Conclusions

Language performance is significantly impacted in both possible and probable bvFTD groups and should not be overlooked in the clinical examination when a diagnosis of bvFTD is considered. Although bvFTD and SD share broad similarities in language performance, the disproportionally severe naming impairment characteristic of SD is not observed in bvFTD. Language deficits in bvFTD appear primarily semantically driven, with executive functioning exerting a modulating influence. Together, these findings highlight the importance of considering both language and executive processes when characterising cognitive change in bvFTD.