Patterns of cortical activity in schizophrenia

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Schizophrenia is a complex psychiatric disorder characterized by cognitive deficits.
• Cortical metabolic activity, measurable by positron emission tomography (PET), is a key area of investigation in schizophrenia.

Purpose of the Study:

• To investigate patterns of cortical glucose metabolism in patients with schizophrenia during a cognitive task.
• To identify specific brain regions and metabolic patterns that differentiate schizophrenia patients from healthy controls.

Main Methods:

• Positron emission tomography (PET) with 18F-2-deoxyglucose uptake was used in 83 schizophrenia patients and 47 healthy controls performing the Continuous Performance Test (CPT).
• The cortex was divided into 16 regions of interest per hemisphere, and factor analysis was applied to identify metabolic patterns.
• Canonical discriminant analysis was used to assess the discriminative power of identified factors.

Main Results:

• Factor analysis revealed five key metabolic patterns, including 'hypofrontality', 'parietal cortex and motor strip', and 'temporal cortex'.
• Schizophrenia patients showed significantly greater hypofrontality and higher values in the 'parietal cortex and motor strip' factor compared to controls.
• The 'hypofrontality' and 'parietal cortex and motor strip' factors effectively distinguished between schizophrenia patients and healthy individuals.
• Hemispheric asymmetry was noted in the temporal lobe, with schizophrenics showing higher left temporal lobe factor scores.

Conclusions:

• Hypofrontality is a significant pattern of cortical metabolic rate in schizophrenia.
• Parietal cortex and motor strip function may play a crucial role in the pathophysiology of schizophrenia.
• These metabolic patterns offer potential biomarkers for differentiating schizophrenia from healthy states.