Severe Hemodynamic Impairment and Border Zone--region Infarction

Purpose: To investigate the relationship between the patterns of cerebral infarction that have been associated with hemodynamic impairment and the presence of severe chronic hemodynamic compromise (increased oxygen extraction fraction) in a large prospectively enrolled group of patients with carotid artery occlusion.

Materials And Methods: At enrollment in a prospective study of cerebral hemodynamics, 110 patients with carotid occlusion underwent (a) positron emission tomography for the measurement of cerebral oxygen extraction fraction and (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 patients. 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, difference not significant). The pattern of multiple white matter lesions arranged parallel to the lateral ventricle was observed only in symptomatic patients 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 lateral ventricle, are associated with severe hemodynamic impairment. This pattern of infarction is likely due to a hemodynamic mechanism.