The clinical and angiographic findings in cases of juvenile Moyamoya disease were reviewed and functional images of cerebral perfusion were observed to clarify the mechanism of transient ischemic attack (TIA) which is the characteristic symptom of this disease. A total of fifty two patients with Moyamoya disease were seen in our hospital between 1963 and 1980. Twenty seven were pediatric patients and twenty five were adults. TIA was observed in nineteen of the twenty seven pediatric cases. In thirteen of these nineteen children, TIA was precipitated by physical exercise or emotional upsets such as running, crying or hyperventilation during EEG recording. Angiograms revealed no correlations among the clinical symptoms, the development of the cerebral basal rete, and the degree of the stenosis of the carotid artery. However, the arterial vascularity of the Sylvian group was reduced on the side related to TIA. In seven of the pediatric patients with TIA, cerebral perfusion images were observed during continuous intracarotid infusion of the solution of Kr-81m. The patients were hyperventilated under infusion of the tracer and the changes in cerebral perfusion were detected by a gamma camera. Prolonged and marked reduction of cerebral perfusion was observed in the fronto-pareital convexity region during and after hyperventilation in six of seven patients. This prolonged reduction of perfusion in the fronto-parietal region seems to be responsible for TIA which often occurred following hyperventilation or strenuous exercise.
transient ischemic attack
cerebral blood flow