CEREBELLAR BLOOD-FLOW IN SCHIZOPHRENIC-PATIENTS AND NORMAL CONTROL SUBJECTS

We used Xe-133 dynamic single-photon emission computed tomography (DSP ECT) to measure the resting cerebellar blood flow in 17 neuroleptic-fr ee schizophrenic and schizophreniform patients and 13 normal control s ubjects. A subset of these subjects (11 patients and 7 control subject s) additionally underwent activation studies during the Wisconsin Card Sorting (WCS) and Number Matching (NM) tests. Baseline relative cereb ellar blood flow was significantly lower in older patients than in age -matched control subjects. For absolute cerebellar flow, there was a s ignificant difference between patients and control subjects in the ove rall activation response (patients: NM 13.4% increase, WCS 15.7% incre ase; control subjects: NM 3.1% decrease, WCS 0.0% change). This differ ence was more pronounced in older subjects. Cerebral blood flow signif icantly increased during NM (patients: 21.3% increase, control subject s: 6.5% increase) and WCS (patients: 16.5% increase, control subjects: 9.7% increase). The difference in the magnitude of cerebral NM activa tion between schizophrenic patients and control subjects, although not statistically significant, may call into question the appropriateness of using NM asa control task in schizophrenic patients. Finally, we f ound no differences between the effects of WCS and NM on cerebellar or cerebral blood flow. Because of the small number of subjects in each group, the results of this study should be interpreted cautiously.