmic nystagmus was present to the left when looking strongly to the left and to the right when looking strongly to the right, but to neither side more marked than to the other does not suggest disease of the inner ear or at least of the membranous part. On this point I wish to emphasize the fact that normal indi- viduals when looking intently enough to the right or left side will manifest a rhythmic nystagmus in the particular direction toward which they are looking. This is purely physiologic. Again, it is possible for the osseous labyrinth to be considerably involved, especially in cases of fistula, before the membranous labyrinth shows any physical or clinical signs of involvement. But how are we to explain the apparently contradictory facts, namely, the absence of spontaneous nystagmus and the presence of vertigo (mentioned in the history) ? The vertigo mentioned in the his- tory was evidently due to causes which were transient (circumscribed congestion) and not present at the time of the examination on the 26th of August. That this was the case is further borne out by the results obtained thru turning. The after-turning nystagmus was of equal duration to the two sides and approximately normal (20 seconds). Had the patient suffered an irritative lesion at the time of the examination he would have mani- fested a longer duration of nystagmus to the affected side. Had he suffered a destructive lesion he would have manifested a much shorter duration of the nystagmus to the affected side. The Caloric Reaction made with cold water douched into 220 A CASE OF LABYRIXTH FISTULA. the left middle ear cavity indicated that the inner ear was reactive and not destroyed, for the patient showed a pronounced rotatory nystagmus to the opposite (right) side. The Galvanic Nystagmus was not examined at this time for I had not yet worked the subjeft up to the point that I had later. We come next to a very important sign in the diagnosis of labyrin- thine fistula, which was present in this case, namely, compression and aspiration nystagmus called also the fistula sign. Prior to this time it was not the routine practice to examine every case for the presence or absence of this sign, however it became so immediately afterwards. In this case the sign was found quite accidentally. The patient after waiting three days in the hospital for his turn to be operated, began to grow anxious because of the postponement of his operation, which was made necessary on account of a rush of other cases demanding more immediate attention. In order to pacify and hold the patient in the hospital for another day it was necessary to do something. Ac- cordingly it was agreed to remove a polyp with the snare. Upon en- gaging the polyp, using the average amount of pressure necessary to reach as near the base as possible, the patient suddenly cried out in terror, extended both arms, grasped the table with one hand and an assistant with the other while his face took on a wild expression with widely open eyes, and sweat flowed freely. He was a very sick look- ing man for a short time. I recognized it immediately as a severe at- tack of vertigo, the result of pressure on some part of the lateral laby- rinthine wall where the capsule was defective. After waiting several minutes until the patient had become quiet and normal again I attempted to demonstrate the presence of com- pression and aspiration nystagmus. Upon applying pressure the eyes made quick horizontal movements to the left (same) side, of about 6 mm. excursion, occurring at an approximate rapidity of three com- plete excursions for each second of time. Upon releasing the pressure and using gentle aspiration, the nystagmus changed to that of hori- zontal to the right of somewhat shorter excursion than it had been to the left. The character and direction of the nystagmus (remembering Ewald's experiment) established in the writer's mind the diagnosis of fistula of the osseous horizontal (external) s e m i c i r - cularcanal with the membranous canal intact, which diagnosis was corroborated at the time of the operation. LABYRINTH PAPERS. 221 After waiting an hour the patient was examined on the goniometer with the result that he showed diminished equilibration. Balance was lost with eyes closed at greatly reduced elevations. The operation report shows the typical findings of a case of chronic middle ear suppuration with cholesteatoma. The cholesteatoma had by its growth caused an absorption of the bone of the prominence of the external semicircular canal ; not an unusual finding in these cases. Altho there was a fistula in the osseous canal, the membranous canal had not been affected, accordingly Prof. Alexander decided to leave the labyrinth alone. Surgically the wound did well, healing occurring completely after a reasonable length of time for such cases. During the period of after treatment we note prominently (a) Vertigo* which was quite pronounced immediately follow- ing the operation and for a day or so afterward. The vertigo then grew gradually less, however it was felt more or less by the patient when going around even after he had left the hospital. This symptom taken together with the next symptom to be men- tioned spontaneous nystagmus to the right (well) side tells us that a destructive process had occurred in the labyrinth after operation which was probably of a slower nature than a diffuse suppuration, for the patient retained hearing for at least some weeks after the opera- tion. (b) Spontaneous Rotatory Nystagmus to the right (well) side was present immediately following the operation and di- minished gradually thereafter, but had not disappeared entirely after five months. At all times the nystagmus was demonstrable, even when the patient looked straight ahead. The character, direction and persistency of the nystagmus found in this case is characteristic of any form of destructive lesion of the labyrinth or more exactly of that part which has to do with the static and dynamic equilibrium. (c) Hearing was present and demonstrable with the three meter speaking tube for a considerable period after the operation, the patient having been able to detect whispered words without failure. *The vertigo following the operation was not due to any fault of the opera- tion but to the uncovering of an existing fistula which had been sealed over with a cholesteatomatous mass the vertigo was an inevitable sequence. 222 A CASE OF LAIiyKIXTII FISTULA. Eventually the hearing- grew less and less until finally all hearing left the patient, he not being able to recognize conversational voice thru the tube. Furthermore he was unable to hear the new, Edelman- Bezold, small (a^ fork that Professor Alexander had just acquired for the clinic. In short the patient grew gradually deaf and the deaf- ness was absolute. (d) Facial palsy developed late and as all facial palsies do which develop late after the radical operation, it disappeared early. Complete recovery occurring after a few weeks. I made several complete examinations of the case for the purpose of study, about a month apart ; however to save space I have outlined but one which was made December loth, 1907. It is shown above in the report and really needs no further special discussion. The patient had an inactive left labyrinth, complete deafness and demonstrable equilibrium disturbance. UNIVERSITY OF CALIFORNIA LIBRARY Los Angeles This book is DUE on the last date stamped below. JUN 1 P.H i Form L9-10m-3,'48(A7920)444 THE LIBRARY OF UC SOUTHERN REGIONAl UWARY FACILITY A 000414489 5