The Relationship of Regional Cerebral Blood Flow, Oxygen Metabolism and Glucose Metabolism Following Acute Stroke

Abstract

Previous studies using positron emission tomography (PET) have established that the normal coupling of cerebral blood flow (CBF) and oxygen metabolism (CMRO2) breaks down in acute stroke (Ackerman et al. 1981; Baron et al. 1981; Lenzi et al. 1981). Initially, there are areas of ischaemic but still surviving brain in which CMRO2 is preserved in relation to the marked fall of blood flow; the oxygen extraction ratio (OER) is high. Prolonged severe ischaemia leads to a subsequent fall of CMRO2 (and hence also of OER) even if there is no further reduction of blood flow. This sequence of events is considered to represent the transition from potentially reversible ischaemia to established and irreversible cerebral infarction. In order to examine the relationship of regional cerebral glucose metabolism (rCMRG1u) to these pathophysiological changes, we have carried out combined, consecutive measurements of CBF, CMRO2 and CMRGIu in patients with acute stroke.