Alzheimer Disease: Controversies in Basic Science Research, Different Theories, and Reasons for Failed Trials

Abstract

Dementia comprises a collection of cognitive and sensory symptoms, including memory loss, communication difficulties, difficulty in planning and problem solving, disorientation and confusion, compromised olfaction, loss of visual perception, agnosia; and psychological symptoms, including personality and behavioral changes, depression, anxiety, hallucination, mood swings, agitation, and apathy. Dementia can be caused by a spectrum of different brain afflictions. The most common cause of dementia is Alzheimer disease (AD) or senile dementia of Alzheimer type. Other types include vascular dementia, dementia with Lewy bodies, frontotemporal dementia, alcohol-related dementia, Down syndrome, Parkinson disease dementia, and HIV-associated dementia [1,2].