Alteration in, and recovery of, cerebral activation during a working memory task following pediatric mild traumatic brain injury

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Introduction: Mild traumatic brain injuries (mTBIs) are most common in children and adolescents. For some, symptoms can persist for an extended duration, especially in the cognitive and working memory domains. The neurological changes that underlie these differences in children with persistent symptoms, and their recovery over time, have not been characterized at distinct time points. Objectives: To determine how cortical activation during a working memory task is different in children with persistent symptoms, relative to control and asymptomatic children, and to observe how that changes with time. Methods: This was a prospective, controlled cohort study of pediatric mTBI at approximately one- and two- months post-injury. Symptom status was determined by the post-concussion symptom inventory (PCSI). A visuospatial n-back working memory task was designed for use with functional magnetic resonance imaging (fMRI). The primary outcome measures were the blood oxygen level dependent (BOLD) signal and n-back working memory task performance. Results: 107 participants (60 symptomatic mTBI, 30 asymptomatic mTBI and 17 controls) were compared approximately one month following mTBI. Mean age was 14.2 years (SD 2.5) and 44% were male. During the n-back task, at approximately one month post-injury, symptomatic mTBI children had decreased activation in the posterior cingulate and precuneus regions compared to asymptomatic children, with no difference in performance. By approximately two months post-injury, we found that symptomatic children had less working memory related cortical activation compared to their own one month post-injury scan, and an improvement in task performance (n=45). Conclusions: Symptomatic mTBI children have cortical activation differences compared to asymptomatic children. Over time, there is a decrease in working memory functional activation within that symptomatic group. Our findings highlight the neurobiological consequences of pediatric mTBI on working memory cortical activation and recovery.
Neuroscience, Pediatric, Concussion, Traumatic brain injury, MRI, Magnetic Resonance Imaging, Functional Imaging, Working memory, Cognition, Children, Youth
Khetani, A. M. (2018). Alteration in, and recovery of, cerebral activation during a working memory task following pediatric mild traumatic brain injury (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from doi:10.11575/PRISM/5435