Swedish researchers have found, through examining studies in sporting injuries, that a protein in the central nervous system could provide a tool for diagnosing concussions. They published their results in JAMA Neurology.
Concussion, sometimes referred to as mild traumatic brain injury, is reported to be a growing problem in contact sports, such as ice hockey, football and boxing. Concussion is when trauma - such as a blow to the head - induces a complex pathophysiological process in the brain.
People who are mildly concussed may feel dizzy and nauseous, and they may also have a headache and trouble remembering or concentrating on things. Severe concussion, however, will cause someone to become unconscious.
When someone is concussed, the neuronal and glial cells in their brain are damaged, which can impair brain function for days or weeks - or much longer in some cases. About 10-15% of concussion cases still display symptoms for more than a year after injury.
If a person continues to get concussions before their brain has recovered properly, then it can cause chronic damage to the brain that gets progressively worse. It is important that doctors are able to accurately judge when athletes are able to return to play, without risking further brain injury.
Biomarkers as diagnostic test for concussion severity
Previous studies have measured changes in the levels of protein biomarkers present in cerebrospinal fluid or blood in athletes who participate in contact sports.
Certain biomarkers - neuron-specific enolase, S-100 calcium-binding protein B, neurofilament light and total tau (T-tau) - have been shown to increase in boxers, correlating with the number and severity of head blows received. After a rest from boxing, these biomarkers return to normal levels.
The Swedish study set out to further investigate whether these biomarkers could be adopted as an accurate diagnostic test for concussion.
Previous studies have shown that biomarkers increase and correlate with the number and severity of head blows in boxers.
To do this, they measured post-concussion levels of these proteins in ice hockey players and compared them with levels in another group of hockey players who had not yet begun the hockey season.
Of the 288 players from the Swedish Hockey League who took part, the researchers analyzed 28 who received a sports-related concussion during the study period between September 2012 and January 2013.
From repeated blood testing, the researchers found that the concussed players had increased T-tau levels after concussion, compared with levels measured in the pre-season players.
The highest levels were found in the first hour after concussion. Though the levels declined over the 12 hours following concussion, they were still higher 6 days later than the levels in the pre-season players.
The researchers also found that the levels of T-tau were associated with the number of days that it took for the concussion to heal and for players to return safely to play.
Consequently, the researchers believe that T-tau blood tests could be a reliable tool for diagnosing concussion and making informed decisions on when a player is safe to return to competition.
In an editorial linked with the study, Joshua Gatson, PhD, of the University of Texas Southwestern Medical Center, and Dr. Ramon Diaz-Arrastia, of the Uniformed Services University of the Health Sciences in Maryland, write that the study "represents an important contribution to this field and introduces an innovative technology that promises to have wide applicability."
Medical News Today also recently reported on a study suggesting that football helmets may do little to protect against concussion.
"Future studies should address whether elevated plasma tau identifies athletes who have sustained multiple mild traumatic brain injuries and are at risk for developing chronic traumatic encephalopathy."