Stability of ventricular size after the onset of psychosis in schizophrenia.

This study examined whether ventricular enlargement in schizophrenia is progressive by scanning 15 schizophrenic patients at the onset of their first psychotic episodes and again 1-3 years later. Sizes of the body of the lateral ventricles, the frontal horns, and the third ventricle were assessed. The results indicated no tendency for the ventricles to get larger in this sample, with lateral ventricular size actually showing a significant decrease across the rescanning interval when the ventricle-to-brain ratio was used as the dependent variable. Methodological issues related to computed tomography and the quantification of ventricular size were considered by developing an alternative method of calculating ventricle-to-brain ratios and examining the reliability of measurements made on a group of 11 medical patients who were scanned twice on the same day.