ASYMMETRY OF RCBF IN SCHIZOPHRENIA - RELATIONSHIP TO AP-GRADIENT AND DURATION OF ILLNESS

This article examines patients with schizophrenia and controls to dete rmine whether asymmetry and anteroposterior (AP) gradient of cerebral blood flow (CBF) are related to duration of illness, and whether they are themselves correlated. CBF was measured with the xenon-133 inhalat ion technique in 108 patients and 108 age-matched and gender-matched c ontrols while the subjects were at rest. Two sets of analyses were per formed. The first analyses indicated AP-gradient to be reduced in pati ents, and hemispheric asymmetry scores to be different from controls o nly in the temporal area. The second set of analyses were based on two groups of 27 patients, selected to represent extremes on duration of illness (less than 5 and greater than 12 years) and equal numbers of a ge-matched and gender-matched controls. These analyses revealed patien ts of both short and long duration of illness to have significantly gr eater temporal asymmetry, whereas only long-duration patients had sign ificant AP-gradient relative to both controls and short-duration patie nts. Regression analyses from each data set found AP-gradient to be re lated to duration of illness, whereas temporal asymmetry was not, temp oral asymmetry and AP-gradient were not correlated. These results sugg est AP-gradient and temporal asymmetry may reflect independent process es.