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.

主要目标：小儿脑震荡在受伤数年后的神经生理学影响仍未得到充分表征。本研究的目的是确定脑震荡史是否与青少年 n-back 工作记忆任务期间的 BOLD 反应差异有关。研究设计：观察性、横断面。方法和程序：参与者包括 52 名儿童和青少年（M = 15.1 岁，95%CI = 14.4-15.8，范围 = 9-19），既往有脑震荡（n = 33）或骨科损伤（OI；n = 19）。受伤后的平均时间为 2.5 年 (95%CI = 2.0–3.0)。措施包括脑震荡后症状评分、神经心理学测试和 n-back 工作记忆任务期间的血氧依赖水平 (BOLD) 功能磁共振成像 (fMRI)。主要成果和结果：在三个 n-back 条件下，各组在准确性或速度上没有差异。它们在 1 对 0 后或 2 对 0 后对比（控制任务性能）的 BOLD 信号变化方面也没有差异。结论：本研究不支持在脑震荡后平均 2.5 年的青年进行 n-back 工作记忆任务期间 BOLD 反应的群体差异。从了解小儿脑震荡后恢复的角度来看，这些发现令人鼓舞。