Severe hemodynamic impairment and border zone-region infarction

PURPOSE: To investigate the relationship between the patterns of cerebral i nfarction that have been associated with hemodynamic impairment and the pre sence of severe chronic hemodynamic compromise (increased oxygen extraction fraction) in a large prospectively enrolled group oi patients with carotid artery occlusion. MATERIALS AND METHODS: At enrollment in a prospective study of cerebral hem odynamics, 110 patients with carotid occlusion underwent (a) positron emiss ion tomography for the measurement of cerebral oxygen extraction fraction a nd (b) computed tomographic (CT) or magnetic resonance (MR) examinations of the brain. Infarcts were categorized retrospectively by vascular territory , location, and pattern. The association of these findings with hemodynamic impairment (increased oxygen extraction fraction) was investigated. RESULTS: No border zone-region infarctions were found in 35 asymptomatic pa tients. In 75 symptomatic patients, cortical border zone-region infarction was found in seven of 36 patients with increased oxygen extraction fraction , and in two of 39 with normal oxygen extraction fraction (P = .08, differe nce not significant). The pattern of multiple white matter lesions arranged parallel to the lateral ventricle was observed only in symptomatic patient s with increased oxygen extraction fraction (eight of 36 patients; P = .002 ; sensitivity, 22%; specificity, 100%). This finding was more frequent with MR imaging (seven of 14 patients) than with CT (one of 22 patients). CONCLUSION: Multiple white matter infarctions, arranged parallel to the lat eral ventricle, are associated with severe hemodynamic impairment. This pat tern of infarction is likely due to a hemodynamic mechanism.