Three Canadian scientists first described progressive supranuclear palsy (PSP) in
1963, and lent their names to its alternative title - Steele Richardson Olszewski
syndrome. Although in its early stages, PSP can mimic Parkinson's disease, it's less
common, and has its own distinct diagnosis, prognosis and treatment.
PSP is a degenerative
disease affecting the brain.
Progressive means it starts slowly and continues to get
worse, supranuclear refers to the affected part of the brain - pea-sized structures
known as nuclei - and palsy describes the outcome - paralysis.
It can cause permanent
and serious problems with a patient's vision and ability to move. Symptoms of PSP
The most obvious and characteristic symptom is the effect on vision. Patients suffer
blurring as lesions in the brain prevent the eyes from moving properly. This is most
characteristically seen as downward gaze palsy - the inability to look down. Other
key symptoms include falls - usually backwards - and the inability to control movement
paired with problems breathing, speaking and swallowing.
As the disease progresses,
the patient may suffer depression, sleeplessness, symptoms similar to Parkinson’s
disease, such as limb rigidity and those in mild dementia, such as memory loss and
difficulty thinking. Causes
Recent research has contradicted the view that men develop PSP more than women, showing
that it is equally common in both sexes. Most cases start between the ages 50 and
60, although the disease can set in at any time from the late thirties to the late
eighties. It is thought to affect about six people in every 100,000.
The cause is
unknown, but scientists suggest several theories as to why the brain would degenerate
in such a way. The first is that, like Creutzfeldt-Jakob Disease, PSP may occur as
the result of a virus-like particle that enters the body and then takes many years
to produce obvious effects. Secondly, it could be the result of a rare genetic mutation.
Thirdly is the possibility that a mystery particle in the air or water might trigger
it - a theory based on the phenomenon of Guam Island in the Pacific. A surprisingly
high proportion of the residents there in the 1950's suffered from a disease known
as Lytico Bodig, which has symptoms remarkably similar to PSP.
There is currently no effective treatment or cure for PSP.
Drug treatments used in
Parkinson's, such as L-dopa, are rarely of much benefit, although they can sometimes
be of temporary benefit in movement disorder symptoms. Anti-depressants such as Prozac
have had some impact, but the effect is not thought to be associated to the drugs
ability to alleviate depression. Dementia treatments such as donezepil are ineffective
Experimental procedures being tested in Parkinson's - such as the implantation
of foetal brain tissue - have proved fruitless in PSP. Treatment instead focuses
on alleviating the symptoms, so patients may need a tube inserted into their stomach
to overcome problems swallowing, a wheelchair to prevent injury from falls or a weighted
walking frame to prevent falling over backwards, and special glasses to correct visual
Although PSP in itself is not fatal, the disease does get progressively
worse, and patients often die from complications such as pneumonia and choking on