Previous studies have found that certain proteins in the blood are associated with concussion or recovery time. These include tau protein, neurofilament light chain protein (Nf-L), and glial fibrillary acidic protein (GFAP). An NIH research team tested whether these three proteins could be used as biomarkers to predict length of recovery time. They studied 127 male and female collegiate athletes. Researchers took blood samples from the athletes shortly after their injuries, when their symptoms resolved, and one week after returning to play. Each athlete also had preseason, baseline blood testing.
Two of the proteins were associated with the length of time needed by the athletes to return to play: tau and GFAP. Athletes who needed less than two weeks of recovery time had significantly higher tau within the first 48 hours after an injury. In contrast, GFAP was significantly lower for these athletes. Nf-L was not linked with the length of time needed for recovery.