Diffusion tensor imaging of white matter involvement in essential tremor

Area of Science:

• Neuroimaging
• Neurology
• Movement Disorders

Background:

• Essential tremor (ET) is the most prevalent movement disorder.
• The underlying pathophysiology of ET, particularly white matter involvement, remains incompletely understood.

Purpose of the Study:

• To investigate white matter integrity in ET patients using diffusion MRI.
• To identify specific brain regions and networks affected by white matter changes in ET.

Main Methods:

• Diffusion MRI scans were acquired from ET patients and control subjects.
• Analysis included region of interest (ROI)-based statistics, voxel-wise analysis (SPM5), and tract-based spatial statistics (TBSS).
• Fractional anisotropy (FA) and mean diffusivity (MD) were measured to assess white matter integrity.

Main Results:

• ROI analysis revealed increased MD and reduced FA in the inferior cerebellar peduncles (ICP) of ET patients.
• Whole-brain TBSS analysis showed widespread increased MD in motor and nonmotor white matter tracts, predominantly in the left parietal lobe.
• No significant differences in gray or white matter density were detected via VBM analysis.

Conclusions:

• The findings provide evidence for white matter alterations in ET, supporting the cerebellum's role in tremor generation.
• Widespread changes in white matter integrity suggest involvement of both motor and nonmotor networks in ET.
• The etiology of the observed diffusion tensor imaging (DTI) changes in ET requires further investigation.