Abstract
An electrophysiological study was done in a 62-year-old man who had had sudden, involuntary jerky movements during volitional movements since age 44. There has been no attack of tonic or clonic convulsions EEG revealed a markedly abnormal record with a slowed background activity and diffuse bilateral spikes and polyspikes-wave complexes during flickering light stimulation. Electromyographic studies demonstrated irregular arrhythmic discharges which synchronized in both agonists and antagonists, and the presence of electrically silent periods, lasting up to 200 m Sec. No relationship was found in the time element between EEG and EMG abnormalities, suggesting that there would be no direct correlation between spike activities and myoclonic discharges.
