ABSTRACT
Purpose: To review current evidence on the relationship between executive control (EC) and post-treatment language gains in adults with post-stroke aphasia.
Method: Electronic databases (CINAHL, Cochrane Trials, Embase, MEDLINE, MEDLINE-in-Process and PsycINFO) were systematically searched (year 2000 – present). Abstracts and full-text articles were reviewed by two independent raters against pre-specified criteria: original research with N > 2; at least 90% adults with stroke, all undergoing treatment for acquired aphasia; pre-treatment EC abilities were compared to language gains post-treatment across studies. Critical appraisal was conducted using the Cochrane group and Single-Case Experimental Design (SCED) methods. Data were extracted and summarised descriptively.
Results: Search results yielded 2272 unique citations; ultimately 15 studies were accepted for review. Both pre-treatment EC and language abilities appear to be important indicators of treatment success, especially in moderate-severe aphasia. This relationship emerged when EC was measured using specific (e.g., divided attention), as opposed to broad (e.g., reasoning) tasks, and primarily when naming therapy was administered; intensive constraint-induced therapy did not correlate with treatment success.
Conclusions: EC is a promising prognostic variable regarding language recovery, but further research is required using a-priori declared theoretical EC models, along with properly powered samples, standardised EC tasks and treatment protocols.
Acknowledgments
We thank Jessica Babineau, a librarian at Toronto Rehabilitation Institute – University Health Network, for assistance with the literature search protocol.
Disclosure Statement
No potential conflict of interest was reported by the authors.
Notes
1. Three additional studies met all inclusion criteria for this review (Fillingham et al., Citation2005a, Citation2005b; Nicholas, Sinotte, & Helm-Estabrooks, Citation2005). The participants presented by Fillingham and colleagues (Citation2005a, Citation2005b), however, were subsets of the participants presented in Fillingham et al., Citation2006, a study already included in this review and aggregated in Lambon-Ralph and colleagues (Citation2010), as described in footnote two. Similarly, the participants presented in Nicholas, Sinotte, and Helm-Estabrooks (Citation2005) represented a subset of those presented in Nicholas et al., Citation2011, therefore we chose to exclude the earlier study in this case.
2. Lambon Ralph et al. (Citation2010) amalgamated data from four previously published single-subject design studies (Conroy, Sage, & Lambon Ralph, Citation2009a; Fillingham et al., Citation2006; Sage et al., Citation2011; Snell et al., Citation2010). One of those studies is represented individually here (Fillingham et al., Citation2006). The inclusion of the Fillingham et al., Citation2006 study was determined by discussion and consensus amongst the authors. Given that this study met all inclusion criteria and presented a more homogeneous subset of the Lambon Ralph et al., Citation2010 data (i.e., the participants in this study only received one block of therapy, as it was the first in a series of studies), it was deemed an informative addition to the review.
