Mild cognitive impairment

Mild cognitive impairment (MCI) is a relatively recent term, used to describe people who have some problems with their memory but do not actually have dementia. This sheet explains the link between MCI and dementia and looks at possible treatments.

Background

People are often not diagnosed with dementia until their symptoms begin to affect their quality of life and their ability to carry out everyday activities. However, in recent years treatments that can temporarily slow down the symptoms of Alzheimer’s disease have become available (Aricept, Reminyl, Exelon and Ebixa). Other treatments that could slow down the progression of the disease in the brain are also being developed. It is important that people with Alzheimer’s disease are identified as early as possible so that they can benefit from these treatments in the future. Identifying people with mild cognitive impairment (MCI) is one way to try to achieve this.

What is MCI?

MCI is not a specific medical condition or disease. It is a form of memory loss that may affect a person’s score on neuropsychological tests, but does not mean that they have dementia. Another term that is occasionally used but does not have the same level of recognition is ‘early cognitive impairment’. There are many different reasons why people may have some mild problems with their memory. Some people will be in the early stages of Alzheimer’s disease or another dementia. Others, however, will have MCI as a result of stress, anxiety, depression, physical illness or just an ‘off day’. Therefore, a doctor will not be able to give a straightforward diagnosis of MCI.

People with MCI usually have impaired memory according to standard tests but no impairments in other areas of brain function, such as planning or attention, and no significant problems in everyday living.

Complaints of memory loss are extremely common and probably occur in everybody at some point during their life, particularly as they get older. It is estimated that 15 per cent of the population may be experiencing MCI.

How many people with MCI develop dementia?

People who have MCI are at an increased risk of going on to develop Alzheimer’s disease (or another form of dementia). In studies carried out in memory clinics, 10-15 per cent of people with MCI went on to develop dementia in each year that the research results were followed up. It is not clear, however, whether everyone with MCI would eventually go on to develop dementia; more research is needed. In community studies and clinical trials the rates are about half this level, but still represent a very increased level of risk. It is therefore very important to identify people with MCI, as they are at increased risk of Alzheimer’s disease and may even already be in the very early stages of the disease. However, many people with MCI also improve or remain stable, and are not in the early stages of Alzheimer’s disease. Treatments would, therefore, be inappropriate for these people.

Can we identify the people with MCI who will go on to develop dementia?

A lot of research has focused upon techniques to try to improve the identification of people with MCI who will go on to develop Alzheimer’s disease. Researchers have used different types of brain scans, detailed neuropsychological tests and measuring proteins in the spinal fluid to try to do this. Although some of these techniques show promise, so far none of them have solved the problem or been developed enough to be used in routine clinical practice by doctors. This is an area of ongoing research.

Treatments

A number of treatments are currently being investigated to see whether they can prevent or delay dementia in people with MCI. The results from initial studies are disappointing, and the potential value of treatments such as Aricept, Exelon and Reminyl has not been established. New research is regularly published, and the situation may change, but at the moment there is not enough evidence to recommend any specific treatments.

How can we minimise the risk of MCI and dementia?

A number of research studies have suggested that our lifestyle can have an effect on our risk of developing dementia. Factors such as low physical activity have been shown to be associated with an increased risk of developing dementia. Other studies have shown that physical exercise, travelling, doing odd jobs, knitting and doing crossword puzzles are all associated with a reduced risk of developing dementia. Leisure activities such as these may well help the brain to keep a reserve capacity that can delay the onset of dementia. Appropriate physical exercise can contribute to a healthy heart and brain.

Information from Alzheimers Soc