Echolalia: Paying Attention To A Forgotten Clinical Feature Of Primary Progressive Aphasia

One decade ago, the diagnostic criteria for three major forms of primary progressive aphasia (PPA) - nonfluent-agrammatic variant (nfvPPA), semantic variant (svPPA), and logopenic variant (lvPPA) - have been established based on expert consensus [1]. However, non-canonical forms of PPA (i.e., dynamic aphasia, pure apraxia of speech, pure anomia, dysprosodia) [2] and some features such as echolalia (repetition of what one has just heard) tend to be underestimated.