MAPT and dementia: The presence of tau filaments is strongly correlated with dementia in tauopathies (Wilcock and Esiri, 1982; Arriagada et al., 1992; Mukaetova-Ladinska et al., 2000; Maruyama et al., 2013; Brier et al., 2016; Gomperts et al., 2016; Smith et al., 2016) and oligomeric tau species are implicated in the spread of tau aggregates through the brain (Clavaguera et al., 2009; Sanders et al., 2014).