MAPT and primary progressive aphasia: These results agree with previous studies with pathological confirmation, which have described some neuroimaging patterns more suggestive of tau than TDP-43 proteinopathies in non-fluent PPA, such as the more medial frontal and subcortical impairment, or the greater involvement of white matter than gray matter in MRI (Caso et al., 2014; Xia et al., 2017; Santos-Santos et al., 2018).