Alzheimer's disease, accounts for approximately 60% of all cases of dementia. The disease typically begins with memory loss, mood swings, and with problems finding the correct words. Later the individual may become more confused, experience mood swings and feelings of sadness or angry. They may feel scared and frustrated and also lose their confidence and interest in life. The cells, nerves and transmitters in the brain are attacked during the course of the disease, the brain shrinks and gaps develop. After death, tangled loops and coils of a fibre-like material of beta-amyloid protein, can be observed in brain tissue.

People with Alzheimer's also have a shortage of certain chemicals in their brain which are involved with the communication of messages within the brain.

Most cases of Alzheimer's develop in later life. Below the age of 65 it is rare, affecting approximately one person in 1000. Over the age of 65 it affects one in 20. By the age of 80 approximately 1 in 5 are affected. Alzheimer's disease affects around 500,000 people in the UK.

Symptoms

The features of Alzheimer’s Disease vary from case to case, but three broad stages can be recognised:

• Alzheimer’s disease starts with gradual, almost imperceptible, loss of brain function, usually first noticed as loss of memory. The loss of the ability to perform even simple arithmetical calculations, may be one of the first signs of Alzheimer’s disease. Initially, there is ordinary forgetfulness that can be compensated for by keeping memo pads and lists. The loss of memory, however, often causes anxiety.
• Secondly, there is a gradual increase in the severity of the memory loss, particularly for recent events. Sometimes this stage includes an element of confusion and even invention (confabulation) to fill the gaps. At the same time there is progressive loss of awareness of the current time or place (disorientation), with uncertainty even in familiar areas and inability to give the date or even the year. Concentration declines with inability to find the right word (dysphasia). These difficulties cause alarm and frustration, and mood may change suddenly and unpredictably.
• In the final stage there is severe disorientation and confusion. There may be perception of non-existent sights, sounds and smells (hallucinations) and false ideas of persecution (paranoid delusions). These are usually worst at night. The individual may become demanding, suspicious and sometimes violent. They become liable to ignore personal hygiene. Incontinence of urine and faeces is common.