CT abnormalities in schizophrenia. A preliminary study of their correlations with P300/P200 electrophysiological features and positive/negative symptoms.

Computed tomographic scans were scored blindly for the size of cerebrospinal fluid spaces in a group of nine medicated schizophrenics and a group of nine age-matched normal volunteers without psychiatric or medical problems. Overall, ten of the 18 computed tomography (CT) features measured were significantly enlarged in the schizophrenic group. These abnormal CT features were then correlated with electrophysiological and clinical measurements performed on the schizophrenic patients. Left sylvian fissure enlargement, thought to reflect temporal lobe tissue loss, was highly correlated with a left temporal scalp region feature of the auditory P300 measure (T3 electrode) that differentiated schizophrenics and normals, and both the left sylvian fissure enlargement and the P300 measure were highly correlated with positive symptoms (total score on the Scale for the Assessment of Positive Symptoms). Frontal superficial (cortical) sulcal enlargement was prominent in the schizophrenic group and was highly correlated with another electrophysiological measure, auditory P200, at left central scalp locations. There was no significant correlation between left sylvian fissure and frontal sulcal enlargement within the schizophrenic group, and intercorrelations between CT variables in the schizophrenic group were, in general, less significant than in the control group. Although we should be cautious about generalizability because of the small number of patients, these data are compatible with the hypothesis that different subgroups of schizophrenic pathological features are characterized by different CT, electrophysiological, and clinical presentations.