What is atypical parkinsonism?
Atypical parkinsonism (also called atypical Parkinson’s) refers to a group of conditions that share similar symptoms and features with Parkinson’s disease. These uncommon disorders may result from certain medications, illnesses, or other conditions of the nervous system.
Specialists in movement disorders care at Penn Medicine have decades of experience diagnosing and treating rare and complex movement conditions. People from across the region come to us for expert evaluation and care.
Common forms of atypical parkinsonism
Parkinsonism is a general term describing Parkinson’s disease and other neurological conditions with similar symptoms. The most common disorder causing parkinsonism is Parkinson’s disease, while other conditions that cause atypical parkinsonism are more rare.
The four most common atypical parkinsonism disorders are:
- Dementia with Lewy Bodies (DLB): This condition is the most common of the four atypical parkinsonism disorders. People with DLB may exhibit difficulty moving, thinking, sleeping, and focusing. They may also have hallucinations that cause them to see, smell, hear, or feel things that aren’t there.
- Progressive supranuclear palsy (PSP): PSP affects balance, walking, eye movements, and swallowing. People with PSP may also experience problems with thinking and focusing.
- Multiple system atrophy (MSA): MSA affects movement and control of the body’s involuntary (autonomic) processes, like blood pressure, breathing, and bladder control.
- Corticobasal syndrome (CBS): In this condition, areas of the brain shrink, and nerve cells die off over time. It is the rarest of the four atypical parkinsonism disorders. People with CBS have problems with moving, balancing, speaking, swallowing, and thinking.
How atypical parkinsonism affects the body
The symptoms of atypical parkinsonism can vary depending on the specific type of disorder, but often include a combination of motor and non-motor symptoms.
Atypical parkinsonism symptoms may include the following:
- Memory loss or confusion (dementia)
- Muscle stiffness or rigidity
- Postural instability and frequent falls
- Problems making facial expressions
- Slowed movements (bradykinesia)
- Soft or low voice, or slurred speech
- Tremors
While symptoms may appear similar, atypical parkinsonism often doesn’t respond well to the standard medication (levodopa) used to treat Parkinson’s disease.
Understanding the root causes
Symptoms of atypical parkinsonism may improve once the underlying cause is identified and treated. For example, treating infections or poisoning can decrease symptoms. Other conditions causing atypical parkinsonism are progressive and cannot be reversed with treatment.
Conditions that may cause atypical parkinsonism include:
- Brain infections such as encephalitis and meningitis
- Brain injuries such as stroke or repeated head injuries from contact sports or accidents
- Brain damage from anesthesia drugs used during surgery
- Infections such as HIV/AIDS
- Medications, especially drugs used to treat psychiatric conditions or nausea
- Poisoning with carbon monoxide, mercury, or other toxic chemicals
- Wilson disease, a rare condition that causes copper to build up in the liver, brain, and other organs
Identifying rare movement disorders
Atypical parkinsonism disorders can be very difficult to diagnose. These disorders are frequently mistaken for Parkinson’s disease, dementia, or other neurological conditions. They may also be confused with one another.
There are no specific blood tests or imaging studies that can confirm atypical parkinsonism on their own. Instead, your care team makes a diagnosis by ruling out other conditions. They may order certain tests to look for signs of other illnesses or to see how the brain is functioning.
At Penn Medicine, movement specialists have the experience and skill to detect the subtle differences between these rare disorders. This expertise is why the Lewy Body Dementia Association recognizes Penn Medicine as a Center of Excellence for the diagnosis and treatment of people with DLB.
Specialized treatment for atypical parkinsonism disorders
There are no cures for these conditions, so treatments aim to manage symptoms and maximize quality of life. A comprehensive approach helps you stay independent for as long as possible and prevents complications, like falls or breathing in food while eating.
Your care team may use a variety of therapies to address specific challenges. Medications may help treat psychiatric or cognitive changes. While the standard medication for Parkinson’s disease doesn’t usually work for these conditions, some people may respond to it briefly before the effects wear off.
Physical and occupational therapy programs are also essential, as they focus on maintaining mobility and safety during daily activities. For those experiencing communication or eating difficulties, speech and other therapies can help. In some cases, your provider may use injections to treat the muscle stiffness or involuntary movements often seen in CBS and MSA.