White matter reduction in the parahippocampal gyrus of patients with schizophrenia.

To the Editor.— A recent postmortem study by Brown et al 1 compared morphometric measurements obtained from photographs of coronal brain slices of patients with schizophrenia and affective disorder. In the schizophrenic group, the lateral ventricles were larger, with the difference between the groups being most marked in the temporal lobe, where the temporal horn cross-sectional area was 97% larger. This difference was associated with a significantly lower average thickness of the nearby parahippocampal cortex (by 11%). The findings further emphasize the temporal lobe as a possible focus of the disease process in schizophrenia. Patients and Methods.— Histologic material stained with phosphotungstic acidhematoxylin at this anatomical level was also available from some of the same brains. Five areas of the medial temporal lobe were demarcated by specific criteria (Figure) and measured (with the diagnosis unknown) at x 10 magnification by computerized image analysis. The sample was selected as previously described