Pathological tau, amyloid-β, α-synuclein and TDP-43 staging. Tau, amyloid-β, α-synuclein and TDP-43 pathologies were individually staged according to established criteria across 13 neuropathologically-defined groups. (A) Tau pathology principally took the form of Alzheimer’s disease-type neurofibrillary tangles, except in FTLD-Tau (i.e. PiD, CBD and PSP), allowing us to assign Braak stages and compare tau prevalence and severity (Montine et al., 2012). Co-pathological tau was nearly universal, and was commonly observed in the hippocampal formation (Braak I–II). (B) McKeith criteria staging of α-synuclein positive Lewy pathology was applied to all cases except the MSA group (McKeith et al., 2017). α-Synuclein (A-syn) co-pathological affected a minority of cases across neurodegenerative disease and was frequently limited to a brainstem or amygdala distribution except in the hAD group. (C) Amyloid phases were used to stage amyloid-β (Aβ) plaques (Montine et al., 2012). Amyloid-β plaque co-pathology was variably abundant across neurodegenerative disease except the nLBD group, which had an increased burden. (D) Distinct distributions of TDP-43 pathology defined the primary TDP-43 proteinopathies, but a common staging was possible for the remaining groups (Josephs et al., 2014). TDP-43 was rare to non-existent in several groups and frequently had a limbic distribution.