Paroxysmal kinesigenic dyskinesia.

Paroxysmal kinesigenic dyskinesia (PKD) is a rare disorder characterised by brief and frequent attacks of abnormal involuntary movements induced by sudden movement. This disorder has not been reported previously in Sri Lanka. We studied six patients with respect to clinical presentation, aetiology, family history and response to treatment, and describe the Sri Lankan patterns of this illness. All the patients were males and the age at onset was from 11 to 22 years. The involuntary movements in all were dystonic and affected one or both sides, involving the face in the majority. All had difficulty in speaking during the attacks. One patient had an occasional attack during exercise. In all, the illness was sporadic, none had a family history of a similar illness and in none was it due to a secondary cause. The attacks usually lasted 10-60 seconds, and occurred up to 20 times a day. All patients responded well to anticonvulsants. PKD in Sri Lanka has a pattern similar to that described worldwide.