Scientists Re-Examine a Treatment for Parkinson's Disease

02 February 2009

VOICE ONE:

This is SCIENCE IN THE NEWS, in VOA Special English. I'm Bob Doughty.

VOICE TWO:

And, I'm Shirley Griffith. This week, we will tell about what is said to be the largest study yet of a treatment for Parkinson's disease. We will also tell about a study of young Americans and their use of social Web sites on the Internet.

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VOICE ONE:

Recently, researchers in the United States studied the effectiveness of a treatment called deep brain stimulation. It has been used for years to treat patients with Parkinson's disease. The study found that the physical condition of Parkinson's patients often improves after they receive deep brain stimulation. But brain stimulation was also shown to have more side effects than drug treatments.

Parkinson's is a disease of the central nervous system. The disease affects between five hundred thousand and one million five hundred thousand Americans. Doctors confirm about sixty thousand new Parkinson's cases in the United States each year. The disease affects a small area of cells in the middle of the brain. The cells slowly lose their ability to produce a chemical called dopamine.

The decrease in the amount of dopamine can result in one or more of the general signs of Parkinson's. These include shaking in the hands, arms and legs. They also include muscle tightness and restricted movements. Another symptom is difficulty keeping balanced while standing or walking. Medicine can help patients. Yet it can become less effective as the disease progresses.

VOICE TWO:

Deep brain stimulation uses electricity to shock the brain in areas that help send messages to the body. In Parkinson's patients, these areas of the brain can become blocked. When this happens, the messages give misinformation to the body.

Deep brain stimulation begins by doctors drilling two small holes in the head of the patient. Two thin, electrical wires are then placed in the brain. They are connected under the skin to another wire that leads to a small battery placed in the chest. The device supplies electricity.

Doctors do not know exactly how the brain stimulation works to help patients with Parkinson's. But experts believe the electrical current might help activate nerve cells that are not working correctly.

VOICE ONE:

The study involved two hundred fifty-five Parkinson's patients. It took place at thirteen medical centers across the United States between May of two thousand two and October of two thousand five. The patients kept written records of their physical abilities.

The Journal of the American Medical Association published results of the study. They showed that patients who received deep brain stimulation had better control of their symptoms than those who only took medicine. In fact, the patients who had the treatment reported an average gain of nearly five hours each day of good control of their symptoms. The average gain was zero hours for the other group.

VOICE TWO:

Deep brain stimulation is not the answer for all Parkinson's patients. Doctors say it is best for patients whose medicines cause side effects or are not working. The treatment is not new. It was first approved for use in the United States in nineteen ninety-seven. However, its effectiveness had never before been compared to that of medicines in a large study.

In the United States, Parkinson's patients can receive deep brain stimulation at about three hundred medical centers. The treatment has been performed about forty thousand times throughout the world.

But several possible side effects make the treatment risky. The side effects include pain in the head, problems speaking and slowed movement. One patient who had the surgery died. However, in many cases, the researchers found the side effects ended within six months. And, some patients said the improvements they experienced were worth the risk.

VOICE ONE:

Deep brain stimulation is also costly. It can cost as much as one hundred fifty thousand dollars. In addition, the battery placed under the skin may require a replacement. This means doctors need to perform another operation.

The company that makes the device, Medtronic, helped to pay for the study. Financial support also came from the United States Department of Veterans Affairs and the National Institute of Neurological Disorders and Stroke.

In addition to people with Parkinson's, the treatment is also being tested for patients with severe depression, lasting pain and epilepsy.

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