Emotional stimuli and motor conversion disorder.

Area of Science:

• Neuroscience
• Psychiatry
• Psychology

Background:

• Conversion disorder involves neurological symptoms linked to psychological distress.
• Amygdala reactivity to emotional stimuli differs in healthy individuals, with higher responses to negative and positive stimuli than neutral ones.

Purpose of the Study:

• To investigate the relationship between conversion disorder and emotional processing by assessing amygdala activity.
• To explore functional connectivity between the amygdala and motor preparation regions in patients with conversion disorder.

Main Methods:

• Functional magnetic resonance imaging (fMRI) study using an affective task with fearful, happy, and neutral faces.
• Comparison of amygdala activity and functional connectivity between 16 patients with conversion disorder and 16 matched healthy volunteers.
• Analysis included psychophysiological interaction (PPI) and Granger Causality Modelling (GCM).

Main Results:

• Patients with conversion disorder exhibited no valence-based differences in right amygdala activity, unlike healthy controls.
• Patients showed increased right amygdala activity to happy (and trend for fearful) stimuli, suggesting impaired habituation.
• Greater functional connectivity was found between the right amygdala and the right supplementary motor area in patients, indicating altered neural pathways.

Conclusions:

• Altered amygdala reactivity and connectivity to motor regions may underlie the pathophysiology of conversion disorder.
• Psychological or physiological stressors might trigger or worsen conversion disorder symptoms through these neural mechanisms.
• Findings highlight the role of limbic-motor pathway dysregulation in conversion disorder.