Pathology in Primary Progressive Aphasia

Alzheimer disease (AD) pathology most often causes amnestic dementia but occasionally underlies primary progressive aphasia (PPA). In most cases, PPA predicts tau- or ubiquitin-positive frontotemporal lobe dementia (FTLD) pathology. In this study, researchers attempted to identify predictors of pathology in patients diagnosed with clinical subtypes of PPA. They assessed autopsy material from 23 patients who had had agrammatic (6 patients), logopenic (11 patients), mixed (5 patients), and semantic (1 patient) PPA. They examined the samples for AD pathology, including neurofibrillary tangles (NFT); markers of FTLD, including tau-positive inclusions (FTLD-T) and ubiquitin-positive inclusions (FTLD-U); and thorny astrocytes.

Of the 23 patients, …