Parkinson's disease is a progressive disorder caused by degeneration of nerve cells in the part of the brain that controls movement.
What is going on in the body?
Parkinson's disease involves a breakdown of the nerve cells in the motor area of the brain. As the cells break down, there is a shortage of dopamine. Dopamine is a neurotransmitter, or chemical that carries messages to the body. When there is a shortage of dopamine, the messages that regulate movement are not sent properly.
What are the causes and risks of the disease?
Why the dopamine-producing cells in the brain break down is not fully understood. However, it is clear that genetic and environmental factors both play a part. First degree relatives of a person with Parkinson's are more likely to develop the condition themselves.
The defect may be caused by one or more of the following factors:
- an environmental toxin, such as pesticides
- a gene defect, such as the abnormality on chromosome 4
- a viral infection
The symptoms of Parkinson's disease usually begin at about age 60, though the disease has been seen in younger adults. It is most common in people in their 70s and 80s. Parkinson's disease is about twice as frequent in men than in women. Research suggests that estrogen, a female hormone, may protect against Parkinson's disease.
What can be done to prevent the disease?
Because the cause is not known, there is no known way to prevent Parkinson's disease. Avoiding exposure to environmental toxins, such as pesticides, may be helpful. Hormone therapy, or HT, in menopausal women may help prevent Parkinson's disease. This potential benefit should be weighed against the risks of HT and women should discuss this with their healthcare providers.
How is the disease diagnosed?
Diagnosis of Parkinson's disease begins with a medical history and physical exam. No single test can diagnose the disease. A
cranial CT scan can appear normal in the early part of the disease. Brain shrinkage and damage will appear later. The healthcare provider may prescribe antiparkinsonian medications to see if the person's symptoms respond to medication. A positive response would support a diagnosis of Parkinson's disease.
Long Term Effects
What are the long-term effects of the disease?
Parkinson's disease is a progressive, degenerative disease. This means that symptoms continue to get worse and new symptoms are seen.
What are the risks to others?
Parkinson's disease is not contagious and poses no risk to others.
What are the treatments for the disease?
There is no cure for Parkinson's disease. The major goal of treatment is to prevent deterioration. Symptoms can usually be well controlled for several years in the early stages of the disease. Early in the disease, medications are used.
One of the most common medicines is a combination of levodopa and carbidopa (i.e., Sinemet). Levodopa travels from the blood into the brain, where it is converted to dopamine, helping to replace the brain's shortage. Carbidopa helps more levodopa get to the brain. Although this combination is effective, it tends to work less and less over time.
Other medications used to treat Parkinson's disease include the following:
- dopamine agonists, these drugs work like dopamine in the brain and include bromocriptine (i.e.,Parlodel), pergolide (i.e., Permax), pramipexole (i.e., Mirapex), ropinirole (i.e., Requip), and apomorphine (i.e., Apokyn)
- catechol-O-methyl transferase (COMT) inhibitors, these drugs help L-dopa work longer and include tolcapone (i.e., Tasmar) and entacapone (i.e., Comtan)
- Monoamine oxidase inhibitors (MAOIs), these drugs reduce the destruction of dopamine and include selegiline (i.e., Eldepryl, Zelapar)
- anticholinergics, these drugs help control symptoms and include trihexyphenidyl (i.e., Artane) or benztropine (i.e., Cogentin)
- amantadine (i.e., Symmetrel), this drug helps dopamine in the brain work better
- donepezil (i.e., Aricept) and modafinil (i.e., Provigil) can help with certain symptoms
Surgical removal of a tiny part of the brain is a treatment option for treatment of individuals who do not respond optimally to medications.
Another approach is deep brain stimulation with electricity. People may need other treatments to deal with the many problems associated with the disease.
If dementia is present, close monitoring may be needed.
Treatment with antidepressants, antipsychotic medications, or sedatives can also help relieve some symptoms. Other medications may be used in late-stage Parkinson's disease to control symptoms. Medicines can be helpful when there are problems with bladder control, for example. Men with Parkinson's disease may be given medications for erectile dysfunction.
The Natural Medicines Comprehensive Database reviews studies from around the world on the use of herbs vitamins and supplements. They rate as "Possibly Effective" for the treatment of Parkinson's Disease black tea, caffeine, coenzyme Q-10, green tea, and vitamin E. They conclude that there is "Insufficient Evidence" to recommend citicoline, cowhage, octacosanol, or phenylalanine.
Physical, occupational, or speech therapy may help. A service dog or a live-in caregiver may be needed for some individuals.
Researchers continue to test new treatments for Parkinson's disease.
What are the side effects of the treatments?
Medications used to treat Parkinson's disease may cause abnormal body movements. Other side effects include nausea, drowsiness, confusion, and dry mouth. Rarely, confusion, hallucinations and delusions can occur. Surgery may cause difficulty with speech or paralysis on one side of the body. Deep brain stimulation usually requires more than one operation. There is also a risk of bleeding, infection, or an allergic reaction to the anesthetic.
What happens after treatment for the disease?
People with Parkinson's disease need treatment for life.
How is the disease monitored?
A family member or caregiver is important when it comes to monitoring Parkinson's disease. They can give the healthcare provider day-to-day input on benefits and side effects of treatment. Any new or worsening symptoms should be reported to the healthcare provider.