A - 149 Association between Brain Network Organization and Symptom Severity from Baseline to Post-Concussion.

Abstract

Concussions have been associated with functional connectivity changes that impact physical and psychiatric health. Previous research has focused on the relationship between average network functional connectivity changes following concussion and symptom severity, but this approach may be insensitive to subtle nodal changes that still result in the disruption of within network organization, and therefore, impact symptom severity. We hypothesized that individuals who exhibit more disruptions in brain network organization post-concussion (~48hrs post-diagnosis) would self-report a higher symptom load acutely post-injury. Resting state functional magnetic resonance imaging data were obtained for collegiate football players (n = 37; Mage = 19.8, SDage = 1.85) at baseline and acute post-concussion. Functional connectivity matrices were constructed using 264 regions (Power et al., 2011). We calculated normalized betweenness centrality (BCnorm) for all DMN nodes at both time-points. Then similarity of pre-post patterns for BCnorm in the DMN were calculated. Symptom load was baseline-post concussion difference severity score from Post-Concussion Symptom Scale clusters (affective, cognitive, sleep, somatic) (Collins et al., 2012). Finally, correlations were calculated of DMN-BCnorm similarity with symptom cluster changes. Athletes who have more disruptions to brain network organization in the DMN from baseline to post-concussion report more somatic symptoms acutely post-concussion. We did not find any relationships between disruption of brain network properties in the DMN and changes in other symptom clusters. Athletes who exhibit more disruptions in the DMN report more somatic symptoms following concussion. These results suggest that examining patterns of brain network organization may be more sensitive than network average when relating brain changes to symptom change.