Abstract TMP114: Functional and Structural Network Reorganization in Higher-Order Language Following Neonatal Stroke

Abstract

Introduction: Neonatal arterial ischemic stroke (NAIS) is a common form of pediatric stroke often affecting classical language areas in the brain’s left hemisphere. While children with NAIS can acquire basic language skills, adolescence typically reveals the emergence of deficits in higher-order language, such as syntactic language. The reorganization of functional and structural brain networks may provide insight into later-emerging language outcomes and serve as a biomarker in prognostication. Methods: A cross-sectional study of eight children with unilateral NAIS (5F; 12.3±3.3 years) and seven neurotypical children (2F; 13.4±2.7 years) was conducted. Participants listened to syntactically correct and incorrect sentences while magnetoencephalography was recorded, and task-related functional connectivity in the time window and frequency band of interest was determined. Structural connectivity between brain regions was investigated using DTI tractography, and language outcomes were assessed using neuropsychological tests. Results: An analysis of the syntactic language network (4-7 Hz, 1.2-1.4s) indicated that unlike the typical correlation between left-lateralized functional connectivity and language skill ( p <0.01), good outcome in patients is correlated with bilateral frontal connectivity (p<0.01). Furthermore, patients exhibit a significant reduction in structural connectivity between the left and right supplementary motor area, compared with controls ( p =0.007), and the bilateral structural connectivity of this region is positively correlated with measures of working memory and information processing ( p =0.036). Conclusions: The preliminary results suggest that reorganization of functional networks towards bilateral connectivity may support language outcome following early stroke. The supplementary motor area’s role in coordination of interhemispheric functions and in information processing may position it as a key structural region in supporting the compensatory reorganization of functional networks underlying language. Ultimately, measures of functional and structural networks may be used as a prognostic tool for language development in pediatric stroke in order to improve long-term outcomes.