Effects of acute alcohol intoxication on cerebral blood flow measured with PET

Regional distribution ofcerebral blood flow was assessed in a group of I3 normal social drinkers under baseline conditions and after acute alcohol intoxica- tion. Blood flow measurements were done using 150-labeled water and positron emission tomography (PET). Each subject underwent two control sessions under baseline conditions and two sessions after alcohol. Seven of the subjects were given 0.5 g/ kg of alcohol and six were given 1 g/kg of alcohol p.o. The first and second post-alcohol scans were done 40 and 60 min after alcohol ingestion. The studies revealed that both the high and the low doses of alcohol reduced blood flow to the cerebellum. This effect was significant only for the high doses of alcohol, which also increased blood flow to the right temporal and the prefrontal cortex. The decrease in blood flow of the cerebellum could account for the muscular incoordination induced by alcohol. Several studies have been done in humans to assess the effects of acute alcohol ingestion on cerebra1 blood flow (CBF). The initial studies ,which measured global changes in CBF after alcohol consumption using the nitrous oxide technique, showed that blood alcohol levels (BAC) 0.32 mg/% were accompanied by a 2Oc/0 increase in global CBF (Batley et al., 1953). The studies done using the '"3Xenon technique to measure regional cerebral blood flow (rCBF) showed that 0.75 g/kg of ethanol resulted in a 20% increase in CBF of the gray matter (Newlin, 1982), and doses of0.5 g/ kg induced a smaller but significant regional increase in CBF (Mathew and Wilson, 1986). These studies suggest that alcohol affects blood flow in the brain in a dose-dependent manner. The measurement of rCBF has been shown to be well suited to investigate cerebral function since in the brain there is a close link between rCBF and regional cerebral