Progressive Supranuclear Palsy

Progressive supranuclear palsy is a rare brain disease that causes serious problems with walking, balance, eye movements, and swallowing, often leading to dangerous falls and complications.

Steele-Richardson-Olszewski syndrome

Table of contents

• What is progressive supranuclear palsy?
• Signs and symptoms
• Types of PSP
• What causes PSP?
• How is PSP diagnosed?
• Treatment and management
• What to expect

What is progressive supranuclear palsy?

Progressive supranuclear palsy, also known as PSP, is a rare brain disease that affects how you move, think, speak, and see. The word “progressive” means that symptoms get worse over time. “Supranuclear” refers to the part of the brain that is damaged—it is above small areas called nuclei in the brainstem. “Palsy” means weakness or difficulty using muscles.^[1][2]

PSP is caused by damage to nerve cells in areas of the brain that control thinking and body movements. These damaged areas include the brainstem, cerebral cortex (the outer layer of the brain), cerebellum (which controls coordination), and basal ganglia (a cluster of cells deep within the brain).^[1] The disease belongs to a family of conditions called atypical parkinsonism, also known as Parkinson-plus disorders.^[2][6]

• Brain (brainstem, cerebral cortex, cerebellum, basal ganglia)

PSP is rare, affecting about 5 to 7 people out of every 100,000. Around 30,000 people in the United States have PSP.^[2][7] The condition most commonly affects people over the age of 60, though symptoms can start in a person’s 40s. It very rarely develops before the age of 40.^[2] Men are slightly more likely to be affected than women.^[3]

Signs and symptoms

The symptoms of PSP vary from person to person and tend to begin gradually. In about two-thirds of cases, the first symptom is a loss of balance when walking or climbing stairs, often leading to sudden falls. These falls often happen backward without loss of consciousness.^[3][4] About one in five cases begin with changes in thinking or memory.^[3]

Common early symptoms include changes in personality, general slowing of movement, and problems with vision. The most common behavioral symptoms include apathy (lack of interest in activities), anxiety, irritability, and a profound feeling of unease.^[3][7]

As the disease progresses, most people develop eye problems. The most important symptom of PSP is difficulty moving the eyes, especially looking downward. This is called vertical supranuclear gaze palsy. People may also experience trouble looking up or sideways, slow eye movements, difficulty controlling eyelids, decreased blinking, or problems opening the eyes.^[1][4][6] Because of severely decreased blinking and reduced facial expressions, people with PSP may have an “astonished” or wide-eyed staring appearance.^[4]

Many people with PSP experience sensitivity to bright light, a condition called photophobia. This can be explained partly by the decreased rate of eye blinking. It can be associated with redness of the eyes and increased tearing, and some people may need to wear sunglasses even indoors.^[2][4]

Other symptoms that develop over time include:

• Stiff muscles that affect the ability to move, especially stiffness in the neck and trunk
• Slowness of movement
• Difficulty speaking—speech may be quieter, slurred, or slow
• Difficulty swallowing, which can lead to choking or gagging
• Changes in mood, such as depression and increased irritability
• Changes in behavior, including poor judgment and impulsivity
• Slowness of thought and memory problems
• Difficulty finding words
• Personality changes
• Sleep problems, including insomnia
• A mask-like facial expression

^[1][2][5][6]

PSP is often mistaken for Parkinson’s disease, especially early in the disorder, because the two conditions share many symptoms. However, there are key differences. People with PSP tend to lean backward and fall backward, while people with Parkinson’s tend to bend forward and fall forward. Tremor is a common symptom in Parkinson’s disease, but people with PSP do not tend to experience tremor. PSP also progresses more rapidly than Parkinson’s disease and responds poorly to medications that work for Parkinson’s.^[6][7]

Types of PSP

There are different types, or subtypes, of PSP. They all share similar symptoms, but there are some unique differences. The two most common types are Richardson syndrome (PSP-RS) and Parkinson’s disease-like variant (PSP-P). Together, they make up 75% of PSP cases.^[2]

Richardson syndrome is the most common form of PSP. It typically starts above age 50 with balance problems that lead to unexplained falls, often backward. People with this type develop stiffness more in their neck and trunk than in their limbs. They tend to walk, turn, and sit as a “block” because of stiffness in their trunk. Other features include difficulty looking up and down, a wide-eyed staring expression, slowness of thought, and problems with attention and decision-making.^[2][4]

The Parkinson’s disease-like variant (PSP-P) has similar symptoms to Richardson syndrome but more closely resembles Parkinson’s disease. A tremor (involuntary shaking) is the main symptom instead of balance problems. This type may respond better to Parkinson’s medications than other types of PSP, at least for some time.^[2]

Other less common subtypes include corticobasal syndrome and pure akinesia with gait freezing.^[2]

What causes PSP?

Scientists do not know the exact cause of progressive supranuclear palsy. However, experts know that a protein called tau is involved. Tau is an important protein for brain health. In people with PSP, tau is not broken down properly and forms harmful clumps in brain cells. The amount and location of abnormal tau in the brain can vary among people with PSP, which means the condition can have a wide range of symptoms.^[2][5]

The condition has been linked to changes in certain genes, but these genetic changes are not inherited. The risk to other family members, including children or siblings of someone with PSP, is very low.^[5]

PSP has no known geographical, occupational, or racial preference. No association has been found between PSP and any particular race, location, or occupation.^[3][7]

How is PSP diagnosed?

