Dementia is a terrible illness. A person with dementia experiences a gradual decline in their abilities to think, remember and carry out their normal daily activities. They consequently require ever-increasing personal care and eventually become totally reliant upon their care-givers. Thus the symptoms and care requirements of dementia present major challenges not only for the person with dementia, but for their family and friends as well. These challenges are so great that even the closest relationships, between a parent and child or two people in a couple, are vulnerable to breaking down.

The odds are increasing that you may be affected in some way by dementia. As we live longer lives, more and more Australians are experiencing some form of dementia. Alzheimer’s Australia advise that about 200,000 Australians now have dementia. With about 54,000 new cases diagnosed every year, this number is expected to grow to 730,000 by 2050.

Of course, we all want to live longer and the good news is that there are steps you can take to reduce the likelihood of you or someone else in your family developing dementia. At the very least you may be able to delay its onset. In addition, if dementia does unfortunately develop, there are measures you can take to help maintain your or your loved ones’ current quality of life.

What is dementia?

Dementia is a term used to describe a broad set of symptoms that occur due to brain disease. These symptoms include the loss of memory, intellect, rationality, social skills and normal emotional reactions. In dementia, these symptoms progressively become worse and cause increasing difficulties in carrying out everyday personal, social and work functions until the sufferer eventually becomes entirely dependent upon care. Although many people with dementia die first from other causes, advanced dementia will result in death.

As you age it is natural to lose some of your cognitive abilities such as your ability to think, learn, remember, understand and judge. In normal ageing, however, these changes take place over decades; the changes due to dementia occur much faster, maybe over several months or just a few years. The changes in dementia are also more extensive. For example, in normal age-related short term memory loss an older person might forget part of a recent movie; someone with dementia might not even be able to remember sitting down to watch the movie.

Most people think of Alzheimer’s disease when they think of dementia. Although Alzheimer’s disease is the major cause of dementia, accounting for about 60 per cent of dementia diagnoses, it is not only the cause. In fact, there are over 100 causes of dementia. There are, however, only another three major causes of dementia in addition to Alzheimer’s: Vascular dementia, which causes about 20 per cent of cases; Dementia with Lewy bodies, which causes 10-15 per cent of dementia cases; and Fronto-temporal dementia, which may account for up to 10 per cent of cases. There may also be an overlap between these types of dementia. So let’s have a more detailed look at these four main types of dementia.

Major causes of dementia

• Alzheimer’s disease
• Vascular dementia
• Dementia with Lewy bodies
• Fronto-temporal dementia

Alzheimer’s disease

In Alzheimer’s disease, insoluble deposits of a protein called beta-amyloid build up to form plaques called amyloid plaques. These plaques stick to the outside of nerve cells (neurons) in the brain, especially to those neurons dealing with memory and other cognitive functions. In addition, “neurofibrillary tangles” of other proteins called “tau proteins” form within the affected neurons. These changes prevent the neurons from communicating properly with each other and the affected cells eventually die. As more and more neurons are affected and die, increasing abilities and functions are lost.