[Evaluations of regional cerebral blood flow (rCBF) by 133Xenon i.v. method in patients with occlusions of bilateral internal carotid arteries].

The studies of changes in regional blood flow (rCBF) have been reported on different clinical courses in the five cases (mean 57.4 y.o.) showing bilateral occlusion or stenosis of internal carotid arteries. Values of rCBF using Fg (fast component in gray matter) were closely correlated with their clinical courses. The three patients (2 males and 1 female) showed bilateral focal decreased patterns of rCBF and their uneventful clinical courses except for mild attacks of transient cerebral ischemia. However, the rest two male patients showed bilateral decreased pattern of rCBF and moderate hemiparesis including attacks of loss of consciousness. The one died suddenly because of the thalamic hemorrhage and the other died also suddenly from the unknown etiology. Such differences between the classification of clinical course and hemodynamics evaluated by rCBF was discriminated more clearly by Fg (fast component in gray matter) than by F mean (mean rCBF). The authors concluded that the evaluation by Fg may be valuable to estimate prognosis of patients with bilateral occlusion of internal carotid artery. There are two patterns of decreased rCBF in our study. The patients with bilateral diffuse decreased patterns of rCBF should be followed up more carefully because of the sudden death from cerebral hemorrhage.