Like the rest of the body, the brain changes as we age. Scientists are starting to shed light on some of the processes behind these changes and to discover the differences between normal ageing and dementia.

What happens to our brains in normal ageing?
Our brains contain billions of nerve cells (neurones) grouped into specific regions that control all our mental and physical processes.

Scientists once thought that we were doomed to lose many of these neurones as we age. They also believed that the complex branching of these neurones was inevitably damaged as we grow older. Thankfully, better ways of looking at the brain’s structure have shown this to be inaccurate.

The brain does alter with age, but in most people these changes are more subtle than was once thought. The changes include:

 
• shrinkage of some neurones;
 
• loss of plasticity (the ability to rearrange connections between neurones); and
 
• damage by free radicals (molecules that react easily with other molecules, thereby damaging cells in the body).

Certain areas of the brain are more vulnerable to these changes than others. The regions most at risk are those involved in memory, learning and complex mental activities such as planning.

Differentiating Normal Aging & Dementia

Typical Aging
Independent in daily activities preserved

Dementia
Person becomes critically dependent on others for key independent living activities

Typical Aging
Complains of memory loss but able to provide considerable detail regarding incidents of forgetfulness
Dementia
May complain of memory problems only if specifically asked; unable to recall instances where memory loss was noticed

Typical Aging
Patient is more concerned about alleged forgetfulness than are close family members
Dementia
Close family members much more concerned about incidents of memory loss than patient

Typical Aging
Recent memory of important events, affairs, conversations not impaired
Dementia
Notable decline in memory for recent events and ability to converse

Typical Aging
Occasional word finding difficulties
Dementia
Frequent word finding pauses and substitutions

Typical Aging
Does not get lost in familiar territory; may have to pause momentarily to remember way
Dementia
Gets lost in familiar territory while walking or driving; may take hours to eventually return home

Typical Aging
Able to operate common appliances even if unwilling to learn how to operate new devices
Dementia
Becomes unable to operate common appliances; unable to learn to operate even simple new appliances

Typical Aging
Maintains prior level of interpersonal social skills
Dementia
Exhibits loss of interest in social activities; exhibits socially inappropriate behaviors

Typical Aging
Normal performance on mental status examinations, taking education and culture into account
Dementia
Abnormal performance on mental status examination not accounted for by education or cultural factors

Positive findings in any of the following areas generally indicate the need for further assessment for the presence of dementia.

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myDr, UBM Medica Australia