Clinical associations of pain in an international facioscapulohumeral muscular dystrophy cohort.

This study aims to characterize pain in patients with facioscapulohumeral muscular dystrophy (FSHD) and determine the interactions between pain and quality of life, mental health, and physical function. We analyzed data from the prospective, international, observational ReSolve study, with primary analyses focused on baseline assessments. Of 219 patients, 83% reported having pain at baseline, most commonly located in the lower back and shoulders. Most baseline characteristics did not differ significantly between patients with and without pain or between those with higher versus lower pain severity. However, patients experiencing more pain had more self-reported psychological problems and reduced performance of resistance exercise. Multivariable linear regression models revealed that both continuous pain intensity (range 0-10) and binary pain status (yes vs. no) were associated with Patient-Reported Outcome Measures Information System (PROMIS) 57 domains: Pain intensity was associated with all domains, including physical function, anxiety, depression, fatigue, sleep disturbance, and pain interference (all p-values <0.05), whereas binary pain status was associated with worse physical function, fatigue, sleep disturbance, and pain interference. Models were adjusted for age, sex, and Clinical Severity Score. These data highlight the significance of pain and the importance of optimizing therapies to treat pain in patients with FSHD.