MAPT and Alzheimer disease: As such, posterior cortical atrophy (PCA) and logopenic variant primary progressive aphasia (lvPPA) are labeled as atypical AD, since the histopathological changes (i.e. Aβ and tau accumulation) in these neurodegenerative diseases determine the “typical” AD features, although the distributional pattern of the pathologic changes seems to be different (Crutch et al. 2012; Harris and Jones 2014).