[Depressive pseudodementia. Diagnostic importance of quantified EEG]

The accuracy of computerized EEG to discriminate depressive pseudodementia from dementia was evaluated in 12 inpatients with recent cognitive impairments (all with DSM III R diagnosis of dementia). EEG were performed during wash-out period, then all subjects underwent an ECT and/or antidepressant trial. After this trial, clinical improvement was significant for six patients, while the six others remained unimproved. According to these two groups, electrophysiological data were retrospectively compared. Discriminant stepwise analysis exhibited that the combination of two parameters: symmetry of occipital alpha power and frontal alpha/theta ratio, was able to discriminate future responders from non responders patients with a greater accuracy than clinical and classical EEG parameters.