Estimating Disability in Patients with Essential Tremor: Comparison of Tremor Rating Scale, Spiral Drawing, and Accelerometric Tremor Power.

Abstract

Although performance rating scales, spiral drawing, water pouring, and accelerometry are commonly used to assess tremor severity, the extent to which their results correlate with impairment in activities of daily living (ADL) remains unclear. The aim was to identify the most effective predictors of ADL in essential tremor (ET). Forty ET patients were examined using The Essential Tremor Rating Assessment Scale (TETRAS), spiral drawing, volume of water spilled, and accelerometric tremor power. Root-mean-square error, R2, and F-test were calculated for models predicting TETRAS ADL subscore. TETRAS Performance Subscale explained the variability in TETRAS ADL with an R2 value of 0.686. Models incorporating spiral rating and accelerometric tremor power (R2 = 0.731) and water spillage volume (R2 = 0.756) were not statistically superior. TETRAS performance subscore predicted nearly 70% ADL impairment in ET patients. Incorporating the spiral rating, accelerometric tremor power, and water pouring test did not enhance ADL estimation.