Alzheimer's disease (AD): is a slowly progressive form of dementia, which is a progressive, acquired impairment of intellectual functions. Memory impairment is a necessary feature for the diagnosis. Change in one of the following areas must also be present for any form of dementia to be diagnosed: language, decision-making ability, judgment, attention, and other related areas of cognitive function and personality.The rate of progression is different for each person. ( La Enfermedad de Alzheimer)