1) What is Parkinson's disease?
PD is a progressive neurological disorder with four cardinal features: shaking, slowness of movements, stiffness, and balance difficulties. Most patients do not have all of these features at the time of diagnosis.
2) What are the "non-motor" symptoms of Parkinson's disease?
PD is associated with a number of symptoms that do not directly affect movement. These can include muscle cramps or pain, sweating, low blood pressure, mental slowing or trouble concentrating, sexual dysfunction, fatigue or tiredness, sleepiness, constipation, and depression.
3) What causes Parkinson's disease?
PD has no known cause in most cases. Some patients may develop the features of PD from a genetic (hereditary) defect or from certain toxins (poisons). The symptoms of PD appear to be due to a lack of the neurotransmitter (brain chemical messenger) called dopamine in a part of the brain called the basal ganglia.
4) What is(are) the basal ganglia?
The basal ganglia are clusters of brain cells located in a deep area of the brain, one on each side. These brain cells control many aspects of movement, including many of the problem areas in PD.
5) How is Parkinson's disease treated?
Most of the therapies for PD attempt to replace dopamine in the brain. Medications such as carbidopa combined with levodopa or dopamine agonists are commonly used to relieve symptoms. In some patients medications that block the neurotransmitter acetylcholine can be used. In others brain surgery can be effective as well.
6) What is a dopamine agonist?
A dopamine agonist is a synethetic medication designed to act like dopamine. These medications are commonly used to treat PD symptoms. Some of the available dopamine agonists are Parlodel (bromocriptine), Mirapex (pramipexole), Requip (ropinirole), and Neupro (rotigotine).
7) What are the advantages of a dopamine agonist over carbidopa/levodopa?
Several studies have suggested that dopamine agonist medications are associated with a lower incidence of certain side effects when used to treat PD symptoms early after diagnosis. In addition, dopamine agonist medications tend to last longer than carbidopa/levodopa.
8) What are the disadvantages of dopamine agonists compared to carbidopa/levodopa?
In general the side effects of dopamine agonists and carbidopa/levodopa are similar. However, a few individuals have developed severe sleepiness and compulsive behavior with some of the dopamine agonists. Dopamine agonists also cost more than carbidopa/levodopa.
9) How does brain surgery work for Parkinson's disease?
There are several surgical procedures used to treat PD. A common procedure is to insert a wire into an area of the brain called the subthalamus. Typically, this wire is attached to a pacemaker-like device that generates electrical energy that interferes with the brain activity in this area. When this pacemaker-like device is turned on, symptoms are often reduced in severity. Similar procedures can also target areas of the brain called the globus pallidus or the thalamus. These procedures can also be done on both sides of the brain to treat symptoms on both sides of the body. For the thalamus, a lesion (or area of damage) can also be created to relieve tremor on one side of the body.
10) Who should have surgery for Parkinson's disease?
This is a difficult question. In general patients who continue to have severe symptoms despite medications should consider surgery. However, if medications are largely ineffective in treating symptoms, surgery is usually not very effective either. Thus, the best patients for surgery tend to have a fair response to medications but also have persistent symptoms or side effects of medication.
11) Where can I get more information about Parkinson's disease?
The National Institute of Neurological Disorders and Stroke web site provides links to several support organizations and to NIH-directed research into Parkinson's disease. Patients should also consult their physician for more information.
The National Parkinson Foundation web site also provides a lot of useful information for patients and caregivers.