What is dementia?

The term “dementia” describes a group of symptoms caused by the impact of disease on the brain. While each person is unique and will experience dementia in their own way, symptoms typically include problems with memory, speech and perception.

Short term memory is usually affected. This may mean for example, that the person with dementia forgets the names of family or friends, or how to perform simple everyday tasks. They may, however, retain their long term memory, clearly remembering events from the past.

The person with dementia may have problems finding the right words, or may seem to have difficulties understanding what is being said to them. As verbal communication diminishes, they may retain the ability to communicate feelings, needs and preferences through facial expression and body language. Perception is also usually affected, as the person with dementia tries to interpret and make sense of the world about them. This may make their behaviour and speech appear different to those of other people.

In some cases, as the dementia progresses, so behaviour, cognition and interpretation becomes more irrational, unpredictable and in contrast to the individuals known personality.

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 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. The symptoms of vascular dementia 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 the 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.

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 can also 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 around 18,500 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 disease that causes 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.

In recent years new drugs have been developed that 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)

These drugs will not cure Alzheimer's disease, but they may stabilise some of the symptoms for a limited period of time. Side affects may include diarrhoea, nausea, insomnia, fatigue and loss of appetite.

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 affect 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 early to middle stage Alzheimer’s disease. Whether you are someone with dementia or a carer, a diagnosis can help you prepare for the future.

Dementia is diagnosed by a doctor, either a GP or a specialist. The 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 protect against dementia.

In particular, not smoking, exercising regularly, avoiding fatty foods and keeping mentally active into old age may help prevent us from developing vascular dementia and Alzheimer's disease.

This information is not intended as a replacement for professional medical advice, and individuals should have personal circumstances investigated. Please consult your GP. Further information can also be found through the Alzheimer’s Society at www.alzheimers.org.uk