Earlier diagnosis, new treatments and better community support offer hope for those
affected by the most common form of dementia.
Around 160,000 Australians currently have moderate to severe dementia. In 2006,
these figures are expected to rise to 183,000; in 2011 to 210,000; and, by 2050,
more than 500,000.
The ageing of Australia's population largely accounts for the increase in people
diagnosed with dementia, according to Alzheimer's Australia.
But scientists now hope the onset of dementia may be able to be delayed. And, where
it cannot be, support groups are gearing up to make all Australians aware of the
need for services that will support people with dementia, their families and carers.
What is Alzheimer’s disease?
Alzheimer's disease is the most common cause of dementia, accounting for about 70%
of this syndrome. It is progressive and irreversible, attacking and killing brain
cells.
As brain cells are killed, the brain shrinks or "atrophies". Tangles of nerves build
up in the centre of brain cells and plaques build up outside the brain cells. A
disruption occurs in the transmission of messages within the brain, resulting in
a decline in brain function.
Symptoms can be subtle and difficult to identify in the early stages of the disease.
Sometimes they are mistakenly shrugged off as a "passing phase". However, over time,
the symptoms of Alzheimer's disease become more pronounced and the changes to behaviour
more dramatic. Abilities will fluctuate from day to day, worsening in times of stress,
fatigue or ill-health. There will always be a deterioration over time.
Symptoms
- Persistent and frequent memory difficulties, initially of recent events, but later
including memory loss of well-known people or places;
- Vagueness in everyday conversation; later the person will be unable to follow a
conversation;
- Apparent loss of enthusiasm for everyday activities; reluctance to try new things;
- Possible personality changes, such as aggression or obsessiveness; emotional unpredictability,
such as becoming easily agitated or upset;
- Difficulty with routine tasks
- Lack of insight or awareness that something is wrong
- Deterioration of social skills - may behave inappropriately;
- In more advanced stages, physical symptoms such as weight loss and incontinence
so that full care is required.
NB: It is important to note that there can be other causes of the symptoms described
above that are unrelated to Alzheimer's disease. Some forms of dementia are treatable
and reversible, if diagnosed early enough. Examples of reversible dementia include:
- Some hormonal or vitamin deficiencies;
- Some psychiatric conditions, such as depression and anxiety (called pseudo-dementia);
- Clashes of medication;
- Certain medical problems that make dementia appear worse (eg, infections, constipation,
pain and uncontrolled chronic disease such as kidney failure).
Progression of Alzheimer’s disease
Alzheimer's disease and other forms of dementia are broadly divided into three stages:
mild, moderate and severe. The rate of deterioration varies from person to person.
Some people experience a rapid decline over a few months; for others it may take
a number of years.
The life expectancy of a person with Alzheimer's disease varies (from the onset
of symptoms) but can range between three and 20 years. But, on average, it ranges
between seven and 10 years.
Who gets it?
Dementia is not a normal part of ageing. Although older people are more likely to
get Alzheimer's or another cause of dementia, it is important to realise most older
people don't have the disease. Among people older than 65, about one in 15 people
develops the disease. Between 80 and 84 this increases to about one in nine. Over
85 the rate is as high as one in four. However, it can appear in people in their
40s or younger.
Possible risk factors include:
- Increasing age
- Genetics: in Familial Alzheimer's Disease (FAD), a rare form of the disease accounting
for only 1% of all cases, symptoms appear before the age of 65. Scientists have
identified gene mutations on three chromosomes known to cause FAD. If there are
two generations of first-degree relatives (parent or sibling) with FAD, there is
a greater chance of the next generation developing the disease. Testing is possible
for people at risk, with professional counselling provided.
In late onset Alzheimer's disease (symptoms appearing after the age of 65) certain
genes have also been identified that appear to increase risk. These genes are not
always passed from one generation to the next.
- Head injury, resulting in a loss of consciousness of at least 15 minutes, is associated
with a slightly increased chance of developing Alzheimer's disease.
Possible causes
Different risk factors may combine with a person's genetic make-up to increase the
chances of developing the disease. Many suspected causes have been investigated.
These include environmental agents (such as aluminium, zinc, solvents and organophosphates)
lifestyle factors (such as physical inactivity) and disturbances in the immune process.
