Myasthenia Gravis Syndrome Following COVID-19 Vaccination and Subsequent Tolerance of Booster Vaccine: A Case Report

ABSTRACT

Objective: The COVID-19 pandemic has led to the rapid development of multiple safe and effective vaccines. Few neurological adverse events (AEs) associated with COVID-19 vaccines have been reported. Background: Myasthenia gravis (MG) is a chronic autoimmune disorder of the neuromuscular junction, which can involve crises of muscular weakness that can be triggered by numerous stressors including medications, infections and vaccines. Little is known about the relationship between COVID-19 vaccines and MG. Here, we present a case of new-onset generalized MG following the mRNA-based Pfizer-BioNTech COVID-19 vaccine. Design/Methods: A 46-year-old female with a past medical history of anxiety and sinus tachycardia reported drooping of her right eyelid within 48 hours of receiving her first Pfizer-BioNTech COVID-19 vaccine. Results: Over the next few weeks, she developed significant progressive fatigable extremity and bulbar muscle weakness, including ptosis, diplopia, dysarthria and fatigable mastication. Within months, she had multiple hospitalizations with unrevealing brain and spinal imaging, negative anti-AchR, anti-Musk and anti-LRP antibodies, a normal chest CT and EMG/NCS demonstrating moderate-to-severe electrical decrements in extremity and bulbar muscles. She was diagnosed with seronegative MG, and her symptoms significantly improved with Pyridostigmine treatment. She was subsequently hospitalized twice for MG crisis and received plasmapheresis, steroids and Mycophenolate with symptom stabilization. She has since tolerated a third dose of the vaccine without worsening of MG symptoms. Conclusions: Given the close temporal association, it is plausible that the vaccine unmasked subclinical MG in this patient, or less likely, induced de-novo MG. Rare COVID-19 vaccine-associated neuro-immunological cases have been observed and this case highlights the need for continued vaccine monitoring, as well as the potential to tolerate booster vaccination if the underlying neuro-immunologic condition is controlled. In addition to this case presentation and review of the relevant literature, we also present our analysis of the ongoing Vaccine AE Reporting System as it pertains to MG.