Altered frontostriatal relationship in unmedicated schizophrenic patients

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Schizophrenia is a complex psychiatric disorder associated with cognitive deficits.
• Frontal lobe dysfunction, or hypofrontality, is a hypothesized neurobiological correlate of schizophrenia.

Purpose of the Study:

• To investigate frontal glucose metabolism in unmedicated schizophrenia patients using positron emission tomography (PET).
• To compare metabolic activity and relationships between frontal cortex and striatum in patients versus healthy controls.

Main Methods:

• Positron emission tomography (PET) with [18F]-fluoro-2-deoxy-D-glucose (FDG) tracer.
• Assessment of absolute and relative frontal glucose metabolism in 15 unmedicated patients and 15 healthy subjects at rest.

Main Results:

• No significant differences in absolute frontal cerebral metabolic rates of glucose (CMRglu) between groups.
• Significantly decreased whole frontal metabolism and frontocaudate ratio in both hemispheres of schizophrenic patients.
• Relative metabolic measures effectively differentiated patients from controls.

Conclusions:

• Confirms the presence of hypofrontality in unmedicated schizophrenia.
• Suggests metabolic disturbances in the frontal cortex-striatum pathways in schizophrenia.
• Highlights the utility of relative metabolic measures in characterizing schizophrenia's neurobiology.