A test being developed by Cleveland Clinic researchers can detect increased serum levels of the protein S100B indicating blood-brain barrier disruption (BBBD) in football players who experience head hits below the diagnostic threshold for a concussion. Additionally, according to the study published online March 6 in PLOS One, there is evidence supporting a potential link between elevated S100B levels and future risk for cognitive changes. Sixty-seven volunteers from three college football teams were studied. None of the players experienced a concussion in the games analyzed. A review of filmed game footage and post-game interviews documented head hits. Complete season data were available for 15 players including blood samples drawn before and after five games. S100B serum levels and S100B auto-antibodies were measured with direct and reverse immunoassays. Multiple magnetic resonance imaging (MRI)-diffusion tensor imaging (DTI) scans and cognitive assessments were also performed in a subset of players. The researchers found that nine players experienced an above BBBD threshold post-game increase in serum S100B. The ceiling for changes indicative of BBBD on this test, the authors say, is 0.12 ng/ml. Transient, increases in serum S100B (post-game compared to baseline) were detected only in players experiencing the greatest number of subconcussive head […]
A test being developed by Cleveland Clinic researchers can detect increased serum levels of the protein S100B indicating blood-brain barrier disruption (BBBD) in football players who experience head hits below the diagnostic threshold for a concussion. Additionally, according to the study published online March 6 in PLOS One, there is evidence supporting a potential link between elevated S100B levels and future risk for cognitive changes.
Sixty-seven volunteers from three college football teams were studied. None of the players experienced a concussion in the games analyzed. A review of filmed game footage and post-game interviews documented head hits. Complete season data were available for 15 players including blood samples drawn before and after five games. S100B serum levels and S100B auto-antibodies were measured with direct and reverse immunoassays. Multiple magnetic resonance imaging (MRI)-diffusion tensor imaging (DTI) scans and cognitive assessments were also performed in a subset of players.
The researchers found that nine players experienced an above BBBD threshold post-game increase in serum S100B. The ceiling for changes indicative of BBBD on this test, the authors say, is 0.12 ng/ml. Transient, increases in serum S100B (post-game compared to baseline) were detected only in players experiencing the greatest number of subconcussive head hits. Players receiving a maximum score of 6 on the Head Hit Index (HHI) had a significantly higher level of S100B (post-game compared to baseline) than players with an HHI of 0. There was no correlation between serum S100B elevation and the number of body contacts or hits. Similarly, players who remained on the sideline had significantly lower measures of S100B than players who experienced head hits.
Auto-antibodies to S100B (an immune response triggered by BBBD) were also only elevated after repeated subconcussive events. Serum levels of S100B auto-antibodies predicted persistence of MRI-DTI abnormalities, which in turn, the authors report, correlated with cognitive changes.
“The clinical significance of elevation of S100B, and therefore of BBBD, measured in players who are not diagnosed with a concussion remains unclear. Our findings show that elevations in S100B correlated with the occurrence of head hits and their intensity,” write the authors, led by Nicola Marchi, Ph.D., from the Cleveland Clinic in Ohio. “This suggests that BBBD follows repeated non-concussive episodes during a game. Thus, S100B may be useful to objectively quantify risk for subsequent pathological sequelae.”
