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What Causes Dementia?

There are several diseases and conditions that cause dementia. These include:

  • Alzheimer's disease − this is the most common cause of dementia. During the course of the disease, the chemistry and structure of the brain changes, leading to the death of brain cells
  • Vascular disease − the brain relies on a network of vessels to bring it oxygen-bearing blood. If the oxygen supply to the brain fails, brain cells are likely to die and this can cause the symptoms of vascular dementia. These symptoms can occur either suddenly, following a stroke, or over time through a series of small strokes
  • Dementia with Lewy bodies − this form of dementia gets its name from tiny spherical structures that develop inside nerve cells. Their presence in the brain leads to the degeneration of brain tissue. Memory, concentration and language skills are affected. This form of dementia shares some characteristics with Parkinson's disease
  • Fronto-temporal dementia (including Pick's disease) − in fronto-temporal dementia, damage is usually focused in the front part of the brain. At first, personality and behaviour are more affected than memory.

Rarer causes of dementia

There are many other rarer diseases that cause dementia, including progressive supranuclear palsy, Korsakoff's syndrome, Binswanger's disease, HIV and AIDS, and Creutzfeldt-Jakob disease (CJD). People with multiple sclerosis, motor neurone disease, Parkinson's disease and Huntington's disease may also be more likely to develop dementia.