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Alzheimer's
- Some Questions and Answers
What is Alzheimer's?
Alzheimer's is the commonest of a group of illnesses called
dementias which affect the human brain. First described by
Alois Alzheimer in 1907, it is a progressive disorder in which
there is a slow but relentless destruction of nerve cells.
This destruction does not occur uniformly, but affects certain
areas such as the hippocampus and amygdala buried deep inside
the brain, and parts of the outer (cortical) areas, thus leading
to selective loss of mental function, especially memory.
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What is dementia?
Dementia is a medical term used to describe a general decline
in mental ability. The Royal College of Physicians' definition
reads as follows:
Dementia is the global impairment of higher cortical functions,
including memory, the capacity to solve the problems of day-to-day
living, the performance of learned perceptuo-motor skills,
the correct use of social skills and control of emotional
reactions, in the absence of gross clouding of consciousness.
The condition is often irreversible and progressive.
Within this definition, you can find all the major characteristics
of Alzheimer's - memory loss, problems in daily living, difficulty
in carrying out simple practical tasks, inappropriate responses
to situations requiring social awareness or emotional control,
and its progressive nature.
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Are there other types of dementia?
There are several other forms of dementia. The commonest
after Alzheimer's are vascular dementia and Lewy body dementia.
The former is caused by numerous blockages in blood flow to
small areas of the brain caused, for example, by very minor
strokes. Over a period of time, the cumulative brain damage
begins to manifest itself as vascular dementia. Lewy body
dementia has some similarities with Alzheimer's, but on closer
examination, some of the symptoms are seen to be different
and the structures inside neurons, called Lewy bodies, that
are visible after death are clearly different. These types
will not be discussed further in this booklet, but specific
leaflets on them are available from the Alzheimer's Society.
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Can a doctor distinguish between Alzheimer's
and other forms of dementia?
There is no simple clinical test to separate Alzheimer's
from other forms of dementia, so the doctor will have to rely
heavily on the pattern of onset of the symptoms and the medical
history of the person concerned. First, he will need to rule
out other possible causes of the symptoms such as vitamin
or thyroid hormone deficiencies, depression, or the side effects
of some medicines or their combinations. Then he will consider
the family history, and finally, seek an assessment by someone
skilled to apply and interpret simple tests of mental performance.
Taken together, the results will enable a correct diagnosis
to be made in 9 cases out of 10. An absolute diagnosis, however,
can only be made after death, when structures called amyloid
(senile) plaques and neurofibrillary tangles made of an abnormal
protein called tau can be demonstrated in the brain.
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Who is affected by Alzheimer's?
All forms of dementia rise steeply with age. In the case
of Alzheimer's, fewer than one person in 1,000 under the age
of 65 is affected, rising to about 3 per cent between the
ages of 65 and 74, and from 10 to 15 per cent in the over
85s. Despite these figures, most people over the age of 80
remain mentally alert, so age itself does not inevitably lead
to this condition. Alzheimer's affects both men and women
from all races, cultures and social backgrounds. It appears
to be more common in women, but this is at least partly due
to the fact that they have a life expectancy significantly
longer than men.
The small number who develop Alzheimer's early (between the
ages of 35 and 60) usually have a family history of the disorder,
and recent studies suggest that such individuals carry genes
that place them at greater risk.
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How common is Alzheimer's?
Alzheimer's has become much more common in the past 40 to
50 years, because Britain now has a rapidly ageing population
and thus many more vulnerable people. About 700,000 people
in the UK have dementia, and of those, just over 55 per cent
have Alzheimer's. People with Alzheimer's in the USA number
about 4 million, while world-wide, the estimated total is
12 million. Unless successful treatments can be found, this
global figure is expected to rise to around 22 million by
2025, because the over-65 population will double from 390
to 800 million in that time.
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What are the main symptoms of Alzheimer's?
