Progressive supranuclear palsy (PSP) - also known as Steele-Richardson-Olszewski syndrome and a number of other names - is a rare degenerative neurological disease - only about 4-5 percent as common as Parkinson's disease. It is the second most common neurodegenerative cause of parkinsonism seen in movement disorder clinics.
Like other neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease, the risk of developing PSP increases with age. The first symptoms usually begin between ages 50 and 70 (peaking in the early sixties), with a range from the early forties to the late eighties and is more common in men than in women.
Thus, the prevalence (number of individuals having a disease at a given time) of PSP will steadily increase over the coming years as the Baby Boom generation ages. The disease appears to affect men more often than women.
PSP was first observed by Dr J. Clifford Richardson during the 1950s in Toronto. He recognised a few patients who exhibited an unusual neurological syndrome of supranuclear ophthalmoplegia [nerve problems that affect the eye muscles], pseudobulbar palsy [nerve problems that affect the muscles of the palate, tongue and throat, causing problems with swallowing, gagging and speech], dystonia [problems with the muscles], rigidity of the limbs, dementia and other less typical symptoms, and invited Dr John Steele and Dr J. Olszewski to study the pathological changes in the central nervous system.
The results of this study were published in a medical journal in 1964. This resulted in the disease also being known as Steele-Richardson-Olszewksi syndrome which is the term still used in much of the world outside the United States.
PSP wasn't a new disease, it was just so rare that no one had determined it was it's own condition and not a variation of Parkinson's disease.
PSP is caused by (or perhaps causes) damage to nerve cells in a portion of the brain called the "midbrain" These cells are involved in eye-movements and balance. The cause of the degeneration of these cells is unknown.
The damage results in progressive lack of coordination, stiffness of the neck and trunk, eating and breathing problems, balance control, unexpected and uncontrollable falling, difficulties with the ability to control eye movement, slow physical movement, cognitive dysfunction, and difficulty with walking and muscle coordination.
People with PSP also have deposits in brain tissues that resemble the deposits found in Alzheimer's disease. There is atrophy (loss of tissue) in most areas of the brain.
We don't know what causes PSP. That said, there does seem to be risk factors leading to the development of the disease that are similar to the recognized risk factors for other neurological diseases such as Parkinson's and Alzheimer's diseases.
Through considerable observations it has been found that the illness is not caused by any single preventable cause. It is not caused by noxious or toxic substances, is not restricted to a specific geographic or climatic region and is not related to race, occupation, social or economic circumstance or diet. Most people who develop PSP come from families with no history of the disease, so it does not seem to be inherited, except in certain rare instances. It is not passed on to children.
The most common first symptom usually is loss of balance while walking or experiencing several unexplained falls over a year. Patients may develop some stiffness and walking awkwardness and be incorrectly diagnosed as having Parkinson's Disease. Patients however rarely develop the resting tremor and stooped posture characteristic of Parkinsonism. Falling can also cause broken bones and fractures that are difficult to treat.
Other common early symptoms may be changes in personality and forgetfulness. This can take the form of a loss of interest in ordinary pleasurable activities or increased irritability and cantankerousness. These mental changes are often misinterpreted as depression. They would be more correctly diagnosed as being symptoms of patient apathy.
Less common early symptoms are trouble with eyesight, slurring of speech, difficuly driving a car and having unexplained accidents.
PSP is a disorder that is often misdiagnosed. Some of the symptoms used to identify the disease do not appear until the patient is several years into the progression of the disease.
The most common first symptom indicating something is wrong is usually a loss of balance while walking or experiencing several unexplained falls over a year. Patients may develop some stiffness and walking awkwardness and be incorrectly diagnosed as having Parkinson's Disease. Patients however rarely develop the resting tremor and stooped posture characteristic of Parkinsonism. Falling can also cause broken bones and fractures that are difficult to treat.
Other common early symptoms may be changes in personality and forgetfulness. This can take the form of a loss of interest in ordinary pleasurable activities or increased irritability and cantankerousness. These mental changes are often misinterpreted as depression. They would be more correctly diagnosed as being symptoms of patient apathy.
Less common early symptoms are trouble with eyesight, slurring of speech, difficuly driving a car and having unexplained accidents.
Those patients incorrectly diagnosed as having Parkinson's Disease may be placed on an antiparkinsonian drug such as carbidopa/levodopa (Sinemet). Since some individuals with PSP may derive some benefit from this drug, the misdiagnosis of Parkinson's disease may well persist for some time. There may also be a referral to a local Parkinson's disease support group, but it will soon become evident that many of the problems faced by the patient with PSP are quite different from those faced by patients with Parkinson's disease.
