ABSTRACT
Dementia is not the name of a disease. It is a descriptive term that describes the mental changes that accompany a variety of different diseases. The most common forms of dementia are degenerative, resulting from intrinsic changes to brain neurons. However, dementia may also occur secondary to vascular disease or may have extrinsic causes. Differentiation between the diverse conditions that give rise to dementia is increasingly important for a number of reasons. First, different diseases are likely to require different remedies. With the advent of new dementia therapies accurate diagnosis is imperative. Second, dementia sometimes runs in families and some diseases are more likely to be familial than others. An accurate diagnosis is vital for appropriate counselling of family members who may be at risk from developing the disease. Third, dementia syndromes are not identical. Different diseases give rise to different patterns of symptoms, reflecting the distribution of the pathological changes within the brain. Understanding the precise manner in which cognition and behaviour are altered by disease helps recognition of individual needs and allows prediction of the future course of disease. It therefore provides the basis for optimal management of dementia sufferers.
