key: cord-0690547-r2pk7lyv
authors: Karimi, Narges; Okhovat, Ali Asghar; Ziaadini, Bentolhoda; Ashtiani, Bahram Haghi; Nafissi, Shahriar; Fatehi, Farzad
title: Myasthenia gravis associated with novel coronavirus 2019 infection: A report of three cases
date: 2021-07-23
journal: Clin Neurol Neurosurg
DOI: 10.1016/j.clineuro.2021.106834
sha: 3ffbe28f9b32be633b9968b4b97749d8493646c6
doc_id: 690547
cord_uid: r2pk7lyv

Several neurological presentations have been reported following coronavirus 2019 (COVID-19) infection. This case report describes three myasthenia gravis (MG) patients presented following COVID-19 infection. We report three adult patients with myasthenic Gravis and COVID-19 infection. The patients are between 38 and 61 years old. Case 1 is a 61-year-old woman with progressive dysphagia, nasal speech, ocular ptosis, diplopia, and proximal muscle weakness for 10 days. She had a COVID-19 infection 6 weeks ago. Case 2 is a 57-year-old man with clinical symptoms of muscular fatigability, diplopia, ptosis, and dysphagia for a week and a positive COVID-19 infection 10 days ago. Case 3 is a 38-year-old woman with fatigability, ptosis, dysphagia, and a diagnosis of COVID-19 infection 4 weeks ago. All patients had a positive RT-PCR for COVID-19 infection by nasopharyngeal swab test and a high-level acetylcholine receptor antibody in the serum. All patients were treated with pyridostigmine and prednisolone with a favorable outcome. MG may appear following COVID-19 infection, and the role of molecular mimicry and latent MG activation should be considered the cause of the disease onset.

Myasthenia Gravis (MG) is an autoimmune disorder caused by the destruction of the post-synaptic neuromuscular junction due to the production of antibodies against nicotinic acetylcholine receptors (AChR) at the neuromuscular junction [1] . The most common clinical manifestations of this disorder are fatigability and weakness of skeletal muscle with varying degrees, which may be generalized or focal, including ptosis, diplopia, nasal speech, dysphagia, muscular weakness of the limbs, and respiratory distress [2] . Previous studies have demonstrated a possible etiological role of different viral infections in MG [3] . The novel coronavirus outbreak of SARS-CoV-2 (COVID-19) first commenced in Wuhan, China, in December 2019 [3] . On 19 February 2020, Iran described the first infected cases with COVID-19 in Qom city.

The virus infects various systems, most commonly involving the respiratory and gastrointestinal tracts [3] . While fever, pneumonia of varying severity, and diarrhea are significant features of COVID-19; nevertheless, the association of various neurological disorders with the COVID-19 has been well established, such as stroke, acute disseminated encephalitis seizure, and Guillan Barre syndrome (GBS) [4] [5] [6] .

Likewise, some studies reported the association of MG disease with COVID-19 infection [7] [8] [9] Thymus was normal on chest CT scan. We prescribed pyridostigmine 60 mg three times a day and prednisone 25 mg daily. Dysphagia and muscle weakness improved after seven days. (Figure 1 ). The brain MRI was normal.

According to the combination of these findings, the patient was diagnosed with seropositive generalized myasthenia gravis (class IIb MGFA). Pyridostigmine 240 mg and prednisolone 25 mg daily were started, with a significant improvement in her symptoms.

At the start of the spread of SARS-CoV-2 throughout the world, it was believed that this infection is principally targeting the pulmonary system; however, other systemic involvement, especially central and peripheral nervous system disorders, were rapidly revealed. [9] , while in the reports by Huber et al. [8] and Sriwastava et al. [7] , this was two weeks. The first of our patients had thymoma in the chest CT.

In the first patient with thymoma, we hypothesize that SARS-CoV-2 infection or Azithromycin administration may have unmasked or triggered a latent myasthenia gravis in this patient. Previously, latent MG unmaking has been described by J o u r n a l P r e -p r o o f antibiotic medictions such as Aminoglycosides or neuromuscular blocking agents [10, 11] or infections such as varicella or West Nile virus [12, 13] .

In general, there are two potential explanations for our patients. First, the SARS-CoV-2, like other viruses, can play a role in activating latent autoimmune diseases such as MG. Second, the antigenic similarity and interaction between the SARS-CoV-2 epitope and the nicotinic acetylcholine receptor at the neuromuscular junction termed molecular mimicry could be responsible for MG induction; however, such associations are far to be demonstrated, and requires further complementary evidence [14] .

We described three patients with MG who began to manifest shortly after the COVID-19 infection. It is not easy to find definite cause-and-effect relationships between MG manifestation and COVID-19 infection; however, latent MG activation by the virus and molecular mimicry may play a role in the initiation of MG.

Myasthenia Gravis: A Review of Available Treatment Approaches

Clinical features, pathogenesis, and treatment of myasthenia gravis: a supplement to the Guidelines of the German Neurological Society

Neurologic Manifestations of Hospitalized Patients With Coronavirus Disease

Guillain-Barre syndrome in patients with coronavirus disease-2019: Report of six cases and review of literature

The association of SARS-CoV-2 infection and acute disseminated encephalomyelitis without prominent clinical pulmonary symptoms

New onset of ocular myasthenia gravis in a patient with COVID-19: a novel case report and literature review

Postinfectious Onset of Myasthenia Gravis in a COVID-19 Patient

Undiagnosed myasthenia gravis unmasked by neuromuscular blockade

A diagnosis of late-onset Myasthenia gravis unmasked by topical antibiotics

Post-varicella myasthenia gravis

West nile virus infection and myasthenia gravis

Figure Legend Figure 1: Lung CT scan of three patients. A: grand glass opacity at bilateral lung in patient 1; B: the patient 1 after treatment COVID-19

The authors request to thank all the patients for their consent to publish the case report.

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.J o u r n a l P r e -p r o o f