Repetitive shots key to understanding MMA-related head injuries

A paper titled “Dynamic blood brain barrier regulation in mild head trauma” by scientists from Trinity College Dublin was recently published in the Journal of Neurotrauma. MMA and rugby participants took part in the study, which took four years to complete.

Hayley Halpin from explains that mild head trauma has come to the fore in recent years as being associated with collision and combat sports like MMA and rugby. However, it is also a very common injury in children and young adults. This represents a significant challenge to doctors due to the lack of any robust biomarkers or objective imaging approaches to manage the injury.

The study, undertaken by the Trinity-led concussion research interest group, used both sensor-enabled mouthguard technology and dynamic contrast-enhanced MRI to confirm the number and severity of head impacts that would result in “leaky” blood vessels within the brain. 

The researchers noted that while it is clear that concussive brain injuries cause clinical symptoms such as dizziness, nausea, and confusion, these symptoms all happen independent of any adverse findings on CT or MRI scans, and without the presence of any clear blood-based biomarkers. Therefore, it can prove challenging to clinically manage concussive brain injuries.

“Our findings for the first time suggest that repetitive head trauma can lead to an MRI signal that we can definitively link to the number and severity of impacts to the head,” said study lead Dr. Colin Doherty. “It appears that the repetitive nature of these impacts as opposed to single events are causing damage to the capillaries of the brain.”

The study reports that repetitive impacts to the head, not necessarily just concussions, are likely able to induce changes to the micro-vessels of the brain. It is these changes that are then readily visible when using a regular form of MRI-based images.

Co-author Professor Mick Molloy asks that sports authorities take note: “This study has highlighted the critical importance of continued efforts to study the underlying effects of concussive brain injuries in all sports. It is imperative that the governing bodies take note of these findings and work together to protect athletes now and in the future.”