Recent studies have demonstrated the association between the AD genetic risk variant ApoE ε4 and EEG in patients with AD, MCI, and healthy subjects (Jelic et al., 1997; Lehtovirta et al., 2000; Babiloni et al., 2006b; Ponomareva et al., 2008, 2012; Lee et al., 2012). This evidence concerns the gene APOE and Alzheimer disease.