If your doctor thinks you may have Parkinson disease, this information sheet will help you talk with him or her about how Parkinson disease is diagnosed and how it will progress.

Neurologists are doctors who treat diseases of the brain and nervous system. Experts in Parkinson disease looked at all of the studies on accurate diagnosis, disease progression, and therapies for Parkinson disease. Then they made suggestions that will help doctors and people with Parkinson disease make choices in their care. In some cases, there were not enough published data for or against specific therapies.

Parkinson disease is a progressive movement disorder. This means the symptoms will gradually worsen over time. In people with Parkinson disease a vital chemical in the brain, dopamine, slowly decreases. Dopamine makes smooth and coordinated muscle movement possible. A loss of dopamine leads to symptoms of Parkinson disease, such as:

  • Shaking (tremor)
  • Stiffness
  • Shuffling walk
  • Slowness of movements
  • Balance problems
  • Small or cramped handwriting
  • Loss of facial expression
  • Soft, muffled speech

Parkinson disease is common, but it can be difficult to diagnose. This is especially true in the early stages or in older people. A doctor will make a diagnosis after a complete medical history, review of the symptoms, and a detailed neurological exam.

Your doctor will try to find out if the symptoms are due to Parkinson disease or another condition that has similar symptoms. According to good evidence, history of falls, no tremor, rapid progression of the symptoms, and no affect of drugs on Parkinson-like symptoms may be signs of a similar condition, not Parkinson disease.

Certain drugs are probably useful in confirming if a person has Parkinson disease versus another condition. This is called a challenge test. If symptoms get better while taking the drugs, the person may have Parkinson disease. The experts found there is good evidence two drugs are probably useful in diagnosing Parkinson disease:

  • Levodopa is a naturally occurring amino acid that the brain converts to dopamine.
  • Apomorphine is a man-made form of morphine. It acts like dopamine and stimulates the dopamine system.

Your doctor may also use other tests. There is good evidence that for some patients a smell test can help doctors decide if a person has Parkinson disease versus another condition. At this time there is not enough evidence for or against the use of brain scans, blood tests, or other tests to diagnose Parkinson disease.

Parkinson disease usually progresses slowly. Doctors cannot estimate exactly how quickly or slowly it will progress in a patient. This will vary from person to person. However, good evidence shows that Parkinson disease may progress more quickly in people who are older when symptoms begin.

Parkinson disease may progress more quickly in people whose symptoms are muscle stiffness and slowness. There is weak evidence that the disease will progress faster in men and people with a history of stroke, hearing, or vision problems.

In 2002, a group of neurologists reviewed all of the studies for the most effective drugs used to treat Parkinson disease. To treat the initial symptoms of Parkinson disease doctors may prescribe:

  • Levodopa or dopamine agonists: There is strong evidence that either levodopa or a dopamine agonist can be used to treat initial symptoms. Dopamine agonists are drugs that stimulate the dopamine system and may lessen motor complications. Levodopa is a naturally occurring amino acid that the brain converts to dopamine. Levodopa provides superior motor benefit but it is associated with a higher risk of dyskinesia.
  • Selegiline: Strong evidence shows that selegiline has very mild benefit as an initial treatment. There is not enough evidence that it is neuroprotective.

Talk to your neurologist

People experiencing the signs of Parkinson disease should seek the care of a neurologist. Your doctor will recommend an individualized treatment plan. This may include lifestyle changes. All treatments have some side effects. The choice of which side effects can be tolerated depends on the individual.

For further information: American Academy of Neurology.