MAPT and Marchiafava-Bignami disease: Some controls in EMIF-AD MBD had increased tau levels, which may have contributed to low memory scores in these individuals, as tau can impair synaptic plasticity and cause synaptic damage (Hu et al., n.d.; Kaniyappan et al., 2017; Ondrejcak et al., 2019; Piacentini et al., 2017).