ISI values and interhemispheric differences in patients with ischemic cerebrovascular disease; correlations with clinical and angiographic findings

Abstract

Xenon 133 inhaJation CBF studies of one hundred patients with ischemic cerebrovascular disease In the territory of the carotid artery were compared in an attempt to gain more insight into the collateral capacity, especially In those with a stenosis or occlusion of one of the major arteries. Asymmetry of the lSI values for the two hemispheres was expressed as a ratio. High ratios (greater lSI asymmetries) were found for Patients with an occlusion of the Internal carotid or middle cerebral artery, especially - but not exclusively - those with the more severe clinlcaJ symptoms. It also appeared that even when the patient Is In a good cllnh:al condition, an elevated ratio reflects Insufficiency of the collateral supply to the affected side. The lSI values for Individual patients seem to be less useful, partly due to the variable age dependency of this flow parameter. © 1986 American Heart Association, Inc.