Ictal muscle discharge pattern and SPECT in paroxysmal kinesigenic choreoathetosis

We studied the pattern of muscle activity of the limbs during attacks and measured post-ictal regional cerebral blood flow (rCBF) in 3 patients with paroxysmal kinesigenic choreoathetosis (PKC). During attacks, a "Jacksonian march" pattern of tonic muscle activity in the limbs was observed. Two of 3 patients, who suffered from unilateral attacks, showed a noticeable increase in rCBF in the basal ganglia on the contralateral side of the attacks. Treatment with phenytoin improved symptoms and reduced the difference in rCBF between the right and left side. These observations suggest that abnormal hyperactivity of neurons in the basal ganglia may cause choreoathetotic movements in patients with PKC.