External Factors Modulating Pain and Pain-Related Functional Impairment in Cervical Dystonia.

Background: Little is known about factors modulating pain and pain-related functional impairment in isolated cervical dystonia (CD).

Objective: The aim was to assess the prevalence and interrelationship between pain-modulating factors and pain-related determinants of functional impairment and quality of life in CD.

Methods: We analyzed pain-aggravating and pain-relieving external factors, the degree of pain-related functional impact on routine activities, and the relationship between these and pain severity, using cross-sectional data collected using the Pain in Dystonia Scale (PIDS) from 85 participants with CD. Pairwise correlation analyses and age- and sex-adjusted linear regression models estimated the relationship between pain-modulating factors and pain severity, and the impact of pain severity, dystonia severity, and psychiatric symptoms on pain-related functional impairment and disease-specific quality of life (measured using the Craniocervical Dystonia Questionnaire-24).

Results: Stress and prolonged fixed position were the most frequent and impacting pain triggers, with women reporting larger impact. The average impact of pain-relieving factors was lower than that of pain triggers. Physical exercise and social gatherings were the most impacted activities by pain in CD. The intensity of external modulating factors was a predictor of pain severity. Severity of pain, CD, and psychiatric symptoms independently predicted pain-related functional impairment, whereas quality of life was predicted by pain severity, pain-related functional impairment, and psychiatric symptom severity, but not dystonia severity.

Conclusion: The PIDS provides insight into external modulation and functional impact of pain in CD. The pattern of external modulation of pain in CD is in line with a multifactorial modulation and complex physiology.