Pain Characteristics and Their Relationship With Motor Dysfunction in Individuals With Parkinson Disease-A Cross-Sectional Study

Background Pain is a common symptom in Parkinson disease (PD). Objectives To analyze the relationship between pain and motor dysfunction in individuals with PD. Methods Fifty-four individuals with PD were screened: Hoehn and Yahr scale score = 2.5 (1 to 4); median (range) age in the "on" period of anti-Parkinson medication was 66 (44 to 85) years. Pain was assessed using King's Parkinson's Disease Pain Scale (KPPS) and the Brief Pain Inventory (BPI). Performance in routine activities and motor function were assessed using Unified Parkinson Disease Rating Scale (UPDRS II and III); gait was assessed using the Dynamic Gait Index; and balance was assessed using the Mini-BESTest. Results Thirty-eight participants (70.3%) reported mild to moderate pain. A positive correlation was found between the total KPPS score and performance in general activities (UPDRS II) (rho = 0.29, P = 0.04); a negative correlation was found between pain intensity (BPI intensity) and motor function (UPDRS III; rho = -0.28, P = 0.04); and a negative correlation was found between pain intensity (BPI intensity) and the bradykinesia subscore of the UPDRS III (rho = -0.29, P = 0.04). There was no correlation between pain and gait performance or balance. The musculoskeletal pain was the predominant type (in 81.5% of subjects), followed by nocturnal pain (52.6%) and fluctuation-related pain (47.3%). The most painful areas were lower limbs (33.0%) and shoulders/cervical area (31.0%). Twenty-one of 38 participants (55.3%) reported pain interference in their working and walking ability and general activities. Conclusions Pain was weakly correlated with performance in general activities and with bradykinesia but was not correlated with the remaining classic motor PD symptoms, either gait or balance performance. Pain was a prevalent symptom in the present sample, and the individuals reported its interference with functionality.