ACUTE EFFECTS OF ALCOHOL ON REGIONAL CEREBRAL BLOOD-FLOW IN MAN

Acute effects of alcohol in a low (0.7 g/kg) and a high dose (1.5 g/kg ) on regional cerebral blood flow (rCBF) were measured with Xe-133 inh alation technique at resting conditions in 13 normals. Mean hemisphere CBF increased globally by 12% at the lower dose and 16% at the higher dose. A normal hyperfrontal flow pattern was seen in both alcohol con ditions. There were, however, significant regional differences in resp onse to alcohol. The largest rCBF increase was observed in prefrontal regions at the lower dose, and in temporal regions at the higher. Expr essed in relative values (% of the whole brain CBF), the temporal rCBF increased linearly with increasing alcohol dosage, while the prefront al rCBF showed an increase at the lower dose followed by a decrease at the higher dose. It is concluded that alcohol has two types of acute effects on rCBF, a global vasodilatory effect and some regional effect s, most clearly seen in prefrontal and temporal regions. The prefronta l flow augmentation following acute alcohol intake may be related to a transient arousal reaction. which has been reported by others. The te mporal flow increase may be related to effects of alcohol on emotions and mood.