Paroxysmal dystonic choreoathetosis in a patient with familial ataxia.

A patient with paroxysmal dystonic choreoathetosis also had familial ataxia. His brother was similarly affected but had rare paroxysmal episodes. No secondary or symptomatic forms of this type of paroxysmal dyskinesia have ever been reported. Episodes were briefly controlled with acetazolamide and were almost completely eliminated by clonazepam therapy.