This sequence of events is not the result of incompetence or lack of compassion; rather, it stems from the fact that the clinical features specific to PSP may not clearly emerge until several years following the initial visit to the neurologist. Furthermore, even when the diagnosis is suspected, there may be some hesitation on the part of the neurologist to communicate suspected PSP to the patient or the patient's family, since the diagnosis is generally less optimistic than that of Parkinson's disease. Nonetheless, in the majority of cases, the clinical "features" of PSP can be quite distinct and the problems faced by patients and caregivers are quite different from those of Parkinson's disease. Thus, it is important for the patient's doctors and caregivers to recognize and deal with these specific problems as early as possible.
As it can happen with Multiple Sclerosis and other diseases, PSP causes loss of the myelin sheath (the covering of the nerve cell that speeds nerve impulse conduction) in some nerves and destruction of the entire nerve in other areas. There is a palsy or paralysis, that slowly gets worse as the disease progresses.
Additional symptoms develop over time due to the increased damage to brain tissue caused by the disease. It is this development of new symptoms that further defines the condition and often leads to a change in diagnosis from some other disease to PSP.
This presense of this symptom (technically known as ophthalmoparesis and uncommon with Parkinson's and Alzheimer's diseases) along with the development of walking difficulties are used as primary indications in the diagnosis of PSP. In most cases the walking problems occur first followed in 3 to 5 years by the problems with the eyes.
Vision is controlled by groups of cells called nuclei in the brainstem. In PSP, the nuclei continue to function, but the mechanisms that control the nuclei are destroyed. The term supranuclear means that the damage is done above (supra) the nuclei.
With gaze palsy there is an impaired ability to voluntarily move the eyes up or down. The effect is so noticible that PSP is often referred to as the 'can't look up and can't look down' disease. The upper eyelids may also be pulled back, the eyebrows raised, and the brow wrinkled, causing a typical wide-eyed stare.
This can interfere with eating. Patients can't see that they are dropping food when they eat. They may esperience difficulty with descending a flight of stairs, among other things. This problem is not usually as vexing for the patient and family as the inability to maintain eye contact or to coordinate eye movements while reading, but is much easier for the doctor to detect.
Eventually patients loose the ability to look up and down at all, and usually about a year later, the ability to look from side-to-side is also lost.
The reduction in the ability to control vertical eye movement is usually the first clue to the doctor that the diagnosis is PSP. The diagnosis is often changed from Parkinson's Disease to PSP at this time.
Other conditions, particularly Parkinson's disease and normal aging, can also sometimes cause difficulty moving the eyes up. However, PSP is nearly unique in also causing problems moving the eyes down.
Because the main difficulty with the eyes is in aiming them properly, reading often becomes difficult or impossible. The patient finds it difficult to shift down to the beginning of the next line automatically after reaching the end of the first line.
This is different from just needing reading glasses. An eye doctor unfamiliar with PSP may be baffled by the patient's complaint of being unable to read a newspaper despite normal ability to read the individual letters on an eye chart.
Another common visual problem is an inability to maintain eye contact during conversation. This can give the mistaken impression that the patient is senile, hostile, or uninterested. The same eye movement problem can create the symptom of "tunnel vision" and can interfere with driving a car.
With PSP reflex or unwilled eye movements remain normal. Thus, when the patient's head is tilted upwards, the eyes move to look down. These reflex movements remain normal until late in the course of the disease.
A different eye problem in PSP can be abnormal eyelid movement - either too much or too little. A few patients experience forceful involuntary closing of the eyes for a few seconds or minutes at a time, called "blepharospasm." Others have difficulty opening the eyes, even though the lids seem to be relaxed, and will try to use the muscles of the forehead, or even the fingers, in an effort to open the eyelids ("apraxia of lid opening"). About 20 percent of patients with PSP, eventually develop one of these problems. Others, on the contrary, have trouble closing the eyes and blink very little. While about 15 to 25 blinks per minute is normal, people with PSP blink, on average, only about 3 or 4 times per minute. This can allow the eyes to become irritated. They often react by producing extra tears, which can itself become annoying.
As it can happen with Multiple Sclerosis and other diseases, PSP causes loss of the myelin sheath (the covering of the nerve cell that speeds nerve impulse conduction) in some nerves and destruction of the entire nerve in other areas.
The face becomes stiff, immobile and furrowed. Facial and jaw jerks are exaggerated, though more often than not the mouth gapes open, and drooling is common. These symptoms are also signs of pseudobulbar palsy.
