A CASE OF ISAACS SYNDROME WITH HIGH CSF PROTEIN AND A LARGE CISTERNA-MAGNA

An 11-year-old boy exhibited continuous muscle fiber activity. He had suffered from stiffness of his hands, difficulty in relaxing his hands after gripping, and making skilled movements with his fingers. His cl inical symptoms improved after treatment with carbamazepine. Electromy ography (EMG) showed that he had continuous electrical discharges both at rest and during sleep. These discharges completely disappeared aft er the peripheral nerve was blocked with Lidocaine. An evoked electrom yogram showed suppression of abnormal discharges after the F response. These electrophysiological findings indicated that the disorder origi nated in the spinal anterior horn cells. CT scanning showed a large ci sterna magna in the posterior cranial fossa. Protein in the cerebrospi nal fluid was elevated.