dementia of the Alzheimer type

dementia of the Alzheimer type, dementia occurring in Alzheimer’s disease, being of insidious onset and gradually progressive course, with histopathological changes characteristic of Alzheimer’s disease that are not due to other central nervous system, systemic, or substance-induced conditions known to cause dementia. It is characterized as early onset or late onset depending on whether or not it begins by the age of 65.