Chronic Pain in Parkinson's Disease: Prevalence, Sex Differences, Regional Anatomy and Comorbidities.

Objective: Chronic pain is prevalent among people living with Parkinson's disease (PD). We analyzed data from 10,631 Australian individuals with PD to assess the prevalence, age and sex differences, severity, anatomical distribution, clinical history, and associated factors.

Methods: We analysed data from 10,631 participants with PD enrolled in the Australian Parkinson's Genetics Study (APGS), an ongoing nationwide cohort. Participants completed an online or paper-based questionnaire assessing sociodemographic factors, PD-related variables, and chronic pain characteristics. Chronic pain was defined as pain persisting for more than 3 months and occurring most days or daily. Statistical analyses included descriptive statistics, correlation analyses, and group comparisons using chi-squared tests, Fisher's exact tests, and independent samples t-tests.

Results: Two-thirds (66.2%) reported chronic pain, with females experiencing higher prevalence (70.8%) and severity (4.7 vs. 4.3 on a 10-point scale). Common pain sites included the buttocks (35.6%), lower back (25.4%), neck (19.4%), and knees (17.2%). Chronic pain was strongly linked to comorbid depression, sleep disorders, and osteoarthritis (p < 0.05). Environmental exposures such as pesticides, heavy metals, and alcohol were associated with higher pain prevalence, especially in males (p < 0.05).

Interpretation: These findings emphasise the substantial burden of chronic pain in PD, highlighting sex differences and strong links to multimorbidity. Further research is warranted to clarify sex-specific treatments and identify novel therapeutic targets.