Alzheimers New Zealand

What is dementia?

Dementia occurs as a result of physical changes in the structure of the brain. These changes affect memory, thinking, behaviour and emotion. Because dementia is a progressive disease, symptoms will gradually worsen. The most common form of dementia is Alzheimer's disease, although there are several other forms. No one single factor has been identified as a cause for dementia or Alzheimer's disease. It is likely that a combination of factors, including age, genetic inheritance and environmental factors are responsible.

Alzheimer's disease

Alzheimer's disease is the most common cause of dementia (50%-70%). As the disease progresses, physical changes occur in the structure of the brain. Brain cells die and the brain shrinks, especially in the inner parts of the brain's temporal lobes. Plaques and tangles form in brain tissue and disrupt molecules which carry messages between brain cells, preventing the brain from working efficiently.

People with Alzheimer's disease experience a gradual decline in their ability to remember, understand, communicate and reason. Some medications are available, which may slow the progression of Alzheimer's disease in the early stages. 

Other forms of dementia include:

• Vascular dementia (also called multi-infarct dementia)
• Dementia with Lewy bodies (often called fronto-temporal dementia)
• Pick's disease (often called fronto-temporal dementia)
• Alcohol-related dementia/Korsakoff's syndrome
• Down's syndrome
• Infection related dementia: AIDS-related cognitive impairment
• Infection related dementia: Creutzfeldt-Jakob disease (CJD)
• Parkinson's disease
• Huntington's disease

Each dementia tends to affect different parts of the brain, but they all have similar symptoms and behaviours.

Dementia usually causes difficulties with some of the following:

• remembering
• cognition
• making decisions
• looking after yourself
• expressing thoughts
• understanding what others are saying
• finding your way around
• managing finances

People of all ages, ethnicities and intellectual ability can get dementia. While it is more common in people over the age of 65, it can also affect younger people.

Dementia does not affect:

• your sense of humour
• the ability to enjoy life
• your ability to love and be loved

Dementia is not:

• normal ageing
• contagious
• something to be ashamed of
  

Further information:

More information about dementia can be found in the Dementia Information Sheet or in The Dementia Booklet.

Books that may be of interest are:

The New Zealand Dementia Guide
By Dr Chris Perkins, Random House, New Zealand 2004. ISBN 1-86941-605-8

Dealing with Dementia A Guide to Alzheimer's Disease and Other Dementias
By Dr Brian Draper, Australia 2004. ISBN 1-86508-853-6

These books are available to be loaned from the Alzheimers New Zealand National Office library.