Problems and controversies in tremor classification

Area of Science:

• Neurology
• Movement Disorders
• Clinical Neuroscience

Background:

• The International Parkinson and Movement Disorder Society (MDS) revised tremor classification in 2018.
• This revision addressed essential tremor (ET), dystonia-associated tremor, and other tremor types.
• The 1998 statement was the previous standard for tremor classification.

Purpose of the Study:

• Critique the limitations of the 2018 MDS Consensus Statement on tremor classification.
• Propose specific revisions to improve tremor diagnosis and categorization.
• Enhance the understanding and clinical management of various tremor disorders.

Main Methods:

• Critical analysis of the 2018 MDS Consensus Statement.
• Review of existing literature on tremor classification and diagnosis.
• Formulation of proposed changes to tremor terminology and diagnostic criteria.

Main Results:

• Identified problems in the definition of tremor and essential tremor (ET).
• Highlighted issues with proposed terms like 'essential tremor plus' and 'orthostatic tremor plus' (OT).
• Noted the absence of a hierarchical structure for tremor classification.

Conclusions:

• Recommended redefining tremor as a symptom and essential tremor (ET).
• Advocated for incorporating severity as a key diagnostic characteristic.
• Proposed abandoning non-hierarchical terms and establishing clear classification rules for tremors.