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Parkinsonism ˈpär-kən-sə-ˌniz-əm

(Secondary Parkinsonism; Atypical Parkinsonism)

By Hector A. Gonzalez-Usigli, MD; Alberto Espay, MD

Parkinsonism refers to symptoms of Parkinson disease (such as slow movements and tremors) that are caused by another condition.

Various conditions can cause parkinsonism:

  • Viral encephalitis, including West Nile virus encephalitis and a rare brain inflammation that follows a flu-like infection

  • Degenerative disorders, such as dementia, multiple system atrophy, corticobasal ganglionic degeneration, and progressive supranuclear palsy

  • Structural brain disorders, such as brain tumors and strokes

  • Head injury, particularly the repeated injury that occurs in boxing (making a person punch-drunk)

  • Drugs, especially metaclopromide (used to relieve nausea), antipsychotic drugs, and the antihypertensive drugs methyldopa and reserpine

  • Toxins, such as manganese, carbon monoxide, and methanol

Certain drugs and toxins interfere with or block the action of dopamine and other neurotransmitters. For example, antipsychotic drugs, used to treat paranoia and schizophrenia, block dopamine ’s action. Use of the substance MPTP (which was first produced accidentally when illicit drug users tried to synthesize the opioid meperidine) can cause sudden, severe, irreversible parkinsonism in young people.


Parkinsonism causes the same symptoms as Parkinson disease (see Cervical Dystonia : Symptoms). They include a resting tremor, stiff muscles, slow movements, and difficulty maintaining balance and walking.

The disorders that cause parkinsonism may also cause other symptoms or variations of parkinsonian symptoms. Some symptoms may indicate the cause is not Parkinson disease. They include

  • Prominent memory loss that occurs during the first year of the disorder (indicating dementia)

  • Symptoms of parkinsonism on only one side of the body (often due to certain brain tumors or corticobasal ganglionic degeneration)

  • Low blood pressure, difficulty swallowing, constipation, and urinary problems (sometimes due to multiple system atrophy)

  • Falls and confinement to a wheelchair within the first months or years of a disorder

  • Abnormalities in eye movements

  • Hallucinations and visual-spatial problems (such as difficulty finding rooms at home or parking a car) that develop early in the disorder

  • Symptoms that do not lessen in response to treatment with levodopa

  • Inability to express or understand spoken or written language (aphasia), inability to do simple skilled tasks (apraxia), and inability to associate objects with their usual role or function (agnosia) due to corticobasal ganglionic degeneration

In corticobasal ganglionic degeneration, the cerebral cortex (the part of the brain that contains most of the nerve cells) and the basal ganglia deteriorate progressively. Symptoms begin after age 60. People become immobile after about 5 years, and death typically occurs after about 10 years.


Doctors ask about previous disorders, exposure to toxins, and use of drugs that could cause parkinsonism. Brain imaging, such as computed tomography (CT) or magnetic resonance imaging (MRI), may be done to look for a structural disorder that may be causing the symptoms.

If the diagnosis is unclear, doctors may give the person levodopa (a drug used to treat Parkinson disease) to rule out Parkinson disease. If the drug results in clear improvement, Parkinson disease is the likely cause.


The cause is corrected or treated if possible. If a drug is the cause, stopping the drug may cure the disorder. Symptoms may lessen or disappear if the underlying disorder can be treated. The drugs used to treat Parkinson disease (such as levodopa) are often not effective in people with parkinsonism but can sometimes result in modest improvement.

Drugs are used if symptoms are bothersome. If the cause is use of antipsychotic drugs that need to be taken indefinitely, amantadine or a drug with anticholinergic effects, such as benztropine, may relieve symptoms.

The same general measures used to help people with Parkinson disease maintain mobility and independence are useful (see General measures). For example, people should remain as active as possible, simplify daily tasks, use assistive devices as needed, and take measures to make the home safe (such as removing throw rugs to prevent tripping). Physical and occupational therapists can help people implement these measures. Good nutrition is also important.

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* This is the Consumer Version. *