POSTURAL MYOCLONUS INDUCED BY PHENYTOIN

Involuntary movements are an infrequent complication of treatment with phenytoin and include tremor, asterixis. myoclonus, parkinsonism, and dyskinesias. The mechanism by which phenytoin exerts its actions is u nclear. Phenytoin has been observed to exert variable effects on dopam ine metabolites and also may induce changes in serotonergic activity. In this report, we discuss the available experimental evidence concern ing the possible mechanisms of involuntary movements induced by phenyt oin. We describe a case of postural myoclonus during treatment with ph enytoin.