Interventional research on morphosyntactic deficits in agrammatic aphasia: A narrative review

Morphosyntactic deficits are the defining features of agrammatic aphasia. However, there is a limited understanding of the available techniques to treat these deficits. Hence, the present study aims to review the literature and compile evidence on the intervention programs for morphosyntactic deficits in persons with agrammatic aphasia across languages. We conducted a literature search across five major databases, including PubMed, Web of Science, Scopus, CINAHL, and ProQuest. The retrieved studies from the database search were then screened. A total of 14 studies met the eligibility criteria, out of which 12 articles were on training the verb tense markers, and the remaining two dealt with training auxiliary and locative prepositions. The majority of these studies are conducted in English, followed by Persian, Italian, and Dutch. The review also outlines the common treatment approaches employed for morphosyntactic-based interventions in aphasia. The study unveiled a generalized dearth of published studies on the intervention of morphosyntactic deficits, with heterogeneity evident in the treatment approaches, the targeted morphosyntactic markers, and a lack of language-specific intervention programs. The present study draws the readers' attention to this research gap and recommends more morphosyntactic-based intervention studies across languages.