Table 1.

Commonly used rating scales for dystonia.

Scale	Feature	Interpretation	Range*
Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS)	Three subscales, assessed by clinician: (1) movement disorder severity (range 0–35) (2) disability (range 0–30) (3) pain (range 0–20)	A decrease in TWSTRS-Total or subscale score indicates an improvement in the person's dystonia. Dystonia trials frequently use TWSTRS-Total or the individual TWSTRS-Severity, TWSTRS-Pain, or TWSTRS-Disability scales as the primary outcome	0–85
Tsui scale	Clinician-assessed scale of impairment that grades severity of postural deviance (rotatocollis, antecollis, retrocollis, head tilt, and elevation of shoulder), acknowledges the presence or absence of head tremor, and includes whether the movements are continuous or intermittent		0–25
Cervical Dystonia Severity Scale (CDSS)	Uses a protractor and wall chart to rate the severity of the head's deviation from neutral in each of the three planes of motion (rotation, laterocollis, anterocollis/retrocollis)
Jankovic Rating Scale (JRS)	Includes two categories: severity and frequency, each with 5 rating classes of 0–4 points		0–8
Blepharospasm Disability Index (BSDI)	Disease-specific self-assessment scale consisting of 6 × 5-point items assessing vehicle driving, reading, watching TV, shopping, getting about on foot, and doing everyday activities	0 = no interference in these activities and 30 = severe interference	0–30
Burke–Fahn–Marsden Dystonia Rating Scale (BFMDRS)	Assessment of severity and frequency of dystonia in 9 body areas (including eyes, mouth, speech or swallowing, neck, right and left arms, trunk, and right and left legs)	0 = no dystonia and 120 = maximum severity	0–120
Writer’s Cramp Rating Scale (WCRS)	Assessment of writing posture (elbow, wrist, and fingers), movements (latency and tremor), and speed of writing	0 = no impairment and 30 = marked impairment	0–30

*Higher score indicates greater severity in all scales.