Progressive Supranuclear Palsy Causes, Symptoms, Diagnosis, Treatment

Progressive Supranuclear Palsy Causes, Symptoms, Diagnosis, Treatment

What is progressive supranuclear palsy?

Progressive supranuclear palsy (PSP) is a rare brain disorder that causes serious and permanent problems with control of gait and balance. The most obvious sign of the disease is an inability to aim the eyes properly, which occurs because of lesions in the area of the brain that coordinates eye movements. Some patients describe this effect as a blurring. PSP patients often show alterations of mood and behavior, including depression and apathy as well as progressive mild dementia.

The disorder's long name indicates that the disease begins slowly and continues to get worse (progressive), and causes weakness (palsy) by damaging certain parts of the brain above pea-sized structures called nuclei that control eye movements (supranuclear).

PSP was first described as a distinct disorder in 1964, when three scientists published a paper that distinguished the condition from Parkinson's disease. It is sometimes referred to as dementia-nuchal dystonia, or as Steele-Richardson-Olszewksi syndrome, reflecting the combined names of the scientists who defined the disorder. Although PSP gets progressively worse, no one dies from PSP itself.

Progressive supranuclear palsy is a rare neurodegenerative disease that is often misdiagnosed as Parkinson's disease because its symptoms are similar. Because of its rarity, PSP is mostly unknown by the general public.

Who gets Progressive Supranuclear Palsy?

Approximately 20,000 Americans - or one in every 100,000 people over the age of 60 - have PSP, making it much less common than Parkinson's disease, which affects more than 500,000 Americans. Patients are usually middle-aged or elderly, and men are affected more often than women. PSP is often difficult to diagnose because its symptoms can be very much like those of other, more common movement disorders, and because some of the most characteristic symptoms may develop late or not at all.

What causes Progressive Supranuclear Palsy?

We know that the symptoms of PSP are caused by a gradual deterioration of brain cells in a few tiny but important places at the base of the brain, in the region called the brainstem. One of these areas, the substantia nigra, is also affected in Parkinson's disease, and damage to this region of the brain accounts for the motor symptoms that PSP and Parkinson's have in common.

Scientists do not know what causes these brain cells to degenerate. There is no evidence that PSP is contagious, and genetic factors have not been implicated in most patients. No ethnic or racial groups have been affected more often than any others, and PSP is no more likely to occur in some geographic areas than in others.

There are, however, several theories about PSP's cause. One possibility is that an unconventional virus-like agent infects the body and takes years or decades to start producing visible effects. Creutzfeldt-Jakob disease is one disease known to be caused by such an agent. Another possibility is that random genetic mutations, of the kind that occur in all of us all the time, happen to occur in particular cells or certain genes, in just the right combination to injure these cells. A third possibility is that there is exposure to some unknown chemical in the food, air, or water which slowly damages certain vulnerable areas of the brain. This theory stems from a clue found on the Pacific island of Guam, where a common neurological disease occurring only there and on a few neighboring islands shares some of the characteristics of PSP, Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis (Lou Gehrig's disease). Its cause is thought to be a dietary factor or toxic substance found only in that area.

Another possible cause of PSP is cellular damage caused by free radicals, unstable molecules produced continuously by all cells during normal metabolism. Although the body has built-in mechanisms for clearing free radicals from the system, scientists suspect that, under certain circumstances, free radicals can react with and damage other molecules. A great deal of research is directed at understanding the role of free radical damage in human diseases.

What are the symptoms of Progressive Supranuclear Palsy?

The most frequent first symptom of PSP is a loss of balance while walking. Patients may have unexplained falls or a stiffness and awkwardness in gait. Sometimes the falls are described by the person experiencing them as attacks of dizziness. This often prompts suspicion of an inner ear problem.

Other common early symptoms are changes in personality such as a loss of interest in ordinary pleasurable activities or increased irritability, cantankerousness, and forgetfulness. Patients may suddenly laugh or cry for no apparent reason, they may be apathetic, or they may have occasional angry outbursts, also for no apparent reason. It must be emphasized that the pattern of signs and symptoms can be quite different from person to person.

As the disease progresses, most patients will begin to develop a blurring of vision and problems controlling eye movement. In fact, eye problems usually offer the first definitive clue that PSP is the proper diagnosis. PSP patients have trouble voluntarily shifting their gaze downward, and also can have trouble controlling their eyelids. This can lead to involuntary closing of the eyes, prolonged or infrequent blinking, or difficulty in opening the eyes.

Another common visual problem is an inability to maintain eye contact during a conversation. This can give the mistaken impression that the patient is hostile or uninterested.

Speech usually becomes slurred and swallowing solid foods or liquids can be difficult. In rare cases, some patients will notice shaking of the hands.

Other common symptoms of Progressive Supranuclear Palsy include:

  • Forgetfulness
  • Change in personality
  • Loss of interest in usual socializing with family and friends

Does Progressive Supranuclear Palsy Affect a Person Mentally?

Most PSP patients eventually experience a mild to moderate degree of mental problems. With PSP, dementia, or mental confusion, causes a person to have a slowed thinking process or difficulty synthesizing ideas. The slowing of thoughts and thinking makes it hard for the person to hold a conversation with others or to analyze problems.

How is Progressive Supranuclear Palsy diagnosed?

Initial complaints in PSP are typically vague and an early diagnosis is always difficult. The primary complaints fall into these categories:
  •  symptoms of dysequilibrium, such as unsteady walking or abrupt and unexplained falls without loss of consciousness; 
  • visual complaints, including blurred vision, difficulties in looking up or down, double vision, light sensitivity, burning eyes, or other eye trouble;
  • slurred speech; and 
  •  various mental complaints such as slowness of thought, impaired memory, personality changes, and changes in mood.

