The prevalence of pain in Huntington's disease in a large worldwide cohort.

INTRODUCTION Pain could be an unknown non-motor symptom in Huntington's Disease (HD). The aim is therefore, to study the prevalence of pain interference, painful conditions and analgesic use across the different stages of HD and compare these levels to non-HD gene mutation carriers. METHODS A cross-sectional analysis of the Enroll-HD study was conducted in premanifest, manifest HD gene mutation carriers (n = 3989 and n = 7,485, respectively) and in non-HD gene mutation carriers (n = 3719). To investigate group differences, multivariable logistic regression analysis was performed with pairwise comparisons. RESULTS In the HD mutation carriers, the overall prevalence of pain interference was 34% (95% CI 31%-35%), of painful conditions 17% (95% CI 15%-19%) and analgesic use 13% (95% CI 11%-15%). Compared to non-mutation carriers, the prevalence of pain interference was significantly higher in the middle stage of HD (33% [95% CI 31%-35%] vs 42% [95% CI 39%-45%], P = 0,02), whereas the prevalence of painful conditions was significant lower in the late and middle stage of HD (17% [95% CI 16%-18%] vs 12% [95% CI 10%-14%], 15% [95% CI 13%-17%], P < 0,01]. No significant group difference was present in analgesic use. CONCLUSIONS The prevalence of pain interference increases as HD progresses, however, the prevalence of painful conditions and analgesics do not increase accordingly. Further studies are necessary to investigate the aetiology of pain in HD and the risk for undertreatment of pain.