TETRAS Spirals and Handwriting Samples: Determination of Optimal Scoring Examples

Area of Science:

• Neurology
• Biomedical Engineering
• Movement Disorders

Background:

• Spiral drawings and handwriting tasks are common but subjective methods for assessing essential tremor severity.
• Current scoring criteria lack objective amplitude-based measures, leading to scoring variance.
• Standardized examples are needed to improve the reliability of these motor tasks.

Purpose of the Study:

• To establish objective scoring criteria for essential tremor assessment.
• To identify and present the best examples for each rating scale of spiral and handwriting tasks.
• To reduce scoring variance in clinical trials and practice.

Main Methods:

• Twenty-one raters from the Tremor Research Group evaluated 94 spiral and 64 handwriting samples using the TETRAS criteria.
• The mode score was determined for each sample, and a total value was calculated based on agreement with the mode.
• Samples with the highest total values were selected as the best examples for each rating.

Main Results:

• Rater agreement was generally good for spiral tasks but poor for handwriting tasks.
• Despite challenges with handwriting, excellent agreement examples were identified for all spiral and handwriting ratings.
• The study presents these best examples for all TETRAS scale ratings (0-4).

Conclusions:

• The identified best examples can serve as objective benchmarks for scoring essential tremor.
• Implementing these standardized examples is crucial for reducing scoring variance in essential tremor assessments.
• This standardization will enhance the consistency and reliability of clinical trials and practice for essential tremor.