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

Various conditions can cause parkinsonism:

• Viral encephalitis, a rare brain inflammation that follows a flu-like infection
• Other 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, such as antipsychotics and the antihypertensives 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 produced accidentally when illicit drug users tried to synthesize the opioid meperidine) can cause sudden, severe, irreversible parkinsonism in young people.

Symptoms

Parkinsonism causes the same symptoms as Parkinson's disease (see Movement Disorders: 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, as in the following:

• Prominent memory loss due to dementia
• Symptoms of parkinsonism on only one side of the body due to certain brain tumors
• Low blood pressure and urinary problems due to multiple system atrophy
• 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, symptoms begin after age 60. People become immobile after about 5 years, and death typically occurs after about 10 years.

Diagnosis

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's disease, to rule out Parkinson's disease. If the drug results in clear improvement, Parkinson's disease is the likely cause.

Treatment

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's disease (such as levodopa) are often not effective in people with parkinsonism but can sometimes offer modest improvement.

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

The same general measures used to help people with Parkinson's disease maintain mobility and independence are useful (see Movement Disorders: 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.

Last full review/revision August 2007 by David Eidelberg, MD; Michael Pourfar, MD