This is Bob Doughty.
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.
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
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
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
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.
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.
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.
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
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
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.
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.
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.
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.
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.
This SCIENCE IN THE NEWS program was written by Oliver Chanler.
It was produced by Cynthia Kirk. This is Bob Doughty.
And this is Steve Ember. Join us again next week for more news
about science in Special English on the Voice of America.
This Science Report is published courtesy