Long-Term Abnormalities in the Corpus Callosum of Female Concussed Athletes

Abstract

Concussion is an injury affecting millions of individuals annually that can be associated with long-term sequelae. Recent studies have reported long-term abnormalities in the white matter (WM) tracts of male athletes. The corpus callosum (CC) and corticospinal tract (CST) have been shown to be particularly vulnerable to concussion, which may be related to abnormal interhemispheric functional connectivity and motor impairments. These anatomical pathways, however, have not been investigated in female athletes despite the functional significance of the CC and CST to adequate sports performance. In the present study, 8 healthy, unconcussed female athletes (soccer, hockey) were compared with 10 female athletes (soccer, hockey, water polo) 6 months post-concussion. Diffusion tensor imaging (DTI) of the CC and CST was conducted in a 3T magnetic resonance imaging (MRI) scanner. DTI analysis showed no significant differences between groups within the CST but revealed differences between groups in the CC. The concussed group had lower mean diffusivity (t = 2.14; p = 0.048) and lower radial diffusivity (t = 2.91; p = 0.010) in the region of the CC projecting to the prefrontal cortex. A lower volume of WM fibers was found in the region projecting to the premotor and supplementary motor areas (t = 2.14; p = 0.048). Finally, lower axial diffusivity (AD) was observed in the CC area projecting mainly to the parietal and temporal area (t = 2.23; p = 0.041). Long-term alterations in the CC of female athletes appear to affect mostly the anterior part of the CC projecting to the prefrontal and premotor areas. Further studies are needed to determine whether these alterations are associated with a higher risk of sustaining a subsequent concussive injury.

Analysis of head impact exposure and brain microstructure response in a season-long application of a jugular vein compression collar: a prospective, neuroimaging investigation in American football

“…As hypothesised, the wearing of the device was effective to prevent diffusion changes after a full season of repetitive head impacts in high school football athletes. Specifically, the CTRL group showed consistent and statistically significant reduction in diffusion coefficients—a change that has been reported frequently in mTBI33–37 and sports-related TBI22 38–44 literature—contrasting with the absence of change in the football players who wore the collar. Combined with the association found between the decrease of diffusivity in the CTRL group and their impact burden, our study has generated initial evidence for a potential protective effect of the collar device.…”

“…38–44 WM integrity changes based on DTI have been correlated with postconcussive symptoms and cumulative risk-weighted exposure 40. Prior analyses of DTI in mTBI and sports-related TBI have shown changes of varying severity and direction, including abnormally lower FA and/or higher diffusivity (MD, AD, RD) in patients, concussed athletes, athletes with a history of concussion,25 27 43 46 or decreased FA and/or increased diffusivity measures in athletes when tested for preseason to postseason changes 39…”

Sex matters: repetitive mild traumatic brain injury in adolescent rats

“…While many of these findings were sex‐dependent and are discussed further in the next section, DTI metrics revealed a significant effect of injury in the contralateral CC with RmTBI rats having significantly lower AD and ADC than shams regardless of sex. Reduced ADC has been observed in the CC of adolescents with mTBI,48 and in university students including concussed male49 and female50 athletes. In the latter study, and consistent with our results here, concussed athletes also had reduced AD in the CC.…”

Predicting Outcome 12 Months after Mild Traumatic Brain Injury in Patients Admitted to a Neurosurgery Service

“…Studies have found reduced white matter integrity in the corpus callosum (60, 61), which has also been associated with functional outcome using The Functional Independence Measure and Glasgow Outcome Scale, although in severe TBI (62). Importantly, we did not include DTI-based indices of white matter microstructure in the present analysis, and the relationship between DTI-based measures and white matter volume is complex (63).…”