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(Secondary Parkinsonism; Atypical Parkinsonism)


Alex Rajput

, MD, University of Saskatchewan;

Eric Noyes

, MD, University of Saskatchewan

Reviewed/Revised Feb 2024

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

Parkinsonism does not include Parkinson disease although the disorders included in parkinsonism resemble Parkinson disease in some ways. There are two main types of parkinsonism:

  • Secondary parkinsonism refers to a group of disorders that have a different cause from Parkinson disease.

  • Atypical parkinsonism refers to a group of degenerative disorders that have some different symptoms and different changes in the brain and that respond to treatment differently. People with these disorders have a worse prognosis.

Causes of Parkinsonism

The most common cause of parkinsonism is

  • Use of medications that block or interfere with dopamine’s action

Certain drugs and toxins interfere with or block the action of dopamine and other chemical messengers that help nerve cells communicate with each other (neurotransmitters). For example, antipsychotic medications, used to treat paranoia and schizophrenia, block dopamine’s action. Dopamine is a key neurotransmitter in the basal ganglia (collections of nerve cells located deep within the brain), which help smooth out muscle movements.

Various other conditions can cause parkinsonism:

Symptoms of Parkinsonism

  • A tremor that occurs in one hand while the muscles are relaxed (a resting tremor)

  • Stiff muscles

  • Slow movements

  • 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 probably not Parkinson disease. They include

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 usually begin after age 60 (see figure ).

People with corticobasal ganglionic degeneration have stiff muscles that affect one side of the body more than the other. As the disorder progresses, moving their limbs becomes increasingly difficult. Coordination and balance are poor, muscle twitch, and swallowing becomes difficult. Thinking is impaired, and people have difficulty finding, saying, and understanding words. Many people lose control of one hand (on the more affected side)—called alien hand syndrome. The hand may move on its own. For example, it may spontaneously open or make a fist.

Diagnosis of Parkinsonism

  • A doctor's evaluation

  • Usually brain imaging

  • Use of levodopa to see whether it helps

Doctors ask about previous disorders, exposure to toxins, and use of drugs that could cause parkinsonism.

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

Treatment of Parkinsonism

  • Treatment of the cause if possible

  • Sometimes medications to help relieve symptoms

  • General measures, such as staying as active as possible

The cause of parkinsonism 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 disorder causing them can be treated.

The medications used to treat Parkinson disease (such as levodopa Levodopa/carbidopa Parkinson disease is a slowly progressive degenerative disorder of specific areas of the brain. It is characterized by tremor when muscles are at rest (resting tremor), increased muscle tone... read more ) are often not effective in people with parkinsonism but can sometimes result in temporary improvement.

If an antipsychotic medication is causing bothersome parkinsonian symptoms and an antipsychotic medication needs to be taken indefinitely, doctors substitute another antipsychotic medication if possible. However, if the medication cannot be changed, amantadine or a medication with anticholinergic effects Anticholinergic: What Does It Mean? Anticholinergic: What Does It Mean? , such as benztropine, may relieve symptoms.

The same general measures General measures used to help people with Parkinson disease maintain mobility and independence are useful. For example, people should

  • Remain as active as possible

  • Simplify daily tasks

  • Use assistive devices as needed

  • Take measures to make the home safe (such as removing throw rugs to prevent tripping)

Good nutrition is also important.

Drugs Mentioned In This Article

Generic Name Select Brand Names
Gimoti, Metozolv, Reglan
Compazine, Compazine Rectal, Compazine Solution, Compazine Syrup, Compro
No brand name available
INBRIJA, Larodopa
GOCOVRI, Osmolex ER, Symmetrel
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