Newslink: New Blood Test COULD Predict Concussion Recovery Time

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I posted recently about work on a new EEG based method for quicker identification of whether an athlete (or anyone for that matter... for those of us who regularly hit our heads!) has a concussion. This technology looks very promising however it still has a big hole in it. How do we know when our brains have fully recovered from the trauma? How do we know when an athlete is truly ready to return to the game?

We are still reliant largely on behavioral symptoms for identifying when the brain has healed enough. Knowing how accurate diagnosis of concussions are in the first place (not very) this should leave you wanting a better test. Well we may all be in luck, a new blood test screening for a brain protein called tau may be able to help!

What is Tau?

Those of us familiar with Alzheimer's disease may recognize the name of that protein as along with the beta amyloid protein, the tau protein is directly involved in Alzheimer's. Tau proteins are involved in stabilizing microtubules (microtubules are protein complexes which form the cellular cytoskeleton and help cells maintain their shape), and are the main component in the formation of neurofibrillary tangles which are characteristic of the disease.

Alzheimer's is not the only reason why neurofibrillary tangles can form, another cause is repeated traumatic brain injury (like concussions for example). In addition to that, it has been reported that high levels of tau protein result in poor recovery from brain injuries like concussions.

How Do Blood Tests Come Into Play?

Well in the research article, the authors took blood samples from 600 american football players at the start of their season. Over the course of the season 46 of those players had concussions, and the researchers collected additional blood samples from them at various times in order to compare the level of tau proteins present after the concussion. What was found was that those concussed athletes who weren't cleared to play for the longest also were likely to have the highest concentration of tau proteins in their blood.

The blood test is far from perfect

The test only had an 81% success rate at predicting whether or not a player would be able to return to playing with in 10 days of a concussion. Not stellar results by any means. Part of the difficulty comes from the fact that tau is a brain protein and these experiments were looking at standard blood. The levels of tau present in the blood are only an indicator of what it may be in the brain and may not reflect what is happening there with 100% certainty (dependant on the ability of tau to cross the blood brain barrier). Still, sampling brain fluids is a very difficult procedure, and certainly not something that most people would like to see happening on the sidelines of a sporting event. So additional work needs to be done to improve this assay before it will be ready for real use.

For more information check out the article from sciencemag.org here:

http://www.sciencemag.org/news/2017/01/blood-test-could-predict-recovery-time-after-concussions

OR check out the primary article here:

http://www.neurology.org/content/early/2017/01/06/WNL.0000000000003587

Additional Sources

https://www.ncbi.nlm.nih.gov/pubmed/12214129
http://www.sciencemag.org/news/2017/01/blood-test-could-predict-recovery-time-after-concussions
https://en.wikipedia.org/wiki/Neurofibrillary_tangle
https://en.wikipedia.org/wiki/Microtubule
http://www.theverge.com/2013/10/16/4842176/what-causes-impact-concussion-test-forms-unreliability
http://www.mayoclinic.org/tests-procedures/eeg/basics/definition/prc-20014093
http://brain.oxfordjournals.org/content/135/4/1268