Alzheimer’s disease was first described in a psychiatry case presentation given in 1907 by Alois Alzheimer. This German doctor had studied a 56 year old lady, Auguste D, in hospital in during the last years of her life. She died in 1906. The condition was christened “Alzheimer’s disease” by Emil Kraepelin – one of the foremost German psychiatrists of that era, who Alzheimer had been working with.

What it is

Alzheimer’s is a progressive degenerative disease of the brain: characteristic structural changes (amyloid protein plaque formation) take place in brain tissue, and there is a shortage of a brain chemical, acetylcholine. It is one of three main types of dementia. The other two are vascular dementia (thought to be caused by lots of tiny strokes in the brain), and dementia with Lewy bodies, so called because of structures in the brain cells seen under a microscope. Many sufferers have a mixture of the three types.

The incredible rate of progress in modern medical science means that the populations of developed countries are surviving to greater and greater ages. The traditional killers of infectious disease, heart disease and cancer are increasingly being beaten, so we are surviving to develop diseases which were much rarer even only a few decades ago. 20% of 80-year olds will develop dementia.

Risk factors

The strongest risk factor for Alzheimer’s is advancing age, and women are twice as likely to develop the disease as men. There is a genetic component: the presence of certain defective genes can increase the risk of developing it at a younger age. It can start as young as age 40. Aluminium saucepans have been suspected as a risk factor because of the presence of aluminium in plaques found in the brains of sufferers, but research has now discounted this connection.

How Alzheimer’s affects an individual

The start of Alzheimer’s disease is usually gradual, and the most prominent feature is a steady but relentless decline in short-term memory. This also happens in other diseases such as hypothyroidism (underactive thyroid gland), vitamin B12 deficiency, and chronic alcohol abuse. Ultimately general mobility and intellectual functioning is completely lost, with an end-stage of total dependency on full nursing care. Average survival is 7 years from the onset.

How it is diagnosed

The first suspicion is often given by a relative: because the sufferer has memory loss, he or she may not realise that there is a problem. Sometimes people are aware that there is a problem with their memory, and retain this insight for some time. Various mental state evaluation tools use simple question-and-answer techniques: these give a score which can be related to a likelihood of dementia.

There are no simple clinical tests for Alzheimer’s disease. General screening tests may detect any other problems that may contribute to the disease. These look at anaemia, vitamin B12 and folic acid deficiency, liver function tests, thyroid function tests, kidney function tests and screening for diabetes. Detailed brain scans can help to rule out the other two main kinds of dementia, so that Alzheimer’s disease is diagnosed by exclusion, and check for other rarer causes of memory loss, such as a brain tumour.

Medical treatment

Until recently there were no specific treatments for Alzheimer’s disease. In 1996 the drug donezepil was developed. This increases the amount of acetylcholine in the brain. In the UK it has been the subject of much controversy and government prescribing restrictions on cost effectiveness grounds. It delays the deterioration in Alzheimer’s disease and the start of the need for institutional care. It can also help reduce some of the agitation and anxiety that often accompanies the perplexed feeling that sufferers have in the early stages of the illness. There are now three other drugs which give similar benefits, galantamine, memantine, and rivastigmine.

Other problems which are often closely associated with dementia, can be treated in their own right: • Depression is a common with dementia, and can be helped by antidepressant drugs • Psychosis is abnormal behaviour based on unshakeable belief in delusions of thought, often with hallucinations of hearing and vision. There are several drugs which help calm the delusions and hallucinations and consequently the distress that accompanies these very real-seeming and often frightening experiences

Self help

There is some evidence that keeping the brain active can help maintain brain function a little longer: doing puzzles, crosswords and other exercise to stretch the intellect. A healthy lifestyle in through adult life has been shown to help preserve brain function into old age.

There is recent evidence of a “cognitive reserve” in the brain: this means that the brain is capable of recruiting new neural networks to compensate for the ones that fail in Alzheimer’s. This reserve is bigger in people who constantly challenge their brains and exercise their thinking skills throughout life. This improved cognitive reserve does not reduce the likelihood of Alzheimer’s, but delays the onset of symptoms even when the brain tissue damage has begun.

In some cases, the brains of people who never showed symptoms of Alzheimer’s have been found at post-mortem to be riddled with plaques. Invariably these individuals had led active intellectual lives. The flip side of keeping your brain active is that when the cognitive reserve has finally reached capacity and symptoms appear, the decline is very rapid compared with people with a small cognitive reserve. It could be argued that this is perhaps the lesser of two evils.

The message is clear: use it or lose it.

Other aids to daily living

Occupational therapy is a programme of work activities tailor made for its physical, mental, emotional, and vocational value and relevance to an individual. It also looks at the sufferer in his or her environment, and makes changes to the environment to make life easier and safer. This could be, for example, the fitting of rails to a bath, or the provision of household gadgets and appliances.

Physiotherapy may help improve mobility and prevent a sufferer from becoming chair- or bed-bound. Its success will depend very much on the thinking and communication abilities that remain.

Day care provides relief to family carers, and welcome social stimulation to the sufferer.

The key here is that the best care for someone with Alzheimer’s disease is a multidisciplinary approach –medical, social and emotional care all need to work together.

There has been work looking at the possibility of a vaccine against Alzheimer’s: a team at Tokyo Metropolitan Institute for Neuroscience have developed a potential DNA vaccine which has produced promising results in mice. In tests, it helped cut levels of key amyloid proteins in the plaques thought to cause the disease by up to 50%, in some parts of the brain. Research in humans is under way.

The partly genetic basis for Alzheimer’s disease is already established. In the future it may be possible not only to test for susceptibility to dementia, but also to give some kind of preventative genetic treatment. This is still years away.

Useful links (UK):

Alzheimer’s Research Trust:

http://www.alzheimers-research.org.uk/

Alzheimer’s Society

http://www.alzheimers.org.uk/

• Find out more about Dr Vince Forte at www.v40.org