DBS and Optimal Therapy May Have Long-Term Benefit in Early Parkinson’s Disease

BALTIMORE—Deep brain stimulation (DBS) of the subthalamic nucleus, along with optimal drug therapy (ODT), produces clinically meaningful improvements in clinician-assessed motor control for at least five years in patients with early-stage Parkinson’s disease, according to a prospective pilot study. If the findings are confirmed in a phase III trial that has been approved, DBS may become a valuable method to achieve long-term improvement in motor skills in patients with Parkinson’s disease.

Mallory Hacker, PhD, Research Assistant Professor of Neurology at Vanderbilt University in Nashville, presented the latest results of a subanalysis of a randomized, controlled, single-blind clinical trial at the 141st Annual Meeting of the American Neurological Association.

Mallory Hacker, PhD

The pilot trial included 30 patients with Parkinson’s disease between ages 50 and 75 and demonstrated the safety and benefit of DBS in conjunction with ODT—which includes drugs such as carbidopa–levodopa, pramipexole, ropinirole, and selegiline—compared with ODT alone in improving motor scores of the patients through two years. The latest subanalysis of the trial data examined the effect of DBS for at least five years.

The subanalysis included 28 patients: 14 in the DBS and ODT group and 14 in the ODT-only group. Both groups were predominantly male and were similar in age (about 61) at baseline. Motor control was assessed using the Unified Parkinson’s Disease Rating Scale (UPDRS) Part III (clinician assessed) and the Hoehn and Yahr scale.

Over the five-year period, mean UPDRS motor scores progressively worsened for the ODT group, but improved for patients who received DBS. Compared with patients who received ODT only, patients who received DBS plus ODT had UPDRS improvements of 4.6 points at 1.5 years, 5.8 points at two years, 8.9 points at four years, and 10.1 points at five years.

“These results demonstrate that subthalamic nucleus DBS applied in early-stage Parkinson’s disease may provide long-term, clinically meaningful improvement in motor function over standard clinical therapy,” Dr. Hacker said.

The exact mechanism of DBS is still unknown, but evidence suggests that synaptic plasticity is involved. Results from the pilot trial led to FDA approval of a large-scale, multicenter clinical trial. Participants will be implanted with a DBS device and will receive ODT. Some subjects will be randomized to receive DBS during the first two years, along with ODT, and the remainder will receive ODT only. In the following two years, all subjects will receive DBS and ODT.

—Brian Hoyle