RESUMO
BACKGROUND: To define the pathophysiology of paroxysmal kinesigenic dyskinesia(PKD), we analyzed detailed clin-ical features. METHODS: We studied characteristics of the attack, family history, response to the treatment and clinical courses of 30 patients with PKD. RESULTS: Twenty-six of the 30 patients were men and four were women. Thirteen patients had a family history of PKD. There were no patients who had symptomatic PKD. In three-fourths of our patients, the attacks ameliorated within 10 seconds and two-thirds experienced one to ten attacks per day. They showed dystonia much more frequently than chorea. In all patients,sudden movements of the legs while standing precipitated the attacks. The attack occurred very rarely during driving or swimming. Sudden movements of the arm did not precipi-tate the attacks. CONCLUSIONS: We suggest that neuronal system maintaining standing posture and strong afferent inputs delivering sudden high velocity movements of the legs to the spinal cord are involved in the genesis of PKD.