What is Alzheimer's disease?

Submitted by Emma Hamilton on Tue, 09/06/2009 - 3:58pm

People living with dementia benefit from quality time and support from family and friends

Alzheimer's disease is the most common form of dementia. Between 50% and 70% of all dementia cases in Australia are associated with Alzheimer's disease (Alzheimer's Australia, 2008). It mostly affects people aged over 65 but can in few cases occur in people as young as 40.

In this article:

What is Alzheimer's disease?
What causes Alzheimer's disease?
Alzheimer's disease signs and symptoms
Alzheimer's disease risk factors
Alzheimer's disease and lifestyle
Alzheimer's disease diagnosis
Alzheimer's disease treatment & management

What is Alzheimer's disease?

Alzheimer's disease causes damage and changes to the structure and chemistry of the brain affecting memory, thinking and behaviour.
Alzheimer's disease is a progressive disease, meaning symptoms will get worse over time. There is currently no cure. Most people with Alzheimer's disease live for an average of 7 to 10 years.

A person's experience of Alzheimer's disease will be influenced by many factors including their general health. Eventually Alzheimer's disease leads to complete dependency for all aspects of daily care. Many people die from complications of advanced dementia such as infection, pneumonia or stroke.

What causes Alzheimer's disease?

Alzheimer's disease causes destruction of nerve cells and the shrinkage of brain tissue. People with Alzheimer's disease have an extensive build up of "tangles" and "plaque" within and outside the brain cells. Initially nerve cells die in the area responsible for memory, thought and language.

Over time, more damage to the brain occurs causing other symptoms to appear. Eventually a person has problems communicating, difficulty with every day tasks and changes to personality.

A shortage of certain chemicals essential for transmitting messages to and from nerve cells also occurs.

Research is still looking into what causes Alzheimer's disease. A combination of genetic, diet and lifestyle factors are thought to contribute to Alzheimer's disease but it is not fully understood.

Alzheimer's disease signs and symptoms

Early signs and symptoms of Alzheimer's disease can be subtle. A person may have problems with forgetfulness or finding words. These signs are often dismissed as signs of "old age". As the disease progresses symptoms become more apparent and start to affect daily life and decision making.

Early signs and symptoms of Alzheimer's disease could include, but are not limited to:

Short- term memory loss; problems remembering names of people and familiar places or how to do everyday things like paying bills.
Difficulties with language including problems finding the correct word for things and following conversations.
Getting lost in familiar places; forgetting how to get home or where they were going; misplacing objects.
Changes in personality; losing initiative; mood swings; lack of good judgment and ability to make decisions.

Alzheimer's disease risk factors

Age and genetics

The most important risk factors for Alzheimer's disease are increasing age and genetics. Most cases of Alzheimer's disease occur after the age of 65 years. 1 in 4 people over 85 years have dementia (Alzheimer's Australia 2008). This type of Alzheimer's disease is called Sporadic Alzheimer's disease.

If you have a parent or sibling with Alzheimer's disease you have a slightly higher risk but you will not necessarily get the disease.

Familial Alzheimer's disease runs in families. This type of Alzheimer's disease is very rare and affects people at a younger age. Familial Alzheimer's disease has a clearer genetic link. Children whose parents have the gene have a 50% chance of inheriting it and developing Alzheimer's disease usually in their 40s and 50s.

Nearly all people with Down syndrome develop Alzheimer's disease.

Alzheimer's disease and lifestyle

Research is ongoing into the protective role that nutrition and lifestyle habits may have on preventing or lowering the risk of getting Alzheimer's disease.

Risk factors associated with Alzheimer's disease include:

Smoking
High blood pressure
High cholesterol levels
Stroke
Poorly controlled diabetes (type 2)
Obesity

People who follow a nutritious diet, keep their weight within healthy levels and engage in regular physical and mental activity appear to have some protection against Alzheimer's disease, but it is not fully understood.

People who sustain a traumatic head injury are at increased risk of dementia and developing Alzheimer's disease.

Alzheimer's disease diagnosis

There is no definitive test for diagnosing Alzheimer's disease. If you are worried about someone close to you encourage them to see a doctor as soon as possible. Many other medical conditions cause similar symptoms to dementia, some treatable.

A diagnosis of "probable" or "possible" Alzheimer's disease is only made after ruling out all other possible causes of dementia symptoms.

A doctor will perform a number of tests. A person will often be referred to other specialists including a neurologist, geriatrician, neuropsychologist or psychogeriatrician.

Some people will be referred to a specialist memory clinic for diagnosis or often signs of dementia become apparent during an examination by an Aged Care Assessment Team (ACAT).

Tests for Alzheimer's disease include:

Taking a medical history
A physical and neurological exam
Blood and urine tests
Mental status exam
Psychiatric assessment
Brain imaging including magnetic resonance imaging (MRI) and computerised tomography (CT) scans.

Alzheimer's disease treatment & management

Alzheimer's disease affects not only the person with the disease but everyone around them.

Management of Alzheimer's disease focuses on maintaining independence whilst providing comfort and support. It is important to encourage people with dementia to continue to make decisions regarding their own care for as long as possible.

For some people medications can slow the progression of the disease. However, early diagnosis is vital, as medications are often more effective in the early stages of the disease.

Caring for someone with Alzheimer's disease can be challenging but also very rewarding. There are many services available to help you. Everyone's experience of Alzheimer's disease will be different. Each person with Alzheimer’s disease is a unique individual with their own life experience, thoughts and feelings. A person with Alzheimer's disease can still lead a full life with help from people around them.

Helpful resources

Visit Alzheimer's Australia the national peak body for people living with dementia and their families.
Call The National Dementia Helpline 1800 100 500. A free service for people with dementia, family and carers.