At the outset, symptoms are variable and innocuous, and easily
mistaken for normal ageing. Common early signs are memory
loss (especially for recent events), confusion, poor concentration,
disorientation, and sometimes changes in personality. These
signs worsen at varying rates between individuals and in later
stages may be accompanied by aggressive behaviour, depression
or a tendency to wander off. Symptoms continue to worsen with,
eventually, almost complete loss of memory, failure to recognise
surroundings and loved ones, loss of language, and of the
ability to recognise and use familiar objects. By now, judgement
and the ability to engage in any kind of intellectual pursuits
will have vanished and the individual becomes fully dependent
for all their basic needs. Finally, people with Alzheimer's
often become wasted and eventually die of infections or other
physical causes.
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Can Alzheimer's be cured?
There is no cure for Alzheimer's and this is unlikely once
significant loss of nerve cells has taken place. However,
a medicine that prevented further deterioration while the
person was still able to interact meaningfully with their
surroundings and family would be a great advance. That goal
at least might be achievable. Although some years away, a
vaccine that would stop the onset of the illness seems a possibility.
If safe, it could be given to people at risk or even to everyone
once they reach their most vulnerable age.
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Can Alzheimer's be prevented or slowed
down?
The areas of the brain most affected by Alzheimer's are rich
in a chemical messenger called acetylcholine (ACh). This is
produced in the brain by an enzyme called choline acetyltransferase
(ChAT) and broken down by another enzyme called acetylcholine
esterase (AChE).
The levels of ChAT fall in the brain of a person with Alzheimer's,
so less ACh is made, and yet its rapid breakdown continues.
Three medicines are now available on the UK market which help
maintain the level of acetylcholine. Evidence suggests that
they benefit mental acuity and awareness, and can help some
people with mild memory loss for up to a year and possibly
longer. Eventually though, the benefit wears off and the downward
progression resumes. As our understanding improves, better
medicines of this type might have longer-lasting effects.
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Are there any known risk factors for
Alzheimer's?
A risk factor is anything that might increase someone's chance
of developing a particular condition. In the case of Alzheimer's,
the major risk factor is clearly age, but that is one we can
do little about. Women are also slightly more vulnerable,
possibly due to lowered oestrogen levels after the menopause.
Head injury, especially if it is accompanied by unconsciousness,
certain viral infections such as cold sores (though the precise
relationship is complex and still unproven), some dietary
factors, and a poor level of education have also been implicated,
but the evidence is far from proven. Culture may also be involved.
For example, studies in China suggest that rates there are
lower, and others comparing people over 65 of African origin
living in either the USA or Nigeria found fewer cases in those
living in Africa. Cigarette smoking may be slightly protective,
possibly due to the stimulation of N receptors by nicotine.
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Is Alzheimer's inherited?
It is known that Alzheimer's sometimes clusters in families
and this suggests that genetic make-up can play a part. But
this is not always so and many cases - called 'sporadic'-
occur when there is no family history. Studies of this aspect
of Alzheimer's have accelerated in recent years as a result
of the revolution in molecular biology. Through such techniques,
it has been shown that in about 5 per cent of people, Alzheimer's
is caused by a mutation in one of three genes. These people
almost invariably develop what is called ‘early-onset
Alzheimer's', where symptoms sometimes begin as early as age
30 and nearly always before the age of 65.
The first gene to be linked to early onset Alzheimer's is
called APP (Amyloid Precursor Protein). Mutations in APP are
very rare indeed, so the search went on for other genes. In
1995, a second was found, called the Presenilin-1 (PS1) gene.
Mutations in this account for between 50 and 60 per cent of
cases. Soon after this, another gene called Presenilin-2 (PS2)
was discovered, accounting for another 10 per cent. Genes
responsible for the remaining cases are still being tracked
down.
In the case of the majority - the 95 per cent of people who
get late-onset Alzheimer's - some genes have been identified
that are thought to increase the relative risk but do not
cause Alzheimer's directly. The most studied is called the
APOE (apolipoprotein E) gene, which exists in several forms
in different people. One in particular, called 4, has been
shown in over 50 studies to have a relationship with Alzheimer's.
