Parkinson's symptoms alleviated by electrical stimulation to the brain

Aug 31 2006

A new study has shown that electrical stimulation to parts of the brain are more effective at alleviating the symptoms of Parkinson's disease than drugs alone.

A team of German researchers at Christian Albrechts University in Kiel say that for some Parkinson's sufferers the neurostimulation of the subthalamic nucleus of the brain, which controls movement, is a powerful treatment that alleviates the burden of advanced Parkinson's disease.

Figures suggest as many as 1 million people in the United States suffer from Parkinson's, which is a chronic and progressive movement disorder that causes tremors, stiffness, slowness of movements, impaired balance and coordination.

Although drugs help to control the symptoms to some extent, they are not as effective over the long term.

Lead author, Dr. Guenther Deuschl, professor of neurology and chairman of the department of neurology at the University, says deep brain stimulation improves the quality of life in patients with advanced Parkinson's disease at a stage when medical treatment is no longer able to improve quality of life.

For the study the researchers recruited 156 people with advanced Parkinson's disease, all were under 75 years old, and were randomly assigned to receive either deep brain stimulation or medications.

Deep brain stimulation entails placing a thin wire to carry electrical currents deep within the subthalamic region of the brain.

The wire is then attached to a deep brain stimulator, which sends an electrical current to that area of the brain.

This action temporarily shuts down the activities of the brain cells in that area of the brain, and blocks the abnormal signals that cause the tremors and other symptoms.

Previous studies have also shown that using implanted electrodes to apply high-frequency electrical stimulation to the brain can improve symptoms, but whether the technique worked better than drugs was questionable, or if the surgery involved in implanting the electrodes was worth the risk.

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, while the 78 who received drug treatment alone had no improvement.

The greatest improvement occurred in activities associated with daily living, 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 researchers say the patients who received neurostimulation had longer periods and better quality of mobility.

Serious adverse events were more common for the deep brain stimulation group than the medication group and three patients died, one from surgery, one from suicide and one from pneumonia.

There was one death in the medication-only group where a traffic accident occurred when the patient was driving during a psychotic episode.

It is noted that 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.

The research is published in the New England Journal of Medicine.