A progressive degenerative process of neural tissue affecting mainly the frontal and temporal lobes of the BRAIN in middle and late life. There is probably a genetic component in all Alzheimer's disease, while early-onset Alzheimer's is linked to certain mutations, or changes, in three particular GENES. Examination of affected brains shows ‘senile plaques’ containing BETA AMYLOID distributed throughout an atrophied cortex. Many remaining neurons, or nerve cells, show changes in their NEUROFIBRILS, which thicken and twist into ‘neurofibrillary tangles’. First symptoms are psychological with gradually increasing impairment of recent memory and disorientation in time and space. This becomes increasingly associated with difficulties in judgement, comprehension and abstract reasoning. Eventually, progressive neurological deterioration produces poor gait, immobility and ultimately death. When assessment has found no other organic cause for an affected individual's symptoms, treatment is primarily provision of appropriate nursing and social care, with strong support being given to the relatives or other carers, for whom looking after sufferers is a prolonged and onerous burden. Proper diet and exercise are helpful, as is keeping the individual occupied. If possible, sufferers should stay in familiar surroundings, with day-care and short-stay institutional facilities a useful way of maintaining them at home for as long as possible.

Drugs such as DONEPEZIL, RIVASTIGMINE and Galantamine, which retard the breakdown of ACETYLCHOLINE, may check – but not cure – this distressing condition. About 40 per cent of those with early or mild DEMENTIA may be helped by slowing down the progression of the disease. In the UK, one drug is approved for use in severe disease, a GLUTAMATE antagonist, Memantine. Much research is currently in progress into drugs or immune complexes which might interfere with the production or accumulation of BETA AMYLOID

The increasing proportion of elderly people in the population is resulting in a rising prevalence of Alzheimer's, which is rare before the age of 60 but increases steadily thereafter, so that 30 per cent of people over the age of 84 are affected.