People unlucky enough to have a pair of 4 genes (one on each
of the pair of chromosome 19) will usually develop Alzheimer's
before the age of 70, while those with either 2 + 4 or 3 +
4 will on average not show symptoms until they are over 90,
i.e. the possession of 2 or 3 can actually protect against
the risk associated with having 4. In any case, the possession
of the 4 gene only accounts for about 50 per cent of cases
of the late-onset type, so other genes are also likely to
be involved. Several are under active investigation. By understanding
what processes these genes orchestrate in the brain, it has
been possible to devise new approaches to medicines discovery.
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| Jennie's diary
conveys her growing sense of insecurity, fear, confusion
and distrust. At the time these entries begin, she
was a kindly lady just diagnosed with Alzheimer's,
but cared for and visited at least three times a
week by her daughter and friends. The words, spelling,
punctuation and underlining are hers. |
| Jan. 23rd 1997 |
Now Saturday must remember
to write my diary every night. Diana [daughter]
came sometime but I can't remember when. My memory
is bad. I don't remember things. It is very difficult
on your own. |
| Feb. 4th |
Damp dull morning usual things.
Just been giving myself a good talking to
about not writing my diary every evening. I think
my memory is getting very bad its worrying. I think
I spent the morning looking for something, I think
my purse. Very windy. |
| Mar. 15th |
Went to village for pension.
Afternoon sorting out pension. missing £10
out of my purse. |
| May 13th |
Diana came this morning can't
remember what for. didn't stay for dinner. Rang
Diana and she came to tell me Bert [brother] died.
How could I forget that. I am now realising I am
doing silly things. |
| June 26th |
I am tired bit achy today.
Keep forgetting. Must remember to ask Diana to write
things down then I know what is going on, otherwise
they think you know and you look a fool, and they
think you are scatty. |
| July 17th |
Talk to Jan [friend] went for
pension pay papers. Lost £10 note taken
from my purse. |
| July 22nd |
Lovely day usual things. it
is now evening just walked along to park. I am worried
about loosing money. I have no one to talk to about
it. I'm wondering about asking the solicitor to
come. |
| Aug. 17th |
Money taken out of bank. That
is very worrying. I feel sad about it when no one
tells you and you just find out. I don't like Sundays.
Bad pain in my hip I think I'm living too long. |
| Aug. 27th |
Rang Diana and talked to Mike
[son-in-law]. He says I rang yesterday. Forgot I
rang yesterday must write these things down.
it's because I am on my own so no one reminds me. |
| Aug. 31st |
Showery usual things. It's
been an odd sort of day. Now 4pm won't go out. Don't
know why its such an odd sort of day. Wish Ivor
[deceased husband] was still with me. Princess
Diana and Dodi killed in car crash. |
| Sept. 28th |
Just found out I haven't written
my diary since 21st. Good job I get paper or I wouldn't
know the day, date or year. Afternoon I was looking
for some things don't know what. Found so many picture
snaps the afternoon has gone. Jean [neighbour] brought
salmon sandwiches and cake. Very nice. |
| Dec. 6th |
Rang Diana. She seemed mad
with me. don't know why. New pills must swallow
whole. |
| Dec. 21st |
Dull misty morning. Envelopes
all over the place some full some empty. Can't cope
any more. It makes me cry but that won't help.
I forgot to go to church and I wanted to go this
morning. |
| Jan. 4th 1998 |
Don't like the feeling just
recently. I feel I don't know what's going on. I
think I ought to move to Arnside. Must get my money
sorted out something odd is going on. If anything
is different I get very confused, I am living too
long. |
| Jan. 23rd |
Rang Mike this morning to tell
him not to let me do silly things. I think the fairies
have been back in my bathroom. I seem to be getting
everything wrong. |
| Mar. 6th |
Paper says its Friday I thought
it was Tuesday. Diana and Mike may be away but can't
remember. If people ask me I'll feel a fool. Now
9th - not in America - keep my mouth shut or I'll
be in trouble. |
| May 9th |
I feel a nuisance to Diana.
