USE OF PREDICTION INTERVALS TO CHARACTERIZE ELECTROENCEPHALOGRAPHIC CHANGES CAUSED BY DIPHENHYDRAMINE

The authors report on progress in the use of a two-channel, microproce ssor-based electroencephalographic (EEG) device and the statistical st rategy of prediction intervals for characterizing the normal limits of variability in cerebral state In older subjects and recognition of ex cessive change caused by mildly toxic medications. Prediction interval s for relative delta, them, alpha, and beta power were calculated from repeated EEG measures on 54 medically stable elderly subjects. The au thors subsequently evaluated the effects of diphenhydramine (25-75 mg) administered to 10 additional subjects. Significant drug-induced chan ges at the group level were apparent only in relative theta power Sign ificant change in relative theta power at the individual level was obs erved in five of nine subjects for whom data at 50 mg were available.