Alzheimer’s disease is the most common form of dementia accounting for between 50% and 70% of all dementias.
What is Alzheimer's disease? What are the symptoms? What are the causes? How is it treated?... these and many more such questions are addressed in this section.
What is Alzheimer's disease?
Alzheimer's disease is a physical disease which attacks the brain resulting in impaired memory, thinking and behaviour. The disease is named for the German physician, Alois Alzheimer who, in 1907, first described it.
As brain cells die, the substance of the brain shrinks. Abnormal material builds up as “tangles” in the centre of the brain cells and “plaques” outside the brain cells, disrupting messages within the brain, damaging connections between brain cells. This leads to the eventual death of the brain cells and prevents the recall of information.
Memory of recent events is the first to be affected, but as the disease progresses, longterm memory is also lost. The disease also affects many of the brain's other functions and consequently, many other aspects of behaviour are disturbed.
There are two different types of Alzheimer's disease:
The disease can affect adults at any age, but usually occurs after age 65
Sporadic Alzheimer's disease is by far the most common form of Alzheimer's disease
It affects people who may or may not have a family history of the disease.
Sporadic Alzheimer's disease
Familial Alzheimer's disease
The disease runs in a few families and is very rare
If a parent has a mutated gene, each child has a 50% chance of inheriting it
The presence of the gene means that the person will eventually develop Alzheimer's disease, usually in their 40's or 50's
Familial Alzheimer's disease affects a very small number of people.
What are the symptoms?
In the early stages the symptoms of Alzheimer's disease can be very subtle. However, it often begins with lapses in memory and difficulty in finding the right words for everyday objects.
Other symptoms may include:
- Persistent and frequent memory difficulties, especially of recent events
- Vagueness in everyday conversation
- Apparent loss of enthusiasm for previously enjoyed activities
- Taking longer to do routine tasks
- Forgetting well-known people or places
- Inability to process questions and instructions
- Deterioration of social skills
- Emotional unpredictability.
Symptoms vary and the disease progresses at a different pace according to the individual and the areas of the brain affected. A person's abilities may fluctuate from day to day, or even within the one day, becoming worse in times of stress, fatigue or ill-health.
However, there is always a deterioration over time. It is a progressive and currently irreversible disease.
What causes Alzheimer's disease?
Scientists are rapidly learning more about the chemical changes which damage brain cells in Alzheimer's disease but apart from the few individuals with Familial Alzheimer's disease, it is not known why one individual gets Alzheimer's disease late in life and another does not.
A variety of suspected causes are being investigated including factors in the environment, biochemical disturbances and immune processes. The cause may vary from person to person and may be due to one factor or a number of factors.
Who gets Alzheimer's disease?
Alzheimer's disease can happen to anybody, but it is much more common after the age of 65. The incidence rate rises with age. For people 85 years and over, 1 in 4 have dementia. It can affect people in their 30's, 40's and 50's.
How is Alzheimer's disease diagnosed?
There is currently no single test to identify Alzheimer's disease. The diagnosis is made only after careful clinical consultation.
The clinical diagnosis might include:
- A detailed medical history
- A thorough physical and neurological examination
- A test of intellectual function
- Psychiatric assessment
- A neuropsychological test
- Blood and urine tests.
These tests will help to eliminate other conditions with similar symptoms such as nutritional deficiencies or depression. After eliminating other causes, a clinical diagnosis of Alzheimer's disease can be made with about 80% to 90% accuracy if the symptoms and signs are appropriate. The diagnosis can only be confirmed after death by examination of the brain tissue.
It is important to have an early and accurate diagnosis to determine whether a treatable condition other than Alzheimer's disease, is causing the symptoms. If Alzheimer's disease is diagnosed medical treatment and other assistance can be discussed.
How does Alzheimer's disease progress?
The rate of progression of the disease varies from person to person.
However, the disease does lead eventually to complete dependence and finally death, usually from another illness such as pneumonia. A person may live from three to twenty years with Alzheimer's disease, with the average being seven to ten years.
Is there treatment available?
At present there is no cure for Alzheimer's disease. However, one group of drugs called cholinergeric drugs appears to be providing some improvement in cognitive functioning for some people with mild to moderate Alzheimer's disease.
Drugs can also be prescribed for secondary symptoms such as restlessness or depression or to help the person with dementia sleep better.
Community support is available for the person with Alzheimer's disease, their families and carers. This support can make a positive difference to managing dementia. Alzheimer's Australia provides support, information and counselling for people affected by dementia. Alzheimer's Australia also aims to provide up-to-date information about drug treatments. For more information contact the National Dementia Helpline on 1800 100 500.
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