INTRODUCTION:
The diagnosis of sports-related concussion is mainly based on subjective clinical symptoms and neuropsychological tests. Thus, reliable brain injury biomarkers to assess when it is safe to return to play are highly desirable. The overall objective of this study was to evaluate the utility of two newly described tau fragments for diagnosis and prognosis of sports-related concussions Materials and Methods: This multicenter prospective cohort study involved all 12 teams of the top professional ice hockey league in Sweden. A total of 288 players consented to participate in the study. Thirty-five players sustained concussions, of whom 28 underwent repeated blood samplings at 1, 12, 36, and 144 hours after the trauma, or when the player returned to play (7- > 90 days).

RESULTS:
There was no significant increase in the levels of tau-A in post-concussion samples compared with preseason values. However, serum levels of tau-C were significantly higher in post-concussion samples compared with preseason. Further, levels of Tau-A correlated with the duration of post-concussive symptoms.

DISCUSSION:
Tau-A in serum, which is newly discovered biomarker, could be used to predict when it is safe to return to play after a sports-related concussion