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SCIENCE IN THE NEWS – November 19, 2002: Parkinson’s Disease - 2002-11-18


VOICE ONE:

This is Bob Doughty.

VOICE TWO:

And this is Steve Ember with Science in the News, a VOA Special English program about recent developments in science. Today, we tell about Parkinson’s disease, a disorder of the central nervous system.

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VOICE ONE:

When he was elected pope in nineteen-seventy-eight, Karol Wojtyla almost immediately changed the traditional image of the leader of the Roman Catholic Church. He was known as a man who liked athletic activities. Pope John Paul the Second swam and walked great distances. He looked like an athlete, showing great energy and power in all his movements.

Boxer Muhammad Ali also showed great energy and power in all his movements as he became the boxing champion of the world. He was probably one of the greatest athletes of the twentieth century.

However, as they grew older, both men began to change. Their power and energy began to disappear. Their movements became slower. Their faces seemed to be made of stone. Although age makes all people lose the energy they had when they were younger, it was not age that changed these two men so much. Their physical changes were caused by a sickness known as Parkinson’s disease.

VOICE TWO:

Parkinson’s disease is a disorder of the central nervous system. It is a progressive disease that makes its victims increasingly unable to move. The disease affects a small area of cells in the middle of the brain called the substantia nigra. 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 or symptoms of Parkinson’s disease.

These symptoms include shaking of the arm or leg on one side of the body, general slowness of movement, or severe difficulty in moving the arms and legs. Another symptom is difficulty walking and keeping balanced while standing or walking.

Other signs observed in some people with Parkinson’s disease include restricted or decreased movement of the face. Also, victims of the disease may feel extremely sad or worried. Victims may swallow less often than normal. And they may have difficulty forming words while talking.

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VOICE ONE:

The disease is named after James Parkinson. He was a British doctor who first described the disease in eighteen-seventeen. But Doctor Parkinson did not know what caused it.

During the nineteen-sixties, medical researchers discovered chemical and other changes in the brains of people suffering from the disease. These discoveries led to medicines to treat Parkinson’s disease. However, the cause of the disease is still a mystery.

Most people have what is called idiopathic Parkinson’s disease. Idiopathic means that the cause is unknown. Patients who develop the disease attempt to link it to some cause they can identify. These can include an accident, a medical operation, or extreme emotional problems.

Most doctors, however, reject the idea of any direct link between these events or problems and Parkinson’s disease. The doctors point to other people who have similar problems and do not develop a movement disorder such as Parkinson’s disease. However, doctors say such events or problems may cause signs of the disease to be seen earlier than normal.

VOICE TWO:

Although the causes of idiopathic Parkinson’s disease remain a mystery, there are other forms of Parkinson’s disease. Some medicines used to treat other problems can cause movement disorders similar to Parkinson’s disease. These include medicines used to treat older people who see things that do not exist. And they include drugs used to treat people suffering from extreme tension or from stomach problems.

VOICE ONE:

The disease encephalitis also can cause movement problems and other disorders like those of Parkinson’s disease. In the early Twentieth Century, encephalitis spread to many parts of the world. Many victims of the disease had symptoms similar to Parkinson’s disease. This led to widespread scientific investigations into the possibility that a virus caused Parkinson’s disease. However, no evidence was found to support this theory. One clear reason for rejecting the theory is that Parkinson’s disease cannot be passed from one person to another the way other viral diseases can.

VOICE TWO:

Another common theory was that the disease could be passed by parents to their children. There are some cases of many members of families having the disease. However, there is no evidence that there is a gene linked to idiopathic Parkinson’s disease.

Most of those suffering from the disease are older people. It reportedly affects one of every one-hundred people over sixty years old. However, fifteen percent of patients develop the disease before they are fifty years old. Also, it affects men a little more often than it affects women. And Parkinson’s disease can be found among people in all parts of the world.

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VOICE ONE:

Parkinson’s disease does not usually cause death for those suffering from the condition. New treatments to ease symptoms of the disease make it possible for many patients to continue to live almost normally. Patients who have lost their ability to do many things may be able to regain some of their old abilities with treatment.

The most commonly used drug to treat the disease is levodopa. When it reaches the brain, levodopa is changed to dopamine. It replaces the natural substance dopamine, which is lacking in Parkinson’s disease patients. Although levodopa helps deal with the signs of the disease, it does not prevent more changes in the brain caused by the disease. Also, levodopa can produce bad effects in some people. These side effects include feeling extremely sick to the stomach. To prevent this from happening, other substances can be combined with levodopa.

Most other drugs used to treat Parkinson’s disease are designed to increase the amount of dopamine in the brain.

VOICE TWO:

Other methods to treat Parkinson’s disease include operating. One operation is called a pallidotomy. It was used often in the past to treat the disease. However, it was used less often after the discovery of levodopa. More recently, improved medical technology has increased the chances of successful pallidotomies. The operation involves placing electrical devices directly on the brain. These devices target cells in the areas that cause unwanted movements of the body. The most serious risk from this treatment is the possibility of the patient suffering a stroke.

VOICE ONE:

The most recent development in treatment of Parkinson’s disease is brain tissue transplants. This involves replacing tissue in areas of the brain that cause symptoms of the disease. Early experiments involved using brain tissue from unborn babies. Doctors said the method appeared to have highly successful results.

However, the experiment became a subject of moral debates among politicians and religious groups opposed to abortions, the ending of unwanted pregnancies. Researchers have begun working with genetically changed cells and different animal cells that can be made to produce dopamine.

Still, most doctors agree that such operations should be considered only after it is clear that drugs are not effective in dealing with the signs of Parkinson’s disease.

VOICE TWO:

There is no way to prevent or cure Parkinson’s disease. So, the victims of the disease need help in many ways. Also, husbands or wives, children, and friends of people with Parkinson’s disease need special help and guidance. Throughout the world, there are organizations that provide education and support services for patients and their families learning to live with the disease. As with many mysterious diseases, understanding and care can help make a major difference.

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VOICE ONE:

This SCIENCE IN THE NEWS program was written by Oliver Chanler. It was produced by Cynthia Kirk. This is Bob Doughty.

VOICE TWO:

And this is Steve Ember. Join us again next week for more news about science in Special English on the Voice of America.

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