Poster C16, Wednesday, August 21, 2019, 10:45 am – 12:30 pm, Restaurant Hall
Prediction of early post-stroke aphasia from initial language severity
Alberto Osa Garcia1,2, Simona Maria Brambati2,3, Amélie Brisebois1, Marianne Désilets-Barnabé1,2, Elizabeth Rochon4,5,6, Alex Desautels1,2,7, Karine Marcotte1,2;1Centre de recherche du Centre intégré universitaire de santé et de services sociaux du Nord-de-l’Île-de-Montréal, Hôpital du Sacré-Coeur de Montréal, 2Université de Montréal, 3Centre de recherche de l’Institut Universitaire de Gériatrie de Montréal, 4University of Toronto, 5Toronto Rehabilitation Institute, 6Heart and Stroke Foundation, Canadian Partnership for Stroke Recovery, Ontario, 7Centre d’études Avancées en médecine du sommeil, Hôpital du Sacré-Cœur de Montréal
Introduction: Post-stroke aphasia (PSA) is an acquired impairment in producing or understanding language generally caused by a perturbation of cerebral blood flow in the brain language network. It is generally due to an ischemic stroke in the left middle cerebral artery (MCA) territory. Several factors related to the patient, such as initial language impairment severity, and to the lesion, such as the integrity of white matter, have been proven to predict long-term recovery well (from 3 to 6 months). However, the greatest degree of recovery takes place in the first weeks following a stroke, and few studies have investigated behavioral changes during the acute phase. Also, the influence of white matter structures related to language (e.g., the arcuate fasciculus) in early recovery is still largely unknown. This study aims to identify which are the best predictors of early recovery in post-stroke aphasia. Methods: Twenty patients who presented with an ischemic stroke of the left MCA were recruited. An MRI and a language assessment were performed 3 days and 10 days (on average) after stroke onset for each patient. Mean values of fractional anisotropy (FA) and mean diffusivity (MD) were extracted in the arcuate fasciculus (AF) in each hemisphere, as well as lesion volume in the acute phase. Aphasia severity was measured using a Composite Score (CS) at both time points. The CS was designed using several subtests from different well validated language tests for patients with aphasia, including tasks of comprehension, naming and repetition. A stepwise regression analysis using age, education, lesion size, FA and MD from the AF in each hemisphere and initial CS was performed with achieved recovery as the outcome. Results: A significant improvement of the CS was observed between the initial assessment and the follow-up. A regression model including initial CS, lesion size and FA from AF in both hemispheres proved to account for 53% of the variance of the achieved recovery. Initial aphasia severity emerged as the best predictor of all (R2 = 36%) in the univariate analyses. Interestingly, albeit not significant, the FA of the AF in the right hemisphere accounted for more variance than the FA of the AF in the left hemisphere. Conclusion: This study has demonstrated that early recovery of PSA has a stronger relationship with initial language severity than with any other factors that were examined. The present results highlight the importance of language assessments in the early stages of post-stroke aphasia. Future studies including other biomarkers and long-term follow-ups will provide a more comprehensive understanding of aphasia recovery. A better understanding of early spontaneous recovery is an essential benchmark for the development of new early treatments.
Themes: Disorders: Acquired, Language Therapy
Method: White Matter Imaging (dMRI, DSI, DKI)