Rating scales for dystonia: A multicenter assessment

Abstract

The evaluation of dystonia requires a reliable rating scale. The widely used Fahn-Marsden Scale (F-M) has not been sufficiently tested across multiple centers and investigators. The Dystonia Study Group developed the Unified Dystonia Rating Scale (UDRS) and a Global Dystonia Rating Scale (GDS) to serve as instruments to assess dystonia severity. In this study, 25 dystonia experts evaluated the UDRS, F-M, and GDS for internal consistency and reliability. One hundred dystonia patients were videotaped using a standardized videotape protocol. Each examiner rated 20 patients using the UDRS, F-M, and GDS in random order. The examiner then assessed each scale for ease of use. Statistical analysis used Cronbach's alpha, intraclass correlation coefficients (ICC), generalized weighted kappa statistic, and Kendall's coefficient of concordance. The UDRS, F-M, and GDS showed excellent internal consistency (Cronbach's alpha 0.89-0.93) and good to excellent correlation among the raters (ICC range from 0.71-0.78). Inter-rater agreement was fair to excellent (Kendall's 0.54-0.87; kappa 0.37-0.91) being lowest for eyes, jaw, face, and larynx. The modifying ratings (Duration in the UDRS and Provoking Factor in the F-M) showed less agreement than the motor severity ratings. Among scales, the total scores correlated (Pearson's r, 0.977-0.983). Overall, 74% of raters found the GDS the easiest to apply. The GDS with its simplicity and ease of application may be the most useful dystonia rating scale.

Patterns of reoccurrence of segmental dystonia after discontinuation of deep brain stimulation

“…For this study, clinical scores were assessed in the following conditions: with the stimulation on (S-On), within the first 5 min after switching off DBS (S-Off/0h), and at 2 and 4 h after switching off DBS (S-Off/2h and S-Off/4h). The standard protocol included the Unified Dystonia Rating Scale (UDRS), the Burke-Fahn-Marsden Dystonia Movement Scale (BFM), the Global Dystonia Rating Scale (GDS) 13 and a standard video protocol. All examinations were performed by EG and CB, and videos were reassessed by the whole group until agreement on the scoring was achieved.…”

Objective, computerized video-based rating of blepharospasm severity

“…Patients underwent a standardized clinical examination based in part on a protocol developed by the Dystonia Study Group, 7 modified to accommodate features of many types of dystonia as described by Yan et al, 18 and recorded with digital video at 30 frames per second. We extracted from the videos the part of the examination protocol focusing on blepharospasm (part I, steps 1-4).…”

“…Site ratings, normally conducted live by clinicians who were familiar with the patient's history, included the upper face item from the BFM 5,6 and GDRS. 7 Three movement disorders experts (M.H., H.J., J.P.), blinded to the live ratings, scored the videos using the BFM, GDRS, and JRS. 8 Interrater agreement was evaluated with the intraclass correlation (ICC), and then the 3 raters' video scores were averaged on each patient for each rating scale.…”

Thiamine Therapy for Dystonia Type 1

“…Some are given a weight (W) of 1/2, and others a weight of 1. All three are multiplied to give the adjusted score; all scores are summed to give an overall score (S) from 0 to 120 [10] Dystonia disability scale (DDS) is a tool assessing the disability provoked by dystonia in seven items, whose six are scored 0-4 and the last 0-6 (the gait assessment must consider the possible use of a wheelchair). The total score ranges from 0 to 30 [10].…”