[Study of diazepam with quantitative EEGs taken with eyes opened and topography]

Diazepam is a representative drug of benzodiazepines. The subjects were 9 right-handed healthy male volunteers 21 25 years of age. Double blind crossover trials with placebo control were conducted in a random sequence at an interval of 1 week. Diazepam 10 mg and placebo were administered as single oral doses. Three-minute EEGs were recorded with subjects' eyes opened before and 2 h after drug administration. One-minute out of the 3-minute EEGs was analyzed with FFT, and the absolute amplitude power (microV) was calculated. These results were subjected to Student's t-test (double difference) and displayed with topographic maps (t statistic significance probability mapping). Diazepam decreased the delta absolute amplitude power over left-parietal dominance, theta absolute amplitude power diffusely and alpha absolute amplitude power over parietal region dominance. It also increased the beta absolute amplitude power over left-antero-temporal region dominance. The EEG profiles taken with subjects' eyes open were different from those of diazepam with eyes-closed vigilance controlled concerning the degree of decrease of delta and beta activities and region of the effect on alpha activity.