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A new study claims that deep brain stimulation might be helpful for a lot of people suffering from Parkinson's disease.

Deep brain stimulation is a treatment that involves surgical implantation of wires in the brain which deliver an electrical current. A study has found that the treatment could improve motor functions for at least three years in people with advanced Parkinson's disease.

The study, authored by Frances Weaver, director of the Center for Management of Complex Chronic Care at the Hines VA Hospital, Illinois, is the longest-running study that has compared the effects of brain stimulations in two different areas which are the most common sites for implantation.

For the study, 159 patients with Parkinson's disease were divided into two groups by the researchers and were assigned to get deep brain stimulation in one of the two areas of the brain- subthalamic nucleus (STN) and globus pallidus interna (GPi). STN is the interior area of the brain while GPi is less studied and is the exterior area of the brain.

All the participant patients were on at least one medication for the disease, the most common being levodopa.

The progress of the patients was studied for 36 months after the implants.

The results revealed that the patients of both the groups showed similar improvements in the symptoms of the disease such as tremors, muscle rigidity and speech, and continued to show the improved symptoms for 36 months after the surgery.

"We've demonstrated that either [area] improves motor function," said study author Frances Weaver. "There was primarily a focus on stimulating the STN area because stimulating that area could reduce the amount of medication that an individual was taking for Parkinson's," Weaver explained.

Also, according to the authors, there is more evidence of long-term benefits of STN than GPi stimulation. A study in 2010 revealed that in a small group of patients, motor improvements associated with STN stimulation were found to be continued for up to 10 years.

However, Weaver said: "Our data really suggest that [health care] providers should think about both targets and what else is going on and not just arbitrarily pick one over the other."

The results revealed that patients who received GPi stimulation showed more improved conditions than the STN group.

"You would expect some decline because the disease progresses over time, but what we saw was that that didn't seem to happen with GPi," Weaver said.

"It was a surprise, at least to me, that the GPi group did as well as the STN group," said Dr. Mark Stacy, a professor of neurology at Duke University Medical Center in Durham, N.C, who generally targets the STN site in his practice. "This further suggests that there is more reason to look into the GPi site on the long term."

The possible explanation by Weaver for better improvement in patients with GPi stimulation is that perhaps a GPi stimulation works on a larger area of the brain than STN, or that may be it has some off-site effects.

No emotional improvement was seen in patients, three years after implants.

The study was published online June 20 in Neurology. An abstract of the study can be read here.