According to new research published in the journal Scientific Reports, the secret to reliably diagnosing concussions lies in the brain’s ability to process sound.
Kraus et al show that children who sustained a concussion exhibit a signature neural profile. Image credit: Pete Linforth.
“Concussions — diffuse, non-penetrating brain injuries following sudden impact — are a public health crisis,” the researchers said.
“An estimated 1.6–3.8 million sports-related traumatic brain injuries occur annually in the United States, and concussions potentially devastate cognition, socioemotional wellbeing, academic achievement, and neurologic function, even after symptoms resolve.”
“Despite widespread scientific and public interest, no single test has been validated to reliably diagnose a concussion; instead, the gold standard for diagnosis remains clinical determination by a physician who must weigh a constellation of symptoms across multiple organ systems.”
The authors have 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 Prof. Nina Kraus, Director of the Auditory Neuroscience Laboratory at Northwestern University and lead author on the study.
“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.”
By observing research subjects’ brain activity as they were exposed to auditory stimuli, Prof. Kraus and co-authors discovered a distinct pattern in the auditory response of children who suffered concussions compared to children who had not.
The researchers 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 they successfully identified 90% of children with concussions and 95% of children in the control group who did not have concussions.
Children who sustained concussions had on average a 35% 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,” Prof. Kraus said.
“What was surprising was the specificity of the findings. This isn’t a global disruption to sound processing. It’s more like turning down a single knob on a mixing board.”
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Nina Kraus et al. 2016. Auditory biological marker of concussion in children. Scientific Reports 6, article number: 39009; doi: 10.1038/srep39009
