Developing a Staging Scheme for Essential Tremor: A Discussion of Organizing Principles

Area of Science:

• Neurology
• Neuroscience

Background:

• Essential tremor (ET) is a progressive neurological disorder impacting patient quality of life.
• Current ET research has advanced, yet disease staging remains an unaddressed fundamental issue.
• Staging systems are valuable tools in managing movement disorders.

Purpose of the Study:

• To highlight the value and challenges of developing a staging system for essential tremor.
• To organize a discussion on potential steps for creating an ET staging system.

Main Methods:

• Reviewing characteristics of diseases with established staging schemes.
• Analyzing ET features that support staging, including premotor phase, onset, tremor progression, and associated conditions.
• Examining pathological changes in the cerebellum during ET progression.

Main Results:

• ET exhibits features amenable to staging: premotor phase, insidious onset, tremor progression, and increased risk of Parkinson's and Alzheimer's diseases.
• Cerebellar pathological changes show an ordered evolution: Purkinje cell compromise, repair/regeneration, and cell death.
• Challenges include the lack of a definitive biological marker and an "end stage" for ET.

Conclusions:

• A staging system for essential tremor would be highly valuable for clinical practice and research.
• Initial thoughts on structuring an ET staging system are provided.
• Further development is needed to overcome current challenges in ET staging.