The Pain in Dystonia Scale (PIDS)-Validation in Craniofacial and Upper Limb Dystonia
Mov Disord Clin Pract. 2026 Feb 18. doi: 10.1002/mdc3.70560. Online ahead of print.
ABSTRACT
BACKGROUND: Pain is one of the most disabling non-motor symptoms in adult-onset isolated dystonia (AOID). The Pain in Dystonia Scale (PIDS) was developed and validated in cervical dystonia. Its applicability to other focal subtypes remains unknown.
OBJECTIVES: To validate the PIDS in patients with craniofacial and upper limb dystonia, expanding its use beyond cervical dystonia.
METHODS: We conducted a two-phase cross-sectional validation study in independent cohorts from Calgary, Canada and Italy. The Calgary pilot cohort (n = 20) included participants with craniofacial and/or upper limb dystonia who completed the PIDS twice for test-retest reliability and a battery of comparator scales. The Italian cohort (n = 109) was recruited through the Italian Dystonia Registry and completed the PIDS after cross-cultural adaptation. Internal consistency, test-retest reliability, construct validity, and distribution properties were assessed using established psychometric standards.
RESULTS: Pain was highly prevalent (90.0% Calgary; 96.3% Italy), with anatomical distribution varying by dystonia subtype. Internal consistency was high across both cohorts (Cronbach's alpha 0.82-0.96), with minimal floor and ceiling effects. Test-retest reliability in the pilot cohort was excellent (ICC = 0.85). Construct validity was supported by strong correlations between PIDS scores and established pain and quality-of-life measures. Functional impact and pain modulators were consistently reported across cohorts, with stress identified as the most frequent aggravating factor and rest and stretching as common relieving factors.
CONCLUSIONS: The PIDS demonstrates reliability, validity, and feasibility in craniofacial and upper limb dystonia, supporting its adoption for evaluating dystonia-related pain in clinical and research settings across the main focal subtypes.
PMID:41704172 | DOI:10.1002/mdc3.70560