Monitoring Cerebral Blood Flow, Oxygen, and Glucose Metabolism

Abstract

More accurate methods for monitoring cerebral blood flow, oxygen, and glucose metabolism with results of their application in human volunteers are described. Subjects with various types of cerebral vascular disease showed decreased cerebral blood flow and oxygen and glucose metabolism but anaerobic glycolysis appeared to be increased. Inhalation of 100% oxygen decreased anaerobic glycolysis, and mixtures of oxygen, 5% CO₂ plus oxygen, 5% CO₂ plus air, and hyperventilation all showed that cerebral vascular reactivity is reduced in cerebrovascular disease. Nevertheless, inhalation of 5% mixtures of CO₂ in air or oxygen significantly increased cerebral blood flow. Inhalation of 5% CO₂ plus oxygen significantly increased cerebral oxygen consumption in cerebrovascular disease within 10 minutes of its institution. The depression of cerebral glucose metabolism and oxygen consumption appears to be amenable to rapid improvement in some subjects with stroke. Intravenous administration of nylidrin hydrochloride decreased cerebral vascular resistance but did not increase cerebral blood flow or metabolism, presumably by autoregulation. Intravenous injection of 100 ml of low molecular-weight dextran increased cerebral blood flow and oxygen consumption but not to the level of statistical significance. A case of brain-stem ischemia showed a large increase of cerebral blood flow, oxygen metabolism, and glucose consumption after surgical reconstruction of the left vertebral artery accompanied by clinical recovery.