Impairment of gait and balance is one of the earliest symptoms experienced by patients with PSP. In fact, unexpected falls, a symptom that rarely if ever occurs in the early stages of Parkinson's disease, often prompt the first referral to a neurologist. This symptom requires immediate attention because, all too frequently, these falls result in serious injuries such as a fracture or concussion. A physical therapist familiar with neurological diseases can be of great assistance in providing gait training, preventative measures aimed at avoiding or buffering falls, in-home safety measures such as grab bars for the hallways and bathrooms, and assessing the need for an appropriate walking aid or wheelchair.
With PSP the neck is usually hyperextended becoming stiff and extended and will resist forward and backward movement. Going up and down stairs becomes difficult. Rigidity and bradykinesia of the limbs develop slowly. The combination of these symptoms (inability to look down, rigidity and stiffness) causes an increasing awkwardness, disturbance of gait and hesitancy. Unsteadiness and falls are common problems and the patient can often totter backwards and fall without knowing why. Walking becomes more and more hesitant and awkward as the tendency to fall backwards continues. The cause of this phenomenon is unknown and is often mistaken for the gait disturbance typical of early Parkinson's.
Because of the tendency for some patients with PSP to fall backward, a walker may not provide adequate protection, although there are now a wide variety of walkers available including some that provide some protection against backward falls.
The decision to use a wheelchair is often one of the most difficult faced by patient and family, because it may be perceived as giving in to the disease or losing independence. Yet, a walking aid or wheelchair may actually reduce dependence on the caregiver and even allow the patient a wider range of activity. Importantly, these devices will reduce the risk of a serious injury stemming from a fall with the possibility of hospitalization and surgery. Although it is never easy to accept the need for a walker or a wheelchair, the patient and caregivers must keep in mind the progressive nature of this disease and the fact that these aids will likely improve the patient's quality of life.
Swallowing tough foods or thin liquids can become difficult because of throat muscle weakness or incoordination. This tends to occur later than the walking, visual, and speech problems, but can become very troublesome if the patient tends to choke on food. Unlike the other difficulties in PSP, this one can sometimes pose a danger for the patient - the danger of food going down the wrong pipe into the breathing passages, termed "aspiration." Usually, difficulty managing thin liquids precedes difficulty with solid food. This is because in PSP, the swallowing muscles have difficulty creating a watertight seal separating the path to the stomach from the path to the lungs. The same is true for the swallowing difficulty of many neurological diseases. For non-neurologic conditions such as stricture of the esophagus, however, difficulties start with solid foods.
Repeated, minor, often unnoticed episodes of small amounts of food and drink dripping into the lungs can cause pneumonia. Often, it is not apparent to the physician or family that the PSP patient's pneumonia is in fact the result of subtle aspiration. But "aspiration pneumonia," in fact, is the most common cause of death in PSP.
There are speech and swallowing difficulties, with repetitive swallowing of saliva, explosive coughing and heightened palate and throat reflexes.
Common signs that a person is having difficulty swallowing might include:
Mental changes are often limited to personality alteration and forgetfulness. As time goes on however most patients develop a mild or moderate degree of mental impairment or dementia.
In PSP, the dementia, if it does occur, does not feature the memory problem that is so apparent in Alzheimer's disease. Rather, the dementia of PSP is characterized by slowed thought and difficulty combining different ideas into a new idea or plan. These mental functions are performed mostly by the front part of the brain (the "frontal lobes"). In Alzheimer's, on the other hand, the problem is mostly in the part of the brain just above the ears (the "temporal lobes"), where memory functions are concentrated.
Alzheimer's disease also includes either difficulty with language (such as trouble recalling correct names of common objects) or difficulty finding one's way around a previous familiar environment. Fortunately, these symptoms almost never occur in PSP.
Slowing of thought can cause major problems for people with PSP by making it difficult to partake in conversation. A question may be answered with great accuracy and detail, but with a delay of several minutes.
In the late stages of PSP, the eyes are fixed centrally, and reflex movement may be totally absent. Bradykinesia is prominent and the person assumes a rigid and double hemiplegic-type posture. That is, the body becomes totally rigid and unable to be moved voluntarily. There is particular difficulty with trunk movements when turning from side to side and sitting up. Because of these symptoms and the inability to control one's movements, the person becomes immobile and bedridden. In extreme cases of poor swallowing a tube may be inserted into the stomach for feeding.
