Factors predicting long-term recovery from post-stroke aphasia

ABSTRACT

Background

It remains widely accepted that spontaneous recovery from aphasia is largely limited to the first related factors. This has direct implications for acute and chronic interventions for aphasia. few months following stroke. A few recent studies challenge this view, revealing that some individuals’ language abilities improve even during the chronic stage.

Aims

To identify prognostic indicators of long-term aphasia recovery.

Methods & Procedures

Eighteen people with aphasia initially evaluated in the chronic stage were retested at least one year later. The Western Aphasia Battery-Revised (WAB-R) Aphasia Quotient (AQ) was used to quantify changes in language impairment. Prognostic factors included those related to the patient (demographic, psychosocial), stroke (lesion volume and location), and treatment (medical, rehabilitative).

Outcomes & Results

Twelve participants improved and 6 remained stable or declined. Linear regression analysis revealed that lesion volume predicted long-term language gains, with smaller lesions yielding greater improvements. Individuals who did not improve were more likely to have lesions encompassing critical frontal and temporoparietal cortical regions and interconnecting white matter pathways. Exploratory regression analysis of psychosocial and treatment-related factors revealed a positive relationship between improvement and satisfaction with life participation, and a negative relationship between improvement and perceived impairment severity. Critically, psychosocial and treatment-related factors significantly improved model fit over lesion volume, suggesting that these factors add predictive value to determining long-term aphasia prognosis.

Conclusions

Long-term aphasia recovery is multidetermined by a combination of stroke-, psychosocial-, and treatment-related factors. This has direct implications for acute and chronic interventions for aphasia.

KEYWORDS:

• Aphasia
• stroke
• neuroplasticity
• neurological rehabilitation
• acquired language disorder
• long-term recovery

Acknowledgments

We thank Myrna F. Schwartz for consultation on design, analysis, and statistical approach as well as feedback on earlier drafts of the manuscript. We also thank Claire Healy for assisting with collecting follow-up language assessment data and follow-up self-report data as well as H. Branch Coslett for overseeing the lesion tracings. This work was supported by the NIH-NIDCD under Grant R01-DC012780 to RHH, and NIH-NICHD under Grant T32-HD071844 to DYH.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary Material

Supplemental data for this article can be accessed here.

Notes

1. Age and MPO at the follow-up assessment were not included in the analysis, as these factors are perfectly correlated with age and MPO at the initial assessment, respectively.

Additional information

Funding

This work was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development [T32-HD071844]; National Institute on Deafness and Other Communication Disorders [R01-DC012780].