A blind, controlled study of occipital cerebral asymmetry in schizophrenia.

In a computed tomography (CT) study, scans from 45 schizophrenic patients on an acute treatment research ward and 62 headache control subjects were blindly compared. A reliable two-dimensional measure of occipital asymmetry did not detect any differences between the two groups. Within the patient sample, however, both a correlational and group analysis indicated that absence of normal left occipital asymmetry was associated with greater psychopathology on measures of quality of interview, incomprehensibility, and auditory hallucinations. Other clinical variables including age, years of illness, previous hospitalizations, childhood adjustment, and therapeutic response to neuroleptics were not found to be related to occipital asymmetry. A relationship between absence of normal asymmetry and abnormalities of language and communication is hypothesized. Furthermore, since the original studies that noted an increased frequency of reversed asymmetry in schizophrenic patients studied populations with a very high frequency of other CT abnormalities (e.g., enlarged lateral ventricles) and this study did not, the importance of defining the relevant characteristics of schizophrenic patients with reversed occipital asymmetry is emphasized.