Spectralanalytical differentiating of the EEC in patients with affective disorder after total sleep deprivation

(TSD) The aim of the present study was to analyse the modifications of slee p deprivation on specifically defined EEG-parameters and to discriminate be tween the potentially different EEG-reaction of sleep deprivation responder s and nonresponders. 26 patients (according to ICD9: 20 patients with 296.1 and 6 patients with 296.3) were included in this study. Responders to slee p deprivation were defined by an improvement of 30% in the daily mean of th e Hamilton Depression Rating Scale. EEC data of all patients were recorded the day before sleep deprivation and day 1 and day 2 after sleep deprivatio n. Evaluation of the EEG data was performed by Fourier-Analysis, in which t he following EEG parameters were included: Zentroid, power, frequency devia tion and coherence. Sleep deprivation produces a modulation of the EEG para meters centroid, power and coherence. The sleep deprivation causes in the e xperimental group a significant (p<0.05) increasing of the centroid in the alpha band. In respect of the EEG parameter power, sleep deprivation leads to a significant reduction in the alpha-power; the effect on parameter cohe rence after sleep deprivation was a significant decrease in the alpha band. The systemical representation of the modifications of sleep deprivation on specific EEG parameters in depressive illness supports the development of a theoretical concept in depressiv investigations, which takes integrativly as well clinical psychopathological and biochemical differences of defined depressive subgroups as the specific electroneurophysiological reactions i nto consideration.