Brain Age Predicts Long-Term Recovery in Post-stroke Aphasia

Authors

Sigfus Kristinsson, University of South Carolina
Natalie Busby, University of South Carolina
Christopher Rorden, University of South Carolina
Roger Newman-Norlund, University of South Carolina
Dirk B. den Ouden, Chapman UniversityFollow
Sigridur Magnusdottir, University of Iceland
Haukur Hjaltason, University of Iceland
Helga Thors, University of South Carolina
Argye E. Hillis, Johns Hopkins University
Olafur Kjartansson, Landspitali University Hospital
Leonardo Bonilha, University of South Carolina
Julius Fridriksson, University of South Carolina

Document Type

Article

Publication Date

10-6-2022

Abstract

The association between age and language recovery in stroke remains unclear. Here, we used neuroimaging data to estimate brain age, a measure of structural integrity, and examined the extent to which brain age at stroke onset is associated with (i) cross-sectional language performance, and (ii) longitudinal recovery of language function, beyond chronological age alone. A total of 49 participants (age: 65.2 ± 12.2 years, 25 female) underwent routine clinical neuroimaging (T1) and a bedside evaluation of language performance (Bedside Evaluation Screening Test-2) at onset of left hemisphere stroke. Brain age was estimated from enantiomorphically reconstructed brain scans using a machine learning algorithm trained on a large sample of healthy adults. A subsample of 30 participants returned for follow-up language assessments at least 2 years after stroke onset. To account for variability in age at stroke, we calculated proportional brain age difference, i.e. the proportional difference between brain age and chronological age. Multiple regression models were constructed to test the effects of proportional brain age difference on language outcomes. Lesion volume and chronological age were included as covariates in all models. Accelerated brain age compared with age was associated with worse overall aphasia severity (F(1, 48) = 5.65, P = 0.022), naming (F(1, 48) = 5.13, P = 0.028), and speech repetition (F(1, 48) = 8.49, P = 0.006) at stroke onset. Follow-up assessments were carried out ≥2 years after onset; decelerated brain age relative to age was significantly associated with reduced overall aphasia severity (F(1, 26) = 5.45, P = 0.028) and marginally failed to reach statistical significance for auditory comprehension (F(1, 26) = 2.87, P = 0.103). Proportional brain age difference was not found to be associated with changes in naming (F(1, 26) = 0.23, P = 0.880) and speech repetition (F(1, 26) = 0.00, P = 0.978). Chronological age was only associated with naming performance at stroke onset (F(1, 48) = 4.18, P = 0.047). These results indicate that brain age as estimated based on routine clinical brain scans may be a strong biomarker for language function and recovery after stroke.

Comments

This article was originally published in Brain Communications, volume 4, issue 5, in 2022. https://doi.org/10.1093/braincomms/fcac252

Recommended Citation

Kristinsson, S., Busby, N., Rorden, C., Newman-Norlund, R., Den Ouden, D.B., Magnusdottir, S., Hjaltason, H., Thors, H., Hillis, A., Kjartansson, O., Bonilha, L., and Fridriksson, J. (2022) Brain Age predicts long-term recovery in post-stroke aphasia. Brain Communications, 4 (5), fcac252. https://doi.org/10.1093/braincomms/fcac252

Peer Reviewed

1

Copyright

The authors

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.