Tremor entities and their classification: an update.

Area of Science:

• Neurology
• Movement Disorders
• Clinical Neurophysiology

Background:

• The consensus criteria for tremor classification, proposed in 1998, are being challenged by new discoveries.
• Advances in diagnostic methods and genetic research have significantly impacted our understanding of tremor subtypes.

Purpose of the Study:

• To review significant new findings in the field of tremor.
• To illustrate how these findings affect the current definition and classification of tremors.

Main Methods:

• Literature review of recent advancements in tremor research.
• Analysis of new diagnostic techniques and genetic studies related to tremor.

Main Results:

• Essential tremor is increasingly viewed as a heterogeneous group of conditions sharing action tremor.
• Dystonic tremor is recognized as a common feature in adult-onset focal dystonia, potentially occurring without overt dystonia.
• New insights have delineated monosymptomatic asymmetric rest and postural tremor, and identified rare conditions with tremor despite normal dopamine transporter imaging.

Conclusions:

• Current knowledge necessitates a revision of tremor classification due to the complex relationship between phenomenology and etiology.
• A more cautious definition of tremors, emphasizing clinical assessment, is required.