MAPT and neurodegenerative disease: Aβ, tau pathologies, reduced brain volume, and impaired memory are all part of the pathological and clinical picture of TBI and age-associated degenerative diseases (Smith et al., 1999; Emmerling et al., 2000; Ikonomovic et al., 2004; Dekosky et al., 2010), creating the potential association between TBI and Alzheimer's disease and related dementias (Sivanandam and Thakur, 2012).