ABSTRACT
Introduction Alois Alzheimer in 1907 described the cerebral cortex of a 55-year-old woman with a progressive dementia, noting the presence of abnormal nerve cells that contained neurofibrillary tangles and neuritic plaques. The prevalence of the disorder varies with age: about 1 in 1000 for the age range 40-65, rising to 1 in 50 for 65-70, 1 in 20 for 70-80, and 1 in 5 for those aged 80.
