People with Parkinson’s disease show better motor control, longer “on” periods, and an improved quality of life when treated with a recently approved deep brain stimulation system, one-year results from a clinical trial show.
The research, “INTREPID: A Prospective, Double Blinded, Multicenter Randomized Controlled Trial Evaluating Deep Brain Stimulation with a New Multiple Source, Constant Current Rechargable System in Parkinson’s Disease,” was presented Tuesday at the 2018 American Academy of Neurology (AAN) Annual Meeting, taking place through April 27 in Los Angeles.
Deep brain stimulation, or DBS, is a surgical procedure to treat disabling neurological symptoms in Parkinson’s, such as tremors, rigidity, stiffness, slowed movement, and walking problems. It uses a small, pacemaker-like device called a neurostimulator to deliver electrical stimulation to electrodes surgically placed in specific areas of the brain.
Although diverse clinical trials have shown DBS to be an effective adjunct Parkinson’s therapy, the degree of improvement is variable.
The INTREPID study (NCT01839396), for this reason, is specifically evaluating the safety and effectiveness of Boston Scientific‘s Vercise DBS system in people with advanced but levodopa-responsive Parkinson’s, whose symptoms are not adequately controlled by the medication. Full study results are expected after it concludes in 2021.
The Vercise DBS system, which targets the subthalamic nucleus (STN) part of the brain that is hyperactive in patients, was approved to treat motor symptoms by the U.S. Food and Drug Administration in late 2017. It works using implanted leads with eight electrodes, and allows a doctor to vary the amount of current delivered by each electrode.
Reported results from this multicenter, double-blinded study involved 292 patients at 23 U.S. medical centers. All used the STN-implanted Vercise system for 12 weeks, and were randomly assigned to either an active (medium and continuous dose) or control (low and intermittent dose) treatment group.
INTREPID’s primarily goal was changes in the duration of “on” periods, characterized by improved motor control following levodopa treatment.
Improvements in motor function and quality of life were evaluated using a Parkinson’s diary, the Unified Parkinson’s Disease Rating Scale (UPDRS), the 39-item Parkinson’s Disease Questionnaire (PDQ-39), and neuropsychological assessments. Safety was measured through reported adverse events.
Results showed that 12 weeks of treatment increased the duration of “on” periods by a mean 3.03 hours in active patients compared with those in the control group. Secondary outcomes included a 49.2% improvement in motor symptoms in UPDRS scores, and a sustained and better life quality through the patient questionnaire, Boston Scientific also reported in a company press release.
Safety data showed low rates of infection and brain hemorrhage during the implant surgery.
Overall, these findings show the “DBS system is safe and effective in the treatment of Parkinson’s disease symptoms,” the researchers wrote.
“This study meets a new level of rigor in evaluating the effectiveness of a DBS system,” Jerrold Vitek, MD, PhD, chair of neurology at the University of Minnesota Medical School and the coordinating principal investigator for INTREPID, said in the release. “The double-blind design gives us confidence that the improvements in patients on time with good symptom control, as evaluated by the diary data, are an objective measure of the outcomes and suggests patients will benefit from the Vercise System.”
The Vercise DBS system is also approved to treat Parkinson’s patients in Europe and Australia.