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

Parkinson's disease is one of the most common neurologic disorders of the elderly. The term "parkinsonism" refers to any condition that causes any combination of the types of movement abnormalities seen in Parkinson's disease by damaging or destroying dopamine neurons in a certain area of the brain.

Secondary parkinsonism may be caused by disorders such as a stroke, encephalitis, or meningitis. Other neurodegenerative disorders such as progressive supranuclear palsy, corticobasal degeneration, and multiple systems atrophy can also damage the dopamine neurons and produce this condition.

Medications including antipsychotics such as haloperidol, metoclopramide, and phenothiazine medications are another common cause of secondary parkinsonism.

Less frequently, exposure to overdoses of narcotics or brain damage caused by anesthesia agents (such as during surgery); exposure to toxins, and carbon monoxide poisoning can cause secondary parkinsonism if they damage the brain area that contains the dopamine neurons.

There have been clusters of cases among intravenous drug users who injected a substance called MPTP, which is a byproduct of an improper technique for synthesizing a form of synthetic heroin (fentanyl derivative). These cases are rare and have affected primarily long-term drug users.

Secondary parkinsonism caused by medications like antipsychotics is usually reversible. If it is caused by toxins, infections, drug-related brain damage, or certain other disorders it may or may not be reversible.

Symptoms of parkinsonism may include stiffness of the trunk, arms, or legs, a decrease in facial expression, soft voice, tremor, some forms of paralysis, and certain problems with control of movement.

Although cognitive dysfunction is not a major feature of Parkinson's disease, it may be more prominent in secondary parkinsonism as the diseases that cause secondary parkinsonism more commonly also result in dementia.

Initial symptoms may be mild and nonspecific, such as mild tremor or a slight feeling that one leg or foot is stiff or dragging.

Specific symptoms include:

• Muscle rigidity (stiffness or difficulty bending arms or legs)
• Unstable, stooped, or slumped posture
• Movement difficulties:
  • Loss of balance
  • Gait (walking pattern) changes
  • Shuffling
  • Slow movements
  • Difficulty beginning to walk, difficulty initiating any voluntary movement
  • Small steps followed by the need to run to maintain balance
  • Freezing of movement when the movement is stopped, unable to resume movement
• Muscle aches and pains (myalgia)
• Muscle cramps and dystonia
• Shaking or tremors:
  • May occur at rest or at any time
  • May become severe enough to interfere with activities
  • May be worse when tired, excited, or stressed
  • Finger-thumb rubbing (pill rolling tremor)
• Changes in facial expression:
  • Reduced ability to show facial expressions, "mask" appearance
  • Staring
  • Difficulty moving eyes up and down
  • May be unable to close mouth
• Voice or speech changes:
  • Slow speaking
  • Low pitched voice
  • Monotone
  • Difficulty speaking
• Difficulty chewing or swallowing
• Loss of fine motor skills:
  • Difficulty writing, may be small and illegible
  • Difficulty eating
  • Difficulty with any activity that requires small movements
  • Frequent falls
• Mild decline in intellectual function (may occur)

Symptoms that may occur along with the disease:

• Depression
• Confusion
• Dementia

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

For example, the tremor may not appear when the person is sitting quietly with the arms in the lap. The posture changes may be similar to those caused by osteoporosis or other changes associated with aging. The lack of facial expression may be a sign of depression.

Examination may show increased muscle tone, tremors of the Parkinson's type, and difficulty initiating or completing voluntary movements. Reflexes are usually normal.

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

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

If the condition is caused by a medication, the benefits of the medication should be weighed against the severity of symptoms and stopped or changed if they seem counterproductive.

Treatment of underlying conditions (such as stroke, infections) can reduce symptoms.

Medications may be used if symptoms interfere with the ability to perform daily activities. The medication, or 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, so monitoring and follow-up by the health care provider are important. Secondary parkinsonism tend to be less responsive to medical therapy than Parkinson's disease.

Medications include:

• Amantadine or anticholinergic medications
• Levodopa/carbidopa
• Dopamine agonists

Neupro is a new skin patch that contains the drug rotigotine. This medicine helps dopamine receptors in the brain work better. The patch is replaced every 24 hours. Neupro is approved for persons with early stage Parkinson's disease.

Additional medications include antihistamines, antidepressants, monoamine oxidase inhibitors, or others to help reduce symptoms or control the side effects of primary treatment medications.

Good general nutrition and health are important. Exercise should continue, with the level of activity adjusted to meet the changing energy levels that may occur. Regular rest periods and avoidance of stress are recommended, because tiredness or stress can make symptoms worse.

Physical therapy, speech therapy and occupational therapy may help promote function and independence, and may help maintain skills and positive attitude and minimize depression.

Simple aids such as railings or banisters placed in commonly used areas of the house, special eating utensils or other devices may be of great benefit to the person experiencing some difficulties with daily living activities.

Social work or other counseling services may help in coping with the disorder, and obtaining assistance as appropriate (such as safety equipment, Meals-on-Wheels, volunteer services or other assistance).

See: Parkinson's disease - support group

The outcome varies and depends on the cause. If the disorder is caused by medications, it is potentially treatable. All other causes are not reversible and, to a greater or lesser degree, progressive.

• Disability, varying degrees
• Difficulty swallowing (eating)
• Difficulty performing daily activities
• Injuries from falls
• Side effects of medications
• Debilitation and associated conditions:
  • Malnutrition
  • Aspiration
  • Deep vein thrombosis

Call your health care provider if symptoms of secondary parkinsonism develop, recur, worsen, or progress.

Call your health care provider if new symptoms appear in a person with this disorder, including possible side effects of medications: involuntary movements, nausea/vomiting, dizziness, changes in alertness/behavior/mood, severe confusion or disorientation, delusional behavior, hallucinations, loss of mental functions, or any other new symptoms that develop (see also information on potential side effects of the specific medication).

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

The treatment of conditions that may cause secondary parkinsonism may decrease the risk of its development. Medication use should only be under the supervision of the health care provider and people with conditions that require long-term use of antipsychotics, like schizophrenia, should be carefully monitored to avoid development of irreversible secondary parkinsonism. Newer antipsychotic medications are less likely to cause secondary parkinsonism.

U.S. Food and Drug Administration. FDA Approves Neupro Patch for Treatment of Early Parkinson's Disease. Rockville, MD: National Press Office; May 9, 2007. Release P07-84.

Goetz, CG. Textbook of Clinical Neurology. 2nd ed. St. Louis, Mo: WB Saunders; 2003: 713-720.

Noble J. Textbook of Primary Care Medicine. 3rd ed. St. Louis, Mo: Mosby; 2001:1612-1618.