For the first time researchers were able to detect blood–brain barrier (BBB) damage caused by mild traumatic brain damage.
In a study published in the Journal of Neurotrauma, researchers from Ben-Gurion University of the Negev (Beersheba, Israel), Stanford University (CA, USA) and Trinity College in Dublin (Ireland) studied populations with high risk of head trauma such as professional mixed martial arts fighters and rugby players. The team aimed to investigate the integrity of the BBB – in hope to develop a better technique to diagnose mild brain trauma.
While the diagnosis of moderate and severe TBI is visible through magnetic resonance imaging [MRI] and computer-aided tomography scanning [CT], it is far more challenging to diagnose and treat mild traumatic brain injury, especially a concussion which doesn't show up on a normal CT," explained study author, Alon Friedman (Ben-Gurion University of the Negev).
The findings from this study demonstrated that mild impact in these athletes can still lead to a leaky BBB, even without a report of concussion.
All the participants were evaluated using an advanced MRI protocol developed at Ben-Gurion University, analyzed for BBB biomarkers in blood and wore a mouthguard with sensors developed at Stanford that track speed, acceleration and force. The athletes were examined pre-fight or pre-season for a baseline, which was compared with their follow-up assessment.
Out of the 19 rugby players, ten displayed signs of a leaky BBB by the end of the season, with two out of eight players who were scanned post-match exhibiting barrier disruptions. The team of researchers were able to correlate the damage seen on MRI with measurements from the mouthguard sensors.
The current theory today is that it is the outer surface of the brain that is damaged in a concussion since, during an impact, the brain ricochets off of skull surfaces like Jell-O," Friedman explained. "However, we can see now that the trauma's effects are evident much deeper in the brain and that the current model of concussion is too simplistic."
The group plan to conduct another similar study with a larger cohort to investigate the recovery of the BBB disruptions.
It is likely that kids are experiencing these injuries during the season but aren't aware of them or are asymptomatic," Friedman commented. "We hope our research using MRI and other biomarkers can help better detect a significant brain injury that may occur after what seems to be a 'mild TBI' among amateur and professional athletes."
If the further larger studies can confirm the findings from this study, then the brain imaging techniques being developed could be used to determine safer return-to-play guidelines.
Sources: O'Keeffe E, Kelly E, Liu Y et al. Dynamic blood brain barrier regulation in mild head trauma. J. Neurotrauma. doi:10.1089/neu.2019.6483 (2019) (Epub ahead of print); www.eurekalert.org/pub_releases/2019-09/aabu-bbd092519.php