I have been looking for something. I have been looking
so long I can't remember what I am looking for.
I am very miserable and frightened. I would like
to move, there is only me in this road. |
| May 23rd |
Dull. Usual things. Trying
to sort myself out. If only I had my Dad's shaving
tin back. I will never forget it being taken from
me. I am very unhappy and upset. Only £40
today and only Saturday. Thursday I got £66.63.
Someone is taking my things. |
| June 17th |
Went to Pine Lodge home [a
retirement home] while Diana and Mike are away. |
| July 7th |
Don't know why I'm at Pine
Lodge. I'm fed up. No friends. I'm fed up
with people trying to run my life. |
| July 11th |
I think I must have come home
from Pine Lodge today. Home from Pine Lodge.
I feel very odd and unhappy and don't really know
where I am. I'm frightened. |
| July 19th |
I don't know anything and all
my pencils seem to have disappeared. Someone has
taken my comb. I don't know why but I think it is
rotten. Going back to Pine Lodge. |
| Aug. 7th |
I don't like Pine Lodge. These
places can send you round the bend. I am very frightened
this morning. Things are going on in my house and
I am terrified. People in my house at night. I am
frightened and don't know how to sort it out. I'm
frightened to go out of my bedroom. |
| Sept. 7th |
Just found out I am in Pine
Lodge for ever. Lived too long. Diana is rotten.
Now 5am. Terrified. Don't know where I am or where
I belong. I am frightened and not in Pine Lodge. |
| Feb. 8th 1999 |
I am in a mess. Life isn't
nice when you are alone. Diana will you please come
and help me. I have forgotten to tell you things. |
| Entries became
very sporadic after October 1998. February 8th 1999
was the last coherent entry, a real cry from the
heart. Today, Jennie is still at Pine Lodge but
losing recognition of friends and family. Memories
are now mostly of childhood places and events, but
she is no longer frightened. |
|
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How do we know these genes are related
to Alzheimer's?
One way is to carry out population studies to determine which
genes and mutations are present in small tissue samples from
people with and without Alzheimer's. In this way, specific
gene defects can be linked to the illness.
Perhaps the most persuasive evidence comes from studies of
special strains of mice in which mutations are present. It
has been shown that mice with the APP mutation have trouble
learning and remembering as they get older, and both the APP
and PS-1 gene cause the development of amyloid plaques in
mice, just like those in humans, though not neurofibrillary
tangles.
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Can diet influence the development of
Alzheimer's?
Some reports suggested that a high intake of aluminium can
act as a trigger for Alzheimer's. However, it has proved impossible
to confirm this link and current opinion is that aluminium
has little, if any, involvement.
The role of several vitamins has also been investigated.
The University of Oxford Optima Study looked at the ageing
brain over many years by analysing scans and blood samples.
Among their findings were that people with lower blood levels
of vitamin B12 or folic acid (another member of the B vitamin
group) were four times and three times as likely to develop
Alzheimer's respectively compared to people with normal levels.
Vitamin E has also been studied and one large trial reported
that vitamin E slowed the progression of moderate to severe
Alzheimer's and the time before nursing home care became necessary.
Recent data suggests that 40-59 year-old people with the
4 gene who have 40 per cent or more fat in their diet in mid-life
have a 29-fold higher risk of developing Alzheimer's compared
to non-4 carriers. A second group with 35 per cent or less
fat in their diet only had a 4-fold risk increase.
A frequent problem in people with Alzheimer's is loss of
body weight, probably caused by inappropriate diet or neglect
of eating. Such weight loss in Alzheimer's correlates with
the loss of brain tissue and possibly with acceleration of
the dementia process. So it is important to ensure that people
with early signs of dementia have an environment where they
are encouraged to eat and that they have a good, balanced
diet. This is explored in much more detail in Food for Thought,
a booklet available from the Alzheimer's Society.
