Computed tomography in schizophrenics and normal volunteers. II. Cranial asymmetry.

We studied cranial asymmetry in 31 schizophrenics and 32 normal volunteers, all of whom were male and right-handed. Automated measures of computed tomographic (CT) scans were used to estimate global hemicranial and hemispheric ventricular volume differences. A manual method was used to measure hemicranial asymmetries between the widths of the frontal and occipital areas on CT images. The observers making the measurements were unaware of the group membership of the subjects. High reliability was established for the manual method. In contrast to findings by other investigators, no group differences were observed. Methodologic flaws in earlier studies may account for this discrepancy.