According to Dr Helen Creasey, deputy director of the Centre for Education and Research
on Ageing at Sydney's Concord Hospital, no hard evidence has been found to link
any of these factors with the development of Alzheimer's disease.
Biochemical disturbances such as a reduction in the amount of acetylcholine in the
brain is believed to impair transmission of messages. Drugs that influence the amount
of acetylcholine in the brain have been developed in response to this and are known
as cholinergic therapies.
Diagnosis
Alzheimer's disease cannot be identified by a single test. Through careful clinical
examination and consultation, doctors can diagnose the disease with an accuracy
of between 80 - 90% (it is only on autopsy that the telltale plaques and tangles
can be seen). Diagnosis is usually made by an appropriately qualified general practitioner
(GP), a geriatrician, a psycho geriatrician or by a neurologist.
Some steps involved in reaching a diagnosis are:
- Detailed medical history
- Thorough physical and neurological examination;
- Basic medical tests such as tests of blood and urine and a brain scan to eliminate
other diseases;
- Neuropsychological examinations: includes tests of memory and other intellectual
functions, such as problem solving, attention, counting and language skills. These
tests help pinpoint areas that are affected, and areas that are still functioning.
- Psychiatric assessment: this may be required to eliminate conditions that mimic
dementia, such as depression or anxiety.
This process is known as "diagnosis by exclusion"; other possible causes of the
symptoms, especially treatable conditions, must be ruled out.
Professor Henry Brodaty, of the Academic Department for Old Age Psychiatry at Prince
of Wales Hospital, NSW, says the advantages of early diagnosis are that other potentially
reversible causes of memory loss or dementia are excluded.
Drug treatment can also be offered and those affected by Alzheimer's can plan for
challenges ahead.
Is there a cure?
Three drugs that inhibit cholinesterase (one of many important enzymes needed for
the proper functioning of the nervous system) are currently licensed for use, says
Prof Brodaty. They are donepezil, rivastigmine, and galantamine. These drugs reduce
the breakdown of acetylcholine in the brain and thereby reduce the apparent loss
of "cholinergic neurotransmitter" that is believed to impair transmission of messages.
Cholinesterase inhibitors have been shown to be clinically effective in some patients
with mild to moderate dementia. There is no evidence that they slow the progression
of Alzheimer's although they may improve quality of life.
The future
According to Professor Anthony Jorm, Director of the Centre for Mental Health Research
at the Australian National University, there are several areas where current research
suggests preventive possibilities.
"It has been proposed that Alzheimer's disease involves inflammatory processes which
lead to damage to nerve cells," says Professor Jorm. Research has found that people
who use the main class of anti-inflammatory drugs, NSAIDs, have around half the
risk of developing Alzheimer's. "However, these drugs can have side effects." Research
with high risk individuals is underway in the United States.
"Oestrogen is thought to protect the brain from deterioration in several ways and
it has been suggested that oestrogen replacement therapy for post-menopausal women
might be protective against Alzheimer's disease." A large trial, the Women's Health
Initiative Memory Study, is underway in the USA.
"A third type of medication which might have a preventive effect is antioxidants.
These mop up destructive molecules in the body called free radicals." Some studies
have suggested that vitamin C may be protective, but more research is needed.
The cost to the community
Currently it is estimated the health system spends $714 million a year on dementia,
with most of this spent on residential and hospital care, according to the Australian
Institute of Health and Welfare. This figure doesn't include financial cost to families,
or emotional cost to carers.
"The last 20 years have seen the stigma of dementia reduced but not removed," says
Alzheimer's Australia National Executive Director, Glenn Rees. "The trauma of diagnosis
for the person with the disease, their family and carers can be reduced if there
is an understanding of dementia in the community and if those needing help are assisted
in finding it."
The vision of Alzheimer's Australia is for a society committed to the prevention
of dementia, while valuing and supporting people living with dementia. The experience
of Alzheimer's Australia is that "people with dementia and their carers can have
a better quality of life for longer if there is access to early diagnosis, information,
support and community services."
Alzheimer's Australia is concerned that there are continuing problems in meeting
demand with the growing dementia epidemic - there is a great need, for example,
for expanded access to respite care. "But the key message is that people with dementia,
their families and carers should not feel that they must manage alone. They need
to know that they can seek - and receive - support through their GP, Alzheimer's
Australia or other organizations such as Carers' Australia."
