Schizophrenia: evidence of a subgroup with reversed cerebral asymmetry.

Normal right-handed individuals often show neuroanatomical asymmetries of the brain on computed tomography (CT), with wider right frontal and left occipital lobes. We examined the frequency of reversals of this normal asymmetry in a group of 57 right-handed, the schizophrenic patients. Compared to 80 normal right-handeders, the schizophrenics had an increased frequency of both frontal and occipital reversals. We then divided the patients on the basis of whether they had CT evidence suggestive of brain atrophy. Those without evidence of atropy had increased frontal and occipital reversals. Those with evidence of atrophy had no increase in reversals. This suggests that reversals of neuroanatomical asymmetry, and by implication abnormalities of lateralization, are relevant to a subgroup of schizophrenic patients with otherwise normal CT scans.