What Is Progressive Supranuclear Palsy

Progressive supranuclear palsy (PSP) is a degenerative condition of the nervous system that was first described in 1964. It can have symptoms and signs similar to Parkinson’s disease and is therefore classed as a “Parkinsonian syndrome”.

It affects the cells in your brain that control thinking, balance, movement, and certain muscles controlling your eyes. It typically develops in the mid to late 60s and worsens with time, with different variants now recognised and most people becoming dependent on care within a few years.¹ While PSP itself isn’t fatal, it can lead to severe complications such as pneumonia from inhaling food or liquid into the lungs or choking because of difficulty in swallowing.

What causes it?

While the exact cause is unknown, research shows that there is damage to certain cells in the brain in certain specific areas. A protein called “tau” is naturally found in the brain, however, in PSP it can accumulate into clumps and cause cells to stop working and die. Because of this cell death, the brain cannot work properly, and symptoms become apparent.² Because it commonly affects the substantia nigra, a part of the brain which has an important role in coordinating movement and dopamine production, there are then symptoms that mimic Parkinson’s.

PSP is usually sporadic, meaning it occurs randomly, although rarely it can result from a change in a person’s genes. There are no risk factors known apart from age.¹

Symptoms of PSP

As symptoms can get worse gradually and mimic other conditions, diagnosis can take some time. People can develop a range of symptoms, which progress at different rates amongst sufferers including:

• A loss of balance making falls (often backward) while walking more likely
• Changes in mood, behaviour, and thinking
• Changes in personality, such as becoming more irritable
• Difficulty controlling eye movements
• Blurred vision
• Inability to control the eyelids
• Extreme tiredness
• Neck stiffness
• Slurred speech
• Tremors in the hands
• Slow movement

Some of these may develop early in the course of the disease, others may take years to or never appear at all.

Subtypes of PSP

There is a wide range of variability in PSP, with many recognised types. Two of the more common examples are:

PSP with Richardson syndrome (PSP-RS)

This is the classic form of PSP, and features falls among its early symptoms, problems looking up and down, and difficulty in thinking. It accounts for 24% of PSP cases.¹

PSP with predominant parkinsonism (PSP-P)

This usually causes symptoms in the limbs at different stages (including tremors) and can respond initially to a drug used in Parkinson’s called levodopa. They have a slower rate of progression than PSP-RS, with falls occurring later.¹

Diagnosis

At present, there are no tests or scans that definitively diagnose PSP. Diagnosis is based on a detailed medical history and a physical and neurological examination. Early diagnosis, therefore, remains difficult, because of the large variety of signs and symptoms a patient may experience and its similarity to other diseases. 

Imaging can support diagnosis especially when there is evidence of brain shrinkage in a specific area of the brain on an MRI scan, but if this is clear it should not rule out PSP.² 

Balance problems and a change in how you walk are the most obvious symptoms in identifying PSP, particularly if they are joined with a problem with controlling your eyes.³

In 2017, the International Parkinson and Movement Disorder Society (MDS)-endorsed PSP Study Group created diagnostic criteria to be used in diagnosing PSP.⁴ This aimed to improve the detection of PSP and help distinguish it from other diseases.

What is the prognosis?

Compared with Parkinson’s, disease progression tends to be more rapid.

With good care from a multidisciplinary team people with PSP can have a better quality of life, however, the disease eventually puts them at risk of serious complications.

It is a good idea to talk with your healthcare team about advanced care planning, so they know your wishes and how best to treat you once you reach the advanced stage of the disease.⁵

Treatment

There are no treatments that change the progression of the disease, however, there are supportive measures available for someone with PSP. This will be given by a multidisciplinary team (MDT), which is a team of health and social care professionals working with you. This may include:

Neurologists are doctors who specialise in conditions affecting the brain and nervous system. You may be given drugs that are prescribed for people with Parkinson’s (like levodopa), although the effects of these are usually not as strong. A drug called amantadine may help with gait (including freezing) in a minority of cases as well.¹

Dietitians and speech and language therapists to help manage any difficulties in swallowing and speech. This can help you communicate more effectively and may involve evaluating your swallowing at set times to assess your risk of inhaling food or liquid. Foods with different consistencies may be offered so your nutritional needs are met.

As swallowing becomes more difficult you may be offered a feeding tube. This is usually a percutaneous endoscopic gastrostomy (PEG) tube and is inserted during an operation.

Occupational therapists are involved in promoting longer independence when performing activities you do daily and can help set up your home so the risk of falls is reduced by installing handrails for example. Mirror prism lenses can let those with severe problems with eye movement read and feed themselves.

Eyes can be taken care of with injections of botulinum toxin (e.g., Botox), and eyelid crutches may be offered as well as artificial tears/eye drops.

Physiotherapists may provide treatment for your reduced mobility, helping minimise falls and instability. A customised exercise program could help improve posture and other aspects of your mobility.

You may be offered walking aides such as walking frames and low-heel nonstick shoes, which could reduce your chances of a fall.

Treating anxiety and depression

Depression is a common symptom of PSP, and the fear of falling could contribute to anxiety and depression. Antidepressants can help with this, and may also help with balance, pain, and sleep issues.⁵

Other possible interventions

A small study looked at spinal cord stimulation in three patients with PSP-RS, finding that it improved gait and freezing symptoms although further, larger-scale studies would be needed to confirm the results.⁶

Studies looking at treatments targeting the protein tau and the energy-generating parts of the cell called mitochondria have been disappointing, but other trials are still ongoing which you may be eligible for.

Palliative care

This may be offered in any stage of the disease and palliative needs may be present from the time of diagnosis. 

It can help with distressing symptoms and should be tailored to the individual’s particular needs, whether they are physical, psychological, or spiritual.

You may wish to discuss where this care would be best offered to you, as some may prefer their home over a hospice or vice versa.

When should I call a healthcare professional?

Since the early symptoms of PSP can appear minor and be dismissed as “just aging”, it is important to visit a doctor at the earliest sign of such symptoms. This is especially vital if you are having problems with your eyes.

With an early diagnosis, good MDT support can be started earlier as well as discussions around social care and support from family and friends.

Those caring for someone with PSP can also contact associations that deal with PSP.

Summary

PSP is a rare neurological condition that has a variety of symptoms affecting body movements, balance, eye movements, and thinking. Damage to specific areas of the brain causes these problems, and because it can mimic Parkinson’s it is known as one of the Parkinsonian syndromes.

There are many variants of it, and no cure is available at present. The average age of onset is roughly 65 years and there have been no cases younger than 40. Although no tests exist to definitively diagnose PSP, diagnostic criteria have been proposed by a group to aid clinicians in diagnosis.

Once diagnosed, an MDT approach is appropriate with specialists providing physical therapy, speech therapy, medication, nutrition support, and other help with managing the condition. Although not fatal, symptoms get worse, and the risk of severe complications increases including choking and pneumonia from inhaled food and drink.

It’s best to have support early, so if you have any of the symptoms you should consult your healthcare professional.