Cerebral blood flow and oxygen metabolism in symptomatic internal carotid artery occlusion by atherosclerosis and by cervical dissection

Abstract

Symptomatic internal carotid artery occlusion by atherosclerosis and by cervical dissection are distinct conditions with different long-term prognoses. The purpose of the present study is to investigate if regional cerebral blood flow and oxygen metabolism, after onset of stroke, differ between both conditions. Seventeen patients with symptomatic unilateral atherosclerotic internal carotid occlusion and 10 patients with symptomatic internal carotid occlusion due to cervical dissection were submitted to a positron emission tomographic (PET) study between 1 and 2 months after stroke onset. The steady state technique with 15O was used in order to determine regional cerebral blood flow, regional oxygen extraction fraction, and regional cerebral metabolic rate for oxygen in the infarct area, the peri-infarct zone, the remaining homolateral hemisphere, and the contralateral hemisphere. The results were compared between both patient’s populations. The patients with cervical dissection were on average much younger than those with atherosclerotic occlusion, but neurological impairment on admission and disability at 3 months were comparable. Between both patient populations, no differences in rCBF, rOEF, and rCMRO 2 could be demonstrated in the different regions of interest when the results were age-adjusted. Except for age-related changes, no differences in PET findings could be demonstrated between patients with symptomatic internal carotid occlusion caused by either atherosclerosis or cervical dissection.