EVENT-RELATED POTENTIAL ABNORMALITIES CORRELATE WITH STRUCTURAL BRAINALTERATIONS AND CLINICAL-FEATURES IN PATIENTS WITH CHRONIC-SCHIZOPHRENIA

Patients with schizophrenia appear to have abnormalities in both brain structures and information processing. Several recent reports have su ggested that correlations exist between such measures. We examined the volume of several brain regions using magnetic resonance imaging (MRI ), and also assessed both information processing, using brain event-re lated potentials (ERPs), and clinical symptomatology in sixteen medica ted patients with schizophrenia. Subjects were tested using auditory a nd visual discrimination tasks. From the ERPs elicited by stimuli pres ented with relative probabilities of 0.1, the N100, N200, and P300 com ponents were identified and measured. All subjects also had MRI scans that included 12 contiguous coronal sections, each 1 cm thick. From th ese scans, the following structures were identified and the volume or area quantified: third ventricle, lateral ventricles (partial), amygda la and hippocampus (one slice), partial brain volume (in one slice thr ough the parietal lobe), and total prefrontal and temporal lobe gray a nd white matter in both cortical regions. Significant correlations wer e found between hippocampal area and the amplitude of the auditory and visual N200, and between the right hippocampus and the visual P300. L ower but significant correlations were seen between auditory P300 and measures of left temporal lobe structures. Auditory P300 amplitude cor related inversely with positive symptoms of schizophrenia. These preli minary results suggest that the ERP abnormalities in patients with sch izophrenia are associated with temporal lobe pathology.