Dystonia rating scales: Critique and recommendations

Abstract

Background Many rating scales have been applied to the evaluation of dystonia, but only few have been assessed for clinimetric properties. The Movement Disorders Society commissioned this task force to critique existing dystonia rating scales and place them in the clinical and clinimetric context. Methods A systematic literature review was conducted to identify rating scales that have either been validated or used in dystonia. Results Thirty six potential scales were identified. Eight were excluded because they did not meet review criteria, leaving twenty-eight scales that were critiqued and rated by the task force. Seven scales were found to meet criteria to be “recommended”: the Blepharospasm Disability Index is recommended for rating blepharospasm; the Cervical Dystonia Impact Scale and the Toronto Western Spasmodic Torticollis Rating Scale for rating cervical dystonia; the Craniocervical Dystonia Questionnaire for blepharospasm and cervical dystonia; the Voice Handicap Index (VHI) and the Vocal Performance Questionnaire (VPQ) for laryngeal dystonia; and the Fahn-Marsden Dystonia Rating Scale for rating generalized dystonia. Two “recommended” scales (VHI and VPQ) are generic scales validated on few patients with laryngeal dystonia, whereas the others are disease-specific scales. Twelve scales met criteria for “suggested” and seven scales met criteria for “listed”. All the scales are individually reviewed in the online appendix. Conclusion The task force recommends five specific dystonia scales and suggests to further validate in dystonia two recommended generic voice-disorder scales. Existing scales for oromandibular, arm and task-specific dystonia should be refined and fully assessed. Scales should be developed for body regions where no scales are available, such as lower limbs and trunk.

Normalization of sensorimotor integration by repetitive transcranial magnetic stimulation in cervical dystonia

“…Diagnosis of dystonia was made based upon established clinical diagnostic criteria [17]. CD symptom severity was assessed using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) [18]. All CD patients were regularly treated with botulinum toxin injections.…”

Designing Clinical Trials for Dystonia

“…In the absence of a biomarker that has been validated as a surrogate for the clinical outcome, valid, reliable, and responsive instruments are needed to evaluate meaningful clinical outcomes. For dystonia, a variety of scales have been developed, yet important limitations exist, and not all types of dystonia have validated instruments [44,45]. The Burke-Fahn-Marsden Scale, Unified Dystonia Rating Scale, and Global Dystonia Rating Scale were developed to evaluate generalized dystonia, but are also used for other dystonia types [44,46].…”

“…The Tsui score [47], the Cervical Dystonia Severity Scale [48], the Cervical Dystonia Impact Profile [49], the Craniocervical Dystonia Questionnaire [50], and the Toronto Western Spasmodic Torticollis Rating Scale [51] have been developed for cervical dystonia; the Jankovic Rating Scale [52] is used for blepharospasm. These scales vary in their ease of use in the clinical setting and appropriateness for use in clinical trials [45]. The nonmotor aspects of dystonia are currently not completely assessed, and there are no validated rating scales for several dystonias, including spasmodic dysphonia, as well as task-specific, limb, oromandibular, and trunk dystonias.…”

Cervical sensorimotor control in idiopathic cervical dystonia: A cross‐sectional study

“…Disease severity was measured by the Toronto Western Spasmodic Rating Scale (TWSTRS) and Cervical Dystonia Impact Profile (CDIP‐58), two internationally used rating scales which have been proven to be valid and reliable (Albanese et al., 2013). The TWSTRS score ranges from 0 to 85, the score on the CDIP‐58 ranges from 0 to 100 with a higher score indicating a more severe form of CD.…”