Two syndromes of schizophrenic psychopathology associated with left vs. right temporal deficits in P300 amplitude. Four case reports.

In four schizophrenic patients, we examined the relationship between clinical course, including neuroleptic response, and the following biological and psychological measures: topography of the auditory P300 event-related potential, computerized tomography (CT), Andreasen's positive and negative symptom scales, the Thought Disorder Index, and a neuropsychological test battery. Two previous studies in our laboratory had shown that schizophrenic patients were differentiated from a matched normal control group by a left temporal scalp region deficit in P300 topography. This present report compares two schizophrenic patients with the typical left temporal P300 topography deficit with two schizophrenic patients with a right temporal P300 topography deficit. The two right temporal deficit patients had more positive symptoms, more thought disorder, more severely impaired functioning, earlier age of onset, poorer response to neuroleptic medications, more diffuse cognitive deficits on a neuropsychological testing battery, and poorer premorbid history than the two left temporal deficit patients. There was some evidence for the presence of more CT abnormalities suggestive of frontal lobe pathology in the right temporal deficit patients.