The secret to reliably diagnosing concussions lies in the brain’s ability to process sound, according to a new study by researchers from Northwestern University’s Auditory Neuroscience Laboratory. The groundbreaking research, to be published Dec. 22 in the journal Nature, Scientific Reports, has found a biological marker in the auditory system that could take the ambiguity and controversy out of diagnosing concussions and tracking recovery. 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.
Kraus and colleagues 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 percent of children with concussions and 95 percent of children in the control group who did not have concussions. Children who sustained concussions had on average a 35 percent 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. “With this new biomarker, we are measuring the brain’s default state for processing sound and how that has changed as a result of a head injury,” Kraus said. “This is something patients cannot misreport, you cannot fake it or will your brain to perform better or worse.”