Concussions: Fundamental Frequency, Biomarkers, and Point-of-Care Testing

              Millions of concussions occur annually in the United States. These concussions can range in severity and can cause impacts ranging from changes in neurologic function to socioeconomic wellbeing, and sometimes the physical and neural effects may remain long after recovery (Kraus et al., 2016).

During Dr. Krizman’s talk at Loyola, she talks about her own research regarding concussions within athletes and children. She highlights the fact that there is no reliable test that can accurately identify a concussion and the range of its severity. Through her research, she has found that the auditory system could be a solution to diagnosing concussions.

Specifically, through Dr. Krizman’s research, her team focuses on the fundamental frequency of sound (F₀), which is the main cue for everyday listening (Kraus et al). The team tested this by playing a fundamental frequency at 100 Hz, and a harmonic frequency from 200-1000 Hz. It was found that children with concussions had difficulty hearing the F₀ in comparison to non-concussed children. Additionally, it was found that children in the concussed and non-concussed groups had the same reaction to the harmonic frequency, which demonstrates that F₀ is the target frequency for diagnosing concussions.

Through her research, Dr. Krizman concludes that children with concussions have worse neural processing compared to children without concussions. This finding is based on the neural processing of the F₀, and that the processing of the F₀ relates to the severity of the concussion (Kraus et al., 2016).

However, while this study had reliable results, it is important to highlight that the study was published nearly a decade ago in 2016. This means that during 2016 until now, there may have been advancements in technology for diagnosing concussions or severity. In 2025, Dr. Kurup et al (2025) published a paper regarding a review of concussion biomarkers and point-of-care testing in 2025.  

In this paper, Kurup et al. (2025) reviewed concussion biomarkers and point-of-care testing from the years 2022-2023 using the National Institute of Health database. The three main categories of diagnosis were neuroimaging, neurologic screening tools, and molecular and protein biomarkers.

Neuroimaging is known for identifying brain damage and the ability to diagnose the severity of brain damage (Kurup et al., 2025). Some of the most common neuroimaging is done with computed tomography and magnetic resonance imaging. However, since traumatic brain injury severity has a wide spectrum, it can be difficult to translate the collected data into clinical care.

Neurologic screening tools are different tests and assessments like a Concussion Challenge Assessment and Sports Concussion Assessment Tool 3. These are used for broad results but fall short when being able to identify concussion symptoms. Neurologic assessments are best used in multifactorial models where they are paired with other categories of diagnosis to have a more accurate outcome prediction for patients (Kurup et al., 2025).

Lastly, molecular and protein biomarkers are useful in point-of-care because they provide evidence of injury during specific detection windows. Examples of biomarkers are blood, saliva, and cerebrospinal fluid, which can offer insight into traumatic brain injuries at molecular levels rather than only relying on symptoms (Kurup et al., 2025). Additionally, some protein biomarkers are involved with the blood-brain barrier such as glial and axonal markers which can indicate multiple concussions or other brain injuries like necrosis. However, a limitation that was noted was that each patient has their own distinctive symptoms and biomarkers can present differently and mean something else to each individual (Kurup et al., 2025).

Together, it is important to conclude from Dr. Krizman et al.’s (2016) F₀ findings and Dr. Kurup et al.’s (2025) concussion biomarker and point-of-care testing review is that the most accurate and useful concussion evaluation is likely a multimodal, paired model. Krizman’s measure shows how an individual hears the fundamental frequency and how it changes when suffering from a concussion. On the other hand, Kurup’s review of neuroimaging, assessments, and biomarkers show evidence of injury and how to best develop a point-of-care. By combining both approaches, concussion diagnoses and recovery decisions could be optimized with molecular data related to diagnosis, injury severity, and patient treatment.

 

References

Kraus, N., Thompson, E., Krizman, J. et al. Auditory biological marker of concussion in children. Sci Rep 6, 39009 (2016). https://doi.org/10.1038/srep39009

Kurup MJ, Agrawal A, Temple SR, Galwankar S. Updated Review of Neurologic Concussion Biomarkers for Time-sensitive Point-of-care Testing. J Emerg Trauma Shock. 2025 Apr-Jun;18(2):74-89. doi: 10.4103/jets.jets_76_24. Epub 2025 Jun 19. PMID: 40666393; PMCID: PMC12258534.