Studies of Japanese cases with cerebral basal rete mirabile (Moyamoya disease) -investigation of cerebrovascular hemodynamics-

Eight children under 15 years of age and 8 adults with basal cerebral rete (so called Moyamoya disease) were examined. Regional cerebral blood flow (rCBF) was measured in 12 of these patients under normocapneic, hypercapneic, hypocapneic and hypotensive states by a (133)Xe-intracarotid injection method using a gamma camera. Patients with neurological deficits due to completed stroke (CS) had angiographically poor normograde vascularization of cortical branches of the middle cerebral artery (MCA) and poorly developed collateral circulation. Hemispheric cerebral blood flow (HCBF) in the resting state tended to decrease according to the severity of neurological deficits, but was within the normal range in patients with no neurological deficits. However, focal reduction of rCBF was seen in half of the patients with transient ischemic attacks. Development of leptomeningeal anastomosis of MCA territories from the posterior cerebral artery seemed to have a more important role than basal rete in maintaining cerebral blood flow. There was a significant reduction of the HCBF under the hypocaneic state, but no significant increase under the hypercapneic state. The lack of a CBF response to increased arterial CO(2) tension seemed to be due to maximum dilatation of cerebral arterioles