What is Parkinson's disease?
Parkinson's disease involves symptoms including slowness of movement, stiffness of the muscles, difficultly walking, tremor (which some people refer to as shakiness) and sometimes difficulty with balance.
What causes Parkinson's disease?
We have a fairly good knowledge of what happens in the brain in Parkinson's disease. We know that a small group of cells die in a very small part of the brain. When those cells die, there's a loss of dopamine, which is a brain chemical or what we call a neurotransmitter. So the chemical basis of Parkinson's is loss of this dopamine chemical in the brain.
The part of the brain that's involved in Parkinson's is called the basal ganglia, and it helps control our movements and how we coordinate them. So when the basal ganglia doesn't work, we end up with slowness, stiffness and tremor.
How common is Parkinson's disease?
Parkinson's disease can affect all individuals and may be slightly more prominent in men. It's estimated that, at least in the United States, there's probably one million people affected with Parkinson's disease. Once you get over age 65, 1 percent (that is, 1 in 10) of people are at risk for Parkinson's disease. About 10 percent of cases occur before age 50, which we call young-onset Parkinson's disease, and of course, Michael J. Fox would be an example of someone with young-onset Parkinson's disease.