The key features of this type of dementia are loss of general intelligence such as impairment of abstract thinking, judgment and problem solving ability. Thinking is slow and inflexible and the ability of logical reasoning is reduced .Minor degrees of forgetfulness are often the first signs of the disease noticed, events of the recent past cannot be recalled and new names are forgotten, patients can’t find their way around in new and eventually familiar surroundings, declining memory may lead to secondary hallucinations. For example the people who forget where they have placed personal possessions may think they are being robbed.
There is also a decline in personal manners and social awareness, behavior becomes rude, tactless and generally insensitive to the feelings of other people, which can lead to episodes of aggression and sexual indiscretion etc. eventually there is deterioration in personal hygiene. Urinary and faecal incontinence is also common in late stages. There is a general decline in interest the patients may sit idle for hours without doing anything. Anxiety, depression and irritability are marked. Rapid mood swings and emotional liability is common, but in late stages the patients seem to be unresponsive of emotional stimuli around them. This disease is a result of degenerative process occurring in brain tissues. Progress of disease is different among individuals.