Functional magnetic resonance imaging study of working memory several years after pediatric concussion
Brian L. Brooks, Shane Virani, Aneesh Khetani, Helen L. Carlson, Zeanna Jadavji, Micaela Mauthner, Trevor A. Low, Vickie Plourde, Frank P. MacMaster, Signe Bray, Ashley D. Harris, Catherine Lebel, R. Marc Lebel, Michael J. Esser, Keith Owen Yeates, Karen Barlow
Abstract
PRIMARY OBJECTIVE: The neurophysiological effects of pediatric concussion several years after injury remain inadequately characterized. The objective of this study was to determine if a history of concussion was associated with BOLD response differences during an n-back working memory task in youth. RESEARCH DESIGN: Observational, cross-sectional. METHODS AND PROCEDURES: Participants include 52 children and adolescents (M = 15.1 years, 95%CI = 14.4-15.8, range = 9-19) with past concussion (n = 33) or orthopedic injury (OI; n = 19). Mean time since injury was 2.5 years (95%CI = 2.0-3.0). Measures included postconcussion symptom ratings, neuropsychological testing, and blood-oxygen-dependent-level (BOLD) functional magnetic resonance imaging (fMRI) during an n-back working memory task. MAIN OUTCOMES AND RESULTS: Groups did not differ on accuracy or speed during the three n-back conditions. They also did not differ in BOLD signal change for the 1- vs. 0-back or 2- vs. 0-back contrasts (controlling for task performance). CONCLUSIONS: This study does not support group differences in BOLD response during an n-back working memory task in youth who are on average 2.5 years post-concussion. The findings are encouraging from the perspective of understanding recovery after pediatric concussion.