Quantitative neurofibrillary tangle density and brain volumetric MRI analyses in Alzheimer's disease presenting as logopenic progressive aphasia

► Left temporoparietal NFT burden was significantly higher in lvPPA than DAT. ► The ratio of left temporoparietal to hippocampal NFT burden was higher in lvPPA than DAT. ► Left temporoparietal volumes on antemortem MRI were smaller in lvPPA than DAT. ► A left temporoparietal neurodegenerative focus is the biological basis for lvPPA.