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Parkinson's Disease

A Chronic Disorder of the Brain and Nervous System


Updated July 05, 2008

Parkinson's disease is a neurodegenerative disorder, meaning it affects the brain and nerves. For unclear reasons, nerve cells in a part of the brain called the substantia nigra die and can no longer produce a chemical called dopamine that is important for coordinated muscle movement.

Parkinson's disease is relatively common -- affecting about 1.5 million people in the U.S., or about one in 100 people older than 60 (the typical age at which it begins). About 5-10% of people with Parkinson's disease start having symptoms at age 40 or younger. It affects both men and women.

Parkinson's disease is chronic, meaning that it continues over a long period of time, and progressive, meaning that it gets worse over time. Some people may have severe symptoms while others have only minor ones. Researchers believe that Parkinson's disease is most likely caused by a combination of genetic factors and environmental exposures. No one specific gene for Parkinson's disease has been found.


The four major symptoms of Parkinson's disease are:
  • Tremor - shaking in the hands, arms, legs, jaw, and face
  • Slowness of movement (called bradykinesia)
  • Rigidity - stiffness of the arms, legs, and trunk
  • Impaired balance and coordination (called postural instability)
These symptoms occur gradually and may be subtle at first. In many people, the symptoms will become worse over time. Symptoms usually start on one side of the body and spread to the other side over time.

Other symptoms of Parkinson's disease may include:

  • stiff facial expression
  • shuffling walk
  • difficulty speaking, chewing, and swallowing
  • depression
  • sleep disruptions
  • problems with urination or constipation
  • skin problems
  • stooped posture


When at least two of the four main symptoms are present, and especially if the symptoms are more evident on one side of the body, a diagnosis of Parkinson's disease is made. There are no specific blood or laboratory tests that help confirm the diagnosis. Some tests may be used to show that the symptoms are not being caused by something else.

Some other disorders that cause symptoms similar to Parkinson's disease are:


In Parkinson's disease there is not enough dopamine in the brain, so medications are given to increase the amount of dopamine. Usually individuals are given Larodopa (levodopa) and Lodosyn (carbidopa), Sinemet (levodopa and carbidopa combined), Stalevo (levodopa, carbidopa, and entacapone combined) or Larodopa and Azilect (rasagiline). Other drugs such as Parlodel (bromocriptine), Mirapex (pramipexole), or Requip (ropinirole) may be given. Anticholinergic drugs may help control tremors and rigidity.

In 2007, the U.S. Food and Drug Administration (FDA) approved a skin patch medication, Neupro (rotigotine) for treatment of Parkinson's disease.

A treatment called deep brain stimulation may be used for some individuals. Electrodes are implanted into the brain and connected to a small electrical device called a neurostimulator that can be programmed. Deep brain stimulation helps reduce the symptoms of Parkinson's disease and may reduce the need for medication.


"NINDS Parkison's Disease Information Page." Disorders. 12 Oct 2007. National Institute of Neurological Disorders and Stroke. 16 Oct 2007

Di Minno, Mariann, & Michael Aminoff. "Overview of Parkinson Disease." A Primer on Parkinson Disease. National Parkinson Foundation. 16 Oct 2007

"About Parkinson Disease." National Parkinson Foundation. 16 Oct 2007

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