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What are the main types of medicines
used to treat Alzheimer's?
Many medicines are used in Alzheimer's, but not to treat
it. They can only relieve symptoms such as anxiety, depression,
agitation and aggression. Their effects can often be beneficial,
but they do not address the underlying disorder and will not
be considered further here.
Three medicines specifically developed for Alzheimer's are
available in the UK for treating mild to moderate illness
and all have been approved for prescription on the NHS. They
are:
- donepezil (Eisai/Pfizer)
- rivastigmine (Novartis) and
- galantamine (Shire/Janssen)
All three belong to a class of compounds that prevent the
breakdown of the brain chemical, ACh, mentioned previously.
They can stabilise or improve some of the early symptoms in
mild to moderate Alzheimer's.
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What impact does Alzheimer's have on
the family?
If someone that you love and care for develops dementia,
the impact can be quite devastating. Alzheimer's develops
differently in different people and may involve memory problems
- at first slight, but later very severe behavioural changes
such as aggression and mood swings, irrational actions such
as going out for a walk at night dressed in night clothes,
and the breakdown of normal reasoning processes that can lead
to distrust, suspicion, unfounded accusations, and quite inappropriate
behaviour. In the later stages, a high degree of physical
dependence may also develop, so that simple everyday activities
like dressing, going to the toilet and eating become almost
impossible without help. In the final stages, these problems
may pose such difficulties that care at home is no longer
possible.
These changes often cause enormous distress for carers and
can lead to profound feelings of guilt. They may impose great
strains on family life and marriages, require the involvement
of many outside agencies which can disrupt the usual patterns
of behaviour and social life, cause financial worries, and
impose a huge psychological impact as the loved one slowly
but surely slips away into an impenetrable twilight world.
Perhaps most frustrating of all is the knowledge that there
is so little that can be done to stop the process.
These important issues cannot be addressed in this short
booklet, but a helping hand will always be there from the
Alzheimer's Society and its local support groups.
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What kind of information and support
is available for people with Alzheimer's?
Confirmation that you or a close relative has Alzheimer's
is likely to be a traumatic and frightening experience. Many
people in this position will experience a period of shock
while the news sinks in, after which they are likely to begin
an appraisal of the impact of the news. These reactions are
natural, but it is important that clear explanations are given
at this time, that appropriate support is available, and that
there is some way of getting answers to the many questions
that will arise. In particular with a condition like Alzheimer's,
there is a need to be informed of the wide range of services
available and how they can best be co-ordinated for each individual.
Social Services are able to carry out an assessment to determine
the needs of the individual and can advise on the statutory
entitlements that are available. There will also be a host
of everyday problems as the disorder worsens. Some of these
may be addressed by occupational, speech and language therapists,
community psychiatric nurses, health visitors, physiotherapists
and chiropodists. Some answers to the many questions that
arise can be provided by these people or by the GP or specialist,
but they may not always be available when needed. The Alzheimer's
Society offers a comprehensive support service, including
a telephone helpline, as well as an extensive and well written
series of booklets and information sheets dealing with almost
every aspect of Alzheimer's that you are likely to meet. There
are also several useful books such as:
- Alzheimer's at Your Fingertips, by Cayton, Graham and
Warner, published by Class Publishing, London [ISBN
1-872362-71-0].
- Opening the Mind: New Frontiers in Alzheimer's Research,
published by the Alzheimer's Society
- Caring for a Person with Dementia: a Guide for Families
and Other Carers, published by the Alzheimer's Society
The Alzheimer's Society also has an extensive range of leaflets
dealing with subjects as diverse as the various forms of dementia
to social services, Council Tax implications and welfare benefits.
There is also a network of local support groups throughout
the British Isles.
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