Posterior cingulate cortex hyperactivity in conversion disorder: a PET/MRI study

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Conversion disorder is characterized by neurological symptoms without a clear organic cause.
• Neuroimaging studies suggest brain abnormalities, but findings are inconsistent.
• Understanding the neural correlates of conversion disorder is crucial for diagnosis and treatment.

Purpose of the Study:

• To investigate brain metabolic activity in conversion disorder using F-18 fluorodeoxyglucose PET/MRI.
• To identify specific neural correlates associated with conversion disorder.
• To explore the role of the default mode network (DMN) in conversion disorder.

Main Methods:

• 20 patients diagnosed with conversion disorder underwent F-18 FDG-PET/MRI.
• Psychometric assessments included Hamilton Depression and Anxiety Rating Scales, Somatosensory Amplification Scale, and Somatoform Dissociation Scale.
• Brain glucose metabolism was analyzed and compared to control groups.

Main Results:

• Hypermetabolism was observed in the posterior cingulate cortex.
• Statistically significant differences in brain metabolism (z-scores) were found in most regions compared to controls.
• Absence of correlation between specific regions in the left hemisphere, contrasting with the right hemisphere, was noted.

Conclusions:

• Findings suggest the involvement of the default mode network (DMN) in conversion disorder.
• Regions associated with arousal, self-referential processing, motor intention, and self-agency may play a role.
• Abnormalities in brain metabolism provide insights into the neural underpinnings of conversion disorder.