Abstract WP220: Structural Connectivity Injury is Associated With Poor Language Outcomes in Perinatal Stroke

Abstract

Introduction: Perinatal stroke refers to brain injury sustained between 28 weeks of gestational age (GA) and 28 days of life. Stroke risk in the newborn period is significantly higher relative to other life stages, and over half of all survivors endure lifelong neurological sequalae. Language deficits are observed in many patients, can emerge at any stage in development, and are difficult to predict. Lesion laterality and location are not sufficient to explain language outcomes in a rapidly developing brain with capacities for reassignment of functions to non-injured structures. Structural connectivity studies describe a “rich club” organization of the brain with 6 bilateral highly connected anatomical structures that form the information backbone for all networks. This organization has been found to exist as early as 30 weeks GA. The effects of injury to this rich club have been studied in adult stroke patients with respect to stroke severity and outcome. Given that language is a network function, we hypothesized that injury to rich club regions - a measure of structural network disruption - is associated with poor language outcomes in perinatal stroke. Methods: Retrospective study that identified perinatal stroke patients in a pediatric stroke clinic database. Clinical and imaging data retrieved included brain MRI scans and longitudinal scores of standardized neuropsychological tests. Multiple linear regression models were created for the following variables: age, sex, Autism Spectrum Disorder diagnosis, lesion volume (cm 3 ), and number of rich clubs affected by the stroke. All analyses were conducted using the computing environment R. Significance was set at p < 0.05. Results: Cohort of 75 patients was identified. Median time to follow up was 7 years, and median time between the first and last test was 30 months. Lesion volume significantly influenced receptive language outcomes at younger ages (beta = -0.446), however the number of rich clubs affected by the injury was the only significant variable associated with a poor expressive language outcome at follow-up (beta = -0.699). Discussion: Number of rich clubs affected by injury, as a global measure of structural network disruption in the neonatal period, can be used to inform language outcome prognostication.