Using a newly created brain imaging technique, researchers have discovered for the first time that professional football players whose mild concussions go unreported may still experience brain damage.
The research team, led by Prof. Alon Friedman of the Ben-Gurion University (BGU) of the Negev in Israel, publish their findings in JAMA Neurology.
According to the Centers for Disease Control and Prevention (CDC), traumatic brain injury (TBI) – including concussion – accounts for around 9% of all sports-related injuries, and the long-term brain damage associated with such injuries has been well documented.
Last year, for example, Medical News Today reported on a study revealing that concussions can cause abnormal brain wave activity and poor memory decades after injury. Another study found that even after mild concussion, brain abnormalities are evident months later.
But Prof. Friedman notes that while there has been growing concern about the long-term impact of repeated mild TBI on the brain, very little is known about the underlying mechanisms that cause long-term complications. He says this is due to a lack of diagnostic methods that allow detailed analysis.
With this in mind, the team created a new brain imaging method called Dynamic Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI), which they say highlights brain regions with abnormal vasculature, or damage to the blood-brain barrier (BBB) – a membrane that protects the brain from harmful chemicals.
According to the researchers, past studies have found that damage to the BBB is a primary cause of brain degeneration and may be a cause of brain complications following head injuries.
The researchers tested their new imaging technique on 16 players from Israel’s professional football team – called Black Swarm – between games during the season, as well as on 13 track and field athletes from BGU.
The team found that 40% of professional football players with unreported concussions had BBB damage, compared with only 8.3% of the athletes from BGU.
Explaining the findings further, Prof. Friedman says:
“The group of 29 volunteers was clearly differentiated into an intact BBB group and a pathological BBB group. This showed a clear association between football and increased risk for BBB pathology that we couldn’t see before. In addition, high-BBB permeability was found in six players and in only one athlete from the control group.”
Prof. Friedman points out that not all of the professional football players demonstrated BBB damage, suggesting that repeated mild concussions may affect some players more than others.
The researchers note that after a head injury, many players return to sports before their brains have had time to heal, which may increase the risk of more severe brain damage later in life. They hope their new brain imaging technique will help in deciding whether players are fit to return to play.
Earlier this year, MNT reported on a study suggesting that an injury to the top of the head may lead to more severe concussion than head injuries elsewhere.