Due to differences in modalities , time course , study design and outcomes , it is not possible to define a single ‘ physiological time window ’ for SRC recovery .
Multiple studies suggest physiological dysfunction may outlast current clinical measures of recovery , supporting a buffer zone of gradually increasing activity before full contact risk .
Aim or objective The aim of this study is to consoli date studies of physiological measures following sport-related concussion ( SRC ) to determine if a time course of postinjury altered neurobiology can be outlined .
This biological time course was considered with respect to clinical ly relevant outcomes such as vulnerability to repeat injury and safe timing of return to physical contact risk .
Subject-Specific Increases in Serum S-100B Distinguish Sports-Related Concussion from Sports-Related Exertion
Background The on-field diagnosis of sports-related concussion ( SRC ) is complicated by the lack of an accurate and objective marker of brain injury . Purpose To compare subject-specific changes in the astroglial protein , S100B , before and after SRC among collegiate and semi-professional contact sport athletes , and compare these changes to differences in S100B before and after non-contact exertion . Study Design Longitudinal cohort study . Methods From 2009–2011 , we performed a prospect i ve study of athletes from Munich , Germany , and Rochester , New York , USA .  Serum S100B was measured in all SRC athletes at pre-season baseline , within 3 hours of injury , and at days 2 , 3 and 7 post-SRC . Among a subset of athletes , S100B was measured after non-contact exertion but before injury . All sample s were collected identically and analyzed using an automated electrochemiluminescent assay to quantify serum S100B levels . Results Forty-six athletes ( 30 Munich , 16 Rochester ) underwent baseline testing . Thirty underwent additional post-exertion S100B testing . Twenty-two athletes ( 16 Rochester , 6 Munich ) sustained a SRC , and 17 had S100B testing within 3 hours post-injury . The mean 3-hour post-SRC S100B was significantly higher than pre-season baseline ( 0.099±0.008 µg/L vs. 0.058±0.006 µg/L , p = 0.0002 ) . Mean post-exertion S100B was not significantly different than the preseason baseline . S100B levels at post-injury days 2 , 3 and 7 were significantly lower than the 3-hour level , and not different than baseline . Both the absolute change and proportional increase in S100B 3-hour post-injury were accurate discriminators of SRC from non-contact exertion without SRC ( AUC 0.772 and 0.904 , respectively ) . A 3-hour post-concussion S100B > 0.122 µg/L and a proportional S100B increase of > 45.9 % over baseline were both 96.7 % specific for SRC . Conclusions Relative and absolute increases in serum S100B can accurately distinguish SRC from sports-related exertion , and may be a useful adjunct to the diagnosis of SRC
Due to differences in modalities , time course , study design and outcomes , it is not possible to define a single ‘ physiological time window ’ for SRC recovery .
Multiple studies suggest physiological dysfunction may outlast current clinical measures of recovery , supporting a buffer zone of gradually increasing activity before full contact risk .
Aim or objective The aim of this study is to consoli date studies of physiological measures following sport-related concussion ( SRC ) to determine if a time course of postinjury altered neurobiology can be outlined .
This biological time course was considered with respect to clinical ly relevant outcomes such as vulnerability to repeat injury and safe timing of return to physical contact risk .