New research finds that for patients with Parkinson disease, subthalamic nucleus deep brain stimulation (STN DBS) either improves pain or eliminates pain eight years after surgery.
However, a majority of patients will develop new pain, of lesser intensity and mostly musculoskeletal in origins.
The findings are reported online in JAMA Neurology.
Pain is a common non-motor symptom in patients with Parkinson disease and it negatively impacts quality of life.
In the new study, Beom S. Jeon, M.D., Ph.D., of the Seoul National University Hospital, Korea, and coauthors evaluated the long-term effect of STN DBS on pain in 24 patients with Parkinson disease who underwent STN DBS.
Assessments of pain were conducted preoperatively and eight years after surgery.
Of the 24 patients, 16 (67 percent) experienced pain at baseline when not taking their medication and had an average pain score of 6.2, on a scale where 10 was maximal pain.
All baseline pain improved or disappeared at eight years after surgery, according to the results. However, the authors discovered new pain developed in 18 of 24 patients (75 percent) during the eight-year follow-up.
New pain impacted 47 body parts and the average pain score for new pain was 4.4. In most of the patients (11), new pain was musculoskeletal characterized by an aching and cramping sensation in joints or muscles, the authors note.
“We found that pain in PD [Parkinson disease] is improved by STN DBS and the beneficial effect persists after a long-term follow-up of eight years.
In addition, new pain developed in most of the patients during the eight-year follow-up period. We also found that STN DBS is decidedly less effective for musculoskeletal pain and tends to increase over time. Therefore, musculoskeletal pain needs to be addressed independently,” the study concludes.
The new study clarifies that new pain arising years after the procedure is common.
Researchers believe “this underscores the importance of performing future trials with larger cohorts, longer observational periods and standard methods to enable effective interpretation of outcomes. For now, we have learned that STN DBS does not take the ouch out of PD in the long run.”
Source: JAMA Neurology