Extensive postradiation ocular and diffuse cranial neuromyotonia mimicking myasthenia gravis

Background: Ocular neuromyotonia is a rare, but well-recognized, complication of cranial irradiation. Case Report: Using figures and videos, we report a 52-year-old man with extensive ocular, brainstem, and lower cranial nerve neuromyotonia postradiation therapy for a fourth ventricle glioma who, in the context of an apparently positive edrophonium test, was initially misdiagnosed with myasthenia gravis. Conclusions: This is the first case of postirradiation neuromyotonia to be reported with such extensive cranial nerve and brainstem involvement.