Cerebral dysfunction revealed by EEG mapping in the schizoform epileptic psychosis.

Twenty schizophrenia-like psychotic patients suspected of epilepsy were explored using EEG techniques (recordings in the 10-20 International System, source derivation, EEG mapping and EEG spectral reaction mapping by photic and somesthetic stimulation). In 16 of them, latent epileptic disorders were found. EEG spiking foci could be located either: (a) in temporal, (b) fronto-basal, or (3) in the sagittal-line leads. A corresponding associated dysrhythmia was clearly revealed by EEG mapping. On EEG spectral reaction mapping a suggestive aberrant displacement of the area of maximal sensory response was found. These EEG disorders were in significant relation with the psychotic syndrome observed in the respective group of patients: (a) patients with fronto-basal (temporal anterior) foci were prevalently paranoid; (b) patients with temporal lobe foci were prevalently depressive; (c) patients with sagittal line (singular) foci presented a predominantly expansive, hypomanic behaviour. The study shows the importance of normal fronto-limbic circuits for the preservation of mental health.