Definition
Secondary parkinsonism is similar to Parkinson's disease, but is caused by certain medicines, an 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 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.
Symptoms
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:
- 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:
Signs and tests
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.
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