The blood-brain barrier (BBB) is a specialized interface between the blood and the brain environment that prevents the transfer of unwanted molecules or infectious organisms from the blood to the brain. Evidence shows that breaching the integrity of this barrier causes many brain diseases and neurodegeneration as a result of aging.
"Since a leaky BBB is also found in CTE and causes brain dysfunction and degeneration, it now seems that this test could provide the first (and so far the only) evidence for brain injury in the players we studied on the Israel football team," says Prof. Alon Friedman, M.D., a neurosurgeon and researcher at BGU and Dalhousie University in Canada.
"Importantly, we believe that those with persistent leak encompassing months or years are more likely to develop CTE. Many players seem to repair their BBB quickly, and if they do not suffer from repeated TBIs [traumatic brain injuries] or are not sensitive to brain injury, they are not likely to develop CTE."
The researchers developed a modified dynamic contrast-enhanced-MRI (DCE-MRI) protocol and analytical methods to investigate vascular pathology and blood-brain barrier disorder (BBBD) associated with repeated mild TBI in American football players. For the first time, using human brain imaging, they distinguished between fast and slow leakage through the pathological BBB and showed that localized, specific post-traumatic vascular pathology may persist for months in a subset of players.
"We generated maps that visualized the permeability value for each 3D section (voxel)”, Prof. Friedman says. "Our permeability maps revealed an increase in slow blood-to-brain transport in a subset of amateur American football players, but not in the control group. The increase in permeability was region specific (white matter, midbrain peduncles, red nucleus, temporal cortex) and correlated with alterations in white matter tracts. Importantly, increased permeability persisted for months, as seen in players who were scanned both on- and off-season."
"Not less important is the observation that few players who did not complain of severe symptoms also showed a leaky BBB. This suggests that DCE-MRI should be used in conjunction with symptom questionnaires before return to play is approved."
MEDICA-tradefair.com; Source: American Associates, Ben-Gurion University of the Negev
