Each year in the United States, about 60,000 people are diagnosed with Parkinson's disease, according to the ]]>Parkinson's Disease Foundation]]>. This neurological condition results from damage to the nerve cells within the brain that produce the neurotransmitters dopamine. The decrease in the amount of dopamine in the brain causes movement problems, such as problems starting movement, rigid muscles and tremors. But other conditions exist that produce similar symptoms to Parkinson's disease, which are called “parkinsonism.”
When the cause of the Parkinson's disease symptoms can be identified, the patient has secondary parkinsonism. The ]]>Mayo Clinic]]> noted that this occurs in around 10 percent of patients with Parkinson's disease. Several conditions can cause secondary parkinsonism. ]]>MedlinePlus, a service of the U.S. National Library of Medicine and the National Institutes of Health]]>, explained that medications are a common cause of the disorder, which include drugs such as metoclopramide, haloperidol and phenothiazine medications. Conditions that injure the brain, such as a stroke, encephalitis or meningitis, can cause secondary parkinsonism. Other possible causes include progressive supranuclear palsy, carbon monoxide poisoning, corticobasal degeneration, narcotic overdose, brain damage that results from anesthesia, multiple system atrophy, diffuse Lewy body disease and toxin exposure.
In some cases, the secondary parkinsonism can be reversed if a doctor can find the cause early in the presentation of symptoms. Secondary parkinsonism caused by an antipsychotic, for example, is reversible if found early. But if the secondary parkinsonism results from toxins, infections or brain damage from drug use, the secondary parkinsonism may not be reversible, according to MedlinePlus.