Exploring Interrater Disagreement on Essential Tremor Using a Standardized Tremor Elements Assessment.

Area of Science:

• Neurology
• Movement Disorders
• Clinical Diagnostics

Background:

• Upper limb action tremor patients often present with additional neurological signs of unclear significance.
• Current clinical interpretations of these signs vary, leading to poor interrater agreement on final diagnoses.

Purpose of the Study:

• Introduce the Standardized Tremor Elements Assessment (STEA) as a tool to assess clinical signs in tremor patients.
• Determine interrater agreement using STEA and identify signs contributing to diagnostic disagreements.

Main Methods:

• Three tremor specialists and one dystonia specialist evaluated 59 videos of upper limb action tremor patients using STEA.
• Calculated interrater agreement for both the final diagnosis and individual STEA items.

Main Results:

• Higher interrater agreement for final diagnosis was observed among tremor specialists compared to between tremor and dystonia specialists.
• Greater agreement was achieved for tremor-related items than for signs of dystonia.

Conclusions:

• The STEA tool successfully identified clinical signs associated with diagnostic disagreement in tremor classification.
• Future research should investigate neurological sign thresholds across subspecialties to improve tremor diagnosis.
• STEA is valuable for future studies investigating diagnostic disagreements in movement disorders.