Cerebellar involvement in essential tremor with and without resting tremor: A Diffusion Tensor Imaging study

Area of Science:

• Neurology
• Neuroimaging
• Neuroscience

Background:

• Essential Tremor (ET) is a neurological disorder with a poorly understood pathophysiology.
• While cerebellar neurodegeneration is implicated in ET, its role in the resting tremor (rET) subtype is unclear.
• Investigating cerebellar microstructure is crucial for understanding ET subtypes.

Purpose of the Study:

• To evaluate cerebellar microstructure in patients with ET, specifically comparing those with (rET) and without resting tremor (ETwr).
• To compare these findings with healthy controls (HC) using Magnetic Resonance Diffusion Tensor Imaging (DTI).

Main Methods:

• Studied 67 ET patients (29 rET, 38 ETwr) and 39 age-matched HC.
• Utilized DTI to measure fractional anisotropy (FA) and mean diffusivity (MD) in cerebellar white matter (WM) and grey matter (GM).
• Analyzed data for the entire cerebellum and individual hemispheres.

Main Results:

• Significantly higher mean diffusivity (MD) in the cerebellar grey matter (GM) of the total ET group compared to HC (p=0.0027).
• ETwr patients showed significantly higher cerebellar GM MD than HC (p=0.0017), while rET patients showed a trend (p=0.067).
• No significant differences in cerebellar white matter (WM) MD or FA values were found across groups.

Conclusions:

• Cerebellar microstructural changes are present in ET patients.
• rET patients exhibited intermediate MD values, suggesting shared pathophysiological mechanisms with ETwr but also indicating that cerebellar involvement alone may not fully explain rET.
• Other neural networks beyond cerebellar pathways likely contribute to the pathophysiology of rET.