Post-Anoxic Action Myoclonus: Improvement with Valproic Acid

Abstract

To the Editor: Since it was described in 1963 by Lance and Adams,¹ the syndrome of action myoclonus after recovery from coma secondary to cerebral hypoxia has become widely recognized. These lightning-like involuntary movements incapacitate the patient in walking, feeding and using the upper limbs for carrying out other activities of daily living. Cerebrospinal-fluid levels of 5-hydroxyindoleacetic acid are usually reduced in this syndrome.^{2 3 4} A lessening of the involuntary movements has been reported with 5hydroxytryptophan^{3 4 5 6} and with clonazepam.^{4 , 7} I have been treating two patients suffering from this syndrome with valproic acid, a recently approved anticonvulsant, in combination with clonazepam and . . .