The average length of illness, from diagnosis to death, is 5 to 6 years, with the range being 2 to 11 years. Men seem to be more affected by the disease than women. There are an estimated 20,000 cases in the USA, 6,000 in the UK and up to 1,500 in Australia. Misdiagnosis is frequent and it is most commonly mistaken for Parkinson's, although it is only about 3 per cent as common.
PSP cannot presently be cured. A true cure would require the ability to regenerate, restore and renew the brain tissue and neurotransmitter connections destroyed or damaged by the disease. There is hope that future medical progress will lead to the ability to control and slow the presently relentless aggressive progression of the disease and by doing this extend the life of its victims.
People with PSP usually can remain at home with their families during its early stages. As the disease progresses they may require more care than the family can provide and access to a skilled nursing facility may be necessary. Falling is always a danger when the patient is able to still get around physically so their activities require constant close supervision. The patient should be checked often by their medical team to monitor the effects of any treatment and make changes if needed.
Individuals with PSP should remain physically, mentally, and socially active as long as they are able.
A balanced diet that includes plenty of fruits and vegetables will help maintain a healthy weight and prevent malnutrition and constipation.
Drugs are sometimes given in an attempt to try to relieve or modify the symptoms associated with the disease. None claim to either cure or slow its progression, Thus, treatment with drugs is usually disappointing and expermental.
Remember too that each drug has the capability of causing serious side-effects either immediately or over the long-term which in turn may cause the patient's condition to worsen rather than improve.
Most persons with PSP are resistant to the dopaminergic medications commonly used used to treat in Parkinson's disease, such as levodopa (Sinemet). This may be because these patients usually have more lesions in non-dopaminergic neurotransmitter systems than they have those in the dopaminergic areas of the brain normally affected by Parkinson's disease.
Though limb rigidity, stiffness, slowness of movement and balance may improve somewhat in patients treated with levodopa, the eye movement problem and axial dystonia - both common with PSP - are unaffected.
Anticholinergic medications, such as trihexyphenidyl (Artane), which restore function to neurotransmitters, or tricyclic drugs, such as amitriptyline (Elavil) may improve speech, walking, and inappropriate emotional responses.
It must be remembered though that since it has been found the lack of a neurotransmitter called acetycholine may also contribute to the symptoms of PSP the use of any anticholinergic medication may also tend to worsen symptoms long-term or increase the speed of progression of this disease.
Medication, if provided, needs to be individualised. Doctors should work with the patient and their caregiver to establish a suitable drug regimen. It is a personal choice whether to provide drugs to the patient at all since most seem to have either have adverse side-effects or do not work at all. Remember too that as we age the liver generally works slower and has a greater problem getting drugs out of the body. Thus, a drug dosage that provides no side-effect problems with a younger person may be too large for an older person.
Surgery - which has been useful to those diagnosed with Parkinson's disease has been tried without success to treat those diagnosed with PSP.
Botulinum toxin can be used to treat eyelid spasms and other types of dystonia that sometimes occur in PSP.
Artificial tears, drops and ointments can help prevent the drying out of the eyes that may occur from decreased blinking. It is important to keep the eyes moist. Failing to do so may cause physical damage to the surface of the eyeball. Ask your medical advisor for product recommendations.
Speech therapy may help manage the swallowing and speech difficulty in PSP. As the disease progresses, the difficulty in swallowing may cause the patient to choke and get small amounts of food in the lungs. This condition can cause aspiration pneumonia. The patient may also lose too much weight. In these cases, a feeding tube may be needed.
The PSP patient may need alternative communication devices, such as pointing boards or computer-based systems. Books on tape provide an alternative when reading is no longer possible.
The home environment should be modified to decrease potential injury from falls. Caregivers can improve the safety of the person with PSP by keeping pathways in the home clear of objects such as toys, floor rugs, or low furniture that are difficult to see without looking down. An occupational therapist can advise on these and other home modifications to improve safety, comfort, and usability of the home environment.
Walkers can be weighted in front, to prevent backward falls and handrails can be installed in the bathroom.
Dry eyes from infrequent blinking can be treated with drops or ointments.
When the patient is trying to eat:
Physiotherapists, occupational therapists, speech pathologists, psychologists and social workers all have important roles in assisting in the management of PSP.
PSP gets progressively worse but is not itself directly life-threatening. The patient's condition gradually deteriorates. After about seven years, balance problems and stiffness make it nearly impossible for the patient to walk. Persons with PSP become more and more immobile and unable to care for themselves. Death is not caused by the PSP itself. It is usually caused by pneumonia related to choking on secretions or by starvation related to swallowing difficulty. It usually occurs within 10 years, but if good general health and nutrition are maintained, the patient may survive longer.