STN-DBS is a non-destructive surgical treatment for Parkinson’s, in which a battery-operated device that generates electrical impulses is implanted to specific regions of the patient’s brain. Since its implementation, it has become an accepted and effective therapeutic option to treat the motor symptoms associated with Parkinson’s and other complications caused by prolonged dopaminergic treatment in advanced forms of the disease.
However, research documenting the long-term effects of STN-DBS on the clinical state of patients with advanced Parkinson’s disease is still scarce. Now, researchers presented two studies during the IAPRD World Congress 2018, held August 19-22 in Lyon, France, where they revealed the effects of STN-DBS after long-term follow-up.
In the study, “Subthalamic deep brain stimulation for advanced Parkinson’s disease beyond the 5-year follow-up,” (abstract e-book, page 11) Russian researchers evaluated the long-term safety and effectiveness of STN-DBS in a group of patients for at least seven years after surgery.
The study enrolled 33 patients with advanced Parkinson’s disease who had undergone STN-DBS surgery with a minimum follow-up period of five years. Several parameters, including motor function, disease impact on daily activities and quality of life, were assessed using the UPDRS-2,3,4, the Schwab & England scale and the PDQ-39 questionnaire, respectively.
After a follow-up period of seven years, there was a significant improvement in patients’ motor functions (42% in UPDRS-3, 24% in UPDRS-2 and 58% in UPDRS-4), ability to perform regular daily activities (23% in Schwab & England scale) and quality of life (9% in PDQ-39 questionnaire).
In addition, researchers also found that 41% of patients who underwent STN-DBS reduced their intake of levodopa and three even completely withdrew from the medication in the course of the study.
“In advanced PD-patients, STN-DBS could provide significant improvement in OFF-state [when medications fail to suppress disease symptoms] and diminish dopaminergic medication up to seven postoperative years,” the authors wrote.
In another study, “Long-term effect of subthalamic deep brain stimulation in young- and late-onset Parkinson’s disease: 10-year follow-up study,” (abstract e-book, page 13) Korean researchers evaluated the long-term safety and effectiveness of STN-DBS in patients with young disease onset (YOPD) and compared it to those who developed the condition later (LOPD) for a follow-up period of 10 years.
The study analyzed motor symptoms (UPDRS scores) of 24 patients with advanced Parkinson’s disease (13 YOPD and 11 LOPD) who underwent STN-DBS between March 1, 2002 and March 31, 2007 at the Asan Medical Center in Seoul, South Korea.
Ten years after STN-DBS, the reduction in the scores of levodopa equivalent dose (a rough technique to compare different medications, LED) and levodopa-induced dyskinesia (measures levodopa side effects, LID) were significantly lower in YOPD compared to LOPD patients.
Levodopa-induced dyskinesia improvement remained statistically significant until five years after the surgery in both groups, but after 10 years, its severity increased substantially in LOPD patients.
However, the decrease in motor symptoms (measured by UPDRS scores), visual hallucinations and adverse effects did not differ between the two groups.
“This study shows that STN DBS showed higher effect on LED reduction in LOPD and LID improvement in YOPD at 10 years after DBS surgery. These results may have clinical implications for tailored application of STN DBS in patients with PD,” the authors wrote.
Altogether, these data suggest that STN-DBS is a long-term beneficial treatment option for patients with advanced Parkinson’s disease.