In 30 adult cats, anesthetized with nitrous oxide and halothane, the middle cerebral artery was occluded using a transorbital approach. Extracellular volume changes were assessed by recording cortical impedance, and correlated with blood flow, tissue osmolality, and water and electrolyte content of brain tissue. Following middle cerebral artery occlusion, cortical impedance, after a free interv...

Regional cerebral blood flow measurements and neuropsychological testing were conducted before and after venesection on 6 patients with polycythemia secondary to chronic obstructive pulmonary disease. Venesection resulted in lowered viscosity and hematocrit, and an accompanying improvement in cerebral perfusion and mental function. Blood flow was significantly increased in the left cerebral hem...

Background and Purpose The aim of this study was to examine the levels of cerebral blood flow in relation to motor and cognitive functions in 300 chronic unilateral stroke patients (age, 64±12 years; mean±SD). Methods Cerebral blood flow was measured by the Xe inhalation method, adjusted for age, sex, and Pco2 level. Motor function was scored according to Brunnstrom hemiplegic staging and cogni...

BLOOD has anomalous rheological properties, particularly in certain disease states. It may therefore be necessary to consider these properties when attempting to assess and perhaps to improve the state of a patient's cerebral circulation. So what evidence is there that cerebral blood flow (CBF) is affected by viscosity? Before attempting to answer this question, one should be aware of what infl...