What is dementia?

The term 'dementia' is used to describe the symptoms that occur when the brain is affected by specific diseases and conditions. These include Alzheimer's disease and stroke.

Dementia is progressive, which means the symptoms will gradually get worse. How fast dementia progresses depends on the individual. Each person is unique and will experience dementia in their own way.

Symptoms of dementia include:

Loss of memory - for example, forgetting the way home from the shops, or being unable to remember names and places.
Mood changes - particularly as parts of the brain that control emotion are affected by disease. People with dementia may also feel sad, frightened or angry about what is happening to them.
Communication problems - a decline in the ability to talk, read and write.
In the later stages of dementia, the person affected will have problems carrying out everyday tasks and will become increasingly dependent on other people.

What causes dementia?
There are several diseases and conditions that cause dementia. These include:

Alzheimer's disease
This is the most common cause of dementia. During the course of the disease the chemistry and structure of the brain changes, leading to the death of brain cells.

Vascular disease
The brain relies on a network of vessels to bring it oxygen-bearing blood. If the oxygen supply to the brain fails, brain cells are likely to die and this can cause the symptoms of vascular dementia. These symptoms can occur either suddenly, following a stroke, or over time through a series of small strokes.

Dementia with Lewy bodies
This form of dementia gets its name from tiny spherical structures that develop inside nerve cells. Their presence in the brain leads to the degeneration of brain tissue. Memory, concentration and language skills are affected. This form of dementia shares some characteristics with Parkinson's disease.

Fronto-temporal dementia (including Pick's disease)
In fronto-temporal dementia, damage is usually focused in the front part of the brain. At first, personality and behaviour are more affected than memory.

Rarer causes of dementia
There are many other rarer causes of dementia, including progressive supranuclear palsy, Korsakoff's syndrome, Binswanger's disease, HIV and Creutzfeldt-Jakob disease (CJD).

People with multiple sclerosis, motor neurone disease, Parkinson's disease and Huntington's disease may also be more likely to develop dementia.

Who gets dementia?
There are about 750,000 people in the UK with dementia.

Dementia mainly affects older people. However, it can affect younger people: there are 18,000 people in the UK under the age of 65 who have dementia.
Both men and women get dementia.
Scientists are investigating the genetic background to dementia. It does appear that in a few rare cases the diseases that cause dementia can be inherited.
Can dementia be cured?
Most forms of dementia cannot be cured, although research is continuing into developing drugs, vaccines and treatments.

Drugs have been developed that can temporarily alleviate some of the symptoms of Alzheimer's disease in the early to middle stages. These drugs act in the brain to maintain supplies of an important chemical called acetylcholine.
These drugs are:

Aricept (donepezil hydrochloride)
Exelon (rivastigmine)
Reminyl (galantamine).
Side-effects may include diarrhoea, nausea, insomnia, fatigue and loss of appetite.

In 2002, a new drug called Ebixa (memantine) was launched in the UK. This works in a different way to the other three drugs and can be helpful for people in the middle to later stages of dementia. Side-effects may include hallucinations, confusion, dizziness, headaches and tiredness.

None of these drugs will cure Alzheimer's disease, but they may stabilise some of the symptoms for a limited period of time.

How can I tell if I have dementia?
Many people fear they have dementia, particularly if they think that their memory is getting worse.

Becoming forgetful does not necessarily mean that you have dementia. Memory loss can be an effect of ageing. It can also be a sign of stress or depression. In rare cases, dementia-like symptoms can be caused by vitamin deficiencies and/or a brain tumour.

If you are worried about yourself, or someone close to you, it is worth discussing your concerns with your GP.

Diagnosing dementia
It is very important to get a proper diagnosis.

A diagnosis will help the doctor rule out illnesses that might have similar symptoms to dementia, including depression.
Having a diagnosis may mean it is possible to be prescribed drugs for Alzheimer's disease.
Whether you are someone with dementia or a carer, a diagnosis can help you prepare and plan for the future.
Dementia is diagnosed by a doctor, either a GP or a specialist. The specialist may be a geriatrician (a doctor specialising in the care of the elderly), a neurologist (someone who concentrates on diseases of the nervous system) or a psychiatrist (a mental health specialist).

The doctor may carry out a number of tests. These are designed to test memory and the ability to perform daily tasks.

Can dementia be prevented?
At present we are not sure what causes most of the diseases that lead to dementia. This means it is difficult to be sure what we can do to prevent dementia.

However, the evidence seems to indicate that a healthy diet and lifestyle may help protect against dementia. In particular, not smoking, exercising regularly, avoiding fatty foods and keeping mentally active into old age may help to reduce the risk of developing vascular dementia and Alzheimer's disease.

Information from Alzheimers Soc