Senile Dementia

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Senile Dementia, form of general intellectual impairment observed in elderly people. Approximately 10 percent of all people more than 65 years of age have clinically important intellectual impairment. Although about 20 percent of these cases may be due to treatable causes such as toxic drug reactions, most cases are what is known as Alzheimer's disease.

Senile dementia begins with failing attention and memory, loss of mathematical ability, irritability and loss of sense of humor, and poor orientation in space and time. Alzheimer's disease is relentlessly progressive and leads to death in 5 to 15 years. Examinations of the brains of persons who have died of Alzheimer's disease show characteristic twisted fibers, called neurofibrillary tangles, in certain areas of the brain, and cores of abnormal protein, called neuritic plaques, interspersed among nerve cells. No cure is known for Alzheimer's disease. A form of this disease strikes younger persons, in whom it is known as presenile dementia.

See also Aging; Geriatrics.

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