Functional magnetic resonance imaging study of working memory several years after pediatric concussion
Brian L Brooks1,2,3, Shane Virani4,5, Aneesh Khetani6
1Neurosciences Program, Alberta Children's Hospital , Calgary, Alberta, Canada.
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.


