Alzheimers

 

What is it?

Alzheimers disease is a progressive degenerative disease of the brain. It was first described as Alzheimers dementia in 1907 by a German scientist who found that certain changes occurred in the tissue of the brain of a 51 year old lady who died after suffering from dementia. The strongest risk factor for Alzheimers is advancing age, and women are twice as likely to develop the disease as men.

Who is at risk?

Alzheimer's disease can affect anyone, but is far more common with increasing age. Less than one in 500 people develop the condition under the age of 65 but the likelihood of having the disease doubles for each five years after this age so that one in every five 80 year olds will have it. Dementia in general is also more common in people who have a history of problems such as depression or anxiety, even though the exact cause of most cases of dementia is still not fully understood.

Family history of the disease is a risk factor, and the risk is increased if a parent, sister or brother has it.

What types of dementia are there?

Dementia is a condition characterised by the progressive loss of mental function, accompanied by observed changes of behaviour, and a gradual loss of the skills of daily living. It is due to the gradual loss of brain cells associated with the progressive degeneration of the brain substance.

It is estimated that there are 650,000 people in the UK who suffer with dementia. In 40-50% of cases there is an identifiable underlying cause such as a circulatory disturbance in the brain (e.g. a small stroke), a genetic disease (e.g. Huntingdon's Chorea) or a transmitted disease is known or suspected (e.g. HIV or Creutzfeldt-Jacob Disease - CJD). In all these cases there will be other clues in the environmental and clinical history and appearance of the patient that lead one to suspect the underlying cause.

The remaining 50-60% of cases do not fit into these categories and these are generally described as Alzheimers disease.

How does Alzheimers occur?

The cause of Alzheimers disease is unknown. Some recent evidence has linked it with elevated aluminium levels in water supplies. However this has not been confirmed and more research is being conducted.

 

What are the symptoms?

The disease progresses through a number of stages:

Memory loss

This nearly always manifests itself early on in the disease and a carer may notice that a person is more forgetful of recent events, or more likely to repeat themselves in conversation. There is a progressive reduction in interest in activities or other people, and a reduced ability to grasp new ideas or adapt to changing situations. Patients may experience difficulty in finding the correct words in conversation and there may be a disturbance in visual /spatial orientation leading to confusing and erratic behaviour.

Depression

This sometimes occurs but becomes less marked as the intellectual ability of the patient declines.

Cognitive functions

A deterioration in performing simple mental calculations, exercising reasoning and making judgements occur. Patients require increasing assistance with daily living tasks.

Personality changes

The personality typically remains intact until later in the disease when a variety of behavioural changes can occur. Examples of this include altered mood and indifference to surroundings; disinhibition (i.e. lack of social control, a tendency to be abusive in public); paranoid delusions (imagining people are talking about the patient); hallucinations, and general agitation.

Seizures

In advanced cases seizures can occur and ultimately, co-ordination of movements and muscle power deteriorate.

The general outlook for a person with Alzheimers is poor and most patients spend the last 5 years in a nursing home or under 24 hour home care and in the final stages, they become bedridden and often incontinent. Death is usually because of a pneumonia or urinary infection.

 

How is Alzheimer's diagnosed?

The only certain way to diagnose Alzheimer's disease is to examine the brain cells of the sufferer under the microscope to look for the characteristic cell changes. Obviously this is not possible until after death in most cases, but the diagnosis is usually fairly accurately made on the basis of the history (the description of the symptoms from the person or their relatives) followed by a more thorough examination of their mental ability. The GP or specialist will usually perform a mental test called a Mini Mental State Examination (MMSE), or a similar test which has been shown to be a useful 'tool' in the assessment of someone thought to be suffering from dementia. This includes tests of memory, orientation (e.g. what is the date?) and simple mental arithmetic. A low score in association with characteristic symptoms will strongly suggest the diagnosis.

Further investigations are often carried out, mainly to rule out other causes for dementia or other mental problems, since about five per cent of elderly people with what seems like dementia actually have an underlying physical illness which, when treated, effectively improves their mental function. These investigations may include:

Blood tests

These are taken to detect an underlying and potentially correctable chemical abnormality. Tests include a blood sugar level (to exclude diabetes), a vitamin B12 and folate level (to exclude a nutritional vitamin deficiency) and tests to detect abnormal liver function, all of which can present with symptoms similar to dementia and Alzheimer's disease. Other tests may also be done to detect certain infections such as syphilis and HIV, which can cause dementia-type symptoms.