There is no single test to diagnose PSP. Instead, the diagnosis is based on the pattern of symptoms. A doctor will try to rule out other conditions that can cause similar symptoms, such as Parkinson’s disease.^[5][7]

PSP can be hard to diagnose because symptoms are similar to those of other conditions. More than 50% of people with PSP are initially misdiagnosed with Parkinson’s disease. Healthcare providers usually begin to rethink the diagnosis when symptoms progress faster than expected or when typical Parkinson’s medications are not working.^[7][8]

Your healthcare professional may suspect PSP rather than Parkinson’s disease if you do not have tremors, are having many unexplained falls, have little or no response to Parkinson’s medicines, and have trouble moving your eyes, particularly looking downward.^[8]

The diagnosis must be made or confirmed by a specialist with expertise in PSP, usually a neurologist (a specialist in conditions affecting the brain and nerves).^[5] You may need to have a brain scan, such as an MRI (magnetic resonance imaging), to look for shrinkage in specific regions of the brain associated with PSP and to help exclude other disorders that may mimic PSP. A PET scan (positron emission tomography) may also be recommended to check for early signs of changes in the brain that may not appear on an MRI.^[8]

You may also need tests of your memory, concentration, and ability to understand language.^[5] Because many healthcare providers are unfamiliar with the disease, it can take a long time for people to receive an accurate diagnosis.^[7]

Treatment and management

There is currently no cure for progressive supranuclear palsy. No medication or procedure is available to stop the progression of the disease. However, treatments are available to help ease symptoms and improve quality of life.^[1][5]

Because PSP can affect many different areas of health, care is provided by a team of health and social care professionals working together. This is known as a multidisciplinary team. Members may include a neurologist, physiotherapist, speech and language therapist, occupational therapist, social worker, eye specialist, and specialist neurology nurse.^[9]

Medications

Some people in the early stages of PSP may benefit from medications used to treat Parkinson’s disease, such as levodopa (often combined with carbidopa). These medicines increase levels of a brain chemical involved in smooth, controlled muscle movements. However, the effectiveness of these medicines is limited and usually temporary, lasting about 2 to 3 years in most patients. Only a few patients respond to these drugs, and responses are often short-lived and incomplete.^[8][9]

Other medications may be used based on specific symptoms. Antidepressants can help with depression, mood changes, and may also help with pain, bladder and bowel problems, and sleep disturbances. Muscle relaxants may be helpful if stiffness is severe. Botox (botulinum toxin) injections may be used to help relax the muscles around the eyes, which can improve eyelid spasms and help with drooling.^[8][9]

Physical therapy

A physiotherapist can give advice about making the most of remaining mobility using exercise, while making sure you do not overexert yourself. Regular exercise may help strengthen muscles, improve posture, and prevent stiffening of joints. Your physiotherapist can advise about equipment that could benefit you, such as a walking frame or specially designed shoes to reduce the risk of slipping and falling. They can also teach breathing exercises to use when eating to reduce the risk of developing aspiration pneumonia (a chest infection caused by food particles falling into the lungs).^[9]

Speech and language therapy

A speech and language therapist can help improve speech and swallowing problems. They can teach techniques to help make your voice as clear as possible and can advise about suitable communication aids or devices you may need as the condition progresses. Your therapist can also advise about different swallowing techniques and may suggest altering the consistency of your food to make swallowing easier.^[9]

Occupational therapy

An occupational therapist can advise about how to increase safety and prevent trips and falls during day-to-day activities. For example, many people with PSP benefit from having bars placed along the sides of their bath to make it easier to get in and out. The occupational therapist will also be able to spot potential hazards in your home that could lead to a fall, such as poor lighting, loose rugs, and crowded walkways.^[9]

Eye care

If you are having problems controlling your eyelids, injections of botulinum toxin (such as Botox) can help relax the muscles. The effects usually last for up to 3 months. Special glasses with prisms may improve vision. Chronic eye irritation is common because of the reduced rate of blinking and can be treated with eye drops.^[9]

Nutrition and feeding

As swallowing problems become more severe, you may need additional treatment. A dietitian can advise on how to have a healthy, balanced diet when making changes to the consistency or texture of what you eat. Feeding tubes may be recommended for severe swallowing problems, where the risk of malnutrition, dehydration, and choking is increased. The main type of feeding tube used is called a percutaneous endoscopic gastrostomy (PEG) tube, which is placed into the stomach through the abdomen during an operation.^[9]

What to expect

PSP is a progressive disease, which means symptoms will keep getting worse over time. The rate at which symptoms progress can vary widely from person to person.^[5] PSP progresses more rapidly than Parkinson’s disease. The disease usually worsens rapidly, and most people with PSP develop severe disability within three to five years of symptom onset.^[6]

PSP worsens over time and can lead to dangerous complications, such as pneumonia (often caused by breathing food into the lungs), choking, trouble swallowing, or head injuries from falls.^[1][6] Survival rates are shortened compared to the general population, with most people living about 7 to 10 years after diagnosis.^[4]

Good care and assistance can help someone with PSP to be more independent and enjoy a better quality of life. It is important to talk to your care team about what you would like to happen as the condition progresses.^[5]

Research is continuing into new treatments that aim to relieve symptoms and slow down the progression of the condition. There are ongoing clinical trials testing new drugs that could lead to the development of therapies for PSP.^[12]