What Other Diseases Resemble Parkinson's?
A number of disorders can cause symptoms similar to
those of Parkinson Disease. People with symptoms that resemble
Parkinson Disease but that result from
other causes are sometimes said to have
parkinsonism. Some of these disorders are listed below.
Just after the first World War, a viral disease, encephalitis lethargica,
attacked almost 5 million people throughout the world, and then suddenly
disappeared in the 1920s. Known as sleeping sickness in the
United States , this disease killed one
third of its victims and led to post-encephalitic parkinsonism in many
others. This resulted in a particularly severe form of movement
disorder that appeared sometimes years after the initial illness. (In
1973, neurologist Oliver Sacks published Awakenings, an account
of his work in the late 1960s with surviving post-encephalitic patients
in a New York
hospital. Using the then-experimental drug levodopa, Dr. Sacks was
able to temporarily "awaken" these patients from their statue-like state).
In rare cases, other viral infections, including western equine
encephalomyelitis, eastern equine encephalomyelitis, and Japanese B
encephalitis, have caused parkinsonian symptoms.
Drug-induced parkinsonism. A
reversible form of parkinsonism sometimes results from use of certain
drugs, such as chlorpromazine and haloperidol, which are prescribed for
patients with psychiatric disorders. Some drugs used for stomach
disorders (metoclopramide), high blood pressure (reserpine), and
epilepsy (valproate) may also produce parkinsonian symptoms. Stopping
the medication or lowering the dosage of these medications usually
causes the symptoms to go away.
Some toxins such as manganese dust, carbon disulfide, and carbon
monoxide can cause parkinsonism. The chemical MPTP also causes a
permanent form of parkinsonism that closely resembles Parkinson Disease. Investigators
discovered this reaction in the 1980s when heroin addicts in California
who had taken an illicit street drug contaminated with MPTP began to
develop severe parkinsonism. This discovery, which showed that a toxic
substance could damage the brain and produce parkinsonian symptoms,
caused a dramatic breakthrough in Parkinson's research: for the first
time, scientists were able to simulate Parkinson Disease in animals and conduct studies
to increase understanding of the disease.
Sometimes known as pseudoparkinsonism, vascular parkinsonism, or
arteriosclerotic parkinsonism involves damage to the brain due to
multiple small strokes. Tremor is rare in this type of
parkinsonism, while dementia the
loss of mental skills and abilities is common. Antiparkinsonian drugs
are of little help to patients with this form of
Parkinsonism-dementia complex of Guam. This disease occurs
among the Chamorro populations of Guam and the Mariana Islands and may
be accompanied by a motor neuron disease resembling amyotrophic lateral
sclerosis (Lou Gehrig's disease). The course of the disease is rapid,
with death typically occurring within 5 years.
Also known as post-traumatic encephalopathy or "punch-drunk syndrome,"
parkinsonian symptoms can sometimes develop after a severe head injury
or frequent head trauma that results from boxing or other activities.
This type of trauma also can cause a form of
dementia called dementia pugilistica.
Essential tremor. Essential tremor, sometimes
called benign essential tremor or familial tremor, is a common condition
that tends to run in families and progresses slowly over time. The
tremor is usually equal in both hands and increases when the hands are
moving. The tremor may involve the head but usually spares the legs.
Patients with essential tremor have no other parkinsonian features.
Essential tremor is not the same as Parkinson Disease, and usually does not lead to it,
although in some cases the two conditions may overlap in one person.
Essential tremor does not respond to levodopa or most other Parkinson
but it can be treated with other medications.
