The association between Parkinson's disease motor impairments and pain

Objective: This study aimed to: 1) examine the severity and frequency of pain and the extent to which pain interferes with work and 2) explore the contributions of motor impairments to pain in people with Parkinson's disease (PD). Method: Pain severity, frequency and the impact of pain on work were determined using subscores from the SF-36^TM, Parkinson's Disease Questionnaire and SF-12v2^TM, respectively, in 231 people with Parkinson's disease. Motor impairments were measured using the Unified Parkinson's Disease Rating Scale. Freezing of gait was determined as its presence or absence in the last month. Associations between impairments and pain were examined using logistic regression. Results: Pain was reported by 187 (81%) participants, with 91 (39%) reporting pain of moderate severity or worse. Pain interfered with work to some extent in 158 (68%) participants. After adjusting for age and gender, increased rigidity was associated with higher pain frequency and more pain that interfered with work (for both models, Odds Ratio=1.14, 95% confidence interval 1.0-1.3). Tremor was not associated with any measures of pain and motor impairments were not associated with pain severity. Conclusions: Most people with PD experience pain at least monthly and pain interferes with daily activities. PD impairments are associated with more frequent pain and pain that interferes with work, with rigidity having the strongest association. Development of Parkinson's disease-specific pain assessments and further investigation into the association between PD impairments and pain is warranted.