Citation

Keightley ML, Saluja RS, Chen JK, Gagnon I, Leonard G, Petrides M, Ptito A. J. Neurotrauma 2014; 31(5): 437-451.

Affiliation

Holland Bloorview Kids Rehabilitation Hospital, Acquired Brain Injury Bloorview Research Institute, Toronto, Ontario, Canada, University of Toronto, Department of Occupational Science and Occupational Therapy, Toronto, Ontario, Canada, University of Toronto, Graduate Department of Rehabilitation Science, Toronto, Ontario, Canada, University of Toronto, Department of Psychology, Toronto, Ontario, Canada ; MKeightley@hollandbloorview.ca.

Copyright

(Copyright © 2014, Mary Ann Liebert Publishers)

DOI

10.1089/neu.2013.3052

PMID

24070614

Abstract

In children, the importance of detecting deficits after mild traumatic brain injury (mTBI) or concussion has grown with the increasing popularity of leisure physical activities and contact sports. While most post-concussive symptoms (PCS) are similar for children and adults, the breadth of consequences to children remains largely unknown. To investigate the effect of mTBI on brain function, we compared working memory performance and related brain activity using blood-oxygen-level-dependent (BOLD) functional MRI in 15 concussed youths and 15 healthy age-matched control subjects. Neuropsychological tests, self-perceived post-concussive symptoms, levels of anxiety and depression were also assessed. Our results showed that, behaviorally, concussed youths had significantly worse performances on the working memory tasks, as well as on the Rey figure delayed recall and verbal fluency. Functional MRI results revealed that, compared to healthy children, concussed youths had significantly reduced task-related activity in bilateral dorsolateral prefrontal cortex, left premotor cortex, supplementary motor area and left superior parietal lobule during performance of the verbal and nonverbal working memory tasks. Additionally, concussed youths also showed less activation than healthy controls in the dorsal anterior cingulate cortex, left thalamus and left caudate nucleus during the nonverbal task. Regression analysis indicated that BOLD signal changes in bilateral dorsolateral prefrontal cortex were significantly correlated with performance such that greater activities in these regions relative to the control condition were associated with greater accuracy. Our findings confirmed functional alterations in brain activity following concussion in youths, a result similar to that observed in adults. However, significant differences were noted. In particular, the observation of reduced working memory accuracy suggests that youths may be unable to engage compensatory strategies to maintain cognitive performance following mTBI. This has significant implications for safe return to daily activities, including competitive sport.

Language: en