One of the challenges with sport-related concussions for team doctors and neurologists is determining how long an athlete will have symptoms. Some athletes are symptom-free within a few days, while others can have headaches, dizziness and other symptoms for weeks.
One strategy for predicting return to play has included the use of baseline neurocognitive tests. Doctors compare the results of those tests to repeat tests after concussions have occurred. Visual and balance tests might become part of the post-injury testing. And evaluation by neurologists and psychologists and the use of neuropsychiatric tests can be appropriate as well.
Researchers at Penn have been studying levels of a particular protein in the blood after concussions. The brain-enriched protein is technically called calpain-cleaved αII-spectrin N-terminal fragment, or SNTF for short. SNTF levels are essentially undetectable when a patient’s brain is healthy, but the protein is produced with trauma to neural cells. The researchers presented their findings in a study recently published in the Journal of Neurotrauma.
Blood test for SNTF levels after concussions
Robert Siman, PhD, and others measured levels of SNTF in the blood of professional hockey players. 28 of the hockey players in their study suffered a concussion in the period monitored. The researchers drew blood regularly from the athletes to measure SNTF levels. In eight of the athletes, concussion symptoms resolved within a few days, while in 20 players, symptoms remained for six days or more.
In the 8 players whose symptoms resolved quickly, SNTF levels essentially remained at baseline. On the other hand, in the 20 athletes with concussion symptoms for six days or longer, serum SNTF levels rose significantly from one hour to six days after the injury. Between 12 and 36 hours after the concussion, SNTF levels were significantly higher in the athletes whose recoveries would be prolonged than in the players whose symptoms resolved quickly.
Essentially, serum SNTF levels appear to accurately diagnose concussions, and they might especially help predict which athletes would have delayed return to play.
“These results show that SNTF has promise as a blood biomarker for sports-related concussion and beyond. High blood levels of SNTF appear to identify acute brain damage that corresponds with persisting symptoms after concussion,” argued Douglas H. Smith, M.D., the study’s senior author.
It is critically important that we identify athletes with concussions and treat them appropriately. Holding an athlete out of competition until he is completely symptom-free can help decrease the risk of recurrent concussion and more severe brain injury.
I’ve written many times about different efforts that can help predict concussion severity and resolution of symptoms. The use of neuropsychiatric tests is key, and some of the newer assessments may help as well. And without a doubt, athletes letting doctors, athletic trainers and coaches know that they’re experiencing symptoms is crucial.
A blood test, whether it’s serum SNTF or another one to be determined in the coming years, can only help. Ideally doctors would assess an injured athlete in an emergency room or clinic, perform neuropsychiatric tests, and yes, draw blood to help predict when the athlete might be able to return to play.
Siman R, Shahim P, Tegner Y, Blennow K, Zetterberg H, Smith DH Dr. Serum SNTF Increases in Concussed Professional Ice Hockey Players and Relates to the Severity of Post-Concussion Symptoms. J Neurotrauma. 2014 Nov 24. [Epub ahead of print]