Concussions among amateur and professional athletes who play competitive contact sports such as football and ice hockey have received a great deal of attention recently. Now, researchers believe they have found a protein detectable in blood that could be used to help rapidly diagnose a concussion, leading to better management of those affected.
A concussion, caused by a bump or blow to the head, is a type of traumatic brain injury (TBI). The brain is made of soft tissue that is cushioned by spinal fluid and surrounded by a hard skull. This allows the brain to move around inside the skull and even bang against it, which can lead to bruising, tearing of blood vessels, and injury to the nerves. That in turn can lead to a concussion, a temporary loss of normal brain function. Studies have shown that TBIs can have a long-lasting impact on cognitive abilities, including the development of dementia.
The signs and symptoms of concussions can be subtle and may not be immediate, varying from headache and confusion to loss of consciousness. This makes it difficult for health practitioners and coaches to determine when it is safe to return an athlete to play following a heady injury. A blood test that can detect a concussion would speed up diagnosis and allow more rapid treatment of the condition.
Researchers in Sweden recently reported that a blood test for a structural protein in the brain called tau (total tau or T-tau) shows promise as a test for concussions. The study analyzed blood levels of T-tau taken from a sample of Swedish Hockey League players who had concussions during the 2012-2013 season. The samples were tested at 1, 12, 36, and 48 hours following their injury as well as 6 days after the injury or when they returned to unrestricted competition.
Results showed that the injured players had significantly increased levels of T-tau compared with pre-season levels. The highest levels of T-tau were found in players at the first hour after a concussion. Values declined during the next 12 hours but remained elevated 6 days later when compared with pre-season samples. The T-tau level one hour after a concussion was also associated with the number of days it took for concussion symptoms to resolve and for players to be safely cleared for play.
The study also evaluated two other biomarkers, S-100 calcium-binding protein B (S-100B) and neuron-specific enolase (NSE), but found them to be less promising. While T-tau needs to be evaluated in larger studies, it raises hope that health practitioners may in the future be able to use blood tests to manage head injuries and make return-to-play decisions following a concussion.
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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.
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