Pathogenesis and pathophysiology of functional (psychogenic) movement disorders

Area of Science:

• Neuroscience
• Neurology
• Psychiatry

Background:

• Functional movement disorders (FMDs), historically termed hysteria or psychogenic disorders, present with voluntary-seeming yet involuntary movements.
• While often associated with anxiety and depression, the direct role of psychiatric disorders in FMDs remains unproven.
• Pathogenic mechanisms are unclear, though stressful events and social factors may contribute.

Purpose of the Study:

• To explore the neurobiological underpinnings of functional movement disorders.
• To differentiate FMDs from organic dystonia through neurophysiological features.
• To identify potential targets for future treatment strategies.

Main Methods:

• Neuroimaging analysis of limbic and motor network connectivity.
• Assessment of top-down motor regulation and cortical activation patterns.
• Evaluation of sense of agency and intentional binding.

Main Results:

• Strengthened limbic-motor connectivity and altered self-awareness network activation observed in FMDs.
• Decreased activation in supplementary motor areas (SMA/pre-SMA) and impaired sense of agency.
• Similarities in neurophysiological features with organic dystonia, but distinct cortical plasticity patterns.

Conclusions:

• FMDs are characterized by specific neurobiological abnormalities, including altered connectivity and motor control pathways.
• Impaired sense of agency and intentional binding are significant findings in FMDs.
• Further research into FMD pathogenesis and pathophysiology is crucial for advancing treatment.