Clinical and radioisotopic follow-up study of 'Moyamoya'.

24 children with 'moyamoya' had average follow-up periods of 5 years and 9 months. The following factors were noted to influence the prognosis for mental function: early onset, repeated transient ischemic attacks followed by residual neurological deficit, symptoms suggesting bilateral or dominant hemispheric lesions, and angiographically widespread occlusion. Futhermore, radioisotopic procedures could replace angiography for follow-up studies of patients with Moyamoya.