Electrical impulses delivered to two areas of the brain that control movement alleviate the symptoms of Parkinson’s disease more effectively than drugs alone, according to a study in Thursday’s New England Journal of Medicine.
About 1 million people in the United States suffer from Parkinson’s, a movement disorder that makes limbs rigid and can produce body tremors. Drugs help keep the symptoms at bay, but not completely, and not always over the long term.
“In carefully selected patients, neurostimulation of the subthalamic nucleus is a powerful treatment that alleviates the burden of advanced Parkinson’s disease,” wrote the team, led by Gunther Deuschl of Christian Albrechts University in Kiel, Germany.
Twenty-one of the study’s 38 authors, including Deuschl, listed financial ties to Medtronic Inc., whose Activa brand of deep brain stimulation therapy was tested in the study.
Earlier studies have shown that using implanted electrodes to apply high-frequency electrical stimulation to the brain can improve symptoms. But questions have lingered over whether the technique works better than drugs, or if the surgery involved in implanting the electrodes is worth the risk.
One of the patients in the study died from complications of surgery, which costs $50,000 to $60,000.
The study included 156 volunteers from 10 medical centers in Germany and Austria.
After six months of treatment, patients who received electrical stimulation and drug therapy had a 25 percent improvement in symptoms. The 78 who received drug treatment alone had no improvement.
“The greatest improvement occurred in activities of daily living,” the researchers wrote. They found that the average amount of time that Parkinson’s rendered patients immobile each day declined from 6.2 hours without brain stimulation to 2 hours with it.
“The patients who received neurostimulation had longer periods [without involuntary muscle movements] and better quality of mobility,” the researchers concluded.
Three patients who received the electrical stimulation died — one from surgery, one from suicide and one from pneumonia. There was one death in the medication-only group. The cause was a traffic accident where the patient was driving during a psychotic episode.