Parkinson's disease (PD) is a progressive movement disorder that causes:
- Muscle rigidity
- Tremor at rest
- Slowing down of movements (bradykinesia)
- Difficulty moving and gait instability
Causes
Symptoms are caused by a loss of nerve cells in a part of the brain called the substantia nigra. Genetic, environmental, or a combination of both factors cause this loss. This loss decreases the amount of dopamine in the brain. Low dopamine results in PD symptoms. A small percentage of people with this condition have an early onset form caused by an inherited gene defect.
Secondary parkinsonism is a condition with similar symptoms. But symptoms can be caused by several factors, including:
- Antipsychotic drugs, such as haloperidol (Haldol), fluphenazine (Prolixin), trifluoperazine (Stelazine), and chlorpromazine (Thorazine)
- Carbon monoxide poisoning
- Manganese poisoning
- Hydrocephalus
- Brain tumors
- Stroke
- Encephalitis
- Meningitis
- Intravenous drug abuse of MPTP (a type of neurotoxin)
- Reserpine
- Insecticide exposure
- Trauma
- AIDS
Risk Factors
A risk factor is something that increases your chance of getting a disease or condition.Risk factors include:
Age: 50 or older
History of polio
Gender: men (slightly more likely to develop PD)
Family members with PD
Nonsmokers
Exposure to toxins, drugs, or conditions listed above
Symptoms
Symptoms of PD begin mildly and worsen over time.
Symptoms include:
"Pill-rolling" tremor in the hands
Tremors are present at rest, improve with movement, and are absent during sleep
Stiffness and rigidity of muscles, usually beginning on one side of the body
Difficulty and shuffling when walking
Short steps
Slowness of purposeful movements
Trouble performing usual tasks, due to shaking in hands
Trouble speaking
Flat, monotonous voice
Stuttering
Shaky, spidery handwriting
Poor balance
Difficulty with rising from a sitting position
Freezing
Anxiety
Seborrhea (a skin problem that causes a red rash and white scales)
Loss of smell
Tendency to fall
Stooped posture
Increasingly mask-like face, with little variation in expression
Trouble chewing and swallowing
Depression
Dementia
Difficulty thinking, problems with memory
Diagnosis
The doctor will ask about your symptoms and medical history, and perform a physical exam. There are no tests to definitively diagnose PD. The doctor will ask many questions to rule out other causes of your symptoms.
Tests to rule out other conditions may include:
Blood tests
Urine tests
CT scana type of x-ray that uses a computer to make pictures of structures inside the head
MRI scana test that uses magnetic waves to make pictures of structures inside the head
PET scana scan that makes images that show the amount of activity in the brain
Treatment
Currently, there are no treatments to cure PD or proven treatments to slow or stop its progression. Some medications are used to improve symptoms. Over time, however, the side effects may become troublesome, and the medications may lose their effectiveness.
Medications
Medications include:
Levodopa/carbidopa (Sinemet)
Amantadine (Symmetrel)
Anticholinergics: benztropine (Cogentin) and biperidin (Akineton)
Selegiline (Eldepryl)
Dopamine agonists: bromocriptine (Parlodel), pergolide (Permax), pramipexole (Mirapex), cabergoline (Dostinex), and ropinirole (Requip)
Pergolide (Permax) was withdrawn from the market in March 2007 due to the risk of serious heart valve damage; cabergoline (Dostinex) has also been associated with a similar risk. *
Apomorphine (Apokyn)
COMT inhibitors: entacapone (Comtan) and tolcapone (Tasmar)
Also, medications to treat depression or hallucinations associated with PD may be given. These may include selective serotonin reuptake inhibitors (SSRIs) and the antipsychotic clozapine. Because these medications can worsen other symptoms of the condition, you will need to be closely monitored
Surgery
Different brain operations are available, and many more are being researched including:
Destroying certain areas of the brain (thalamotomy and pallidotomy)to improve tremor when medication does not work
Deep brain stimulationimplanting a device to stimulate certain parts of the brain to decrease tremor and rigidity
Nerve-cell transplants (research only)to increase amount of dopamine made in the brain
Physical Therapy
Physical therapy, exercise, and stretching can improve muscle tone, strength, and balance.
Psychological Support
Joining a support group with other people who are learning to live with the challenges of PD can be very helpful.
Prevention
There are no guidelines for preventing PD.
RESOURCES:
American Academy of Neurology
http://www.aan.com/
National Institute of Neurological Disorders and Stroke
http://www.ninds.nih.gov/
National Parkinson Foundation
http://www.parkinson.org/
Parkinson's Disease Foundation, Inc.
http://www.pdf.org/
CANADIAN RESOURCES:
Health Canada
http://www.hc-sc.gc.ca/index_e.html/
Parkinson Society
http://www.parkinson.ca/
References:
American Academy of Neurology. American Academy of Neurology website. Available at: http://www.aan.com/professionals/. Accessed June 13, 2008.
Frank S. Parkinson's disease. In: Gilman S, ed. MedLink Neurology. San Diego, CA: MedLink Corporation. Available at: http://www.medlink.com. Accessed May 12, 2008.
Goetz CG. Textbook of Clinical Neurology. Philadelphia, PA: WB Saunders Company; 1999.
Parkinson's disease. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what.php. Accessed May 12, 2008.
Parkinson's disease information page. National Institute of Neurological Disorders and Stroke website. Available at: http://www.ninds.nih.gov/disorders/parkinsons_disease/parkinsons_disease.htm. Updated April 10, 2008. Acessed June 13, 2008.
Rowland LP, Merritt HH. Merritt's Neurology. 11th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2005.
Samii A, et al. Parkinson's disease. Lancet. 2004;363:1783-1793.
Samuels MA, Feske SK. Office Practice of Neurology. Philidelphia, PA: Churchill Livingstone; 2003.
Siderowf A, et al. Update on Parkinson's disease. Ann Intern Med. 2003;138:651-658.
* 4/10/2007 DynaMed's Systematic Literature Surveillance: US Food and Drug Administration. FDA announces voluntary withdrawal of Pergolide products [press release]. March 29, 2007. US Food and Drug Administration website. Available at: http://www.fda.gov/bbs/topics/NEWS/2007/NEW01596.html
Last reviewed March 2008 by J. Thomas Megerian, MD, PhD, FAAP
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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