[Eaton-Lambert myasthenic syndrome: clinical, electrophysiologic, histological and ultrastructural study].

In this case, showing the classical features of the Eaton-Lambert myasthenic syndrome, the neuromuscular symptoms appeared 21 months before the bronchial carcinoma was diagnosed. The electrophysiological study demonstrated, beside the marked potentiation under repetitive nerve stimulation at 30 c/sec., some modifications of distal latency, specially after administration of Edrophonium chloride. The muscle biopsy showed changes secondary to a peripheral motor nerve involvement; electronmicroscopic study of the motor end-plates revealed a highly developped subneural apparatus. Long-run treatment by guanidine hydrochloride determined haematologic and renal toxic manifestations. Prednisolone was for a time active on the myasthenic syndrome.