PSP is often misdiagnosed because some of its symptoms are very much like those of Parkinson's disease, Alzheimer's disease, and more rare neurodegenerative disorders, such as Creutzfeldt-Jakob disease. In fact, PSP is most often misdiagnosed as Parkinson's disease early in the course of the illness. Memory problems and personality changes may also lead a physician to mistake PSP for depression, or even attribute symptoms to some form of dementia. The key to establishing the diagnosis of PSP is the identification of early gait instability and difficulty moving the eyes, the hallmark of the disease, as well as ruling out other similar disorders, some of which are treatable.

How is Progressive Supranuclear Palsy different from Parkinson's disease?

Both PSP and Parkinson's disease cause stiffness, movement difficulties, and clumsiness. However, patients with PSP usually stand straight or occasionally even tilt their heads backward (and tend to fall backward), while those with Parkinson's disease usually bend forward. Problems with speech and swallowing are much more common and severe in PSP than in Parkinson's disease, and tend to show up earlier in the course of the disease. Both diseases share other features: onset in late middle age, bradykinesia (slow movement), and rigidity of muscles. Tremor, almost universal in Parkinson's patients, is rare in PSP. Although Parkinson's patients markedly benefit from the drug levodopa, patients with PSP respond poorly and only transiently to this drug.

How Is Progressive Supranuclear Palsy Treated?

There is a range of medication that can help curb PSP's symptoms.

Sinemet is sometimes used because it contains levodopa, which aids in controlling shakiness and tremors.

Antidepressants are often suggested by doctors, along with sleeping pills, to help PSP patients who are experiencing sleep problems. Many drugs being developed to treat other neurological disorders are also being utilized to help treat PSP.

Non-drug treatment for PSP can take many forms. Patients frequently use weighted walking aids because of their tendency to fall backward. Bifocals or special glasses called prisms are sometimes prescribed for PSP patients to remedy the difficulty of looking down. Formal physical therapy is of no proven benefit in PSP, but certain exercises can be done to keep the joints limber.

A surgical procedure that may be necessary when there are swallowing disturbances is a gastrostomy. A gastrostomy (or a jejunostomy) is a minimally invasive procedure which is performed when the patient has difficulty swallowing or when severe choking is a definite risk. This surgery involves the placement of a tube through the skin of the abdomen into the stomach (intestine) for feeding purposes. Surgical procedures such as fetal brain cell implantation and pallidotomy, which are being tested as treatments for Parkinson's disease, are not effective in PSP.

Complications of progressive supranuclear palsy 

Progressive supranuclear palsy (PSP) can have serious complications including choking and pneumonia caused by problems with swallowing (dysphagia), or injuries caused by falls.


Falls are a common complication of PSP due to the associated problems with balance and vision. They can be very serious as people often fall backwards and without warning.

In the most serious cases falls can cause fractures or head injuries, which can be life-threatening.

The risk of a fall can often be reduced through good care and assistance. Treatment includes the use of walking aids, methods to improve balance and eyesight problems, and identifying potential hazards in the home.

Aspiration pneumonia

Aspiration pneumonia is one of the most potentially serious complications of progressive supranuclear palsy (PSP). Aspiration pneumonia is a lung infection that is triggered when fluids or small pieces of food enter your lungs.

People with PSP are particularly vulnerable to aspiration pneumonia because their impaired swallowing reflexes mean that their larynx (voice box) does not close during swallowing, leaving their lungs unprotected.
The symptoms of aspiration pneumonia include:
  • high temperature (fever) above 38°C (100.4°F) 
  • fatigue
  • chest pain
  • shortness of breath
  • blue skin (cyanosis) - due to a lack of oxygen
  • wheezing

You may also have a cough which sometimes produces foul-smelling phlegm and may contain traces of blood and pus.
The symptoms of aspiration pneumonia can range from mild to severe. Severe cases will require hospital admission and treatment with intravenous antibiotics (antibiotics that are given through a vein).

In particularly vulnerable or frail people, there is a risk that the infection could lead to their lungs becoming filled with fluid, preventing them from working properly. This is known as acute respiratory distress syndrome (ARDS). 

Unfortunately, as most people with advanced PSP are vulnerable and frail, repeated episodes of aspiration pneumonia can be fatal.

Is There a Cure for Progressive Supranuclear Palsy?

There is no cure for PSP. Attention for a doctor and family of a PSP patient should be focused on keeping the person comfortable and creating the best quality of life possible.

Management for Progressive Supranuclear Palsy

  • No therapy is currently proven to be effective.
  • Only a few patients respond to dopaminergic or anticholinergic drugs, and responses often are short-lived and incomplete. No medication is effective in halting the progression of the disease.
  • Chronic conjunctivitis is common because of the reduced blink rate and often requires treatment.
  • Several medications, including dopamine agonists, tricyclic antidepressants, and methysergide, may provide modest symptomatic improvement in some of the clinical features.
  • Levodopa generally produces no dramatic difference in symptoms.
  • Bromocriptine may have a better effect, but this is modest and short-lived in most patients.
  • Botulinum toxin A may be useful in the treatment of rigidity, in particular nuchal rigidity, and dystonia, such as blepharospasm and focal limb dystonia. It may also be useful for sialorrhoea.
  • Electro-convulsive therapy may ameliorate motor symptoms in some patients, but significant adverse effects, eg confusion, limit its usefulness.