Pain intensity on and off levodopa in patients with Parkinson's disease

Pain is frequently reported by patients with Parkinson's disease (PD). In this study, intensity of pain as measured by a visual analogue scale (VAS) was assessed on and off levodopa in 15 patients with PD. All patients had motor fluctuations and suffered from pain of various types. Description of pain was assessed with the McGill pain questionnaire. Ratings for pain intensity on the VAS were increased during off period for all patients but one (P = 0.001). There was a correlation (P = 0.04) between changes in motor performance (Unified Parkinson's Disease Rating Scale part III) and pain intensity (VAS). Compared with a historical sample of subjects with different pain syndromes without PD, terms related to fear and punishment were used more frequently by patients with PD in this study. In two patients, pain was exclusively limited to the off period. The majority of subjects suffered from secondary pain possibly related to lumbar osteoarticular degeneration. Secondary pain was relieved but not completely abolished by levodopa. The results of this study suggest that aggravation of secondary pain should be considered as a part of the spectrum of nonmotor off symptoms. Analgesics should not be given as first line drugs when pain occurs or increases in off conditions, and pain can be significantly alleviated or abolished by adjustments of dopaminergic medication.