(RxWiki News) Pain is a common symptom of Parkinson's disease, and for many patients, it's an everyday reality. A new procedure, however, could reduce this pain.
One type of brain surgery might help people with Parkinson’s disease who have pain, a new study found. A technique known as subthalamic nucleus deep brain stimulation (STN DBS) is used to help decrease the tremors, rigidity and muscle stiffness of Parkinson’s disease.
The authors of this study found that STN DBS relieved patients' pain both immediately after surgery and for up to eight years after that. However, many patients later developed new sources of pain — primarily in the muscles and joints.
Beom S. Jeon, MD, PhD, of Seoul National University Hospital in South Korea, led this study.
“We found that pain in PD [Parkinson's disease] is improved by STN DBS and the beneficial effect persists after a long-term follow-up of eight years," Dr. Jeon and team found. "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.”
Marcie L. Rabin, MD, a movement disorders neurologist at the Atlantic Neuroscience Institute at Overlook Medical Center in Summit, NJ, told dailyRx News that the number of patients with new pain could have been higher if they hadn't had STN DBS.
"All in all, it is possible that patients with pain could benefit from DBS," Dr. Rabin said. "However, pain is generally not a standard indication for DBS in Parkinson’s disease patients. Additional research is needed to determine if this should change. Typically pain in Parkinson’s patients is treated with various types or oral medications, depending on the type of pain it is. Physical and occupational therapies, injections of joints with steroids or muscles with botulinum toxin (Botox), and occasionally surgery are also used."
Dr. Jeon and colleagues looked at 24 patients who had received STN DBS treatment for Parkinson’s symptoms. STN DBS is a surgical technique used for people who do not respond to medications for Parkinson’s disease. The surgeon places a small battery-powered device about the size of a stopwatch under the skin near the collarbone. A wire from the device is threaded into the brain and an electrode implanted in the area of the brain that controls movement.
The device sends electric pulses from the battery to the electrode in much the same manner as a heart pacemaker. STN DBS blocks the abnormal nerve signals that cause the symptoms of Parkinson’s disease.
One advantage of STN DBS over other types of brain surgery is that the electric pulses can be adjusted, Dr. Jeon and team noted.
Prior to the surgery, patients said their pain was an average of 6.2 on a scale of 1 to 10.
All of the patients said their pain had lessened or disappeared immediately after the surgery and eight years later. At eight years postsurgery, however, 18 of the 24 patients said they had new pain.
Patients described the new pain as an aching or cramping sensation in joints or muscles. The average pain score for the new pain was 4.4 out of 10.
In an editorial about this study Pravin Khemani, MD, and Richard B. Dewey Jr., MD, wrote that, “Although there is a growing consensus that STN DBS decreases the level of pain in people with PD, the literature is mixed on the subtypes of pain that are responsive to DBS, and the study by Jung and colleagues shows that new pain arising years after the procedure is common. 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.”
The study and editorial were published March 23 in JAMA Neurology.
The Korea Health Technology R&D Project funded this research. Dr. Jeon and team disclosed no conflicts of interest.