Reliability of a new scale for essential tremor

Area of Science:

• Neurology
• Clinical assessment tools
• Movement disorders

Background:

• Essential tremor is a common neurological condition.
• Accurate clinical assessment is crucial for diagnosis and management.
• Existing scales may have limitations in reliability.

Purpose of the Study:

• To evaluate the reliability of a novel scale for essential tremor assessment.
• To determine the inter- and intrarater reliability of the Essential Tremor Rating Assessment Scale (ETRAS).

Main Methods:

• The Essential Tremor Rating Assessment Scale (ETRAS) includes 9 performance items.
• Ten specialists rated videos of 44 patients and 6 controls on two occasions.
• Inter- and intrarater reliability was assessed using intraclass correlation coefficients (ICCs).

Main Results:

• High inter- and intrarater ICCs were found for head and upper-limb tremor ratings (0.86–0.96).
• Total score ICCs were also high (0.94–0.96).
• Ratings for voice, face, trunk, and leg tremor showed less robust reliability.

Conclusions:

• The Essential Tremor Rating Assessment Scale (ETRAS) is a highly reliable tool for clinical assessment of essential tremor.
• The scale shows excellent consistency for head and limb tremor evaluations.
• Further refinement may be needed for other tremor locations.