[New entities and the criteria of FTLD]

This article provides an overview of the historical entity hitherto, the pivotal clinical symptoms of FTLD (frontotemporal lobar degeneration), and an introduction for the revised criteria for bvFTD (behavioral variant frontotemporal dementia): FTDC (International Behavioral Variant FTD Criteria Consortium) presented by Rascovsky et al(2011), and the classification criteria for PPA(primary progressive aphasia) heralded by Gorno-Tempini et al (2011). According to the former criteria, bvFTD can be diagnosed by the clinical symptoms as having possible bvFTD or probable bvFTD, and the pathological findings could lead definite bvFTD. In the latter classification criteria of PPA, two types are implicated in FTLD: one is the non-fluent/agrammatic variant PPA(PNFA/nfvPPA/naPPA), and the other is semantic variant PPA(SD/svPPA).