Dementia. Coloured magnetic resonance imaging (MRI) scan of the brain of a 76 year old patient with dementia. The brain has atrophied (shrunk) and the ventricles, the fluid filled spaces (dark brown) at the centre of the brain, have become enlarged. Areas within the brain are also showing degeneration. Dementia is mainly a disease of old age. It has varying symptoms depending upon the areas of the brain affected, but these may include, confusion, loss of memory, personality changes and neglect of personal care. Often the cause is unknown and there is no cure.