Background: Pain is a well-recognized feature of Parkinson disease (PD), which is primarily a motor disorder. In a previous study, we showed that subthalamic deep brain stimulation (STN DBS) improves pain as well as motor symptoms 3 months after surgery in PD patients.
Objective: To determine whether there is a long-term beneficial effect of STN DBS on pain in PD.
Methods: We studied 21 patients with PD who underwent STN DBS. Motor symptoms were assessed using the Unified Parkinson's Disease Rating Scale and Hoehn and Yahr staging. Pain was evaluated by asking patients about the quality and severity of pain in each body part. Evaluations were performed at baseline and at 3 and 24 months after surgery.
Results: At baseline, 18 of the 21 patients (86%) experienced pain. After surgery, most of the pain reported at baseline had improved or disappeared at 3 months and improved further at 24 months. The benefit of STN DBS for pain evaluated at 24 months was comparable to that with medication at baseline. At 24 months, 9 patients (43%) reported new pain that was not present at baseline. Most of the new pain was musculoskeletal in quality. Despite the development of new pain, the mean pain score at follow-up was lower than at baseline.
Conclusion: STN DBS improves pain in PD, and this beneficial effect persists, being observed after a prolonged follow-up of 24 months. In addition, in many of the PD patients new, mainly musculoskeletal pain developed on longer follow-up.