Objective:

Examine the clinical course of COVID-19 associated myasthenia gravis (MG).

Background:

Myasthenia gravis is an autoimmune disorder clinically characterized by motor fatigability. Paraclinical findings of autoantibodies are diagnostic, and the acetylcholine receptor antibody (AChR Ab) is the most common autoantibody. Myriad autoantibody mediated syndromes following infection with COVID-19 have been appreciated, including Miller Fisher Syndrome, myelin oligodendrocyte glycoprotein (MOG) antibody associated autoimmune encephalitis, and MG. Per literature review, fewer than 20 cases of COVID-19 associated MG have been reported to date.

Design/Methods:

Case report

Results:

A 78-year old male presented to clinic with ptosis and diplopia, with no associated shortness of breath or motor fatigability. He reports no previous autoimmune disease or symptoms suggestive of undiagnosed myasthenia gravis. Symptoms began approximately four weeks after initial infection with COVID-19. Neurologic symptoms improved over the subsequent weeks, and he remained symptom free for approximately one year. However, ptosis and diplopia recrudesced approximately four weeks after prolonged COVID-19 exposure, when his wife had symptomatic COVID-19. Symptoms again resolved over the course of weeks without directed therapy. Ptosis and diplopia returned two months later following another prolonged exposure to COVID-19. Serologies at that time were noteworthy for AChR Ab seropositivity. Low dose pyridostigmine was initiated with unclear clinical benefit.

Conclusions:

Myasthenia gravis onset following COVID-19 has previously been reported, the vast majority of which are AChR Ab positive. Uniquely, this case demonstrates waxing and waning symptomatology, potentially attributable to repeated exposure and/or subclinical infection with COVID-19. Further data will be helpful in delineating prognosis, risk factors for post COVID-19 development of myasthenia gravis, and potential strategies for effective management.