What is Parkinson’s disease?
Parkinson’s disease is a progressive nervous system disorder characterized by tremors, muscle stiffness, and bradykinesia (slowness of movement).
The area of the brain that regulates movement, called the substantia nigra, has a concentration of cells that produce dopamine. Dopamine acts as a neurotransmitter, carrying signals to other parts of the brain to control movement. In Parkinson’s disease, these cells degenerate and produce less and less dopamine. When between 60% and 80% of these cells are damaged, the motor symptoms of Parkinson’s appear and the patient is increasingly unable to regulate movements and emotions.
Experts do not know what causes Parkinson’s. Most people do not develop the disease until they are over 60 years old. It is possible that exposure to environmental toxins might be responsible; some cases suggest a hereditary factor.
According to the American Parkinson’s Disease Association, approximately one million Americans suffer from Parkinson’s. The disease is the second most common neurodegenerative disorder in the country, following Alzheimer’s, and currently the 14th leading cause of death across all age groups.