What Is Parkinsonism?
This Q&A was originally published in the New York Times.
Parkinsonism refers to a group of movement abnormalities — such as stiffness, slowness, shuffling of the feet and often tremor — that are classic features of Parkinson’s disease but that can also be caused by medications and other disorders with overlapping symptoms, said Dr. Michael S. Okun, a neurologist and the national medical director of the Parkinson’s Foundation. He said that he makes no assumptions about the cause of parkinsonism “until I see the patient and pinpoint the diagnosis.”
Determining the cause of parkinsonism involves asking a series of questions, starting with, “Do we think this is regular Parkinson’s disease?” said Dr. Okun, who is also co-director of the Center for Movement Disorders and Neurorestoration at the University of Florida College of Medicine in Gainesville.
Though a diagnosis of Parkinson’s disease strikes fear in patients, Dr. Okun said that the illness, a neurodegenerative brain disorder caused by the loss of dopamine-containing neurons and other cells, progresses slowly in many people and generally responds well to drugs that replenish dopamine in the brain. Some patients whose parkinsonism is not caused by Parkinson’s disease also respond to these drugs, but the medications are most effective for people with Parkinson’s disease, Dr. Okun said.
It’s important to rule out other potential causes of parkinsonism, he said. The condition can be triggered by antipsychotic medications that affect dopamine levels in the brain, as well as by other drugs, including stimulants like amphetamines and cocaine. Discontinuing the drugs may stop the symptoms over time, though not always. Parkinsonism may also be caused by repeated injuries to the head, exposure to various toxins or brain lesions.
Once doctors rule out Parkinson’s disease, they must consider several other serious neurological disorders. The three most common ones are multiple system atrophy, a degenerative disorder also referred to as Shy-Drager syndrome, which may or may not respond well to Parkinson’s medications; progressive supranuclear palsy, or PSP, which also may respond to high doses of drugs that replace dopamine in the brain; and corticobasal degeneration (CBD). Patients with a form of dementia called Lewy body dementia may also exhibit symptoms of parkinsonism, which may or may not respond to dopamine. Various other movement disorders, called ataxias or dystonias, also may display features of parkinsonism.