Taking words to a new level: a preliminary investigation of discourse intervention in primary progressive aphasia

Abstract

© 2017 Informa UK Limited, trading as Taylor & Francis Group Background: Despite a growing literature characterising connected speech and discourse impairments associated with primary progressive aphasia (PPA), intervention in PPA has focused predominantly on lexical retrieval and picture-naming treatments, with limited generalisation of therapy gains reported. Recent developments in the post-stroke aphasia literature with discourse-level approaches have provided highly promising findings for the generalisation of language gains to everyday communication, and an opportunity to investigate whether the same benefits may be found in the PPA population. Aims: This study evaluated the effectiveness of a discourse intervention in two individuals with PPA to determine whether significant improvements were seen in word retrieval and discourse organisation in everyday discourse. Methods & Procedures: KW, a 54-year-old man, who presented with semantic variant PPA, and AS, a 59-year-old woman, presenting with logopenic variant PPA, completed the NARNIA intervention programme (Whitworth, Leitão et al., 2015) in 20 sessions over a 10-week period. Discourse performance was sampled prior to intervention across 10 tasks involving four different genres, at one time point, and compared to performance immediately and four weeks post intervention. The multilevel intervention protocol aimed to increase awareness of word retrieval, sentence structure, and macrostructure of a range of discourse genre. Outcomes & Results: Both participants made significant gains in discourse production immediately after intervention and when reassessed four weeks later, in the absence of change on naming tasks and in the context of stable overall cognitive performance. Significant gains were seen in the amount of overall output, noun and verb usage, and the number of body elements in macrostructure in everyday discourse in topics that were not trained in treatment. Further to the findings of the original NARNIA study in post-stroke aphasia, significant gains were also seen in narrative discourse across lexical categories for both participants. Informativeness and efficiency of communication also improved significantly for KW across all genres. Both participants reported significant gains in measures of social communication and participation. Conclusions: The study suggests that improvements in everyday discourse may be possible when the discourse level is directly targeted, that lexical access can improve in the absence of targeting lexical items, and that discourse-level interventions have the potential to impact real-life communication in individuals with PPA. As the first known study to trial a multilevel intervention in the context of PPA, the findings may be of clinical and theoretical significance, and warrant further investigation.