What is Progressive Supranuclear Palsy?
Progressive Supranuclear Palsy
Progressive supranuclear palsy (PSP) is a rare brain disorder that causes problems with movement, balance and eye movements. It results from the breakdown of nerve cells in parts of the brain and brainstem that control movement and thinking. PSP shares many features with Parkinson’s disease and is considered an atypical parkinsonian disorder. It is progressive, its cause is not fully understood, and there is currently no cure. There are also no treatments yet that slow its progression, so care focuses on managing symptoms.
People with PSP often have stiffness and slow movement. Walking problems are common, and falls and fall-related injuries are a major concern. As PSP progresses, people may develop problems with thinking and memory, along with emotional changes. Difficulty moving the eyes, especially looking down, can cause blurred or double vision and add to balance problems. Non-movement symptoms are also common, including changes in sleep, mood and sexual function (1).
How Common Is PSP?
PSP is rare, affecting about 5 to 10 people per 100,000. Symptoms usually begin around age 65, and men and women are affected about equally (2).
What Causes PSP?
The exact cause of PSP is not known. It mainly involves the breakdown of cells in the brainstem, and as it advances, other brain systems are affected too. The substantia nigra, a brainstem area that produces dopamine, is involved. Dopamine is essential for controlling movement, and its loss causes many of the movement symptoms seen in both Parkinson’s disease and PSP.
PSP belongs to a group of disorders called tauopathies. Tau is a protein that helps give nerve cells their structure, and it is normally broken down and rebuilt all the time. In tauopathies, this process fails, and tau builds up abnormally inside cells. Over time, this buildup disrupts other cell functions and the cells die. As more cells are lost, communication between brain pathways breaks down and symptoms appear (3).
Most cases of PSP have no clear cause. Some appear to be linked to genetic variations (4). Researchers are also studying whether factors like infections, chemical exposures or metabolic problems that cause oxidative stress may play a role (5).
Despite growing understanding of tauopathies like PSP, diagnosing PSP early and accurately remains challenging (6).
What Are the Symptoms of PSP?
PSP can affect movement and coordination, walking and balance, speech, swallowing, eye movements and vision, thinking, behavior and mood. Symptoms vary from person to person, but the most common early symptom is loss of balance while walking. Often the first sign is an unexpected fall.
As PSP progresses, most people develop vision-related problems. These can include trouble opening and closing the eyes, changes in blinking, eyes closing on their own, slow eye movements and difficulty looking down. People may need to turn their head to look in different directions.
PSP usually affects emotions and behavior as well. Depression, apathy, thinking problems, trouble finding words, memory problems and personality changes are common. Some people have emotional reactions that don’t match the situation. Speech changes, difficulty swallowing and reduced facial expression are also common (7).
If you or a loved one with PSP has trouble swallowing, frequent coughing or choking while eating, or unexplained weight loss, talk with your doctor promptly.
How Is PSP Different From Parkinson’s Disease?
PSP is often mistaken for Parkinson’s disease, since both tend to begin later in life and share many movement symptoms. One clue is posture. People with Parkinson’s tend to stoop forward, while people with PSP often stand very upright, sometimes with the neck tilted back. PSP usually progresses faster, and speech and swallowing problems tend to appear earlier. Tremor is common in Parkinson’s but uncommon in PSP. And while people with Parkinson’s usually respond well to levodopa, people with PSP respond poorly, if at all (8).
How Is PSP Diagnosed?
PSP is diagnosed by a physician, usually a neurologist. There is currently no test that can confirm PSP during life. A definite diagnosis can only be made by examining the brain after death (8).
In practice, PSP is diagnosed based on clusters of findings. These include eye movement problems, such as limited or slow up-and-down eye movements, frequent small jerks when trying to hold the eyes steady, or difficulty opening the eyelids; balance problems, such as repeated unprovoked falls or a tendency to fall backward when tested; movement problems, such as freezing while walking, stiffness of the spine and little or no response to levodopa; and thinking and communication problems, such as speech and language difficulties and changes in planning, judgment and behavior (9).
How Does PSP Affect the Brain?
PSP is a protein buildup disorder, like Parkinson’s and Alzheimer’s diseases, although different proteins are involved in each, alpha-synuclein in Parkinson’s and amyloid beta in Alzheimer’s. Strong evidence suggests that misfolded proteins in these disorders can disrupt communication between nerve cells and lead to cell death and brain damage (10).
Under the microscope, the hallmark of PSP is a buildup of tau in nerve cells and their supporting cells. This affects many brain regions, including the basal ganglia, substantia nigra, subthalamic nucleus, brainstem and motor cortex (8).
