Corpus Callosum Structural Alterations in Essential Tremor with and Without Resting Tremor: A Multimodal MRI Study

Area of Science:

• Neuroscience
• Neurology
• Radiology

Background:

• Essential tremor (ET) is a prevalent movement disorder.
• ET can present with resting tremor (ET-plus subtype).
• Corpus callosum (CC) involvement is noted in ET, but differences between ET subtypes are unstudied.

Purpose of the Study:

• To investigate structural differences in the CC between ET patients with and without resting tremor (ETrt).
• To compare CC structure in ET and ETrt patients against healthy controls (HC).
• To explore potential shared pathophysiological mechanisms using multimodal MRI.

Main Methods:

• 128 participants (63 ET, 38 ETrt, 27 HC) underwent multimodal MRI.
• Evaluated CC genu, body, and splenium for thickness, mean diffusivity (MD), and fractional anisotropy (FA).
• Utilized group comparisons and unsupervised clustering analysis.

Main Results:

• Both ET and ETrt groups showed CC thickness reductions and increased MD in the body compared to HC.
• No significant structural differences were found between the ET and ETrt groups.
• Clustering analysis grouped ET and ETrt patients together, distinct from HC, indicating similar CC abnormalities.

Conclusions:

• ET patients with and without resting tremor display analogous macro- and microstructural CC changes.
• Findings suggest shared pathophysiological processes within the CC, despite clinical variations.
• CC structural integrity is altered in ET, irrespective of resting tremor presence.