Secondary parkinsonism

Definition

Secondary parkinsonism is similar to Parkinson's disease, but it is caused by certain medicines, a different nervous system disorder, or another illness.

Alternative Names

Parkinsonism - secondary

Causes, incidence, and risk factors

Parkinson's disease is one of the most common nervous system (neurologic) disorders of the elderly. "Parkinsonism" refers to any condition that causes Parkinson's-type abnormal movements. These movements are caused by changes in or destruction of the nerve cells (neurons) that produce the chemical dopamine in a certain area of the brain.

Secondary parkinsonism may be caused by disorders such as:

• Encephalitis
• Meningitis
• Stroke

Other disorders can also damage the dopamine neurons and produce this condition, including:

• Corticobasal degeneration
• Diffuse Lewy body disease
• Multiple system atrophy
• Progressive supranuclear palsy

Another common cause of secondary parkinsonism is medication, such as:

• Antipsychotics (haloperidol)
• Metoclopramide
• Phenothiazine medications

If they damage the area of the brain that contains the dopamine neurons, the following may cause secondary parkinsonism:

• Brain damage caused by anesthesia drugs (such as during surgery)
• Carbon monoxide poisoning
• Exposure to toxins
• Overdoses of narcotics

There have been cases of secondary parkinsonism among intravenous drug users who injected a substance called MPTP, which can be produced when making a form of heroin. These cases are rare and have mostly affected long-term drug users.

Secondary parkinsonism caused by antipsychotics or other medications is usually reversible if identified soon enough. However, it may not be reversible if it is caused by:

• Drug-related brain damage
• Infections
• Toxins

Symptoms

Symptoms of parkinsonism may include:

• Decrease in facial expressions
• Difficulty starting and controlling movement
• Soft voice
• Some types of paralysis
• Stiffness of the trunk, arms, or legs
• Tremor

Although cognitive problems are not as common in Parkinson's disease, they may be more likely in secondary parkinsonism. This is because the diseases that cause secondary parkinsonism often lead to dementia.

For a more detailed description of symptoms, see Parkinson's disease.

Signs and tests

The health care provider may be able to diagnose secondary parkinsonism based on your history, symptoms, and a physical examination. However, the symptoms may be difficult to assess, particularly in the elderly.

Examination may show:

• Difficulty starting or stopping voluntary movements
• Increased muscle tone
• Problems with posture
• Slow, shuffling walk (gait)
• Tremors of the Parkinson's type

Reflexes are usually normal.

Tests are not usually specific for secondary parkinsonism. However, they may be used to confirm or rule out other disorders that can cause similar symptoms.

Treatment

Treatment is aimed at controlling symptoms. If the symptoms are mild, no treatment may be needed.

If the condition is caused by a medication, the benefits of the medication should be weighed against the severity of symptoms. Medications should be stopped or changed if the risks outweigh the benefits.

Treating underlying conditions such as stroke or infections can reduce symptoms.

Medications may be used if symptoms interfere with the ability to perform daily activities. The medication, dose, timing, or combination of medications may need to be adjusted as symptoms change.

Many of the medications used to treat this condition can cause severe side effects. Monitoring and follow-up by the health care provider are important. Secondary parkinsonism tends to be less responsive to medical therapy than Parkinson's disease. However, medications are worth trying if the cause of the condition is not treatable.

Medications used to treat symptoms of Parkinson's disease are:

• Levodopa (L-dopa), Sinemet, levodopa and carbidopa (Altamet)
• Pramipexole (Mirapex), ropinirole (Requip), bromocriptine (Parlodel)
• Selegiline (Eldepryl, Deprenyl), rasagiline (Azilect)
• Amantadine or anticholinergic medications (to reduce early or mild tremors)
• Entacapone (to prevent the breakdown of levodopa)

For a more detailed description of treatment, see Parkinson's disease.

Support Groups

See: Parkinson's disease - support group

Expectations (prognosis)

What will happen varies and depends on the cause of the disorder. If the disorder is caused by medications, it may be treatable. All other causes are not reversible and tend to get worse over time.

Complications

• Difficulty performing daily activities
• Difficulty swallowing (eating)
• Disability (varying degrees)
• Injuries from falls
• Side effects of medications

Side effects from loss of strength (debilitation):

• Aspiration
• Deep vein thrombosis
• Malnutrition

Calling your health care provider

Call your health care provider if:

• Symptoms of secondary parkinsonism develop, come back, or get worse
• New symptoms appear, including:
  • Changes in alertness, behavior, or mood
  • Delusional behavior
  • Dizziness
  • Hallucinations
  • Involuntary movements
  • Loss of mental functions
  • Nausea or vomiting
  • Possible side effects of medications
  • Severe confusion or disorientation

Discuss the situation with your health care provider if you are unable to care for the person at home (after treatment begins).

Prevention

Treating conditions that cause secondary parkinsonism may decrease the risk.

Only use medications under a health care provider's supervision. People with conditions (such as schizophrenia) that require long-term use of antipsychotics should be carefully monitored to prevent the development of secondary parkinsonism. Newer antipsychotic medications are less likely to cause secondary parkinsonism.

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References

Lang A. Parkinsonism. In: Goldman L, Ausiello D. Cecil Textbook of Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 433.

Lang AE. When and how should treatment be started in Parkinson disease? Neurology. 2009;72(7 Suppl):S39-43.

Lewitt PA. Levodopa for the treatment of Parkinson's disease. N Engl J Med. 2008;359(23):2468-76.