Deep brain stimulation can delay tremors in early Parkinson’s

DBS was earlier prescribed only for patients who are at an advanced stage of the disease

Deep brain stimulation (DBS) may slow the progression of tremor for early-stage Parkinson’s disease patients.

A Vanderbilt University Medical Center study released in the June 29 online issue of Neurology®, the medical journal of the American Academy of Neurology has provided first evidence of the efficacy of DBS.

DBS is the first treatment that raises the hope of slowing the progression of one of the cardinal features of Parkinson’s. However a larger-scale clinical trial across multiple investigational centers is needed to confirm the finding. Parkinson’s Disease is a disease of the nervous system associated with rest tremors that tend to become worse when the patient tries to do any voluntary muscle movement.

“The finding concerning tremor progression is truly exceptional,” said senior author David Charles, MD, professor and vice-chairman of Neurology. “It suggests that DBS applied in early-stage Parkinson’s disease may slow the progression of tremor, which is remarkable because there are no treatments for Parkinson’s that have been proven to slow the progression of any element of the disease.”

FDA has approved Vanderbilt to lead a large-scale, Phase III multicenter study that will enroll 280 people with very early-stage Parkinson’s disease, beginning in 2019

Patients in the Vanderbilt study were randomized to receive DBS plus drug therapy or drug therapy alone; the drug therapy alone group was seven times more likely to develop new rest tremor after two years in comparison to the DBS plus drug therapy group.

The trial, which began in 2006, was controversial because it recruited patients with early-stage Parkinson’s disease for DBS brain surgery. At that time, DBS was approved for only advanced-stage Parkinson’s disease when symptoms were no longer adequately controlled by medication.

“Since this was the first early DBS trial, it was unknown whether there were individual motor symptoms very early in Parkinson’s disease that may be more potently improved by DBS,” said lead author Mallory Hacker, PhD, research assistant professor of Neurology.

The post hoc analysis showed that 86 percent of the drug therapy patients developed rest tremor in previously unaffected limbs over the course of the two-year period. New rest tremor occurred in only 46 percent of patients who had received DBS therapy in addition to drug therapy. Four of the DBS patients had rest tremor improvement and rest tremor completely disappeared from all affected limbs for one DBS patient.

The FDA has approved Vanderbilt to lead a large-scale, Phase III multicenter study that will enroll 280 people with very early-stage Parkinson’s disease, beginning in 2019. Seventeen other U.S. medical centers have joined the DBS in Early Stage Parkinson’s Disease Study Group to participate.