Researchers studied professional ice hockey players in Sweden from 12 teams during the 2012-2013 season. Forty-seven players underwent blood testing prior to the start of the season; 35 of them had a concussion during the season. Of those players, 28 underwent repeated blood testing at 1, 12, 36, and 144 hours after the event, as well as when they returned to play.
Researchers tested the blood samples for biomarkers known as total tau and S-100 calcium-binding protein B. Players who had concussions had increased levels of biomarkers compared with pre-season values. The highest biomarker concentration in the blood was measured immediately after a concussion, and the levels decreased during rehabilitation.
Approximately 1.6 million to 3.8 million sports-related concussions occur annually in the United States. During the last decade, doctor visits for sports and recreation-related brain injuries, including concussions, increased by 60 percent. Sports-related concussions are often tough to appropriately diagnose.
Also, the decision about when to return to play remains a challenge for clinicians. Currently, the diagnosis of concussion is often missed as the criterion is based on clinical findings only, and imaging is typically normal. There is no objective marker that that can confirm diagnosis. These findings will aid clinicians in making an acute diagnosis and in the decision making process about return to play after sports-related concussion.