Parkinson’s Disease

Parkinson’s Disease (PD) is a progressive neurological disorder that is characterized by four cardinal motor symptoms:

Tremor (shaking, mostly at rest), Rigidity (stiffness, particularly in the limbs), Bradykinesia (slowness of movement), and Postural Instability (tendency to lose balance or fall backwards)

Other motor symptoms of PD may include changes in speech and handwriting. PD may also be associated with non-motor symptoms such as constipation, changes in sleep patterns, and depression.

PD is caused by a lack of dopamine in a part of the brain called the substantia nigra. Dopamine is a chemical, or neurotransmitter, that helps the brain communicate effectively with muscles. If there isn’t enough dopamine, muscles do not get the right messages which causes them to work improperly.

Age at onset of PD symptoms is typically between 55-65, although some patients may show symptoms at younger or older ages.

Researchers are unsure what causes PD although it may be related to environmental factors, heredity, or a combination of both.

There are several treatments available for PD patients. It is important to talk to your doctor about what treatments may work best for you and if you are eligible to participate in research studies.

Updated 7/23/2004
Reviewed 6/4/2007