| what are the symptoms ? | what causes the disease ? |
| how is it diagnosed? | what possible treatments are there ? |
Alzheimer's disease is the most common cause of dementia, responsible for just over half of the 670,000 cases in the UK. This leaflet describes symptoms and the likely course of the disease, as well as diagnosis and prospects for treatment.
Typically Alzheimer's disease begins with lapses of memory, difficulty in finding the right words for everyday objects or mood swings. Mild symptoms may be a natural effect of ageing, but in Alzheimer's disease a pattern of problems emerges over six m months or more. As it progresses the person may:
In advanced cases people may also:
Finally, the personality disintegrates and the person becomes totally dependent or bed-bound. Relatives have described this experience as like living with a stranger.
Click for more information on the later stages of dementia
Alzheimer's is a physical disease which attacks brain cells (where we store memory) and brain nerves and transmitters (which carry instructions around the brain). Production of a chemical messenger acetylcholine is disrupted, nerve ends are attacked an and cells die. The brain shrinks as gaps develop in the temporal lobe and hippo-campus, important for receiving and storing new information. The ability to remember, speak, think and make decisions is disrupted. After death, tangles and plaques made from protein fragments, dying cells and nerve ends are discovered in the brain. This confirms the diagnosis.
The short answer is we don't know. It may be a combination of factors, some we are born with, some in our environment and some which happen to us. Things that make Alzheimer's disease more likely are called risk factors . They include:
The greatest risk factor is increasing age.
Although the risk continues to rise, a majority of 90-year-olds are still unaffected.
Some people are born at risk because of the genes they inherit.
About 17,000 people in the UK are affected below the age of 65, sometimes as young as 35 years old. Alzheimer's disease in younger people often progresses more rapidly. A number of rare genetic faults make the disease more likely at a young age. Some people with a strong family history of Alzheimer's seek genetic counselling , to discuss whether they should have a test to see if they have inherited a faulty gene.
A gene is also associated with Alzheimer's disease later in life. This is a variation of the apolipoprotein E gene (ApoE), which we all carry and which comes in three forms, ApoE2, 3 and 4. ApoE2 seems to protect against Alzheimer's, while ApoE4 seems to make it more likely. If we inherit one ApoE4 version we have an increased chance of the disease. If we inherit ApoE4 from both parents as about two people in every 100 do we are much more likely to develop the disease by the age of 80.
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People who have had a severe head injury with loss of consciousness are at increased risk of dementia. This is also true of boxers who have become punch-drunk.
Because of their chromosomal defect, people with Down s syndrome are more likely to develop Alzheimer's disease. As more people with Down's syndrome survive into their 50s and 60s, more will develop the disease.
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It is important not to become over-concerned at minor mental slips, but early and accurate diagnosis is important to clarify whether a treatable condition is causing symptoms, and to provide the best possible care.
A health professional records the pattern of symptoms, and uses simple tests to see what someone remembers and if they can hold simple information in the memory. These can be repeated after a few months to measure change. Where dementia is suspected brain scans can show chemical activity and whether areas of the brain are shrinking.
Diagnosis can be 80 to 90 per cent accurate in life but can only be confirmed after death.
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There is no cure for Alzheimer's disease and none is likely in the near future, but prospects for management have improved. New drugs are being developed which seek to slow down the rate of mental decline. These are promising in the early stages of the disease, although it is unclear for how long they can help and they are not yet widely available. In April 1997, donepezil (Aricept) became the first drug to be licensed for Alzheimer's in Britain.
Affected people should live as normal a life for as long as they can. Memory aids and familiar routines are helpful. As the disease progresses, people need more support and may need close supervision and eventually nursing care.
Click for more information on possible treatments.
October 1997
Page Text supplied by The Alzheimer's Disease Society of Great Britain