Progressive supranuclear palsy

Progressive supranuclear palsy
Specialty	Neurology

Progressive supranuclear palsy (PSP) (or the Steele-Richardson-Olszewski syndrome, after the Canadian physicians who described it in 1963) is a rare degenerative disease involving the gradual deterioration and death of selected areas of the brain.

Both males and females are affected approximately equally and there is no racial, geographical or occupational predilection. Approximately 6 people per 100,000 population have PSP.

Symptoms and signs

The initial symptom in two-thirds of cases is loss of balance and falls. Other common early symptoms are changes in personality, general slowing of movement, and visual symptoms.

Later symptoms and signs are dementia (typically including loss of inhibition and ability to organize information), slurring of speech, difficulty swallowing, and difficulty moving the eyes, particularly in the vertical direction. The latter accounts for some of the falls experienced by these patients as they are unable to look up or down.

Some of the other signs are poor eyelid function, contracture of the facial muscles, a backward tilt of the head with stiffening of the neck muscles, sleep disruption, urinary incontinence and constipation.

The visual symptoms are of particular importance in the diagnosis of this disorder. Notably, the ophthalmoplegia experienced by these patients mainly concerns voluntary eye movement. Involuntary eye movement, as elicited by Bell's phenomenon, for instance, may be closer to normal. On close inspection, eye movements called "square wave jerks" may be visible when the patient fixes at distance. These are fine movements, similar to nystagmus, except that they are not rhythmic in nature. Difficulties with convergence, where the eyes come closer together while focusing on something near, like the pages of a book, is typical. Because the eyes have trouble coming together to focus on things at near, the patient may complain of double vision when reading.

Cardinal Manifestations:

• Supranuclear ophthalmoplegia
• Neck dystonia
• Parkinsonism
• Pseudobulbar palsy
• Behavioral and Cognitive impairment
• Imbalance and Difficulties walking
• Frequent Falls

Prognosis

There is currently no effective treatment or cure for PSP, although some of the symptoms can respond to nonspecific measures. The average age at symptoms onset is 63 and survival from onset averages 7 years with a wide variance.

Differential diagnosis

PSP is frequently misdiagnosed as Parkinson's disease because of the slowed movements and gait difficulty, or as Alzheimer's Disease because of the behavioral changes. It is one of a number of diseases collectively referred to as Parkinson plus syndromes.

Pathophysiology

The affected brain cells are both neurons and glial cells. The neurons display neurofibrillary tangles, which are clumps of tau protein, a normal part of a brain cell's internal structural skeleton. These tangles are often different from those seen in Alzheimer's disease, but may be similar when they occur in the cerebral cortex . Lewy bodies are seen in some cases, but it is not clear whether this is a variant or an independent co-existing process..

The principal areas of the brain affected are:

• the basal ganglia, particularly the subthalamic nucleus, substantia nigra and globus pallidus;
• the brainstem, particularly the portion of the midbrain where "supranuclear" eye movement resides;
• the cerebral cortex, particularly that of the frontal lobes;
• the dentate nucleus of the cerebellum;
• and the spinal cord, particularly the area where some control of the bladder and bowel resides.

Some consider PSP, corticobasal degeneration, and frontotemporal dementia to be variations of the same disease . Others consider them separate diseases.

Genetics

Fewer than 1% of those with PSP have a family member with the same disorder. A variant in the gene for tau protein called the H1 haplotype, located on chromosome 17, has been linked to PSP. Nearly all people with PSP received a copy of that variant from each parent, but this is true of about two-thirds of the general population. Therefore, the H1 haplotype appears to be necessary but not sufficient to cause PSP. Other genes, as well as environmental toxins are being investigated as other possible contributors to the cause of PSP.

Notable cases

• Teel Bivins (1947-2009), a former U.S. Ambassador to Sweden and a former member of the Texas State Senate from Amarillo, Texas, died at the age of sixty-one of progressive supranuclear palsy, first diagnosed in 2006, while he was in Stockholm, Sweden.
• Actor Dudley Moore, who suffered from progressive supranuclear palsy, increased public awareness of this disease. He died on March 27 2002 at the age of sixty-six from its complications.
• Lee Philips, the 1950s actor-turned-director of such shows as Peyton Place and The Ghost & Mrs. Muir, also died after suffering from this disease.
• American singer Teresa Brewer ("Music! Music! Music!"), 76, died of this disease on October 17, 2007.
• Film Director and Playwright Joshua Logan
• Dr. Anne Turner, who was the basis of the BBC drama A Short Stay in Switzerland about assisted suicide.

Support groups

Several international organizations serve the needs of patients with PSP and their families and support research. The Society for PSP ("CurePSP") is based in the US and the PSP Association (PSP-Europe Association) is based in the UK.

External links

• The Society for Progressive Supranuclear Palsy ("CurePSP")
• The PSP-Europe Association
• psp at NINDS
• Medical Notes at BBC
• Houston PSP Review at Baylor College
• 02040 at CHORUS

• synd/3806 at Who Named It?