Normal pressure hydrocephalus. Normal pressure hydrocephalus
(NPH) is an abnormal increase of cerebrospinal fluid (CSF) in the
brain's ventricles, or cavities. It occurs if the normal flow of CSF
throughout the brain and spinal cord is blocked in some way. This causes
the ventricles to enlarge, putting pressure on the brain. Symptoms
include problems with walking, impaired bladder control leading to
urinary frequency or incontinence, and progressive mental impairment and
dementia. The person also may have a general slowing of movements or may
complain that his or her feet feel "stuck." These symptoms may
sometimes be mistaken for Parkinson Disease. Brain scans, intracranial pressure
monitoring, and other tests can help to distinguish NPH from Parkinson
other disorders. NPH can sometimes be treated by surgically implanting
a CSF shunt that drains excess cerebrospinal fluid into the abdomen,
where it is absorbed.
Progressive supranuclear palsy. Progressive
supranuclear palsy (PSP), sometimes called Steele-Richardson-Olszewski
syndrome, is a rare, progressive brain disorder that causes problems
with control of gait and balance. People often tend to fall early in
the course of PSP. One of the most obvious signs of the disease is an
inability to move the eyes properly. Some patients describe this effect
as a blurring. PSP patients often show alterations of mood and behavior,
including depression and apathy as well as mild dementia. The symptoms
of PSP are caused by a gradual deterioration of brain cells in the
brainstem. It is often misdiagnosed because some of its symptoms are
very much like those of Parkinson Disease, Alzheimer's disease,
and other brain disorders. PSP symptoms usually do not respond to
Corticobasal degeneration. Corticobasal
degeneration results from atrophy of multiple areas of the brain,
including the cerebral cortex and the basal ganglia. Initial symptoms
may first appear on one side of the body, but eventually affect both
sides. Symptoms are similar to those found in Parkinson Disease, including rigidity,
impaired balance and coordination, and dystonia. Other symptoms may
include cognitive and visual-spatial impairments, apraxia (loss of the
ability to make familiar, purposeful movements), hesitant and halting
speech, myoclonus (muscular jerks), and dysphagia (difficulty
swallowing). Unlike Parkinson Disease, corticobasal degeneration usually does not
respond to medication.
Multiple system atrophy.
Multiple system atrophy (MSA) refers to a set of slowly progressive
disorders that affect the central and autonomic nervous systems. MSA may
have symptoms that resemble Parkinson Disease. It also may take a form that primarily
produces poor coordination and slurred speech, or it may have a mixture
of these symptoms. Other symptoms may include breathing and swallowing
difficulties, male impotence, constipation, and urinary difficulties.
The disorder previously called Shy-Drager
syndrome refers to MSA with prominent orthostatic hypotension a fall
in blood pressure every time the person stands up. MSA with
parkinsonian symptoms is sometimes referred to as striatonigral
degeneration, while MSA with poor coordination and slurred speech is
sometimes called olivopontocerebellar atrophy.
Dementia with Lewy bodies.
Dementia with Lewy bodies is a
neurodegenerative disorder associated with abnormal protein deposits (Lewy
bodies) found in certain areas of the brain. Symptoms can range from
traditional parkinsonian symptoms, such as bradykinesia, rigidity,
tremor, and shuffling gait, to symptoms similar to those of
Alzheimer's disease. These symptoms may
fluctuate, or wax and wane dramatically. Visual hallucinations may be
one of the first symptoms, and patients may suffer from other
psychiatric disturbances such as delusions and depression. Cognitive
problems also occur early in the course of the disease. Levodopa and
other antiparkinsonian medications can help with the motor symptoms of
dementia with Lewy bodies, but they may make hallucinations and
accompanying other conditions. Parkinsonian symptoms may also appear
in patients with other, clearly distinct neurological disorders such as
Wilson's disease, Huntington's disease, Alzheimer's disease,
spinocerebellar ataxias, and Creutzfeldt-Jakob disease. Each of these
disorders has specific features that help to distinguish them from
MSA, corticobasal degeneration, and progressive
supranuclear palsy are sometimes referred to as "Parkinson's-plus"
diseases because they have the symptoms of Parkinson Disease plus additional features.
National Institute of Neurological
Disorders and Stroke (NINDS)
National Institutes of Health
Brain Resources and Information Network
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