Altered frontostriatal relationship in unmedicated schizophrenic patients.

Positron emission tomography with [18F]-fluoro-2-deoxy-D-glucose as tracer was used to investigate frontal glucose metabolism in 15 unmedicated schizophrenic patients and 15 healthy subjects under resting conditions. Although no difference in absolute frontal cerebral metabolic rates of glucose (CMRglu) were found between schizophrenic patients and control subjects, relative measures significantly differentiated the two groups. Whole frontal metabolism and frontocaudate ratio were significantly decreased in both hemispheres in the patients. The results confirm the existence of hypofrontality in unmedicated schizophrenia and indicate disturbances in metabolic relationships between the frontal cortex and the striatum in this disorder.