Interrater reliability of Tremor Characterization

Tremor is a repetitive movement with multiple subtypes requiring accurate characterization for diagnosis and treatment. A research team developed the Tremor Waveform Morphology Questionnaire (TWMQ) and analyzed video recordings of 34 individuals with upper-extremity tremor during various tasks with simultaneous sensor measurements. Movement disorder experts rated tremor presence, shape, symmetry, regularity, and rhythmicity. Results showed high agreement for tremor presence and symmetry, while characteristics such as jerkiness, rhythmicity, and amplitude stability showed lower reliability. Analysis revealed that amplitude primarily influenced assessment of tremor presence and diagnosis, while frequency variability determined ratings of rhythmicity. The study concluded that objective definitions based on amplitude and frequency variability could improve the reliability of tremor characterization.