CEREBRAL BLOOD-FLOW AND OXYGEN-METABOLISM IN HEMIPARETIC PATIENTS WITH CHRONIC SUBDURAL-HEMATOMA QUANTITATIVE-EVALUATION USING POSITRON EMISSION TOMOGRAPHY

BACKGROUND It remains unclear why chronic subdural hematoma (CSH) can cause hemiparesis, although the contribution of impaired cerebral bloo d flow and metabolism has been suggested. METHODS We studied six hemip aretic patients (five men, one woman; mean age 60.5 +/- 7.5 years) wit h unilateral CSH using positron emission tomography. The O-15(2) stead y state technique was used to measure regional cerebral blood flow (rC BF), regional oxygen extraction fraction (rOEF), and regional cerebral metabolic rate of oxygen (rCMRO(2)) followed by the 1-minute inhalati on of (CO)-O-15 to measure regional cerebral blood volume (rCBV). RESU LTS On the hematoma side, rCBF and rCMRO, were significantly reduced i n the caudate nucleus and the cingulate gyrus. We observed a tendency toward reduced levels of rCBF and rCMRO, in the lentiform nucleus. rCB V was not elevated. rOEF was significantly elevated in the lentiform n ucleus, the cingulate gyrus, the frontal gray matters under the hemato ma and the semioval center. On the nonhematoma side, rCBF and rCMRO, w ere normal except for the significant reduction in the cingulate gyrus . rCBV was elevated in the lentiform nucleus, the middle temporal gyru s and the inferior frontal gyrus. rOEF was elevated significantly in t he cingulate gyrus, the precentral gyrus and the semioval center. CONC LUSIONS Our hemiparetic patients with CSH were oserved to have a circu latory disturbance of blood; it was manifested by an elevation of rOEF , specifically in the hemisphere adjacent to the hematoma. This circul atory disturbance was highly pronounced and resulted in a consistent r eduction in rCBF and rCMRO(2) in the anterior central cerebral area su ch as the caudate nucleus, the lentiform nucleus and the cingulate gyr us.