It has long been hypothesized but never proven that an organic brain injury early in life could predispose to schizophrenia. One approach to this question is to search for a correlate of brain pathology that itself could be relegated in time to early development. Skull growth is approximately 75% completed by 2 years of age with the final period of rapid growth occurring at puberty. Since brain and cranial development are closely linked, if pathology to the brain occurred early enough in life, it could conceivably affect skull architecture. The occipital bone depth (OBD) and the occipito-median angle (OMA) were assessed bilaterally in the CT scans of 50 chronic schizophrenics (DSM-IIIR) and the asymmetry index (AI) (R-L/R + L x 100) was computed. The chief findings of the study are that in patients with schizophrenia: 1) occipital skull asymmetry appears to be a marker which covaries with parenchymal brain asymmetries; 2) the mean OBD asymmetry index for the 50 patients with schizophrenia in our study was not significantly different from that of 35 normal control subjects described in an earlier study; 3) The right temporal lobe was wider in a large majority of our subjects; 4) The left occipitopetalia was more prominent and the left parieto-occipital lobe wider in most of the patients. Both a relatively wider right parieto- occipital area and a more protuberant right occipito-petalia were associated with crossed dominance in this sample; and 5) Positive OBD asymmetry indices (flatter left occipital bone) correlate with increased prefrontal cortical markings.
