glycogen and Muscle-Rigidity

A 48 year old woman is described who presented with increasing muscular rigidity and who was found to have a mediastinal tumour. Electrophysiological studies revealed that the muscular stiffness resulted from very high frequency motor unit activity which outlasted voluntary effort, and which was abolished by nerve block. The abnormal activity may have arisen at the anterior horn cell level. Marked improvement followed the administration of diphenylhydantoin.

Topics: Anterior Horn Cells; Electromyography; Electrophysiology; Female; Glycogen; Humans; Lipid Metabolism; Mediastinal Neoplasms; Memory Disorders; Middle Aged; Muscle Contraction; Muscle Rigidity; Muscles; Neural Conduction; Neuromuscular Diseases; Phenytoin