Psychiarry Research, 39:293-301 Elsevier Electroencephalographic Sleep and Cerebral in Functional Psychoses: A Preliminary Computed Tomography 293 Morphology Study With Matcheri S. Keshavan, Charles F. Reynolds, III, Rohan Ganguli, Jaspreet Brar, and Patricia Houck Received October 31, 1991; accepted November 10. 1991. Abstract. We investigated the association between cerebral morphology as revealed by computed tomography and sleep polysomnographic findings in patients with functional psychoses. The third ventricle-brain ratios, caudate ratios, and anterior horn ratios were significantly negatively associated with sleep mainte- nance and were positively correlated with rapid eye movement (REM) latency. When the effects of illness severity were covaried out, the relation between REM latency and anterior horn ratios remained significant. Disturbances in sleep in some patients with schizophrenia and schizoaffective disorders may be related to dysfunction of forebrain structures, and may be similar to those seen in dementia. Key Words. Schizophrenia, rapid eye movement latency, polysomnography. ventricle-brain ratios, neuroradiology. There is evidence for impaired sleep maintenance, reduced slow wave sleep (SWS), shortened rapid eye movement (REM) sleep latency, and increased REM sleep in some patients with schizophrenia and schizoaffective disorders (Lairy et al., 1965; Stern et al., 1969; Jus et al., 1973; Hiatt et al., 1985; Zarcone et al., 1987). There is wide variability, however, between these studies, with some schizophrenic patients showing normal REM sleep latency and SWS (Ganguli et al., 1987); such discrepancies are presumably related to the pathophysiological heterogeneity of this disorder (Kesha- van et al., 1990b). The clinical and neurobiological correlates of the sleep electroencephalographic (EEG) findings in schizophrenia remain poorly researched. Cerebral morphological abnormalities such as enlarged lateral and third ventricles have been consistently demonstrated in a significant proportion of schizophrenic patients by computed tomographic (CT) scans (for a review, see Shelton and Weinberger, 1986). Basal forebrain structures such as the thalamic reticular formation (Moruzzi and Magoun, 1949) and the caudate nuclei (McGinty, 1985) are involved in the regulation of sleep and arousal as well as in sleep maintenance and architecture. Alterations in these Matcheri S. Keshavan, M.D., is Associate Professor of Psychiatry: Charles F. Reynolds. 111. M.D., ia Professor of Psychiatry and Neurology; Rohan Ganguli, M.D., is Associate Professor of Psychiatry and Pathology; Jaspreet Brar, M.D., is Senior Clinician; and Patricia Houck, M.S.. is Principal Senior Research Associate, Department of Psychiatry. Western Psychiatric Institute and Clinic, Pittsburgh. PA. (Reprint requests to Dr. M.S. Keshavan, Dept. of Psychiatry, Western Psychiatric Institute and Clinic. 381 I O’Hara St., Pittsburgh, PA 15213-2593, USA.) 016%1781/91/$03.50 @ 1991 Elsevier Scientific Publishers Ireland Ltd.