About the Disease
If you or someone close to you has been diagnosed with Progressive Supranuclear Palsy (or PSP), you probably have quite a few questions to ask, or maybe you simply want to find out more about this disease.
Within this section you will find a number of helpful areas, including a range of the most commonly asked questions of those newly-diagnosed, information on research into PSP and information on related disorders, including Cortico Basal Degeneration (CBD). The Useful Links page on the menu to this section provides links to other PSP societies worldwide, as well as to organisations based in the UK that can provide more information to help support those suffering from PSP.
What is PSP?
What Causes PSP?
Prevalence
Progression of the Disease
Diagnosis
Symptoms of PSP
What is PSP?
Progressive Supranuclear Palsy (PSP) is a brain disease. It entails the progressive death of neurons or nerve endings in the brainstem and basal ganglia above the nuclei in the brain (hence ‘supra’nuclear). This is the area that controls balance, movement, vision (particularly upgaze and downgaze) speech and the ability to swallow, hence the main symptoms, some of which may not appear or progress at all or until later in the disease. However, other symptoms, including behavioural changes, may also appear. The rate of progression of symptoms varies considerably from person to person.
What Causes PSP?
No one really knows, though the mechanism of its progression, the areas within the brain in which the neurons die and the resulting neuro fibrillary tangles of the protein ‘tau’ deposited in the brain (a similar process to that occurring in Alzheimer’s Disease, but in a different part of the brain) are increasingly understood, as are the genetics involved. These already provide answers to the cause of some neurodegenerative diseases. There is now known to be a complex genetic component to PSP, which predisposes about a third of the UK population to it (though with a very low level of risk), but the disease itself appears to be triggered environmentally and selectively, perhaps by any one of a variety of neurotoxins, or even by a blow on the head.
Prevalence
Recent research has indicated a prevalence of at least 5 to 6 per 100,000 of population (the equivalent of some 3,500 living patients across the UK), though leading neurologists consider this figure to be seriously low, estimating the true figure across the UK to be up to 15 per 100,000, (10,000 living patients) many misdiagnosed and many, particularly amongst the elderly, left undiagnosed. It would appear that the prevalence of this disease is not affected across the world by climate, ethnic background, colour or creed, though interestingly an epidemical level of similar diseases has occurred on the pacific islands of Guam and Guadeloupe.
Progression of the Disease
Like other neurodegenerative diseases, PSP gets worse over time. The average life expectancy of a patient is some seven years, the last two of which can be wheelchair or bedbound, but it is a very individual disease and with good care, many patients often live well into their seventies and beyond.
Diagnosis
PSP is a difficult disease to diagnose, particularly in its early stages, when it often mimics Parkinson's and other related diseases, although it is clinically, biologically and pathologically quite distinct and different from these. For example, pathological examination of brain tissue of Parkinson's Disease will reveal tell-tale ‘Lewy bodies’ deposited in the brain, whereas in PSP (and in Alzheimer’s Disease) deposits of neuro fibrillary tangles of a protein called tau can be seen. There is no blood test or other test yet available to provide a clinician with a diagnostic marker, though MRI (Magnetic Resonance Imaging) scanning shows loss of volume and signal strength in areas of the brain, providing evidence of neurological degeneration.
Pathological examination of brain tissue remains today the only way to confirm a diagnosis. Clinical diagnosis and differentiation between neurodegenerative diseases such as PSP, MSA (Multiple System Atrophy), CBD (Cortico Basal Degeneration), FTDP-17 (Fronto Temporal Dementia Parkinson’s), Parkinson’s Disease and Motor Neurone Disease can be extremely difficult, particularly in the early stages of PSP. Today, a good neurologist who achieves a ninety percent accuracy in diagnosis by the third year from onset against the ‘gold standard’ is doing well. This is particularly hard both for the neurologist and the patient and their family. Research into diagnostic markers using scanning techniques may soon lead to a means of supporting or even confirming the clinician’s judgement.
Symptoms of PSP
PSP is an older person’s disease and it is unusual for symptoms to appear before the age of fifty. As part of the normal ageing process, neurons in the brain anyway progressively die, but not in the numbers or specific areas seen in PSP and in related neurodegenerative diseases.
Early symptoms such as cramped handwriting, dislike of bright lights, fear of falling, tunnel vision and more nebulous symptoms and feelings are often only recognised in hindsight. This adds to the problems of the clinicians seeking to offer a diagnosis in the early stages of the disease. Because PSP is such an individual disease, with symptoms reflecting the areas in the brain where neurons die, the order of appearance of such early symptoms vary considerably. Indeed, current research is pointing to at least two variants of PSP, each with different early symptoms. Problems with balance and unexpected falls, often backwards, with resulting breakages or damage, often lead to the initial involvement of the medical profession. Vision problems such as the classical upgaze and downgaze restrictions, with related difficulties in opening and closing eyelids, a slow rate of blink, leading to dry eyes and tunnel vision can also occur early in the disease.
As the disease progresses, problems with slurred speech and ability to swallow usually follow and physical movement itself becomes jerkier and less stable. ‘Weighted walkers’ and wheelchairs may become necessary for mobility; and communication may also become more difficult. At this stage decisions may need to be made on tube feeding to counter the increasing risk of aspirational pneumonia from food ‘going down the wrong way’ and entering the lungs.
As stated earlier, PSP is a very individual disease and the type and level of symptoms will vary from person to person.
