The Lingraphica Blog

Exploring Long-Term Improvement in People with Chronic Aphasia

Aug 06, 2019 | by Richard Steele, PhD

Researchers from the University of South Carolina conducted analyses of data on persons with chronic aphasia (PWA.chr), individuals for whom the period of spontaneous recovery following stroke had elapsed.  The purpose of this study was longitudinally to characterize changes in severity of language involvement among PWA.chr, with an eye to identifying demographic and/or health factors that may improve prognoses regarding such changes.

Investigators searched an archival database to assemble a convenience sample of 39 PWA.chr who had received their aphasia diagnosis following a single-event, left-hemisphere ischemic stroke, and who also had received two or more Western Aphasia Battery (WAB) language assessments separated by at least six months.  Of these, 26 were male and 13 – female.  Mean age was 54.7 y/o (range 39.0 – 71.0), and mean WAB Aphasia Quotient (AQ) was 53.5 (range 5.6 – 88.8).  Ten of the subjects presented also with co-occurring diabetes.  In total, 26 subjects had received 2 WAB language assessments, 6 had completed 3, another 6 had completed 4, and 1 had completed 5.  All had participated as subjects in one or more language treatment studies of varying types, lengths, and purposes.  In analyzing subjects’ data, the authors used a linear mixed-methods model to estimate the respective impacts of treatment, of demographic factors, and of health factors on observed language changes.

Approximately half of the subjects improved during the period under study, as shown by a rise of at least 3 points in their WAB AQ score.  Of the rest, 26% declined (AQ dropping 3 points or more), and the remaining 23% clinically did not change (∆AQ < ±3).  Across the sample, higher numbers of hours spent participating in the various therapeutic activities significantly predicted language improvement (p < .03).  Language declines, on the other hand, were significantly predicted by more advanced ages (p < .04).  Among the 10 participants with co-occurring diabetes, younger ages combined with increased exercise levels were significantly predictive of improved outcomes (p < .05). 

The authors have introduced a practical approach to the retrospective study of chronic aphasia longitudinally, and they report findings from its initial application. About half of the subjects in their sample improved over time, approximately a quarter remained stable, and approximately a quarter declined.  Furthermore, they found that: (i) therapy participation is significantly predictive of improvement, (ii) more advanced age is a significant risk factor for decline; and (iii) among chronic PWA with cooccurring diabetes, those who are younger and who exercise fare better over time.  Future research studying even larger numbers of PWA.chr is a desirable next step, to refine the initial findings and to consider additional factors as prognostic indicators.

For further reading:  L. Johnson, A. Basilakos, G. Uourganov, et al.,  2019.  Progression of aphasia severity in the chronic stages of strokeAmerican Journal of Speech-Language Pathology, 28(2):639-649