Blood–Brain Barrier Dysfunction and Exposure to Head Impacts in University Football Players

Abstract

Objective: To investigate the link between dysfunction of the blood–brain barrier (BBB) and exposure to head impacts in concussed football athletes. Design: This was a prospective, observational pilot study. Setting: Canadian university football. Participants: The study population consisted of 60 university football players, aged 18 to 25. Athletes who sustained a clinically diagnosed concussion over the course of a single football season were invited to undergo an assessment of BBB leakage. Independent variables: Head impacts detected using impact-sensing helmets were the measured variables. Main outcome measures: Clinical diagnosis of concussion and BBB leakage assessed using dynamic contrast-enhanced MRI (DCE-MRI) within 1 week of concussion were the outcome measures. Results: Eight athletes were diagnosed with a concussion throughout the season. These athletes sustained a significantly higher number of head impacts than nonconcussed athletes. Athletes playing in the defensive back position were significantly more likely to sustain a concussion than remain concussion free. Five of the concussed athletes underwent an assessment of BBB leakage. Logistic regression analysis indicated that region-specific BBB leakage in these 5 athletes was best predicted by impacts sustained in all games and practices leading up to the concussion—as opposed to the last preconcussion impact or the impacts sustained during the game when concussion occurred. Conclusions: These preliminary findings raise the potential for the hypothesis that repeated exposure to head impacts may contribute to the development of BBB pathology. Further research is needed to validate this hypothesis and to test whether BBB pathology plays a role in the sequela of repeated head trauma.