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Dementia is a broad term for the deterioration of brain function resulting in memory loss, reduction in language skills and behavioural and emotional problems. Alzheimers disease is the most common type of dementia, accounting for more than half of all cases. Alzheimers disease is rare before the age of 60 but the risk of developing it increases with age. Around 25% of people over 80 years old have the disease. As the population ages, the number of people with Alzheimers disease, and other dementias, will increase.
The cause of Alzheimers disease remains uncertain. It is likely that no single factor is responsible but that a variety of factors, which may differ from person to person. Since people whose parents or siblings develop the disease appear at greater risk of developing it themselves, there may be a genetic component. However, no straightforward pattern of inheritance has been found. Its known that head injury is a risk factor and that Alzheimers disease often affects people with Downs Syndrome.
Some researchers have suggested that people who exercise their brains (doing crosswords and other mental agility exercises) are less likely to develop the disease. But there is no firm evidence to show that environmental factors play a part in the development of the disease.
Whatever the underlying cause, Alzheimers disease is the result of the destruction of nerve cells (neurones) in the brain. These nerve cells cannot be replaced, so the person with Alzheimers disease gets progressively worse as more cells are destroyed. This process causes the breakdown of the brains communication systems. When functioning normally, the brain exchanges signals from other parts of the body, and other parts of the brain, across the gaps (synapses) that exist between nerve cells. These signals are essential for brain activity such as language and problem solving. They are also involved in controlling motor functions, such as instructing muscles when and how to work.
These message signals cross over these gaps with the help of chemicals known as neurotransmitters, including acetylcholine. Doctors believe that nerve cell destruction causes a reduction in acetylcholine, leading to impaired transmission of nerve signals. Drugs that boost the amount of acetylcholine are used to limit the impact of the disease.
The onset of Alzheimers disease is often difficult to pinpoint as it starts with forgetfulness and difficulty in finding the right word, common problems associated with the ageing process.
In these early stages, those closest to the person with Alzheimers disease may notice personality changes. For example, a previously cheerful person may become irritable and even aggressive and may no longer be able to cope with the demands of a busy life.
As the disease progresses, loss of memory, difficulty in completing simple tasks, and more overt personality changes, often combined with depression, become more evident. Mathematical and verbal skills decline, which may mean that a person is no longer able to read instructions or count their change. Conversation can become empty and meaningless. Sometimes people with Alzheimers may become paranoid, believing, for example, that their carers are trying to poison them or that their partner is being unfaithful. The sense of time and place can also be lost, with sufferers getting dressed in the middle of night or wandering off and becoming lost, even on once-familiar territory. This can cause a great deal of stress and upset for the persons carers and family who, in effect, have lost the person they once knew.
During the late stages of the disease, people with Alzheimers may become totally dependent upon others for their care. Walking can become difficult, confining a sufferer to bed. He or she may become incontinent, experience hallucinations and become increasingly unaware of their surroundings. It is at this stage that residential care, with round the clock nursing, is often considered.
The average duration of the disease is about ten years, with a range of between 3-20 years from diagnosis and death. Often the cause of death in a person with Alzheimers is another illness, such as pneumonia, which becomes more common in people who are bed-bound and so less resistant to infection.
There is no single test for Alzheimers disease and diagnosis depends in part on excluding other potential causes of dementia. These include vascular dementia (often known as multi-infarct dementia or MID), dementia with Lewy bodies (DLB), fronto-temporal dementia (including Picks disease), Parkinsons disease, and alcohol-related dementia (Koraskoffs syndrome). In a person with suspected of having Alzheimers, the GP will try to establish some of the symptoms such as memory loss and verbal impairment. Physical examination and blood and urine tests may be carried out to help exclude other causes of dementia. If the GP is unable to make a diagnosis, a referral will usually be made to a specialist (a neurologist, a care of the elderly physician or a psychiatrist) for more specialist tests. These tests may include the Mini-Mental State Examination (MMSE). This is a series of questions and tests looking at memory, language and mathematical skills. Other investigations may include a brain scan, typically magnetic resonance imaging (MRI). Some people may also be referred to a memory clinic specialising in mental state assessments.
In a person with suspected of having Alzheimers, the GP will try to establish some of the symptoms such as memory loss and verbal impairment. Physical examination and blood and urine tests may be carried out to help exclude other causes of dementia. If the GP is unable to make a diagnosis, a referral will usually be made to a specialist (a neurologist, a care of the elderly physician or a psychiatrist) for more specialist tests. These tests may include the Mini-Mental State Examination (MMSE). This is a series of questions and tests looking at memory, language and mathematical skills. Other investigations may include a brain scan, typically magnetic resonance imaging (MRI). Some people may also be referred to a memory clinic specialising in mental state assessments.
These tests may include the Mini-Mental State Examination (MMSE). This is a series of questions and tests looking at memory, language and mathematical skills. Other investigations may include a brain scan, typically magnetic resonance imaging (MRI). Some people may also be referred to a memory clinic specialising in mental state assessments.
