635P Pain impacts quality of life, psychological disorders and exercise in a large international cohort of patients with facioscapulohumeral muscular dystrophy.

Facioscapulohumeral muscular dystrophy (FSHD) is one of the most common forms of muscular dystrophy. Although pain is common in FSHD, it has been less well characterized in the literature. This study aims to characterize pain in an international population of FSHD patients and to determine which factors are associated with pain and pain severity. We analyzed data from a prospective multicenter observational cohort of adult patients with FSHD, the ReSolve study, from 2018 to 2021. We compared patient-reported data, motor assessments, and the pharmacologic management of FSHD between patients with and without pain. Patient-Reported Outcome Measures Information System (PROMIS) 57 modules were analyzed for their association with pain. Of 219 patients, 83% reported pain, most commonly located in the lower back and shoulders. There were no significant regional differences in pain medication usage between patients in the USA and Europe. Analysis of PROMIS modules identified an association with the presence of pain and physical function, fatigue, and sleep disturbance. Linear regression modeling of the PROMIS scores revealed that pain intensity had a negative impact on physical function, social participation, depression, anxiety, and sleep interference. Additionally, univariate analysis found a significant association between pain and self-reported psychological problems and resistance exercise rates. Taken together, these data point to the significant impact of pain in FSHD patients and the importance of developing therapies to treat pain in FSHD. [ABSTRACT FROM AUTHOR]