Principal components analysis (PCA) in 11 cases of chronic traumatic encephalopathy based on all histological variables (PCA-1). A plot of cases in relation to PC1 and PC2. The various comorbidities are plotted in relation to each case [AD, Alzheimer’s disease neuropathological change; AGD, Argyrophilic grain disease; PART, Primary age-related tauopathy; HS, Hippocampal sclerosis; TDP, Transactive response (TAR) DNA-binding protein of 43 kDa (TDP-43)-immunoreactive pathology].