Galcanezumab-Induced Myasthenia Gravis-Like Symptoms

Fluctuating weakness affecting the ocular, bulbar, and/or appendicular muscles is characteristic of myasthenia gravis. Autoimmune components and certain drugs have been implicated in the pathophysiology of this disease. I report a case of chronic migraine in which the patient developed symptoms of myasthenia gravis after using galcanezumab, the recently approved anti-calcitonin gene-related peptide (anti-CGRP). This case shows that anti-CGRP medications could affect the neuromuscular junction and cause such symptoms. Moreover, this case illustrates the clinical approach and management of such a presentation.