Hemiparetic forms of cerebral palsy in relation to epilepsy and mental retardation.

Fifty-one children with hemiparetic cerebral palsy underwent clinical, EEG and CT examinations to assess mental performance, laterality of CP and incidence of epilepsy, 80 per cent of the children had epileptic abnormalities on EEG, but less than half had clinical signs of epilepsy. Clinical paroxysms were more frequent in those with right-sided hemiparesis. Focal or epileptic EEG changes were usual in those with right-hemisphere involvement, but unless clinical paroxysms developed, these had no bearing on mental performance. Lower IQ was found in the patients with clinical epilepsy--in nearly all cases with left-sided hemiparesis and in half of those with right-sided hemiparesis.