Understand the process and experience of dementia

Handout 1: Dementia

Learning outcome 1 Assessment criteria: 1.1, 1.2

Dementia

Dementia is a broad term used to describe a range of signs and symptoms consistent with damage to the brain caused by specific conditions. These signs and symptoms are associated with progressive and degenerative changes in the intellectual functioning.

Dementia is on the increase in the UK and the likelihood increases with age. According to a report into the prevalence and cost of dementia, Dementia UK[1], there are over750,000 people with a form of dementia.

If you have access to the Internet, follow the link below and watch the slide show. This shows images of the how the brain is affected in different types of dementia.

There are different types of dementia with a variety of causes.

Dementia syndrome or ‘mixed dementia’

This term is used to describe a condition where Alzheimer’s disease and vascular dementia occur together. Symptoms may be similar to either Alzheimer’s disease or vascular dementia or a combination of the two.

Alzheimer's disease

This is the most common cause of dementia, accounting for 55% of all cases of dementia. Changes in the brain are caused include the loss of brain cells, shrinking of the brain cells and the presence of abnormalities in the brain cells called ‘tangles’ and ‘plaques’. These are so tiny that can only be seen in a microscope. but they cause the brain cells to die off and shrinkage of brain tissue.

Alzheimer’s disease is characterised by loss of short-term memory, deterioration of behaviour and language, cognitive skills and limited judgement. It has a long progression, and may continue for 20 years.

Vascular dementia

This is the second most common cause of dementia and accounts for about 20% of people with dementia. If blood vessels become blocked, for example because of a clot, the blood is unable to supply oxygen to the brain and the cells affected will then die.

The individual’s condition deteriorates in a ‘step-like’ way, sometimes maintaining at the same level and then showing a sudden change following a small stroke causing more damage.

Multi-infarct dementia (MID) is a form of vascular dementia and occurring when the individual experiences a series of ‘mini-strokes’, which although may be barely detected, have an accumulative effect on areas of the brain as they are deprived of oxygen.

Dementia with Lewy bodies (DLB)

This name comes from the presence of abnormal proteins, called Lewy bodies which are found in certain areas of the brain. As the brain’s function is affected, symptoms include stiffness, shaking and problems with walking similar to that experienced by people with Parkinson’s disease. About 15% of people with dementia have DLB.

Lewy bodies are abnormal proteins that are thought to cause brain cells to die. Lewy body deposits are found in the part of the brain called the cerebellum and in the occipital lobe, affectingbalance and causing hallucinations. DLB symptoms are similar to those of Parkinson’s disease.

Symptoms in people with DLB vary from day to day, with their level of abilities inconsistent. This can be difficult for supporters to understand. Individuals also experience periods of lucidity which can lead to depression.

Fronto-temporal (Pick’s disease)

This form of dementia affects the frontal and temporal lobes of the brain, and though the symptoms of the condition vary, the early symptoms involve problems with language and behaviour. Pick’s disease is a less common form of dementia, accounting for about 5% of incidences. It tends to affect people at a slightly younger age (between 40-65).

The individual may experience extreme mood swings, changes in personality and behaviour, although memory is not affected in the early stages.

HIV-associated dementia

This is a form of dementia caused by the HIV virus, though it is not known how it damages brain cells. Behaviour, memory, thinking and co-ordination are affected.

Symptoms caused are forgetfulness, poor concentration, difficulty learning new things, confusion, changes in behaviour, problems with balance and co-ordination and muscle weakness.

This is becoming less common as treatment for HIV infection has improved with the use of antiretroviral therapy.

Huntington’s disease (HD)

This is an inherited condition of the brain and body which generally affects people between 30 and 50 years old. It is degenerative, and the symptoms include memory problems, involuntary movements, aggression and depression. About one in every 10.000 people is affected.

An abnormal protein is produced which is thought to cause destruction of neurons. Most of the damage occurs in the basal ganglia, which controls movement, but other areas of the brain affected involve thinking, memory, and perception. Other symptoms include abnormal movements and emotional and behavioural changes

CJD (Creutzfeldt-Jakob disease)

A type of prion disease, where a form of protein is found in the central nervous system which forms clusters in the brain, destroying brain cells and making holes (spongiosis) in the tissue. This degenerative condition causes brain cells to die and can affect younger people. It develops rapidly, often taking one year from diagnosis to death. It can be inherited or contracted.

Symptoms usually progress very rapidly, from minor memory losses and mood changes progressing to clumsiness, slurred speech and jerky movements. The individual eventually loses the ability to move or speak; loses bowel and bladder control and becomes unaware of their surroundings.

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[1] Personal Social Services Research Unit (PSSRU), 2007, Dementia UK