CEREBRAL HEMODYNAMICS AND METABOLISM IN MOYAMOYA-DISEASE - A POSITRON-EMISSION-TOMOGRAPHY STUDY

We studied the cerebral blood flow (CBF), cerebrovascular response to hypercapnia, oxygen extraction fraction (OEF), metabolic rate for oxyg en (CMRO2), blood volume (CBV) and transit time (TT: CBV/CBF) in Moyam oya disease using positron emission tomography (PET). The subjects con sisted of 23 patients with Moyamoya disease, including eight pediatric and 15 adult patients. Among them, ten patients were examined both be fore and after surgery. The pediatric patients showed a marked increas e in the CBV and a prolonged TT, especially in the striatum. The adult patients also showed a prolonged TT, but it was less prominent than t hat observed in pediatric patients, while the CBF remained at the leve l of the normal controls. The cerebrovascular response to hypercapnia was markedly impaired in both the pediatric and adult patients, which thus indicates a decrease in the hemodynamic reserve capacity. After s urgery, the CBV, TT and cerebrovascular response to hypercapnia all im proved, mainly in the temporal cortex where extracranial-intracranial (EC-IC) bypass surgery had been performed. In the striatum, the CBV al so decreased, while the TT was shortened after surgery. A PET study wa s thus found to be useful for evaluating the cerebral hemodynamics in Moyamoya disease and monitoring the effect of surgery. (C) 1997 Elsevi er Science B.V.