Improving Accuracy of Concussion Tests Using Saliva

Written by Sarah Wornow ‘23
Edited by Geat Ramush ‘23

An estimated 3.8 million concussions occur annually as a result of professional or recreational sports [1]. Concussions are the most common type of traumatic brain injury, and the impacts of sustaining a concussion, including amnesia and loss of brain function, can last a lifetime [2]. Diagnosing a concussion can be a time-consuming process that usually involves a physical exam, cognitive testing, and an MRI or CT scan [3]. Even with various diagnostic tools, many sports concussion tests are unreliable and leave many concussions undiagnosed [4]. Part of this inaccuracy could be a result of most diagnostic tests (besides imaging tests) relying on the patient’s accounts of their symptoms, which could lead to an inaccurate description of the injury present.

In the past few years, there have been advances in developing non-invasive, molecular biology-based concussion tests. These tests could provide a biological standard of determining whether a person has a concussion, enabling increased diagnosing accuracy. Last year, for example, a rapid blood test was developed and cleared by the FDA that accurately diagnoses concussions by looking for specific blood markers prevalent in people with concussions. These tests have been approved for use during sporting events, and they rule out the need for CT scans [5].

In a similar way, researchers at the University of Birmingham have recently developed a rapid, non-invasive saliva test to diagnose concussions. The test only requires a sample of saliva from a patient with a suspected concussion, allowing for rapid testing that requires minimal lab equipment and no blood draws. 

In their study, the researchers used Next Generation Sequencing, a type of genome sequencing, to identify 14 small non-coding RNAs (sncRNAs) that were biomarkers for concussion. These biomarkers directly relate to concussion pathology, as the concentration of these molecules rapidly changes if the person is experiencing a concussion. 

The researchers narrowed their study to professional Rugby players in the UK, examining a total of 1,028 saliva samples. Samples from players were obtained before, during, and after games to serve as controls for the expression of these biomarkers and improve data accuracy [5]. The tests were performed throughout two rugby seasons, and at the end of both seasons, the researchers reported that the tests were 94% accurate in determining whether an individual had a concussion or not. These positive results pave the way to further explore saliva testing as a concussion diagnostic tool that relies on biological data.
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This test could potentially serve as a non-invasive method to diagnose concussions more accurately than the standard procedure, saving time and money. However, one important limitation brought up by the researchers was that they only tested professional male athletes, so generalizing the data may prove to be inaccurate. The researchers hope, however, that these tests can be utilized at the community level for sporting events, giving communities who lack health care resources used by professional athletes the necessary tools to accurately diagnose concussions.

References
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[1] Daneshvar D, Nowinski C, McKee A, Cantu R. The Epidemiology of Sport-Related Concussion. Clin Sports Med. 2010; 30. [Cited 2021 Apr 10] Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2987636/

[2] Tator, C. Concussions and their consequences: current diagnosis, management and prevention. CMAJ. 2013; 185, 11. [Cited 2021 Apr 10] Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3735746/#:~:text=Concussion%20is%20the%20most%20common,and%20can%20have%20serious%20consequences.

[3] Concussion. Mayo Clinic. [Internet] [Cited 2021 Apr 11] Available from: https://www.mayoclinic.org/diseases-conditions/concussion/diagnosis-treatment/drc-20355600

[4] Fuller G, Tucker R, Starling L, Falvey E, Douglas M, Raftery M. The performance of the World Rugby Head Injury Assessment Screening Tool: a diagnostic accuracy study. Sports Medicine- Open. 2020; 6, 2. [Cited 2021 Apr 10] Available from: https://sportsmedicine-open.springeropen.com/articles/10.1186/s40798-019-0231-y

[5] Abbott Receives FDA 510(K) Clearance For The First Rapid Handheld Blood Test For Concussions. Abbott. [Internet] [Cited 2021 Apr 11] Available from: https://abbott.mediaroom.com/2021-01-11-Abbott-Receives-FDA-510-k-Clearance-for-the-First-Rapid-Handheld-Blood-Test-for-Concussions#:~:text=TBIs%2C%20including%20concussions%2C%20are%20an,tool%20used%20to%20diagnose%20concussion.

[6] Di Pietro V, O’Halloran P, Watson C, Begum G, Acharjee A, Yakoub K, Bentley C, et al. Unique diagnostic signatures of concussion in the saliva of male athletes: the Study of Concussion in Rugby Union through MicroRNAs (SCRUM). British Journal of Sports Medicine. 2021; 0. [Cited 2021 Apr 11] Available from: https://bjsm.bmj.com/content/early/2021/02/09/bjsports-2020-103274

[7] Rugby study identifies new method to diagnose concussion using saliva. Science Daily. [Internet] [Cited 2021 Apr 10] Available from: https://www.sciencedaily.com/releases/2021/03/210323183823.htm