Unfortunately, no cure has yet been found for Alzheimers disease. However the disease can be managed with drug treatment, non-drug treatment and support from a range of services.
The introduction of a new class of drugs called cholinesterase inhibitors is the first time there has been an effective drug treatment for Alzheimers. Cholinesterase breaks down and destroys acetylcholine, the neurotransmitting chemical. Cholinesterase inhibitors help to prevent this breakdown and so promote a more plentiful supply of acetylcholine. There are three drugs available in this class: Aricept (donepezil hydrochloride), Exelon (rivastigmine) and Reminyl (galantamine). In people in the early to middle stages of the disease, they may slow down the progression of symptoms.
Sometimes anti-depressants are prescribed to help treat the depression that can be associated with Alzheimers disease. The inappropriate prescribing of potent psychiatric drugs (neuroleptics) used to manage challenging behaviour, of people in residential care, has been recognised and criticised.
There are other techniques for helping to cope with Alzheimers disease. These include techniques known as reality orientation, reminiscence therapy and validation therapy. Art and music therapies are also used, but their effectiveness is not proven.
Help and support in terms of respite care (giving carers a break), social services and residential care is an important part of the overall care of someone with Alzheimers disease.
1. I have been diagnosed with mild cognitive impairment. Does this mean I will develop Alzheimer's disease?
No, a diagnosis of mild cognitive impairment doesn't mean that you will necessarily develop Alzheimer's disease. Mild cognitive impairment (MCI) is a relatively new term used by doctors and describes age-related exaggerated absent-mindedness. If you have this, it means you have some problems with your memory, but it doesn't mean that you have dementia.
MCI isn't a specific medical condition or disease. People with it don't usually have any other signs or symptoms of dementia. It's very common to have memory problems, particularly as you get older, and most people will have this at some time in their lives.
There can be a number of reasons why you may have developed memory problems. With age, memory becomes more inefficient. However, exaggerated forgetfulness can also be caused by stress, anxiety, depression or a physical illness. It's important to see your GP if you have memory problems.
Although many people with MCI find their memory improves or remains stable and they don't go on to develop dementia, for some it can be an early symptom of Alzheimer's disease.
There aren't any tests to find out the cause of MCI or to tell if it will lead to Alzheimer's disease or another type of dementia. Talk to your GP if you're worried about MCI and Alzheimer's disease.
2. Does aluminium cause Alzheimer's disease?
Doctor's don't yet know exactly what causes Alzheimer's disease, but it's thought to be a combination of factors. At the moment, there is no direct evidence to show that aluminium causes the condition.
Aluminium is a metal found in some of the foods we eat and in drinking water. It's also used to make packaging, cooking pots and pans and some medicines. The aluminium that you eat or drink passes through your body and very little of it is taken in.
During the 1960s and 1970s researchers discovered a possible link between aluminium and Alzheimer's disease. Since then, more research has been done that found some links but hasn't shown that aluminium causes dementia. It's difficult for researchers to be more sure of the effects of aluminium because Alzheimer's disease is a common condition that has many causes, and because aluminium is found in many places in our environment.
3. Can ginkgo biloba help improve my memory?
Ginkgo biloba is a herbal remedy traditionally used to improve memory. The results of research on the effects of taking ginkgo biloba to treat Alzheimer's disease are uncertain. Some research shows that it may help to improve symptoms whereas other research shows no effects.
Ginkgo biloba comes from the maidenhair tree and has been used in traditional Chinese medicines for many years. A number of research trials have looked at whether or not ginkgo biloba may be able to treat dementia. The results of this research have been mixed, some showing that it may help to improve symptoms and other research showing no effect. A recent study by the Alzheimer's Society found that ginkgo biloba didn't slow down the development of dementia or have any effect on the quality of life or mental ability and thinking of people taking it.
Ginkgo biloba can cause bleeding if you take it with warfarin or aspirin and it may also cause health problems if mixed with some other medicines. Don't start taking any herbal remedies without speaking to your GP or pharmacist first.
- Alzheimers Disease Society
Helpline: Tel: 0845 300 0336
- Alzheimers Research Trust
- Alzheimers Association (USA)
- National Institute of Neurological Disorders and Stroke
- Alzheimers Association of NSW
- Carers UK
- Management of patients with dementia. Scottish Intercollegiate Guidelines Network (SIGN), February 2006. www.sign.ac.uk
- What is Alzheimer's disease? Alzheimer's Society. www.alzheimers.org.uk, published January 2011
- Treatments. Alzheimer's Research Trust. www.alzheimers-research.org.uk, accessed November 2010
- Dementia. Clinical Knowledge Summaries. www.cks.nhs.uk, published March 2010/span>
- Donepezil, galantamine, rivastigmine (review) and memantine for the treatment of Alzheimer's disease. National Institute for Health and Clinical Excellence (NICE), November 2006 (updated August 2009). www.nice.org.uk
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