New concussion biomarker may lead to better diagnosis

The secret to reliably diagnosing concussions lies in the brain's ability to process sound, according to a "groundbreaking" research which has found a biological marker for the traumatic brain injury.
Widely considered a crisis in professional sports and youth athletic programmes, sports-related concussions have had devastating neurological, physical, social and emotional consequences for millions of athletes, researchers said.
Still, no single test has been developed to reliably and objectively diagnose concussions.
The groundbreaking research by Northwestern University in the US has found a biological marker in the auditory system that could take the ambiguity and controversy out of diagnosing concussions and tracking recovery.

"This biomarker could take the guesswork out of concussion diagnosis and management," said Nina Kraus, Professor at Northwestern University's Auditory Neuroscience Laboratory.
"Our hope is this discovery will enable clinicians, parents and coaches to better manage athlete health, because playing sports is one of the best things you can do," said Kraus.

Concussions, a type of mild traumatic brain injury, are the result of a direct or indirect blow to the head that causes the brain to be jostled within the skull.
However, there is little relation between the force of an impact and the potential for injury - two athletes can suffer similar hits but experience vastly different outcomes.

By observing research subjects' brain activity as they were exposed to auditory stimuli, Kraus and her team discovered a distinct pattern in the auditory response of children who suffered concussions compared to children who had not.
They placed three simple sensors on children's heads to measure the frequency following response, which is the brain's automatic electric reaction to sound.
With this measure, researchers successfully identified 90 per cent of children with concussions and 95 per cent of children in the control group who did not have concussions.
Children who sustained concussions had on average a 35 per cent smaller neural response to pitch, allowing the scientists to devise a reliable signature neural profile.

As the children recovered from their head injuries, their ability to process pitch returned to normal.
"Making sense of sound requires the brain to perform some of the most computationally complex jobs it is capable of, which is why it is not surprising that a blow to the head would disrupt this delicate machinery," Kraus said.
What was surprising, Kraus said, was the specificity of the findings.
"This isn't a global disruption to sound processing. It is more like turning down a single knob on a mixing board," she added.
The research was published in the journal Nature Scientific Reports.