A Case Report and Literature Review of New-Onset Myasthenia Gravis After COVID-19 Infection

Abstract

Myasthenia gravis (MG) is an autoimmune disorder affecting the neuromuscular junction caused by a B-cellmediated, T-cell-dependent immunologic attack at the end plate of the postsynaptic membrane. Attack on muscle acetylcholine receptors (AChR) of the postsynaptic membrane due to the AChR, muscle-specific tyrosine kinase, or lipoprotein receptor-related peptide 4 antibodies lead to symptoms of painless, fluctuating weakness of muscle groups and often begins with ocular signs and symptoms. Coronavirus disease 2019 (COVID-19) is an acute respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus closely related to SARS-CoV. Serious neurologic complications are infrequent and diverse with reported cases of stroke, encephalitis/meningitis, Guillain-Barré syndrome, acute disseminated encephalomyelitis, ataxia, and unspecified limb weakness. MG is a rarely reported sequela of COVID-19 infection. To date, there are 15 reported cases of post-COVID-19 MG. In this article, we present a case of post-COVID-19 MG and a concise review of other reported cases. An 83year-old Caucasian male with a medical history of atrial fibrillation status post-ablation and non-ischemic cardiomyopathy was initially admitted for COVID-19 pneumonia. He was treated with remdesivir, convalescent plasma, and supplemental oxygen therapy but did not require invasive mechanical intubation. One month after discharge, he started experiencing fatigue with muscle weakness and progressive dyspnea. He progressed to develop dysphonia, especially at the end of the day. After extensive workup, he was diagnosed with MG with a positive antibody against the AChR. The chronological events of developing slowly worsening muscular weakness after recovering from COVID-19 infection and positive AChR antibody led to the diagnosis of post-COVID-19 new-onset MG. Post-COVID-19 fatigue, long-term use of steroids, and intensive care unit-related physical deconditioning can be confounders in the clinical presentation of post-COVID-19 new-onset MG. Careful history-taking and meticulous assessment of chronological events are needed to diagnose this rare entity.

Autoimmune myasthenia gravis and COVID-19. A case report-based review

“…In a case from the USA, also without RNS/SF-EMG data, an 83-year-old man was diagnosed as having MG based on elevated serum titres of antibodies against AchR and positive response to corticosteroids and azathioprine. 28 The 18 cases we identified originated from four continents: Europe (10 cases); Middle East (4 cases); Asia (2 cases); North America (2 cases). There were 10 male and 8 female patients and ages ranged from 19-83 years.…”

“…59 Our literature search identified 14 publications that reported 18 cases in the specified time frame (Table 1). [15][16][17][18][19][20][21][22][23][24][25][26][27][28] An additional publication that presented the case of an 86-year-old man with generalized muscle weakness, diplopia, ocular ptosis and dyspnoea in the subacute phase of COVID-19 was inconclusive. 60 For this patient, the diagnosis of MG was not supported by paraclinical investigations (i.e., no data were provided on RNS, SF-EMG or edrophonium/ neostigmine test, and AchR and MuSK antibodies were within the normal range).…”

“…In a case from the USA, also without RNS/SF-EMG data, an 83-year-old man was diagnosed as having MG based on elevated serum titres of antibodies against AchR and positive response to corticosteroids and azathioprine. 28 While he had signs and symptoms of COVID-19, no details of laboratory diagnosis were provided in the case report. In all other cases, a positive COVID-19 diagnosis was made by nasopharyngeal/sputum/cerebrospinal fluid swab reverse transcriptase polymerase chain reaction (RT-PCR) positive for SARS-CoV-2, or by serum levels of SARS-CoV-2 antibodies.…”

“…13,14 Conversely, cases of new-onset autoimmune MG have been reported worldwide by several groups, following COVID-19 or any type of vaccination against it. [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] Moreover, one study reported a case in which MG appeared as an initial symptom of COVID-19. 35 The purpose of this present review was to assess the relationship between COVID-19 infection and new onset MG by reviewing case studies published between 01 December 2019 and 30 June 2023 identified by a search of PubMed/Medline database.…”

“… 13 , 14 Conversely, cases of new-onset autoimmune MG have been reported worldwide by several groups, following COVID-19 or any type of vaccination against it. 15 – 34 Moreover, one study reported a case in which MG appeared as an initial symptom of COVID-19. 35…”