Resting state functional magnetic resonance imaging after pediatric mild TBI: Association of whole brain functional connectivity with diagnosis and post-concussive symptoms

Date
2022-08
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Abstract
Accurate diagnosis and prognosis is important after pediatric mild traumatic brain injury (TBI), but limited objective measures exist for either purpose. Advanced neuroimaging has garnered increased interest as a means to better understand mild TBI, with the potential to support objective assessment. Broadly, the goal of this dissertation was to examine resting state functional magnetic resonance imaging (RS fMRI) after pediatric mild TBI. Study 1 is a scoping review that aimed to examine the literature on RS fMRI after pediatric and adolescent mild TBI to summarize findings, determine research themes, review methodological approaches, and identify areas for further research. Study 2 is an original research study that aimed to predict group status [i.e., mild TBI versus orthopedic injury (OI)] as well as post-concussive symptoms (PCS) from whole brain functional connectivity (FC) patterns in participants aged 8.00 to 16.99 years (N = 430). Study 1 identified 16 articles with four main research themes: 1) RS fMRI differences between mild TBI and comparison groups; 2) changes in RS fMRI over time; 3) RS fMRI differences in subsamples of mild TBI; and 4) relations of RS fMRI to outcome measures (e.g., symptoms, behaviour, and cognition). Overall, a clear pattern of findings of RS fMRI after mild TBI was difficult to discern, likely due to heterogeneity in study methods and a high proportion of cross-sectional studies with small sample sizes. Study 2 found that significant models of group (mild TBI versus OI) could be built from whole brain RS FC profiles. These FC profiles were characterized primarily by widespread differences in connectivity between networks, largely involving the default mode network, mesolimbic network, executive function/task positive networks, and the cerebellum. However, the observed prediction accuracy did not exceed the proportion of mild TBI cases in the sample. Additionally, no significant models of cognitive or somatic PCS could be built. While these findings provide insight into RS FC profiles that differentiate mild TBI from OI, the models have limited clinical utility, and PCS shortly after injury was not reflected in RS FC. While the results of this dissertation provide an important first step in understanding RS fMRI after pediatric mild TBI, more longitudinal research is needed.
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Keywords
Mild traumatic brain injury, Concussion, Pediatrics, Resting state fMRI, Functional magnetic resonance imaging
Citation
Deighton, S. (2022). Resting state functional magnetic resonance imaging after pediatric mild TBI: association of whole brain functional connectivity with diagnosis and post-concussive symptoms (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.