The complex relationship between pre-stroke and post-stroke language abilities in multilingual individuals with aphasia

Background: While many studies that focus on assessment or intervention in multilingual people with aphasia report both pre-stroke proficiencies and post-stroke language abilities, the relationship between them is not always clear. Aim: We illustrate the relationship between pre-stroke language proficiencies and post-stroke language abilities by examining the factors that contribute to impairment patterns in multilingual people with aphasia. Main contribution: We demonstrate that it is preferable to assess proficiency comprehensively by considering both absolute and relative pre-stroke proficiencies in addition to pre-stroke language use and exposure as well as absolute and relative post-stroke language abilities within the context of post-stroke language exposure and use. Moreover, we suggest referring to post-stroke language abilities, rather than proficiency to minimize the confusion of stroke-related effects and proficiency-related effects on performance. Conclusions: Post-stroke language abilities are a complex consequence of a multitude of factors, including language background, pre-stroke proficiency, attrition of one or more languages, language of the environment (as it relates to exposure and use), and brain lesion. We aim to bring this issue to the forefront of research and clinical work, to better understand how to serve multilingual populations in the aphasia clinic.