Using cutting-edge scanning to peer into the brains of football players, Israeli scientists have discovered that even unremarkable cases of concussion can cause significant damage to the blood-brain barrier – and that the problem is not rare.
The blood–brain barrier is a complex structure that keeps the blood circulating the body separate from the brain, which confers the evolutionary advantage that nasties in your blood won't get into your brain. That is good.
The membrane does allow certain things to permeate, including gases, water and relatively smaller molecules such as glucose and amino acids. But when the barrier is breached, bacteria can merrily infest your brain. That is bad.
Now scanning by advanced magnetic resonance imaging noticed, for the first time, significant damage to the blood-brain barrier among pro football players right after “unreported” trauma or mild concussions.
Put otherwise, the barrier is leaking and their brains are therefore exposed to infection.
"Past studies had been based on standard questionnaires developed by the NFL. Players were asked if they'd taken a hit to the head and that sort of thing," says Dr. Alon Friedman of the Ben-Gurion University Brain Imaging Research Center, the discoverer of the new diagnostic.
But the "findings" from those questionnaires seemed dubious: they weren't reporting any more injuries than, say, volleyball players, Friedman chuckles.
"It isn't that the players were necessarily lying," he hastens to qualify. "But they may simply not be taking their injuries seriously." Also, they want to get back into the game, not be sidelined because of an ouchie to their head caused when one player jumps another.
In short, studies based on the NFL questionnaires proved pretty useless and until now there had been no methodology to gauge mild brain injury right days after trauma, explains Friedman: An objective gauge was needed, not the answer to "Did somebody bounce off your cranium".
"We suspect the problem is a combination – minor injuries that go unreported, but are repeated," says Friedman.
Published in the current issue of JAMA Neurology, this study could finesse the decision as to when an injured athlete should return to play, he points out. However, he qualifies that nobody knows how long the condition stays pathological.
The fact that sports, notably football, do no favors to the brain has long been clear. In September, the National Football League, itself admitted that it expects one in three pro footballers to develop long-term cognitive problems. Moreover, their functioning is likely to be impaired at an earlier age than the average for the general public, the NFL admitted in court, pursuant to being sued by 5,000 former players who still had the faculties to hire a lawyer.
Almost half suffer barrier breakdown
The paper, a collaboration of Ben-Gurion University of the Negev and Soroka University Medical Center, describes a new diagnostic approach using MRI for detection and localization of vascular pathology and blood-brain barrier breakdown in sports stars.
The use of Dynamic Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) generates more detailed brain maps, showing brain regions with abnormal vasculature – meaning their barrier is leaking, the team explains in its paper.
Their study was done on 16 Israelis belonging to the local football (not soccer) league, named "Black Swarm". The controls were 13 track and field athletes from Ben-Gurion University who don't normally fall on their heads. All underwent the newly developed MRI-based diagnostic.
The scans were done between games during the season and revealed significant damage.
Forty percent of the examined football players with unreported concussions had evidence of “leaky barriers” compared to 8.3 percent of the control athletes.
In short, the scientists showed a clear association between football and increased risk for blood-brain barrier pathology that hadn't been evident before, Friedman explains. "In addition, high-BBB permeability was found in six players and in only one athlete from the control group.”
Apparently not all players will develop the same problems from similar injuries, he added: evidently mild concussive events impact some players differently than others. But meanwhile, absent a means to detect damage from a mild concussion, today players may be returning to the game with unhealed brains.
A decade of research in the BGU Laboratory for Experimental Neurosurgery has shown that vascular pathology, specifically dysfunction of the blood-brain barrier, plays a key role in brain dysfunction and degeneration. It may lay a role in neurodegenerative complications after brain injuries, the university says.
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