If you live in the United States, you have probably either attended a football game or watched one on television. In those games, you likely noticed the players getting tackled, taking hits, and falling in almost every single play. When those hits are hard enough, a player might get a concussion.
Concussions are diagnosed based on the evaluation of multiple organ symptoms, and once the patient reports that those symptoms have subsided, it is said that the patient has “recovered.” However, recent research indicates that repeated concussions and blows to the head can lead to brain damage, from which a patient does not recover.
From postmortem evaluations of the brains of football players, researchers have developed a term known as “chronic traumatic encephalopathy.” This describes the patterns of neurodegeneration that typically coincide with changes in cognition, mood, and behavior. Researchers now believe that chronic traumatic encephalopathy can be caused not only by concussions but also by repeated “subconcussive” blows to the head.
One of the difficulties is that up until recently, chronic traumatic encephalopathy could only be diagnosed postmortem. This makes earlier diagnosis and treatment impossible. However, new research indicates that an evaluation of the hearing brain may help researchers and medical professionals recognize symptoms of chronic traumatic encephalopathy at an earlier point.
In a recent study, researchers used an approach called frequency-following response (FFR). In this approach, the researchers are able to measure sound-evoked synchronous neural activity and brain health. They specifically tested the neural coding of the fundamental frequency of speech (F0). Because this response is involuntary, it removes the issue of whether patients report that they have recovered from any concussion symptoms.
This first study focused on children. The neural coding of F0 was acutely disrupted in children who had sustained concussions. However, it was also found that the neural coding of F0 improved as the children recovered, although it was still possible to classify children into concussion or control groups based on their responses with 90 percent accuracy.
In another study, 50 collegiate football players were tested using FFR. Half of these players had sustained a concussion within the last one to six years, while the other half had never had a concussion. Those who had sustained a concussion did not show any remaining symptoms at the time of the study.
Researchers found that the football players who had sustained a concussion had a weaker response to F0, performing at the 20th percentile. The football players who had never had a concussion displayed a stronger response, yet performed at the 40th percentile. Researchers hypothesize that this may be due to the cumulative effects of subconcussive blows to the head.
In order to determine the effects of both concussions and subconcussive blows, it is necessary to complete longitudinal studies of athletes through multiple seasons. With this data, we would better understand how blows to the head affect long-term brain health. This could also help researchers and athletes better understand the real risks to brain health associated with certain sports.
To learn more about the effects of concussions on the brain, especially the hearing brain, we welcome you to contact our audiology practice today. We look forward to getting to know you.