CT scan

This may be done to confirm atrophy (shrinkage) of the brain and to exclude other causes of disordered brain function such as brain tumours, strokes and haemorrhages.

ECG and EEG

TThese are tests for electrically recording heart and brain activity respectively. The ECG test may be carried out to establish if there is any cardiac (heart) cause for a disturbance in the blood circulation to the brain, which would impair the brain function.

 

What is the treatment?

At present there is no treatment that will cure Alzheimer's disease. However, there is now medication, which in somecases can delay the deterioration in mental functions, or at least, can control some of the more distressing symptoms. Therefore it is helpful to make the diagnosis as early as possible as this will give the patient and carers early access to the support services that can improve the quality of life. It is important to keep patients with dementia active and happy. This is most likely to be achieved if the patient is kept at home in familiar surroundings although this is not always possible especially as the disease makes it increasingly difficult to manage the individual. Support will be necessary not only for the patient but also for the carers and the types of support services that are available are set out below, along with types of drug treatment.

Social workers

A social worker will be able to provide social support (i.e. home help and meals on wheels) as well as financial support (i.e. mobility and attendance allowance).

Occupational therapists

Their services can provide useful aids for the home and practical advice on how to avoid accidents.

District nurses and health visitors

They will advise on any health matters as well as attending to dressings and providing incontinence aids.

Day centres

Attendance at a centre may provide valuable relief for the carer as well as stimulation for the patient.

Respite services

The considerable burden that the Alzheimer patient places on the carer is well recognised and it may be possible, through the social worker, to arrange a respite holiday. This means that the patient will be admitted for a while to a hospital or old people's home while the carer has a break.

Drug therapy

A most important recent development relates to the chemical transmitter theory. It is now clear that this disease is characterised by a loss of brain cells in the front part of the brain. These cells produce a chemical transmitter substance called acetylcholine, which spreads to other areas of the brain in a linked circuit. This system is critical to normal memory and other functions such as logical thinking and deductive reasoning. Depletion of these brain cells has led to a decline in the transmitter chemical and this has been correlated with loss of memory and intellectual function.

As a result of research in this area, several drugs called the 'cholinesterase inhibitors' have been developed which boost the levels of acetylcholine in the brain. These include donepezil (Aricept), rivastigmine (Exelon) and galantamine (Reminyl). It is important for sufferers and relatives alike to be aware that not everyone with Alzheimer's will benefit from this treatment and that even those who take it will not necessarily show any dramatic improvement in their symptoms. However, many of those who are prescribed cholinesterase inhibitors show a slowing of the deterioration in the condition.

Guidelines now exist for the correct and appropriate prescribing of this group of drugs. These state that in general these drugs should only be recommended by a specialist for people with mild to moderate Alzheimer's as part of an overall package of management including those aspects mentioned above such as carer support etc.

Different medication may also be given which can help to control other symptoms associated with dementia. For instance antidepressants and anti-psychotic medication may be prescribed since both depression and other mental problems are often connected with dementia. Relief from these symptoms can help both the patient and, by controlling behaviour problems, the carer.

 

Are there any advances?

Most recently, promising research has centred on a possible genetic cause for Alzheimer's, and in particular, on the detection of a substance called apolipoprotein E (ApoE for short). This is a cholesterol carrying protein and the gene for this carrier protein has been located on a chromosome inside the body which is specific to this condition. It may be possible, by detecting this protein in the blood, to improve diagnostic accuracy and even predict the likelihood of developing the condition in those with a significant family history. However further research is awaited.

Where can I get further information?

Apart from contacting your GP, the following organisation may be of further help:

Alzheimer's Disease Society
Gordon House
10 Greencoat Place
London
SW1P 1PH
Helpline: 0845 300 0336
Telephone: 020 7306 0606
Website: www.alzheimers.org.uk

Alzheimer's Society
Membership Hotline: 0845 306 0868

Alzheimer's Disease International
Web Page: www.alz.co.uk
(An umbrella organisation of Alzheimer's Associations around the world)