MAPT and Brain atrophy: Although PA was found to be associated with an increased concentration of p-tau181 in AD in previous studies (Lehmann et al., 2013; Mao et al., 2021), we did not find any association between CSF tau and brain atrophy possibly because CSF tau was a biomarker of global neurodegeneration, whereas visual rating scales were markers of local neurodegeneration (Abdelnour et al., 2020).