Dementia--Alzheimer type.

At least half of the patients who present with progressive decline in their memory, cognitive, and intellectual abilities will eventually be diagnosed as having Alzheimer's disease. The diagnosis is reached by clinical and ancillary evaluation and exclusion of all other causes of dementia. Recently, considerable advances have been made in our understanding of the neurobiologic features of Alzheimer's disease. Cortical neurons contain paired helical filaments with a very specific electron microscopic appearance. These filaments contain proteins with unusual properties. A severe decline in cholinergic activity in the cortex is related to a marked loss of cholinergic neurons in deep cerebral structures, such as the nucleus basalis of Meynert in the substantia innominata. No specific treatment is available for Alzheimer's disease. Patients and the relatives who take care of them require substantial help and assistance in coping with the disease.