Prolonged neonatal myasthenia gravis: electrophysiological studies

A female infant with neonatal myasthenia gravis remained weak for an excessively long period compared to the usual situation in this disease process. At 71 days of age, electrophysiological studies revealed evidence of a defect in neuromuscular transmission that improved with intravenous Tensilon therapy. Repeat study at 183 days of age was normal. This case represents an unusually long time for an affected infant to have neonatal myasthenia gravis. Electrophysiological studies are of value in the diagnosis and management of patients with neonatal myasthenia gravis.