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Parkinson's Disease
What Causes Parkinson's Disease?
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What is Parkinson's Disease?
What Causes Parkinson's Disease?
What are the Symptoms of Parkinson's Disease?
How is Parkinson's Disease Detected?
How Can Parkinson's Disease be Prevented?
What is the Prognosis for Parkinson's Disease?
What Does the Future Hold for Parkinson's Disease?
How Can I Help?

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The image shows the loss of dopamine in the striatum of a Parkinson's patient.

Since the disease was first described nearly 200 years ago, researchers have come to understand some of the causes of the disease. It is now known that Parkinson's disease occurs when dopaminergic neurons in the area of the brain known as the substantia nigra are destroyed. Normally these nerve cells release dopamine, a chemical that transmits signals between the substantia nigra and the corpus striatum. These signals cause muscles to make smooth, controlled movements. It is a normal aspect of aging to lose some dopamine-producing neurons however Parkinson's disease sufferers have lost anywhere from 60 to 100% of their neurons in the substantia nigra. Researchers are currently trying to determine what causes the loss of these neurons.

Researchers believe the major causes for the loss of these neurons are:

# Genetic Factors: About 15-25% of Parkinson's patients have a close relative with the disease. One study found that having two first degree relatives with the disease increases an individuals chance of having Parkinsons ten times. When Parkinson's occurs in families, the pattern of inheritance is difficult to pin down. Genes on chromosomes 4, 5, 6, 7, 8 and 17 have been linked to Parkinson's. Scientists have also found that the mitochondria of cells in the brain of some Parkinson's disease patients do not function as efficiently as normal. The majority of Parkinson's disease cases is sporadic however.

# Environmental Factors: People with exposure to herbicides and pesticides are more likely to develop Parkinson's. Certain drugs like haloperidal, chlorpromazine, metoclopramide, prochlorperazine and valproate have been linked to Parkinson's. Exposure to the toxins manganese dust and the chemical MPTP may also cause Parkinson's.

Researchers now believe that Parkinson's disease results from a combination of both genetic and environmental factors.

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What are the Symptoms of Parkinson's Disease?