Brain imaging and neuropathologic mechanisms in Alzheimer's disease: vascular versus neurodegenerative and amyloid-beta versus tau.

Over the past several decades, there has been extensive research devoted toward determining the cause of Alzheimer's disease. Numerous biochemical, histological, and imaging investigations have elegantly characterized the neuropathologic and functional changes associated with AD. Proponents of one theory or another can find supporting data among the myriad of studies in the literature.