Synopsis: Progressive supranuclear palsy (PSP) is a form of rare brain disorder involving permanent issues with control of balance and gait.
PSP is many times misdiagnosed because some of the symptoms associated with the disease are similar to those of Alzheimer's disease or Parkinson's disease, as well as more rare neurodegenerative disorders like Creutzfeldt-Jakob disease.
Progressive supranuclear palsy (PSP), also known as Steele-Richardson-Olszewski syndrome, is defined as a rare brain disorder that causes serious and progressive problems with control of gait and balance, along with complex eye movement and thinking problems. One of the classic signs 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. Initial symptoms in two-thirds of cases are loss of balance, lunging forward when mobilizing, fast walking, bumping into objects or people, 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.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.
Progressive Supranuclear palsy (PSP) is a form of rare brain disorder that causes people to experience permanent issues with control of their balance and gait. The clearest sign of the disease in an inability on the part of the person to aim their eyes properly, something that happens due to lesions in the area of their brain that coordinates eye movements. Some people describe the effect as a, 'blurring.' People with PSP many times experience alterations in their behavior and mood, to include apathy and depression, as well as progressive mild dementia. The signs and symptoms experienced among individuals with the disease can vary greatly.
The symptoms of PSP are caused by a gradual deterioration of the person's brain cells in a few small, yet important place at the base of their brain stem. PSP is many times misdiagnosed because some of the symptoms associated with the disease are similar to those of Alzheimer's disease or Parkinson's disease, as well as more rare neurodegenerative disorders like Creutzfeldt-Jakob disease. The key to achieving a diagnosis of PSP is the identification of early gait instability and difficulties on the part of the affected person with moving their eyes, something considered to be the hallmark of the disease. Ruling out other similar disorders, some of which are treatable, is also important. While PSP is progressive and worsens, no one dies from PSP itself.
PSP is also known as, 'Steele-Richardson-Olszewski syndrome,' after the people who discovered the syndrome in 1964. PSP is an uncommon disorder and usually starts affecting people when they are between the ages of fifty and sixty. People affected by the syndrome grow progressively worse, becoming disabled within five to ten years after they receive a diagnosis.
Estimates place the prevalence of PSP among people over the age of fifty-five at around seven per one-hundred thousand people. There are studies that indicate there may be slightly more males with PSP than females. Perth, Australia, for example, has an estimated incidence of PSP of around five people per one-hundred thousand between the ages of fifty and sixty. PSP is not believed to be a syndrome that is genetically transmitted in families, although there are some reported cases of inherited transmission. Research results from a survey in the year 1996 showed that people with PSP were less likely than others to have finished twelve years of education, something that suggests education level is a marker for direct risk factors which may include chemical exposure, or nutritional problems.
Causes of PSP
Medical science does not know the cause of degeneration of nerve cells. People affected by PSP experience a gradual and progressive damage to cells in their mid-brain, leading to atrophy. People who are affected by the syndrome experience neuronal loss and neurofibrillary tangles in the diencephalon, brain stem and basal ganglia. A number of theories have been presented related to potential causes. Initially, the main cause of PSP was believed to possibly be a virus, perhaps related to the influenza virus, or to a slow acting toxin such as a drug abuse contaminant, herbal Caribbean teas, or Cycad nut poisoning in Guam.
More recent research from the year 1999 suggests that PSP could be a genetic disorder that is transmitted with autosomal recessive transmission. The gene that is implicated with the syndrome is referred to as the, 'tau,' gene. Molecular biology techniques used to analyze the tau gene indicate that the gene in PSP is different from genes that are observed in Alzheimer's disease. Studies have indicated that the tau gene in PSP is similar to the gene in Cortico basal degeneration. Genetic studies indicate that some nerve cells might be, in part, controlled by genetic susceptibility and related to additional environmental stressors or triggers, such as toxins and viruses.
Symptoms of PSP
The symptoms people with PSP experience commonly include a prolonged phase of dizziness, headaches, fatigue, depression, and arthralgias. The more common symptoms include dyarthria, instability, and falls. Additional, and important symptoms to note, include:
The eyelids of people with PSP might be held wide open with eye movement paralysis, resulting in a facial expression that may be described as, 'astonished,' 'staring,' or, 'puzzled.' The eye movement difficulties people with PSP experience commonly begin with difficulties looking up or down. They might have difficulties looking right or left. The eye abnormalities can cause trouble trouble with reading or driving. Unfortunately, there is no form of treatment for these eye movement abnormalities. People with PSP do not have eye nerve or eye muscle problems, the problem originates in their brain stem area.
Both neuroimaging and lab tests may be performed with the intention of eliminating other potential causes. One specific high-resolution neuroimaging study called, 'positron emission tomography,' or PET may give enough information about the person's blood flow and oxygen supply to their brain. PET scan analysis has revealed a decrease in blood flow and oxygen metabolism in areas of the brain thought to degenerate in people with PSP. Sleep patterns in people with PSP are many times abnormal, and demonstrate increased awakenings, progressive loss of REM sleep, and a diminished total sleep time. People with the syndrome may also develop REM sleep behavior consisting of abnormal motor activity as well as vivid dreams.
Treatment of PSP
Medical science currently does not have an effective form of treatment for PSP. Scientists are searching for better ways to manage the disease. People with PSP who experience stiffness, slowness and balance issues might respond to anti-parkinsonian agents such as levodopa or levodopa in combination with anticholinergic agents, although the effects tend to be temporary. Vision, speech and swallowing difficulties associated with PSP often do not respond to medication treatment, unfortunately. One group of medications that has had some level of success in people with PSP are antidepressant medications. Of this group, the medications Elavil, Prozac and Tofranil have encountered the most success. Interestingly, the anti-PSP benefit of these medications seem not to be related to their ability to relieve depression.
People with PSP often use weighted walking aids due to their tendency to fall backward. Special glasses called, 'prisms,' and bifocals are prescribed for people with PSP on occasion to assist them with looking down. While physical therapy has not demonstrated any proven benefit for people with PSP, there are certain exercises that can be performed to help keep their joints limber. There is a surgical procedure called a, 'gastrostomy,' that might become necessary if a person with PSP experiences swallowing disturbances. The surgery involves the placement of a tube through the person's skin of their abdomen into their stomach for the purpose of feeding.
PSP is a progressive syndrome and worsens, but it is not directly life-threatening. PSP does; however, predispose people to serious complications that include pneumonia secondary to difficulties with swallowing. The most common complications of PSP include choking and pneumonia, fractures caused by falling, and head injuries. The most common cause of death among people with PSP is pneumonia. However, with good medical attention and proper nutrition, the majority of people with PSP can live average life spans.