Oculobulbar involvement is typical with Lambert-Eaton myasthenic syndrome

Oculobulbar symptoms and/or signs were present in 18 of 23 (78%) of Lambert-Eaton myasthenic syndrome (LEMS) patients evaluated at the Lahey Clinic (Table). Sixty-five percent (15 of 23) of our patients had ptosis and/or diplopia, each present in 11 individuals. Bulbar signs and symptoms, including dysarthria in 10 and dysphagia in 8 patients, also were observed among our LEMS population. More than one prereferral oculobulbar feature occurred in 13 of our LEMS patients. Prereferral diagnostic considerations included myasthenia gravis, myopathies, and psychiatric disorders. These findings suggest that these atypical characteristics served to dissuade some colleagues from a diagnosis of LEMS. Thus, the presence of oculobulbar symptoms and signs cannot be used to exclude LEMS from the differential diagnosis.