What Causes Parkinson's Disease?
Parkinson’s Disease Overview
Parkinson’s disease is chronic disorder of the nervous system. According to the National Parkinson Foundation, it affects about one million people. Each year, 50,000 to 60,000 new cases occur in the United States.
This disease isn’t fatal, but it can cause debilitating symptoms that impact everyday movement and mobility. Hallmark symptoms of this disease include tremors, gait, and balance problems. These symptoms develop because the brain’s ability to communicate is damaged.
Researchers aren’t yet certain what causes Parkinson’s. However, several factors contribute to the disease.
Some studies suggest that genetics play a role in the development of Parkinson’s. According to the Parkinson’s Disease Foundation, around 15 to 25 percent of people with Parkinson’s also have a relative affected by the disease.
The Parkinson’s Disease Foundation also reports that someone with a first-degree relative (such as a parent or sibling) who has Parkinson’s is at a 4 to 9 times greater risk of developing Parkinson’s than someone with no relatives affected by the disease.
So how does genetics factor into Parkinson’s in some families? Through the mutation of genes that are responsible for producing dopamine and certain proteins essential for brain function.
There’s also some evidence that one’s environment can play a role. According to the Parkinson’s Disease Foundation, exposure to certain chemicals have been linked to Parkinson’s disease, including:
- Agent Orange
Living in rural areas, drinking well water, and consuming manganese has also been linked to Parkinson’s.
However, not everyone exposed to these environmental factors develops Parkinson’s. In fact, researchers suspect that a combination of genetics and environmental factors cause Parkinson’s.
Lewy bodies are abnormal clumps of proteins found in the brain stem of people with Parkinson’s disease. Lewy bodies contain a protein that cells are unable to break down. Lewy bodies surround cells in the brain, interrupting the way the brain is able to function.
Over time, clusters of Lewy bodies cause the brain to degenerate. This causes problems with motor coordination in people with Parkinson’s disease.
Loss of Dopamine
Dopamine is a neurotransmitter, or chemical, that aids in communicating messages between different sections of the brain. The cells that produce dopamine are damaged in people with Parkinson’s disease.
The brain is unable to send and receive messages without an adequate supply of dopamine, and the transmission is disrupted. This affects the body’s ability to coordinate movement and can cause walking and balance problems.
Age and Gender
Aging also plays a role in Parkinson’s disease. According to the Parkinson’s Disease Foundation, most cases of Parkinson’s disease occur in people over age 60. Younger people rarely have the disease.
Researchers believe that the brain and dopamine function begin to decline as the body ages. This makes a person more susceptible to Parkinson’s.
Gender also plays a role in Parkinson’s. The disease more often affects men, with men one-and-a-half times more likely to develop Parkinson’s than women, according to the Parkinson’s Disease Foundation.
Some reports suggest that certain occupations may put a person at greater risk for developing Parkinson’s. According to the Parkinson’s Disease Foundation, Parkinson’s disease occurs more frequently in people who have jobs in welding, agriculture, and industrial work. This may be because individuals in these occupations are exposed to toxic chemicals. However, studies have been inconsistent and more research needs to be done.
We have some clues as to why Parkinson’s disease develops, but there’s still a lot that we don’t know. Because this disease is progressive, early detection and treatment are key in minimizing symptoms.
While there are treatments that help the symptoms, currently there is no cure. More research is needed to identify the exact role that genetics and environment play in causing this disease.
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- Causes - Parkinson's Disease Foundation (PDF). (n.d.). Parkinson's Disease Foundation (PDF) - Hope through Research, Education and Advocacy. Retrieved October 22, 2013, from http://www.pdf.org/en/causes
- Parkinson's disease: Causes - MayoClinic.com. (n.d.). Mayo Clinic. Retrieved October 22, 2013, from http://www.mayoclinic.com/health/parkinsons-disease/DS00295/DSECTION=causes
- Tanner, C. M., M.D.., & Ph.D.. (n.d.). Environmental Factors and Parkinson's: What Have We Learned? - Parkinson's Disease Foundation (PDF). Parkinson's Disease Foundation (PDF) - Hope through Research, Education and Advocacy. Retrieved October 22, 2013, from http://www.pdf.org/environment_parkinsons_tanner
- Simón-Sánchez, J. (2009). Genome-wide association study reveals genetic risk underlying Parkinson's disease. Nature Genetics, 41, 1308-1312. Retrieved October 23, 2013, from http://www.nature.com/ng/journal/v41/n12/
- What is Parkinson’s Disease? - Parkinson's Disease Foundation (PDF). (n.d.). Parkinson's Disease Foundation (PDF) - Hope through Research, Education and Advocacy. Retrieved October 22, 2013, from http://www.pdf.org/about_pd