Symptom-severity-related brain connectivity alterations in functional movement disorders

Area of Science:

• Neuroscience
• Neurology
• Medical Imaging

Background:

• Functional movement disorders are common causes of neurological disability with varied motor symptoms.
• Functional weakness is one such manifestation, but its underlying brain mechanisms remain unclear.

Purpose of the Study:

• To investigate brain connectivity alterations associated with functional weakness.
• To identify specific brain regions and network changes involved in functional weakness using functional MRI.

Main Methods:

• Task-free functional MRI was conducted on 48 patients with functional movement disorders (28 with functional weakness) and 65 healthy controls.
• Network centrality was analyzed using global correlation, eigenvector centrality, and intrinsic connectivity approaches.
• Motor symptom severity was assessed and correlated with network centrality measures.

Main Results:

• Significant differences in network centrality were observed in the left temporoparietal junction and precuneus between patients with and without functional weakness.
• Patients with functional weakness exhibited increased centrality in these regions compared to controls.
• A positive correlation between motor symptom severity and network centrality was found in these regions, specific to functional weakness.

Conclusions:

• The temporoparietal junction and precuneus are identified as key brain regions with altered connectivity in functional weakness.
• These regions are proposed as potential targets for phenotype-specific non-invasive brain stimulation therapies.