Aphasia management in growing multiethnic populations

Multiethnic aphasia caseloads in post-stroke services are estimated to grow extensively. The convergence of a larger prevalence of chronic neurogenic complications in a rapidly aging world population with the exponential growth of global ethno-racial diversity is estimated to considerably expand ethno-geriatric caseloads in neurorehabilitation services worldwide (Cummings-Vaughn, 2017; Kristiansen et al., 2016; Prince et al., 2015). A global demographic transition into larger multiethnic older groups, while having a tremendous impact on local social and healthcare services in many world regions, will particularly require increased research and workforce to meet the clinical demands of burgeoning multiethnic adult groups in post-stroke caseloads (Centeno, 2017; Centeno & Harris, in press; Dwolatzky et al., 2017; Yeo et al., 2017).

As the number of people aged 60 years or over continuously grows from 901 million to 1.4 billion between 2015 and 2030 worldwide (United Nations, Department of Economic and Social Affairs, Population Division, 2017), a parallel steady growth in international migration has steadily expanded numerous local multiethnic scenarios, consisting of multiple ethno-racial groups including Indigenous populations, across the world. Global migration has progressively grown from 173 to 258 million individuals between 2000 and 2017 (United Nations, Department of Economic and Social Affairs, Population Division, 2016). Continuous worldwide increase in ethno-geriatric populations already constitutes a global healthcare priority, especially in high-migration regions (Centeno & Harris, in press; Kristiansen et al., 2016; Sheets & Gallagher, 2013; Yeo, 2009).

With increased vulnerability to cardiovascular complications in an aging population, including stroke (Prince et al., 2015), stroke survivors are anticipated to number 73 million by 2030, consistent with global geriatric growth (Feigin et al., 2014). A large minority representation in adult stroke caseloads is expected. Minority elders in ethno-racially diverse environments have been reported to have a high incidence and prevalence of cardiovascular disease from the multifactorial interaction of social, economic, political, cultural, and institutional elements (Australian Institute of Health and Welfare, 2016; Mozaffarian et al., 2016). Many of these stroke survivors will have aphasia, a frequent post-stroke disability that has been ranked to occur from 21% to 38% among stroke patients (Engelter et al., 2006).

This innovative issue is an international effort to advance the evidential and clinical foundations needed to support aphasia services for the growing ethno-racially diverse adult populations. With expanded stroke ethno-geriatric groups, linguistic and sociocultural heterogeneity in neurorehabilitation programs, including aphasia services, will grow considerably (Centeno et al., 2017). Particularly, language diversity has crucial impact on aphasia management. Because there are about 7,111 languages in an international landscape of 195 sovereign states in the world (Eberhard et al., 2019), the multilingual environments, created by language coexistence in many countries, is continuously amplified by newly arriving migrants. In these growing hyper-diverse environments, individuals represent multiple linguistic profiles (i.e. monolingual speakers of minority languages, bi-/multilingual speakers and users of dialectal varieties of local languages) and life realities (i.e. socioeconomic circumstances, educational experiences, sociocultural histories, and worldviews) (Armstrong et al., 2015; Centeno & Harris, in press; Penn et al., 2017). Yet, despite the high aphasia prevalence in the growing multilingual-multiethnic neurorehabilitation programs worldwide, there are critical evidential and clinical limitations in aphasia management. Much of the aphasia research has focused on monolingual speakers, mostly Standard English users, in mono-cultural social environments (Beveridge & Bak, 2011; Karanth, 2000). In fact, aphasia in ethnically diverse neurorehabilitation programs, often solely seen as a communication impairment without its sociocultural context (Penn, 2012), has been ranked to be the most clinically challenging disorder faced by speech-language pathologists (Centeno, 2015).

Contributions in this issue, stimulated by different multiethnic neurorehabilitation environments across the world, advance the foundations in aphasia services in multiethnic populations in three important directions by (1) increasing our understanding of the factors that explain post-stroke language abilities in bilingual individuals, (2) extending neurocognitive accounts of bilingualism to aphasia in bilingual speakers, and (3) exploring culturally secure methodologies to be used in assessment and treatment contexts in culturally diverse adult neurorehabilitation services. In the first article in this Special Issue, to facilitate the often difficult process of interpreting post-stroke language profiles in bilingual persons with aphasia (Kuzmina et al., 2019), Lerman et al. (2020) review multiple case studies to propose that interpretive accuracy in aphasic language analysis in bi-/multilingual speakers may be enhanced by integrating multiple factors, including pre-stroke language proficiency, language exposure and use, post-stroke language impairment, post-stroke language practices, and nature of the brain lesion. Next, in line with current influential neurocognitive accounts implicated in aphasic language performance in bilingual individuals (e.g. Abutalebi et al., 2009; Abutalebi & Green, 2007), two studies aim to illuminate the operations participating in neurocognitive control of spoken language in dual language users with aphasia. Carpenter et al. (2020) report evidence on verbal fluency tasks, under single and dual-language use constraints, that highlights the increased demands in cognitive control in bilingual persons with aphasia relative to their healthy counterparts. Dash et al. (2020), exploiting the fine-grained ex-Gaussian data analysis to examine attentional control subcomponents, provide evidence to support a possible bilingual advantage in attentional mechanisms when comparing monolingual and bilingual persons with and without aphasia.

In the last three articles, authors discuss their efforts to meaningfully integrate cultural, linguistic, and social experiences in the clinical approaches and training to serve multiethnic adult caseloads with acquired communication dysfunctions, including aphasia. Armstrong et al. (2020) discuss the assessment of a future screening instrument for the culturally and linguistically non-biased evaluation of post-morbid language skills in Australian Aboriginal individuals. Likewise, Brewer et al. (2020) describe the evaluation of a pilot professional development program that aims to enhance culturally-grounded services for Māori adults with aphasia in New Zealand. Finally, using the illustrative South African context, Watermeyer (2020) proposes a novel community-based framework for ecologically realistic intervention protocols to work with an extensively multilingual aphasia population beyond the therapy room.

Articles in this issue offer a promising illustrative sample of the broad empirical and clinical enterprise required to enhance efficiency and sensitivity in aphasia service provision in ethno-racially diverse contexts. As aphasia neuroscientific advances expand (Kiran & Thompson, 2019), the systematic integration of these findings with client-unique factors and group-specific social, cultural, and linguistic understandings (Armstrong et al., 2015; Penn et al., 2017) will propel the evolution of aphasia management in the rapidly growing ethno-geriatric stroke caseloads across the world (Centeno & Harris, in press).

The issue specifically acknowledges the lifelong work of the late Professor Claire Penn – dedicated to improving aphasia services for marginalized and multiethnic communities and highlighting the integral role of culture in determining and developing aphasia assessments and treatments.

Disclosure statement

No potential conflict of interest was reported by the authors.