Imaging the pathophysiology of essential tremor—a systematic review

16th June 2021

Essential tremor (ET) is one of the most common movement disorders seen in adults. However, the pathophysiology underlying ET is poorly understood, and its classification as a neurodegenerative disorder remains a matter of contention. In addition, mounting evidence indicates that alterations in the gamma-aminobutyric acid neurotransmitter system are involved in ET pathophysiology.

In an attempt to bring together current research relating to ET, this systematic review considers structural, functional, and metabolic neuroimaging studies and discusses current concepts of ET pathophysiology from an imaging perspective.

The review concludes that robust evidence exists indicating that the cerebellum plays a significant role within a multiple oscillator tremor network which underlies tremor genesis. However, the extent to which cerebellar dysfunction relies on a neurodegenerative process remains unclear. Differentiating ET from Parkinson’s disease (PD) can be challenging in the early course of the diseases. However, dopaminergic and iron imaging do not suggest a substantial overlap of ET with PD pathophysiology. In addition, limited evidence was found for alterations of the GABAergicneurotransmitter system in ET.

In light of this review, the authors suggest that in order to solve the remaining controversy of whether cerebellar neurodegeneration is the pathological foundation of ET, future studies should focus more rigorously on the demographical, genetic, and clinical heterogeneity of ET using multimodal imaging techniques with higher spatial resolution.

Original publication

Imaging the Pathophysiology of Essential Tremor—A Systematic Review