Home > Diagnosis, Types of dementia > What is Progressive Supranuclear Palsy?

What is Progressive Supranuclear Palsy?

Progressive supranuclear palsy is a degenerative disease which involves the gradual deterioration of specific parts of the brain.  Some experts consider it to be a variation of frontotemporal dementia or corticobasal degeneration, although others see them as separate disorders.  It is sometimes called the Steele-Richardson-Olszewski Syndrome, after the Canadian physicians who first published a paper in 1964 which differentiated it from Parkinson’s disease.  It is estimated that 6 out of 100,000 people, a few more men than women, have PSP.

In about two-thirds of cases, the first symptoms noted are a loss of balance, fast walking, bumping into people and things, and falls.  Other early signs include personality changes (loss of interest in ordinary pleasurable activities, irritability, emotional lability, and forgetfulness), slowing in movements, and visual symptoms.  As the disease progresses, the afflicted person will develop signs of dementia including loss of inhibition and lack of organizational skills, slurred speech, dysphagia, and difficulty moving the eyes (particularly in the vertical plane).  This inability to look down may actually be responsible for the frequent falls experienced by those with PSP.  Also observed may be problems with muscles of the face and neck, disruption in sleep, urinary incontinence, constipation, Parkinsonism, and behavioral and cognitive deficits (including depression and apathy).  The person may be viewed mistakenly as hostile or unfriendly because of a difficulty making eye contact.

Specific visual symptoms are characteristic of PSP, especially a difficulty with voluntary eye movements called ophthalmoparesis.  Persons with the disorder initially have trouble looking down, and then develop a difficulty looking up.  However, involuntary eye movements appear close to normal.  When the person looks into the distance, he may be observed to show peculiar eye movements called “square-wave jerks,” that resemble nystagmus.  He may complain of diplopia (double vision) while reading, due to an inability of the eyes to move toward the center when focusing on close objects.

The person with PSP is frequently misdiagnosed as having Parkinson’s disease or Alzheimer’s disease, or even Creutzfeldt-Jacob disease, due to the motor and behavioral symptoms that are often present.  One of the features that helps to differentiate PSP from Parkinson’s disease is a poor response to levodopa.

Symptoms of PSP typically are first observed at around the age of 63, with an average survival of seven years.  However, there is a wide variance here.  Less than one percent of those with PSP have family members who also had the disease.  Current theory holds that it is associated with a specific variant in the gene for tau protein, called the H1 haplotype, however presence of this gene does not necessarily mean that the disease will develop.  It is thought that other genes, as well as environmental factors, are also responsible for development of PSP.  One theory is that the disease is due to a virus-like agent that takes years to cause any noticeable symptoms.  Another is that it is caused by a random genetic mutation.  Still another holds that unknown elements in the environment damage particular parts of the brain.

PSP affects both neurons and glial cells in the brain.  Neurofibrillary tangles, or clumps of tau proteins, are found in neurons, but these are different from those found with Alzheimer’s disease.  Lewy bodies are sometimes seen, but this may be due to the co-existence of a separate disease process.  Areas of the brain most commonly affected include the basal ganglia (especially the subthalamic nucleus, substantia nigra, and globus pallidus), the brainstem (most notably that part of the midbrain responsible for “supranuclear” eye movements), the frontal lobes of the cerebral cortex, the dentate nucleus of the cerebellum, and those parts of the spinal cord which control the bowels and bladder.

Although PSP is a progressive disorder, it is not thought to be directly life-threatening.  Death usually comes due to secondary complications, such as aspiration pneumonia caused by swallowing problems, and head injury or fractures due to falls.  Pneumonia is the most common cause of death.

No effective treatment currently exists for PSP, although some symptomatic treatments may prove beneficial for a short time.  It has been suggested that rivastigmine may be of some benefit with the cognitive symptoms, however studies regarding this have to date been conducted only with small groups of subjects.  Botulinum injections can help with some visual symptoms, as can glasses with a prism built into the lenses.  Occupational and physical therapy may be helpful with regard to the motor difficulties inherent in the disease.  It should be noted, however, that there are few evidence-based studies here, and most reports are anecdotal.

Occupational and speech therapy can be useful for the development of compensatory strategies, to assist in daily functioning and promote independence for as long as possible.  Speech therapy can also help with the swallowing problems that are common with PSP.  It is recommended that the person use a walker over a cane, due to a tendency to fall backwards.  However, as the disease progresses, all affected will eventually lose the ability to walk and become confined to a wheelchair.

Well-known persons who were afflicted with PSP include actor Dudley Moore (died in 2002 at the age of 66), who was influential in increasing public awareness of the disease.  Former U.S. ambassador Teel Bivins (1947-2009), Nobel laureate Dr. Abdus Salam (1926-1996), and American popular singer Teresa Brewer (died in 2007 at the age of 76), also died from complications of PSP.




  1. January 20, 2013 at 9:26 PM

    OMG, our health is SO COMPLICATED! hanks for this one, very interesting.

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