Diffusion tensor imaging in blepharospasm and blepharospasm-oromandibular dystonia.

Area of Science:

• Neuroimaging
• Neurology
• Radiology

Background:

• Blepharospasm (BSP) and blepharospasm-oromandibular dystonia (BOM) are focal dystonias with unknown white matter (WM) abnormality patterns.
• Understanding WM changes and their clinical correlations is crucial for diagnosing and managing these conditions.

Purpose of the Study:

• To investigate WM microstructural abnormalities in BSP and BOM patients using diffusion tensor imaging (DTI).
• To explore the correlation between WM diffusion behaviors and clinical features in BSP and BOM patients.

Main Methods:

• Voxel-based analysis of DTI parameters (FA, MD, RD, axial diffusivity) comparing 20 BSP patients, 11 BOM patients, and 11 healthy controls (HCs).
• Correlation analyses between WM diffusion metrics in affected areas and clinical measures like disease severity (Jebsen-Taylor Hand Function Test) and duration.

Main Results:

• BSP patients showed reduced FA in the left cerebellum and increased MD/RD in the right lentiform nucleus and thalamus compared to HCs.
• BOM patients exhibited reduced FA in the right precuneus, increased MD in the right lentiform nucleus and insula, and increased axial diffusivity in the right insula.
• WM abnormalities in the left cerebellum (BSP) and right parietal lobe (BOM) negatively correlated with disease severity and duration, respectively.

Conclusions:

• Both BSP and BOM involve microstructural WM abnormalities in the basal ganglia.
• WM changes outside the basal ganglia may indicate phenotype-specific traits in dystonia.
• DTI parameters show potential clinical utility for assessing and monitoring disability in BSP patients.