A Primer on Parkinson's Disease
Parkinson's disease, a chronic progressive illness, is one of the medical mysteries of the 21st century. The disease belongs to a group of conditions called motor system disorders, according to the National Institute of Neurological Disorders and Stroke. Some people with Parkinson's become severely disabled, but others have only minor problems.
Scientists know this much: The disease develops when nerve cells (neurons) in an area of the brain that controls movement begin to die. The death of these cells creates a shortage of a brain-signaling chemical called dopamine. Dopamine acts as a kind of messenger, sending out signals from the brain to the muscles. As these messengers fade away, muscle movement suffers. When about 80 percent of the brain's dopamine is gone, the symptoms of Parkinson's appear.
What researchers don't understand is what causes the nerve cells to die.
Subtle symptoms
No test is currently available to confirm Parkinson's disease, which doctors usually diagnose after ruling out other ailments. The condition usually develops after age 65. Some Parkinson's symptoms, such as slowness or stiffness, are so subtle that they may be mistaken for normal signs of aging.
"It usually takes a neurologist to tell the difference and uncover some of the more specific signs of Parkinson's disease, such as the development of a tremor, small handwriting and a lowering of the voice," says Abraham Lieberman, M.D., from the Parkinson Research Foundation.
There is no cure for Parkinson's disease. Although Parkinson's affects each person differently, most patients have a slow progression of the disease over 15 to 20 years. When symptoms grow severe, doctors usually prescribe levodopa (L-dopa), which helps replace dopamine in the brain. Other drugs that affect dopamine also are available. In severe cases, a type of brain surgery called pallidotomy may be done to ease symptoms. Doctors also encourage patients to exercise to strengthen their muscles.
"The disease is treatable and most, but not all, patients can lead a reasonably good life with treatment," Dr. Lieberman says.
The facts on Parkinson's disease
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It usually shows up after age 65, but 15 percent of those diagnosed are younger than 50.
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It is slightly more common in men than in women.
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It is usually diagnosed after other diseases have been ruled out because there is no test to confirm it.
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It has no cure at this time.
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It affects patients to varying degrees.
What to look for
These are the main symptoms of Parkinson's disease:
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Tremor (shaking) of a limb, often a hand, when at rest
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Rigidity or stiffness of limbs
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Slow movement
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Stooped posture
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Difficulty with balance
Other symptoms:
Source: National Parkinson Foundation
To learn more
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National Parkinson Foundation
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American Parkinson Disease Association
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National Institute of Neurological Disorders and Stroke
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Parkinson Research Foundation