What Is Dementia?

Dementia is a term used to describe the symptoms that occur when the brain is affected by a specific illness, such as Alzheimer’s disease, vascular dementia and many other rarer conditions. Symptoms of dementia include loss of memory, confusion and problems with speech and understanding. The word 'Dementia' simply means a loss or impairment of mental functioning and comes from two Latin words meaning 'away' and 'mind'. Alzheimer's disease is by far the most common form of dementia, accounting for approximately 55% of all cases, and Vascular Dementia is the second most common form, accounting for about 20% of cases. A further 20% of cases are a mix of Alzheimer's disease and Vascular Dementia and the remaining 10% are made up of the rarer dementias, including Dementia with Lewy Bodies, Fronto-temporal Dementia/Pick's Disease and Huntington’s Disease. The main conditions are described in detail below.

ALZHEIMER'S DISEASE is a gradually worsening illness which increasingly affects the sufferer's brain and results in a gradual decline in their ability to remember, to learn, to think and to reason. The most usual early symptoms are a gradual loss of short-term memory; increasing confusion and forgetfulness; communication difficulties; and problems in performing everyday tasks, such as driving, managing money, cooking meals, or even washing and dressing oneself. In the early stages of the illness the personality of the person with dementia may change and their behaviour may become unfamiliar or strange, sometimes being difficult for the carer to understand and manage.

Over a period of several years, as the person with dementia becomes more increasingly affected by the illness, their symptoms usually become more obvious and disabling and their confused and sometimes risky behaviour may become far more difficult for the carer to manage, especially if they are coping alone. At this stage behavioural problems, such as wandering, restlessness, or frustration and angry outbursts may be experienced, often during the night as well as in daylight hours. Similarly, physical problems may arise, such as difficulty with walking and postural problems; problems with eating or drinking and subsequent weight loss; or continence problems. Eventually the person with dementia may become so severely mentally impaired and physically frail that they are totally dependent on others to meet their needs.

In the later stages of the illness the multitude of care-giving problems may become so many that the lone carer simply cannot continue to care for the person at home alone and specialist community support, or placement within a specialist residential or hospital care setting may be required. It is the duty of specialist services to help support people with dementia and their carers in such a way as to enable them to remain at home for as long as is possible and desirable and, if and when care-giving becomes too difficult, to facilitate a gradual and planned admission to the most appropriate continuing care setting.

The symptoms of VASCULAR DEMENTIA may be almost indistinguishable from those described above. However, unlike Alzheimer's disease, Vascular Dementia usually has a more abrupt onset and a person with dementia will have good and bad days, with a fluctuation in their level of confusion and self-care skills. Vascular Dementia is often caused by a series of 'mini strokes’ (also known as infarcts), which destroy small areas of the brain, thereby producing the symptoms of dementia. As further damage occurs the level of confusion and memory loss in the person with dementia will increase, often suddenly and dramatically. Similarly, their level of self-care skills may deteriorate, sometimes overnight, and the carer has to adjust their coping and caring strategies to compensate for their changing needs. Slight improvements in the condition of the person with dementia may be apparent for a time, but sadly once the damage has taken place it is permanent and irreversible. Similarly, after each mini stroke the level of skills and abilities of the person with dementia, and the carer's roles and responsibilities, may level off and appear to reach a plateau for some time before the next infarct occurs. Eventually over several years, through this process of 'stepwise decline’, the person with dementia will reach a level of moderate to severe dementia which is indistinguishable from advanced Alzheimer's disease.

Last Updated: April 2013
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