A case of syringomyelia: electrophysiological analysis and treatment for attacks of periodical spasms and intractable pain.

A 31-year-old woman underwent cervical laminectomy for decompression and diagnosis of syringomyelia which involved the higher cervical cord. After surgery, the patient complained of paresthesia with severe deep pain which appeared in her feet and migrated upwards in succession to her hands. At the same time, the patient suffered intense muscle spasms which started in the sternocleidomastoid and migrated downwards in succession to her legs. These attacks occurred all day, repeatedly, at intervals of 120 to 300 sec. Based on electrophysiological analysis, these attacks were considered to be due to abnormal discharges which developed in the lesion in the cervical cord, and stimulation of the pathways showing somatotopic laminations in the cord. Electrical stimulation of the median nerve at the wrist was effective against these attacks and complete remission was obtained by diphenylhydantoin administration.