Cerebrovascular reactivity changes in asymptomatic female athletes attributable to high school soccer participation

Abstract

As participation in women's soccer continues to grow and the longevity of female athletes' careers continues to increase, prevention and care for mTBI in women's soccer has become a major concern for female athletes since the long-term risks associated with a history of mTBI are well documented. Among women's sports, soccer exhibits among the highest concussion rates, on par with those of men's football at the collegiate level. Head impact monitoring technology has revealed that "concussive hits" occurring directly before symptomatic injury are not predictive of mTBI, suggesting that the cumulative effect of repetitive head impacts experienced by collision sport athletes should be assessed. Neuroimaging biomarkers have proven to be valuable in detecting brain changes that occur before neurocognitive symptoms in collision sport athletes. Quantifying the relationship between changes in these biomarkers and head impacts experienced by female soccer athletes may prove valuable to developing preventative measures for mTBI. This study paired functional magnetic resonance imaging with head impact monitoring to track cerebrovascular reactivity changes throughout a season and to test whether the observed changes could be attributed to mechanical loading experienced by female athletes participating in high school soccer. Marked cerebrovascular reactivity changes were observed in female soccer athletes, relative both to non-collision sport control measures and pre-season measures and were localized to fronto-temporal aspects of the brain. These changes persisted 4-5 months after the season ended and recovered by 8 months after the season. Segregation of the total soccer cohort into cumulative loading groups revealed that population-level changes were driven by athletes experiencing high cumulative loads, although athletes experiencing lower cumulative loads still contributed to group changes. The results of this study imply a non-linear relationship between cumulative loading and cerebrovascular changes with a threshold, above which the risk, of injury likely increases significantly.

Persistent effects of playing football and associated (subconcussive) head trauma on brain structure and function: a systematic review of the literature

“…Most players were professionals (active=56; former=26) or amateurs (n=37). Only two studies were prospective 38 54. In one prospective study, no conventional MRI changes could be depicted in professional players (observation period=5 years) 38.…”

“…In one prospective study, no conventional MRI changes could be depicted in professional players (observation period=5 years) 38. Prospectively observing female high-school players over one season using fMRI, significant reductions in frontotemporal cerebrovascular reactivity persisting up to 4–5 months after the season had ended were reported,54 resembling the pattern described in mTBI 60 61. Retrospectively, in former professionals, VBM demonstrated cortical thinning in the right inferolateral parietal, temporal and occipital cortex37 and MRS showed higher choline and myo-inositol levels in the posterior cingulate gyrus 51.…”

Comparative Analysis of Head Impact in Contact and Collision Sports

“…Dotted line identifies the line of equality (i.e., ratio equals 1). 41,49,51,61,65,68 The difference between the presented data and the published data could reflect true head impact differences in our population; however, it is more likely the result of measurement differences between the xPatch and HITS, with xPatch likely overestimating PRRA values. HITS is a helmetmounted sensor system that was used to collect most of the published football data, but its helmet-mounted nature does not allow for use in non-helmeted sports such as lacrosse and soccer.…”

“…Many studies that try to quantify impact burden use the summation of a metric that was developed for individual impacts. 19,44,51,60,61,65,66 study chooses to use PRLA sum and PRRA sum, for their ease of calculation, and to match similar studies with the same accelerometer. 60,67 The GEE version of the Cox proportionate hazard model was used to compare the empirical cumulative distribution for PRLA sum per practice between players from different teams as well as to compare the empirical cumulative distribution of PRRA between players from different teams.…”

“…The xPatch accelerometer used in the present study appears in eight published studies, 60,62,65,66,[70][71][72][73] three of which test biomechanical validity in different settings. 60,62,73 Wu and coworkers compared the in vivo performance of the xPatch against video capture in a simulated low-impact soccer setting; that study examined 25 impacts, one impact location, one mastoid placement location, and one xPatch device.…”