There is a new appreciation for concussions and the long-term effects they can have on younger adults. How can you really tell if you or your child had a concussion, and what would you do differently? A very cool study published in JAMA Neurology reveals a potential blood test for concussion. This matters because there is evidence that kids with sports-related concussions need to give their brains a rest by avoiding physical activity and abstaining from cognitive challenges such as reading, texting, or playing video games for several days. The brain heals faster that way.
Blood levels of a protein that signals damage to the axons in the brain, called total-tau (T-tau), could be used as a blood test to discern the severity of concussions in athletes and help decide when it is safe to return to play. The authors report that T-tau is a promising biomarker for the diagnosis and prognosis of concussion in athletes.
Hockey players were the subject of this study, which showed that players with sports-related concussions had higher levels of T-tau. The highest levels of T-tau (5 to 10 times normal) were measured immediately after the injury, then the levels continued to decline back to normal. Another key finding was that T-tau concentrations 1 hour after concussion predicted the number of days it took for the concussion symptoms to resolve and the players to return to play safely.
Why T-tau? The protein T-tau is usually found only in the cerebral spinal fluid (CSF), but gets into the bloodstream after concussion if the blood-brain barrier is damaged (yuck). So, raised levels are a marker of brain injury. You may remember hearing about T-tau because it is increased in the CSF in Alzheimer’s disease. In any case, more studies need to be done to sort out the usefulness of the blood test for T-tau to diagnose concussion, but it’s an interesting start.