Imaging of brain activity and behavioral disorders

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Brain imaging techniques now allow measurement of metabolic variables reflecting central nervous system (CNS) energy utilization in psychiatric patients.
• These variables include regional cerebral blood flow, oxygen utilization, oxygen extraction, and glucose utilization.
• The precise relationships between these metabolic parameters, neuronal activity, and higher cortical functions are not well understood.

Purpose of the Study:

• To evaluate the significance of metabolic changes observed in brain imaging studies of psychiatric conditions.
• To differentiate between metabolic changes associated with episodic symptoms versus chronic disease processes.
• To explore the potential of advanced neuroimaging techniques for understanding psychopathology.

Main Methods:

• Review and interpretation of existing brain imaging studies measuring metabolic variables (e.g., cerebral blood flow, glucose utilization).
• Analysis of how metabolic changes correlate with specific psychiatric conditions like affective disorders and dementia.
• Consideration of the impact of episodic versus chronic disease processes on metabolic findings.

Main Results:

• Metabolic changes in affective disorders are difficult to interpret due to episodic nature and rapid response to medication, with some studies showing left or right metabolic predominance.
• Imaging studies in dementia consistently demonstrate decreased glucose utilization, particularly in the left temporal/parietal area, correlating with poor verbal performance.
• Current neuroimaging studies are in early stages but show promise for future research.

Conclusions:

• Interpreting metabolic changes in psychiatric disorders requires careful consideration of disease chronicity and symptomatology.
• Neuroimaging shows potential for identifying distinct metabolic patterns in conditions like dementia.
• Future advancements in measuring regional receptor distribution and kinetics will enhance the study of psychopathology.