Understanding Parkinson’s Disease

What is Parkinson’s disease?

Parkinson’s disease PD is a neurodegenerative disorder that affects dopamine-producing neurons in a specific area of the brain called substantia nigra.

What does it do?

Symptoms generally develop slowly over years. The progression of symptoms differs from one person to another due to the diversity of the disease. People with PD may experience:

• Tremor, mainly at rest and described as pill rolling tremor in hands. Other forms of tremor are possible
• Slowness of movements (bradykinesia)
• Limb rigidity
• Gait and balance problems

In addition to movement-related (motor) symptoms, Parkinson’s symptoms may be unrelated to movement (non-motor).People with PD are often more impacted by their non-motor symptoms than motor symptoms. Examples of non-motor symptoms include: apathy, depression, constipation, sleep behavior disorders, loss of sense of smell, and cognitive impairment.

Who has it?

About one million Americans and more than 10 million people worldwide are living with PD. While Parkinson’s is not limited to a certain type of person, men are more likely to have it. Muhammed Ali, George H.W. Bush, Neil Diamond, and Michael J. Fox are a few prominent figures who were diagnosed with Parkinson’s disease.

What causes Parkinson’s disease?

While the exact cause is unknown, most experts agree that the condition is caused by a combination of genetic and environmental factors. Directly inheriting the disease is quite rare. Only about 10 to 15 percent of all cases of Parkinson’s are thought to be solely genetic forms of the disease (monogenetic).

Familial Parkinson’s disease types include:

• Autosomal dominant: the presence of one altered copy of this gene is sufficient to cause the disease. This kind of genetic Parkinson’s is rare, (one to two percent of people with PD).
• Autosomal recessive: the presence of two altered copies of this gene is required to cause the disease.
• Risk factor modifiers genes: genes that modify the risk of developing Parkinson’s in some families.

Even if you carry a gene mutation, it doesn’t mean you will be diagnosed with the disease. It’s not simply a mutation in one gene that matters. Experts believe that PD is caused by a complex interaction of genetic and non-genetic factors.

While age is the biggest risk factor for PD, many chemicals used in various professions — such as welding, farming, military activities and industrial processes — have been associated with the disease. Exposure to any one of these factors does not necessarily mean a person will actually develop the disease. Some specific risk factors include:

• Age: About one percent of people over age 60 have PD.
• Gender: PD is more common in men than in women.
• Head Injury: Traumatic brain injury —injury that results in alteration in level of consciousness — has been associated with an increased risk of developing PD years after the injury.
• Area of Residence: There are differences in the geographic distribution of PD. These could be due to differences in environmental factors and differences in genetic risk factors.
• Occupation: Certain occupational categories or job titles have been associated with a higher incidence of PD, but results have been inconsistent. By contrast, lower rates of PD are associated with shift work and jobs involving vigorous physical work.
• Exposure to pesticides, herbicides, various solvents and metals.

Often, a person’s genetic makeup will help to determine the effect of an environmental exposure. For example, agricultural workers exposed to pesticides were at an increased risk of PD only if they also had inherited a reduced ability to metabolize toxicants. In another study, head injury was associated with a higher risk of PD only in people with one form of a particular gene. In people without this gene variant, head injury was not associated with a higher risk of PD.

Is there a cure?

Although there is no cure, treatment options vary and include medications and surgery.

There are many medications available to treat the Parkinson’s symptoms, although none yet that reverse the effects of the disease.

The combined direct and indirect cost of Parkinson’s, including treatment, social security payments and lost income, is estimated to be nearly $25 billion per year in the United States alone. Medications alone cost an average of $2,500 a year and therapeutic surgery can cost up to $100,000 per person.

What can I do to help?

Research is essential for a disease with so many unanswered questions.  Breakthroughs in treatment and improved care that bring hope to the entire Parkinson’s community have been funded by the Parkinson’s Foundation. They host various events as well as an online store and donation page.