At a microscopic level, the neuroanatomical hallmarks of AD are the formation of neuritic plaques (NP), and the presence of neurofibrillary tangles (NT) appearing first in the hippocampal region, and spreading to the association cortices with disease progression (Filley, 1995; Salman, 2004; Salmon, Butters, & Chan, 1999; Yilmazer-Hanke & Hanke, 1999).
There is a growing body of evidence that suggests that early in the development of the disease structural and functional brain abnormalities develop, and the functional changes can be regarded as precursors of structural change (Meguro, Blaizot, Kondoh, & Mestric, 1999; Meguro, Mestric, Landeau, & Desgranges, 2001; Mosconi et al., 2004).