Interet pronostique de l'eeg au cours de l'evolution des schizophrenes

Abstract

This report concerns the progression of the electro-clinical syndromes of schizophrenia. 209 EEG's of 62 female schizophrenic patients treated at the psychiatric Hospital of Bonneval (France) have been reviewed. First, morphologically “normal” records (pure alpha rhythm, well localized to the occipital leads, without superimposed fast or theta activity) are found in 46 per cent of the cases, most of which show a continuous clinical evolution. Successive records show the persistence of the same electrical pattern throughout the evolution, sometimes despite intensive treatments. This poor EEG plasticity seems to define a psychotic structure, with psychobiologic hyperstability. When associated with a clinical picture of schizophrenia, this “normal” record takes on the most unfavourable prognosis. On the contrary, “dysrhythmic” records (alpha rhythm more or less poor, mixed with fast and theta activity, spatially ill-differentiated) or “abnormal” records (slow waves foci, paroxysmal activity) are seen in 54 per cent of the patients, more often those whose illness develops in a discontinuous evolution, sometimes interrupted by phases of improvement or at least of temporary social adjustment. These cases show a higher sensitivity to treatments from both clinical and EEG points of view. If not always favourable, these records reflect more plasticity and may correspond to a schizophrenic process. This prognostic value of EEG in schizophrenia is more accurate in young patients than in old patients. In the latter, the evolution is obscured by chronicity of the process of by secondary dementia.