By Tamara C. Valovich McLeod, PhD, ATC, FNATA, Professor and Director, Athletic Training Programs, John P. Wood D.O. Endowed Chair for Sports Medicine Research Professor, School of Osteopathic Medicine in Arizona A.T. Still University
The Federal Drug Administration (FDA) published a press release Feb. 14 regarding the approval of a blood biomarker test for the detection of intracranial hemorrhage following traumatic brain injury. The media reaction to the press release resulted in headlines of “Concussions Can Be Detected With New Blood Test Approved by F.D.A” (New York Times) and “FDA Clears First Blood Test to Aid in Concussion Diagnosis” (www.medscape.com). Unfortunately, these headlines and the information contained in many of these media articles are not correct and provide a false sense of the state of biomarker science related to concussion.
Athletic trainers are experts in the diagnosis and management of sport-related concussion and will likely be called upon to discuss these headlines at their institutions or in their local communities. Therefore, understanding the facts regarding the FDA approval is important when communicating with other stakeholders.
There are several important facts that should be understood about the approved biomarker test that are relevant to the conversation. First, this test was not approved to diagnose concussion, sport-related or not. The biomarker is intended to detect the presence of two proteins that may suggest intracranial hemorrhage and was developed to assist emergency department providers in determining whether a CT scan is indicated. Indeed, if the markers are present a CT scan may be warranted, but the absence of the markers does not indicate or refute the presence of brain injury. The goal with the development of the biomarker is to reduce the need for unnecessary exposure to radiation that results from CT scans in patients with a suspected intracranial hemorrhage. With respect to sport-related concussion and imaging, the current body of evidence is clear that there is no imaging modality, including CT, that can diagnose or rule out concussion.1,2 Perhaps more importantly, even if the results of the biomarker test were negative, and may reduce suspicion of an intracranial hemorrhage, it would not rule out a concussion.
Second, this is not a sideline test. Results from the biomarker test can be made available to clinicians in three to four hours, which is often outside of the window in which athletic trainers are needing to make decisions regarding the removal of play for suspicion of concussion. Based on the numerous state laws and interscholastic or intercollegiate concussion policies, suspicion of concussion requires removal and evaluation by a licensed health care provider, which may include athletic trainers. As a result, the clinical exam remains the most important aspect in determining whether an individual has sustained a concussion.
Third, the biomarker test was approved for use in adults, 18 years of age and older. It is not approved for testing in children and adolescents, patient populations with whom many athletic trainers work. It is prudent to evaluate a younger patient with a suspected concussion with age-appropriate assessments.3
While this approval may be an important first breakthrough in our understanding of biomarkers related to brain injury and may lead to the development of tests for sport-related concussion in the future, it is important to keep in mind these facts about concussion form our most recent position and consensus statements. Concussion remains a clinical diagnosis determined by the mechanism of injury, on-field signs and patient-reported symptoms.1,4 While numerous studies are being conducted to assess the efficacy of advanced neuroimaging, fluid biomarkers and genetic testing to detecting alterations following concussion, these are primarily research tools and are not yet ready to be implemented into clinical practice.1,5 As a result, there is no need for athletic trainers to modify their existing concussion management practices. Athletic trainers should be following the recommendations set forth in the NATA Position Statement: Management of Sport Concussion4 and the most recent recommendations from the Concussion in Sport Group stemming from the 2016 Berlin conference.1
References
- McCrory P, Meeuwisse W, Dvorak J, et al. Consensus statement on concussion in sport-the 5th international conference on concussion in sport held in Berlin, October 2016. Br J Sports Med. 2017.
- McCrea M, Meier T, Huber D, et al. Role of advanced neuroimaging, fluid biomarkers and genetic testing in the assessment of sport-related concussion: a systematic review. Br J Sports Med. 2017;51(12):919-929.
- Davis GA, Anderson V, Babl FE, et al. What is the difference in concussion management in children as compared with adults? A systematic review. Br J Sports Med. 2017.
- Broglio SP, Cantu RC, Gioia GA, et al. National Athletic Trainers' Association position statement: management of sport concussion. J Athl Train. 2014;49(2):245-265.
- Kamins J, Bigler E, Covassin T, et al. What is the physiological time to recovery after concussion? A systematic review. Br J Sports Med. 2017;51(12):935-940.