Fillingham, J. K., Sage, K., & Lambon Ralph, M. A. (2005a). Treatment of anomia using errorless versus errorful learning: Are frontal executive skills and feedback important? International Journal of Language and Communication Disorders, 40(4), 505–523. doi: 10.1080/13682820500138572 Fillingham, J. K., Sage, K., & Lambon Ralph, M. A. (2005b). Further explorations and an overview of errorless and errorful therapy for aphasic word-finding difficulties: The number of naming attempts during therapy affects outcome. Aphasiology, 19(7), 597–614. doi: 10.1080/02687030544000272 Nicholas, M., Sinotte, M., & Helm-Estabrooks, N. (2005). Using a computer to communicate: Effect of executive function impairments in people with severe aphasia. Aphasiology, 19(10–11), 1052–1065. doi: 10.1080/02687030544000245 Fillingham, J. K., Sage, K., & Lambon Ralph, M. A. (2005a). Treatment of anomia using errorless versus errorful learning: Are frontal executive skills and feedback important? International Journal of Language and Communication Disorders, 40(4), 505–523. doi: 10.1080/13682820500138572 Fillingham, J. K., Sage, K., & Lambon Ralph, M. A. (2005b). Further explorations and an overview of errorless and errorful therapy for aphasic word-finding difficulties: The number of naming attempts during therapy affects outcome. Aphasiology, 19(7), 597–614. doi: 10.1080/02687030544000272 Fillingham, J. K., Sage, K., & Lambon Ralph, M. A. (2006). The treatment of anomia using errorless learning. Neuropsychological Rehabilitation, 16(2), 129–154. doi: 10.1080/09602010443000254 Lambon Ralph, M. A., Snell, C., Fillingham, J. K., Conroy, P., & Sage, K. (2010). Predicting the outcome of anomia therapy for people with aphasia post CVA: Both language and cognitive status are key predictors. Neuropsychological Rehabilitation, 20(2), 289–305. doi: 10.1080/09602010903237875 Nicholas, M., Sinotte, M., & Helm-Estabrooks, N. (2005). Using a computer to communicate: Effect of executive function impairments in people with severe aphasia. Aphasiology, 19(10–11), 1052–1065. doi: 10.1080/02687030544000245 Nicholas, M., Sinotte, M., & Helm-Estabrooks, N. (2011). C-Speak aphasia alternative communication program for people with severe aphasia: Importance of executive functioning and semantic knowledge. Neuropsychological Rehabilitation, 21(3), 322–366. doi: 10.1080/09602011.2011.559051 Lambon Ralph, M. A., Snell, C., Fillingham, J. K., Conroy, P., & Sage, K. (2010). Predicting the outcome of anomia therapy for people with aphasia post CVA: Both language and cognitive status are key predictors. Neuropsychological Rehabilitation, 20(2), 289–305. doi: 10.1080/09602010903237875 Conroy, P., Sage, K., & Lambon Ralph, M. A. (2009a). Errorless and errorful therapy for verb and noun naming in aphasia. Aphasiology, 23(11), 1311–1337. doi: 10.1080/02687030902756439 Fillingham, J. K., Sage, K., & Lambon Ralph, M. A. (2006). The treatment of anomia using errorless learning. Neuropsychological Rehabilitation, 16(2), 129–154. doi: 10.1080/09602010443000254 Sage, K., Snell, C., & Lambon Ralph, M. A. (2011). How intensive does anomia therapy for people with aphasia need to be? Neuropsychological Rehabilitation, 21(1), 26–41. doi: 10.1080/09602011.2010.528966 Snell, C., Sage, K., & Lambon Ralph, M. A. (2010). How many words should we provide in anomia therapy? A meta-analysis and a case series study. Aphasiology, 24(9), 1064–1094. doi: 10.1080/02687030903372632 Fillingham, J. K., Sage, K., & Lambon Ralph, M. A. (2006). The treatment of anomia using errorless learning. Neuropsychological Rehabilitation, 16(2), 129–154. doi: 10.1080/09602010443000254 Fillingham, J. K., Sage, K., & Lambon Ralph, M. A. (2006). The treatment of anomia using errorless learning. Neuropsychological Rehabilitation, 16(2), 129–154. doi: 10.1080/09602010443000254 Lambon Ralph, M. A., Snell, C., Fillingham, J. K., Conroy, P., & Sage, K. (2010). Predicting the outcome of anomia therapy for people with aphasia post CVA: Both language and cognitive status are key predictors. Neuropsychological Rehabilitation, 20(2), 289–305. doi: 10.1080/09602010903237875 Additional information
Funding
This research was supported by a Heart and Stroke Foundation of Ontario (#NA7015) grant to Elizabeth Rochon and a Heart and Stroke Foundation of Canada, Canadian Partnership for Stroke Recovery award to Tijana Simic. Rosemary Martino received support from her Canada Research Chair (Tier II) in Swallowing Disorders.