Alterations in Structural Correlation Networks with Prior Concussion in Collision-Sport Athletes
This addresses the need for objective biomarkers of concussion effects in athletes, though it is incremental as it applies an existing method to a new population.
The study tackled the problem of detecting brain structural changes from prior concussion in collision-sport athletes using graph-based topological properties, finding that athletes without concussion history had significantly greater small-worldness than controls, and those with prior concussion showed disrupted integration with longer path lengths.
Several studies have used structural correlation networks, derived from anatomical covariance of brain regions, to analyze neurologic changes associated with multiple sclerosis, schizophrenia and breast cancer [1][2]. Graph-theoretical analyses of human brain structural networks have consistently shown the characteristic of small-worldness that reflects a network with both high segregation and high integration. A large neuroimaging literature on football players, with and without history of concussion, has shown both functional and anatomical changes. Here we use graph-based topological properties of anatomical correlation networks to study the effect of prior concussion in collision-sport athletes. 40 high school collision-sport athletes (23 male football, 17 female soccer; CSA) without self-reported history of concussion (HOC-), 18 athletes (13 male football, 5 female soccer) with self-reported history of concussion (HOC+) and 24 healthy controls (19 male, 5 female; CN) participated in imaging sessions before the beginning of a competition season. The extracted residual volumes for each group were used for building the correlation networks and their small-worldness, , is calculated. The small-worldness of CSA without prior history of concussion, , is significantly greater than that of controls, . CSA with prior history have significantly higher (vs. 95% confidence interval) small-worldness compared to HOC+, over a range of network densities. The longer path lengths in HOC+ group could indicate disrupted neuronal integration relative to healthy controls.