Progressive supranuclear palsy
Progressive Supranuclear Palsy, or Steele-Richardson-Olszewski's Syndrome
Progressive Supranuclear Palsy (PSP), also known sometimes as the Mona Lisa disease, is a distinctive and not uncommon cerebral degenerative disease of late adulthood, the cause of which is unknown at present.
It 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.
They found that neuronal cell loss, neurofibrillary degeneration and gliosis [conditions in which the nerve fibres in the brain can become dense and tangled] were extensive in the brain stem, diencephalic and cerebellar nuclei. Damage to pontomedullary reticular nuclei was also likely. Changes in the metabolism of glucose were found in the prefrontal, premotor ungulate cortex and thalamus parts of the brain.
Analysis of protein in the cerebrospinal fluid (CSF) may provide a useful tool in differential diagnosis (i.e. between cortico-basilar degeneration and supranuclear palsy).
Through considerable observations it has been found that the illness 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. There seems to be a familial background in some cases.
Diagnosis
Symptoms begin in the fifth to eighth decade (the range of age of onset of PSP is 45-73). Early indications are variable and indefinite, and include symptoms such as :
- unsteady gait;
- abrupt falls;
- slowness (akinesia and rigidity);
- cervical dystonia (problems with the neck muscles);
- blurred vision;
- difficulty maintaining eye contact;
- disturbed vertical gaze;
- altered speech;
- dysphagia [difficulty in swallowing];
- forgetfulness;
- short temper and irritability;
- abnormally aggressive behaviour and subtle changes in personality which may be noticed by family members;
- depression; and
- impaired concentration.
As the early symptoms are common to many cerebral illnesses (such as cerebellar degeneration or dementia), accurate diagnosis is difficult and often not possible until further symptoms develop; in fact, the disease is often initially mistaken for Parkinson's.
As the disease progresses however, symptoms become more defined and characteristic of PSP, so that accurate diagnosis becomes easier. Progression is also more rapid than in Parkinson's.
Definition
Owing to the difficulty previously experienced by doctors in diagnosing PSP, the following diagnostic criteria have recently been produced. PSP is a progressive disorder (familial examples are rare), beginning in middle or old age with supranuclear ophthalmoplegia including down gaze abnormalities and at least 2 or more of the following 5 cardinal features:
- axial dystonia and rigidity (a broad-based sailor's walk);
- pseudobulbar palsy [nerve problems that affect the muscles of the palate, tongue and throat, causing problems with swallowing, gagging and speech];
- bradykinesia [slowness of movement] and rigidity;
- frontal lobe signs; and
- postural instability with falls backwards.
Other features which may be present include:
- resting tremor;
- chorea [loss of function of the neurones in the brain];
- dystonia [muscle problems] of the limbs and face;
- cerebellar ataxia [loss of muscle co-ordination caused by disorders in the brain];
- muscle wasting, fasciculation [brief, irregular twitching of muscles that can be seen under the skin] and weakness;
- dysphagia and dyspraxia [difficulty and pain when swallowing];
- respiratory dyskinesias (inspiratory gasps);
- depression;
- sleep disturbances;
- schizophreniform psychoses;
- echolalia and palilalia [involuntary repetition of the same word or phrase when speaking];
- myoclonus [muscle spasms or twitching];
- perceptive deafness;
- other ocular abnormalities such as slowness of blink or difficulty opening the eyes; and
- emotional incontinence.
Symptoms
Gaze palsy
This is the most evident symptom of this condition, along with walking difficulties. This is so apparent that PSP is often referred to as the 'can't look up and can't look down' syndrome. This symptom, technically known as ophthalmoparesis, is first noticed as a slowness and limited vertical movement of the eyes. By contrast, full reflex eye movement is possible with passive head movement. This symptom progresses through a loss of eye reflex to a complete failure to control eye movements up or down, with some loss of control over horizontal movements, making focusing a problem. Driving and reading also become difficult.
Facial stiffness
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.
Gait and muscles
The head is usually hyperextended and the neck becomes stiff and extended and will resist forward and backward movement, making going up and down stairs 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 (often the first symptoms) and the person 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.
Swallowing problems
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:
- frequent coughing while eating or drinking;
- multiple swallows on a single mouthful;
- the sensation of food 'sticking' in the back of the throat;
- weight loss; and
- chest congestion after eating or drinking.
Mental changes
Mental changes are often limited to personality alteration and forgetfulness. However, more recent studies have shown dementia is more common than first thought. A study done in 1986 found that while cognitive impairment did not parallel motor impairment it did correlate with visual impairment. There is evidence of some impairment of judgement and loss of abstract thinking.
Late stages
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.
Management
Medication
Most people with PSP are resistant to dopaminergic medications, probably because they have lesions in non dopaminergic neurotransmitter systems more profound than those in Parkinson's. Though limb rigidity and bradykinesia and balance improve in patients treated with levodopa, ophthalmoplegia and axial dystonia are unaffected. Other treatments which seem to show some effect are tricyclic antidepressants (e.g. amitryptiline), bromocriptine, pergolide, idazoxan and lisuride. Medication needs to be individualised and doctors should work with the patient to establish a suitable drug regimen. Surgery has been tried without success.
Eating
- Check that the person is sitting up as straight as possible.
- Minimise distractions such as TV.
- Concentrate on the task, considering speed and quantity, as well as how well the person is chewing.
- A teaspoonful of food at a time is ample.
- Allow enough time for the person to eat so that they don't feel rushed.
- Be sure they have completed the swallow before offering another spoonful.
Walking
- An aid to walking may need to be weighted in front.
- Raising heels of shoes may reduce the tendency to tip backwards.
- Rails in the bathroom may be helpful.
- Remove low objects to prevent the patient falling over them.
- Prismatic glasses have been of limited assistance.
Other exercises
- Exercises can help retain some joint mobility.
- Breathing exercises may be needed to prevent complications of bed rest.
Carers and coping strategies
- It is important to understand changes that are part of the disease process and are therefore out of voluntary control.
- Fluctuation in function and personality are to be expected.
- Lists can help with memory loss.
- Include the individual in all discussion and normal decision-making.
- Carers should not blame themselves but blame the disease.
- If irritability is a problem, distraction is better than argument.
- Reserving time for carers' own interests is important.
Consultants
Physiotherapists, occupational therapists, speech pathologists, psychologists and social workers all have important roles in assisting in the management of PSP.
Last Reviewed: 19 July 2002
