[Electroencephalography and the confusional syndrome in a hospital center specializing in psychiatry].

In psychiatric hospitals confusional states are frequent and represent about 20% of requests for EEG's. This study, covering a one year period, at S-Jean de Dieu psychiatric hospital in Lyon, revealed among all EEG's carried out for a confusional state the existence of a high proportion of pathological signs (59%). Etiological research demonstrates that a large proportion of these patients is diagnosed as senile dementia. Nevertheless, even if pure organic causes are rare, EEG remains an indispensable complement to clinical practice.