Familial paroxysmal exertion induced dyskinesia with a good response to phenytoin

Paroxysmal dyskinesias are neurologic conditions characterized by sudden episodes of abnormal involuntary movements. Paroxysmal exertion induced dyskinesia is a rare condition characterized by abnormal involuntary movements on exercise, which get relieved with rest. In general, these movements are poorly responsive to medical treatment. We report one family in which all three male members are affected and had good response to phenytoin.