Parkinson's disease (PD) belongs to a group of conditions called motor system disorders, which are the result of the loss of dopamine-producing brain cells. The four primary symptoms of PD are tremor, or trembling in hands, arms, legs, jaw, and face; rigidity, or stiffness of the limbs and trunk; bradykinesia, or slowness of movement; and postural instability, or impaired balance and coordination. As these symptoms become more pronounced, patients may have difficulty walking, talking, or completing other simple tasks. PD usually affects people over the age of 50. Early symptoms of PD are subtle and occur gradually. In some people the disease progresses more quickly than in others. As the disease progresses, the shaking, or tremor, which affects the majority of PD patients may begin to interfere with daily activities. Other symptoms may include depression and other emotional changes; difficulty in swallowing, chewing, and speaking; urinary problems or constipation; skin problems; and sleep disruptions. There are currently no blood or laboratory tests that have been proven to help in diagnosing sporadic PD. Therefore the diagnosis is based on medical history and a neurological examination. The disease can be difficult to diagnose accurately. Doctors may sometimes request brain scans or laboratory tests in order to rule out other diseases.
At present, there is no cure for PD, but a variety of medications provide dramatic relief from the symptoms. Usually, patients
are given levodopa combined with carbidopa. Carbidopa delays the conversion of levodopa into dopamine until it reaches the
brain. Nerve cells can use levodopa to make dopamine and replenish the brain's dwindling supply. Although levodopa helps
at least three-quarters of parkinsonian cases, not all symptoms respond equally to the drug. Bradykinesia and rigidity respond
best, while tremor may be only marginally reduced. Problems with balance and other symptoms may not be alleviated at all.
Anticholinergics may help control tremor and rigidity. Other drugs, such as bromocriptine, pramipexole, and ropinirole, mimic
the role of dopamine in the brain, causing the neurons to react as they would to dopamine. An antiviral drug, amantadine,
also appears to reduce symptoms. In May 2006, the FDA approved rasagiline to be used along with levodopa for patients with
advanced PD or as a single-drug treatment for early PD.
In some cases, surgery may be appropriate if the disease doesn't respond to drugs. A therapy called deep brain stimulation
(DBS) has now been approved by the U.S. Food and Drug Administration. In DBS, electrodes are implanted into the brain and
connected to a small electrical device called a pulse generator that can be externally programmed. DBS can reduce the need
for levodopa and related drugs, which in turn decreases the involuntary movements called dyskinesias that are a common side
effect of levodopa. It also helps to alleviate fluctuations of symptoms and to reduce tremors, slowness of movements, and
gait problems. DBS requires careful programming of the stimulator device in order to work correctly.
PD is both chronic, meaning it persists over a long period of time, and progressive, meaning its symptoms grow worse over
time. Although some people become severely disabled, others experience only minor motor disruptions. Tremor is the major
symptom for some patients, while for others tremor is only a minor complaint and other symptoms are more troublesome. No
one can predict which symptoms will affect an individual patient, and the intensity of the symptoms also varies from person
to person.
The National Institute of Neurological Disorders and Stroke (NINDS) conducts PD research in laboratories at the National Institutes
of Health (NIH) and also supports additional research through grants to major medical institutions across the country. Current
research programs funded by the NINDS are using animal models to study how the disease progresses and to develop new drug
therapies. Scientists looking for the cause of PD continue to search for possible environmental factors, such as toxins, that
may trigger the disorder, and study genetic factors to determine how defective genes play a role. Other scientists are working
to develop new protective drugs that can delay, prevent, or reverse the disease.
American Parkinson Disease Association 135 Parkinson Avenue Staten Island, NY 10305-1425 apda@apdaparkinson.org http://www.apdaparkinson.org Tel: 718-981-8001 800-223-2732 Calif: 800-908-2732 Fax: 718-981-4399 |
National Parkinson Foundation 1501 N.W. 9th Avenue Bob Hope Road Miami, FL 33136-1494 contact@parkinson.org http://www.parkinson.org Tel: 305-243-6666 800-327-4545 Fax: 305-243-5595 |
Parkinson Alliance P.O. Box 308 Kingston, NJ 08528-0308 admin@parkinsonalliance.org http://www.parkinsonalliance.org Tel: 609-688-0870 800-579-8440 Fax: 609-688-0875 |
Michael J. Fox Foundation
for Parkinson's Research Grand Central Station P.O. Box 4777 New York, NY 10163 http://www.michaeljfox.org Tel: 212-509-0995 |
Parkinson's Action Network (PAN) 1025 Vermont Ave., NW Suite 1120 Washington, DC 20005 info@parkinsonsaction.org http://www.parkinsonsaction.org Tel: 800-850-4726 202-638-4101 Fax: 202-638-7257 |
Parkinson's Disease Foundation (PDF) 1359 Broadway Suite 1509 New York, NY 10018 info@pdf.org http://www.pdf.org Tel: 212-923-4700 800-457-6676 Fax: 212-923-4778 |
Parkinson's Institute 1170 Morse Avenue Sunnyvale, CA 94089-1605 info@thepi.org http://www.thepi.org Tel: 408-734-2800 800-786-2958 Fax: 408-734-8522 |
Parkinson's Resource Organization 74-090 El Paseo Drive Suite 102 Palm Desert, CA 92260-4135 info@parkinsonsresource.org http://www.parkinsonsresource.org Tel: 760-773-5628 877-775-4111 877-775-4111 Fax: 760-773-9803 |
WE MOVE (Worldwide Education & Awareness for Movement Disorders) 204 West 84th Street New York, NY 10024 wemove@wemove.org http://www.wemove.org Tel: 212-875-8312 Fax: 212-875-8389 |
Bachmann-Strauss Dystonia & Parkinson Foundation Mt. Sinai Medical Center One Gustave L. Levy Place P.O. Box 1490 New York, NY 10029 Bachmann.Strauss@mssm.edu http://www.dystonia-parkinsons.org Tel: 212-682-9900 Fax: 212-987-0662 |
Prepared by:
Office of Communications and Public Liaison
National Institute of Neurological Disorders and Stroke
National Institutes of Health
Bethesda, MD 20892
NINDS health-related material is provided for information purposes only and does not necessarily represent endorsement by or an official position of the National Institute of Neurological Disorders and Stroke or any other Federal agency. Advice on the treatment or care of an individual patient should be obtained through consultation with a physician who has examined that patient or is familiar with that patient's medical history.
All NINDS-prepared information is in the public domain and may be freely copied. Credit to the NINDS or the NIH is appreciated.
Last updated January 29, 2009