The Essential Tremor Rating Assessment Scale

Abstract

The Essential Tremor Rating Assessment Scale was developed by the Tremor Research Group (www.tremorresearchgroup.org) to quantify essential tremor severity and its impact on activities of daily living. This scale requires only a pen and paper, and can be completed in about 10 minutes. Upper extremity action tremor is the main focus of this scale, but action tremor is also assessed in the head, face, voice, and lower limbs. The scale has excellent face validity, inter-and intra-rater reliability, and sensitivity to change. The activities of daily living section correlates strongly with the performance section, and this scale also correlates strongly with transducer measures of tremor and with the Fahn-Tolosa-Marín tremor rating scale. In the Fahn-Tolosa-Marín tremor rating scale, upper extremity tremor greater than 4 cm corresponds to a maximum rating of 4, while grade 4 tremor in the Essential Tremor Rating Assessment Scale corresponds to an amplitude greater than 20 cm. Therefore, the Essential Tremor Rating Assessment Scale is better suited for assessment of severe essential tremor.