The study, conducted at seven Veterans Affairs and six university hospitals with participation from 299 patients, compared the 24-month results of patients assigned randomly to receive DBS via one of the two common targets in the brain – the subthalamic nucleus (STN) or globus pallidus interna (GPi).

The results of the study showed that improvement in motor function, based on the Unified Parkinson’s Disease Rating Scale (UPDRS) Part III, did not differ between the STN and GPi patient groups. Both groups experienced a significant improvement in average UPDRS motor scores at two years.

In the study, serious adverse events (SAEs) occurred in approximately half of both GPi and STN patients, with the most common SAE among both groups being surgical site infection, which occurred in less than 10% of each group. One death was reported in the study related to the surgical procedure (intracranial hemorrhage) and one GPi patient committed suicide. Ninety-nine percent of the SAEs were resolved by the 24-month study follow-up.

Tom Tefft, president of the Neuromodulation business and senior vice president at Medtronic, said: “Data collected from this study demonstrate not only the long-term efficacy of Medtronic DBS Therapy for Parkinson’s disease but also the positive impact the therapy has on patients. These results are representative of Medtronic’s commitment to provide innovative, long-term solutions for patients with chronic disease.”

Kenneth Follett, professor and chief, division of neurosurgery at University of Nebraska Medical Center, said: “These long-term data show that DBS provided sustained improvement in motor function and symptom control and increased quality of life in patients with advanced Parkinson’s disease, with no statistical difference in efficacy between the two primary surgical sites.

“Clinicians should be assured that both of the commonly used stimulation locations are equally viable targets for DBS, which has become the surgical procedure of choice for treatment of advanced Parkinson’s disease.”