Research published by American Academy of Neurology shows that elevated levels of certain biomarkers can help to predict concussion recovery times.

Researchers matched 41 high school and college American footballers, who experienced concussion during a full season, with 43 players of the same age and ability who did not.

None of the players fell out of consciousness with their concussions.

All of the participants had blood tests at the beginning of the season. Those with concussion had blood tests within six hours of the injury, then again 24 to 48 hours later – and also eight, 15 and 45 days later. Those who did not have concussion had tests at similar times for comparison.

Seven biomarkers for inflammation were chosen because of their relation to more severe head injuries. Two of them – interleukin 6 and interleukin 1 receptor antagonist – increased in concentration six hours after a concussion in comparison to the athletes with no concussion.

Notably, interleukin 6 levels rose exponentially from 0.44 picograms per millilitre (pg/ml) at the beginning of testing up to 1.01 pg/ml six hours after the concussion.

Interleukin 6 levels in those who did not suffer a concussion remained stagnant from the previous levels, 0.40 pg/ml to 0.39 pg/ml.

Study author Timothy Meier, of the Medical College of Wisconsin in Milwaukee, said: “These results demonstrate a meaningful increase in the levels of Interleukin 6 for athletes who sustained a concussion compared to athletes who did not.

“Athletes with higher levels of interleukin 6 six hours after the injury were also more likely to take longer to recover from their symptoms. Overall, the athletes with concussions had symptoms for an average of 8.9 days.