Regional cerebral glucose metabolism in never-medicated patients with schizophrenia

Objective: The purpose of this study was to assess regional cerebral glucose metabolism in patients with schizophrenia who had never received antipsychotic medication and whose olfactory identification ability had been assessed Two hypotheses were examined First, the patients were compared with normal controls to determine whether differences in regional cerebral metabolism were apparent. Second, regional rates of metabolism were correlated with olfactory ability and the relation between them determined. Methods: The patient (n = 26) and control (n = 32) subjects were scanned at rest using position emission tomography (PET) after administration of F-18-fluorodeoxyglucose (FDG). In addition, the University of Pennsylvania Smell Identification Test was administered to each patient. Results: Patients with schizophrenia had reduced rates of glucose metabolism in the right and left thalmus that reached significance if not corrected for multiple comparisons. However, if a Bonferroni correction was applied over the 27 regions of interest. When scores were analysed using multiple regression, the left frontal cortex and the medical parietal cortex were significant predictors. Conclusions: The findings of reduced metabolism in the thalami is consistent with some of the previous literature, whereas the negative correlations between specific regions and olfactory function are not consistent with studies using activating paradigms.