Over time, the damage can become visible on brain imaging. MRI can show shrinkage of the midbrain, the subthalamic nucleus and a cerebellar pathway called the superior cerebellar peduncle, along with other changes (11).
How Is PSP Usually Treated?
There is currently no cure for PSP (12). Care focuses on managing symptoms and may include speech therapy, occupational therapy and physical therapy, along with medications and Botox injections for certain symptoms (13).
How the NeuroRescue Program Can Help
We cannot cure PSP or stop its progression. Our goal is to help you make the most of the function you have, with a focus on balance, walking, safety, eye movements, thinking and quality of life. Our care works alongside your neurologist and other providers, never in place of them. Please don’t change any medication without talking with your prescriber.
Eye movements and balance. Much of the difficulty in PSP involves knowing where you are in space. Your brain combines signals from your muscles and joints, your inner ear and your eyes to build a picture of where you are. Your eyes constantly scan your surroundings using saccades, quick jumps from one point to another.
To move safely through the world, saccades need to be fast, accurate and quick to start. Because the basal ganglia help control saccades, they often become slow, less accurate and quick to tire in parkinsonian disorders. Research has linked these saccade problems to poor balance (14), difficulty turning (15) and freezing while walking (16). We use targeted saccade exercises with the goal of supporting balance, walking and stability.
Anti-saccades are a more complex type of eye movement, in which a person must hold back the urge to look at a new target and look the other way instead. Anti-saccades draw on the brain’s planning and self-control systems. Research shows that anti-saccades are affected in parkinsonian disorders, and these changes have been linked to problems with planning, reasoning and emotional control (17). We use anti-saccade exercises with the goal of supporting flexible thinking and emotional regulation.
Other therapies. Much of the research on these therapies has been done in Parkinson’s disease and related conditions rather than in PSP specifically. Depending on your needs, your program may include vestibular rehabilitation, which has been studied for balance, walking and thinking (18); optokinetic visual stimulation, which has been studied for movement control and posture (19, 20); various forms of electrical stimulation, applied through the skin, which have been studied for balance, walking, eye movements, tremor, blood pressure regulation and swallowing (21, 22, 23, 24); and virtual reality exercises, which have been studied for improving daily function and reducing fall risk (25).
Transcranial magnetic stimulation. TMS has been studied for improving movement, balance and mood in parkinsonian conditions (26). At our clinic, TMS is provided by our psychiatric mental health nurse practitioner, who will evaluate whether it’s appropriate for you.
Nutrition. Cells normally clear out damaged proteins through a cleanup process called autophagy, and this process falls behind in protein buildup disorders. Research, mostly in animals, suggests that fasting and related eating patterns can boost this cleanup process (27, 28), but research in people with PSP is limited. Because weight loss and swallowing problems are common in PSP, any changes to eating patterns should be made carefully and discussed with your physician.
Recovery between sessions. Some programs include mild hyperbaric therapy as a structured recovery option between more demanding therapy sessions.
Every person with PSP is different, and so is every NeuroRescue Program. Your plan is based on your test results and the specific factors of your case.
How the NeuroRescue Program Works
Your NeuroRescue Program begins with your Discovery Day. We start with a detailed history of your condition and your life on a timeline. This helps us understand the factors that may have contributed to where you are now, and identify related conditions that may be making it harder to move forward. When appropriate, we may also look at metabolic factors such as gut health, oxidative stress and mitochondrial function.
We measure how your visual, vestibular and balance systems are working through computerized analysis of your eye movements, inner ear reflexes and balance under different conditions. Our testing includes videonystagmography and saccadometry to measure several types of eye movements, the video head impulse test to measure inner ear reflexes, and CAPS computerized posturography to assess your balance under different sensory conditions. We also use NeuroSensoryMotor Integration testing to evaluate hand-eye coordination and cognition, and Virtualis testing to assess dynamic eye tracking and your perception of vertical in a virtual reality environment.
We combine this with a thorough physical and neurological exam of your sensory, motor, autonomic and cognitive systems. We also review any relevant lab work, imaging and prior testing, and integrate it with our findings.
Together, this helps us understand which parts of your nervous system are working well, which are struggling, and how quickly they tire. We use that information to design your personal NeuroRescue Program, aimed at supporting function and endurance in the systems that need it. Our testing also helps us decide when to push and when to let you rest.
We can’t bring back nerve cells that have been lost. What we can do is work with the pathways that remain, helping them work as efficiently as possible and work better together. Our goal is to help you stay as active, safe and independent as possible, for as long as possible.
Your Next Step
Living with PSP is challenging. While we cannot cure it, many symptoms can be managed, and function and quality of life can often be supported. To find out if the NeuroRescue Program is right for you, contact one of our patient care coordinators to schedule your Discovery Day.
It’s never too late to take the next step.
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