Electroencephalographic changes during experimental hangover.

The EEG was recorded in 27 subjects during hangover. Male healthy volunteers drank 1.75 g/kg body weight of ethanol in 3 h and the EEG was recorded 14-16 h later when the degree of hangover was highest. For control purposes a second EEG was recorded after a similar session when subjects drank water instead of ethanol. A third record was taken in normal laboratory conditions. T5-A1 and O1-A1 derivations were subjected to computer analysis from which spectral and frequency parameters were calculated. Visual analysis of the EEG during hangover showed a decrease and slowing of alpha activity and an increase in theta activity. Spectral analysis of the EEG gave a statistically significant increase in 7-8 c/sec activity during hangover. The EEG change could not be explained in terms of blood alcohol level, hypoglycaemia or acidosis. Also fatigue could be excluded as a cause of EEG change by means of "water controls". The conclusion is that the slowing of the EEG during hangover is caused by the depressant action of ethanol, or its metabolites, on cortical function.