Intelligence in children with moyamoya disease: evaluation after surgical treatments with special reference to changes in cerebral blood flow

The effect of surgical treatment upon the intelligence of 20 children with moyamoya disease was evaluated and related to changes in cerebral blood flow (CBF). The patients were treated by various surgical revascularization procedures, mainly by encephalo-myo-synangiosis. Intelligence was tested using the Wechsler intelligence scale for children (WISC) in 19 children and the Wechsler adult intelligence scale (WAIS) in one child. Measurements of regional CBF were performed by a 133Xe inhalation method. In the preoperative state, the degree of reduction in the intelligence quotient (IQ) correlated well with the age of the patients; the older patients revealed a more marked reduction of IQ, and the patients with lower intelligence scores in general showed a tendency for more marked depression of mean CBF. Postoperatively, most of the patients showed increase in IQ, especially in performance IQ which improved significantly in 10 patients, remained unchanged in 3 and deteriorated in 2. Mean CBF increased by an average of 11.4%, and postoperative changes in mean CBF correlated well with the changes in IQ in most patients. This may show that the postoperative increase in CBF is quite possibly responsible for the changes in IQ.