Evidence based management of sports related concussion

In the article “Return to Play After Concussion: Clinical Guidelines for Young Athletes” [1] from the December 2019 issue of Journal of the American Osteopathic Association, Drs Berry and Wacker detailed a management strategy for sports related concussion (SRC). However, the approach proposed by the authors contradicts current expert recommendations and evidence based practice guidelines [2], [3], [4] for the treatment of SRC. Therefore, we provide this Commentary as an accurate update regarding evidence based recommendations for the management of SRC.

The most current statements that are often cited and utilized to standardize comprehensive, multidisciplinary care for the treatment of SRC include a consensus statement from the the 5th International Conference on Concussion in Sport held in Berlin in October 2016 [3] and the American Medical Society for Sports Medicine’s Position Statement on Concussion in Sport [2]. These consensus statements provide overviews of the definition of SRC, including the etiology and pathophysiology of the injury; guidelines for appropriate diagnosis, evaluation, and management of SRC; SRC clinical domains; the role of various therapy modalities and neuropsychiatry in the management of SRC; and risks and long term sequelae of SRC.

In brief, SRC is defined as “a traumatically induced transient disturbance of brain function that involves a complex pathophysiological process” [2]. The pathophysiology of SRC is not completely understood, but has its basis in a traumatic stretching of neuronal cell membranes and axons within the brain resulting in an intricate cascade of ionic, metabolic, and pathophysiological factors [5]. Presenting symptoms of concussion generally include headaches, mood changes, mental fogginess, dizziness, visual changes, fatigue, and neck pain [6]. SRC is a clinical diagnosis that should be made via physical examination and supported with a validated clinical tool. The most recommended SRC concussion evaluation tool is the Sport Concussion Assessment Tool-5th Edition (SCAT-5) [7], which consists of guidelines for on field assessment, the Maddocks memory assessment questions, symptom checklist, cognitive screening, and neurological screening [6], [, 7]. In order to facilitate sideline evaluation of an acute injury for diagnosis of concussion, preseason baseline screening for athletes participating in sport is generally recommended [3, 8, 9]. Often, healthcare providers managing patients with SRC may find that patients who present to the clinic for evaluation do not have previous baseline/sideline evaluation information to lend insight into the patient’s baseline functional status. If that is the case, a symptom checklist is still recommended, and the patient should still be evaluated using the aforementioned process [6], [, 7]. When it comes to evaluation and diagnosis of SRC, the earlier the patient can enter a treatment and recovery phase, the better. Patients who present later in the course of SRC (8 days or longer) tend to have prolonged recovery, particularly in the pediatric population [10], [, 11].

When an athlete shows any signs of having a concussion, the current recommendations state that the player should be removed from competition and immediately evaluated by a physician or other licensed healthcare provider on site [2], [, 3]. If no urgent first aid issues or cervical spine injury are present, evaluation on the sideline with SCAT-5 is appropriate. If an athlete is suspected of having a concussion, they should not be allowed to return to sport on the day of injury. Rather, the athlete should be removed from competition and monitored closely for any deterioration in status [3]. Serial examination and symptom checklists, like the one found in the SCAT-5 [7], should be administered. Eventually, a graduated return to play (RTP) protocol should be followed before allowing an athlete to participate in competition again [12].

Concussion grading systems have largely fallen out of favor and do not have evidence based clinical utility [13], as the nuanced nature of SRC diagnosis was not fully appreciated when they were issued. The AMSSM consensus statement [2] proposes a domain driven diagnostic paradigm that encourages a management strategy customized to each patient with SRC. We also encourage readers to consult the figure in AMSSM’s consensus statement [2] that offers a comprehensive visual display of SRC domains: cognitive, vestibular, ocular, headache/migraine, anxiety/mood, and fatigue.

Once the diagnosis of SRC is made, management should proceed under the direction of “healthcare professionals with appropriate training and experience.” [2] A multidisciplinary team contributing to care of patients with SRC is encouraged, with neuropsychological evaluation taking a central role [4]. Various therapy modalities, including physical therapy, vestibular therapy, cognitive behavioral therapy, neurocognitive rehabilitation, ocular rehabilitation, and speech therapy can be involved in the treatment of SRC, should the patient’s clinical scenario warrant it [2, 3, 14].

In addition to cross disciplinary team input in SRC patient rehabilitation, brief relative rest for 24–48 hours following the inciting trauma is recommended, followed by a gradual increase in activity while “staying below their cognitive and physical symptom exacerbation thresholds.” [3] Activity based rehabilitation of SRC has been detailed in the Buffalo Concussion Treadmill Test and the Buffalo Concussion Bicycle Test protocols, which demonstrated improved recovery from SRC with the implementation of exercise at a submaximal symptom exacerbation threshold [15], [16], [17], [18].

It is unclear what the window of recovery is for SRC, though most adult patients will recover in 10–14 days [19], while children may take longer, with recovery time often longer than four weeks [20]. Comorbidities such as learning disorders, attention deficit hyperactive disorder, migraine disorder, and other preexisting behavioral concerns have been linked to prolonged recovery from concussion in children as well [21], [22], [23], [24]. As mentioned previously, a graduated RTP protocol such as the one included in the AMSSM statement and adapted in Table 1 should be followed prior to allowing an athlete to return to full competition.

Proposed long term sequelae of repeated SRC or subconcussive impacts include cognitive impairment, chronic traumatic encephalopathy (CTE), mental illness, depression, or suicide [25]. CTE as a pathologic diagnosis has a proposed definition of progressive tau protein deposition in the perivascular region that tends to appear in the depths of sulci in the cerebral cortex [26]. No definitive link between repeated subconcussive blows to the head/SRC and the subsequent progression to CTE has been established in the current literature; however, the existing evidence is concerning [25, 27, 28]. It is also possible that studies on CTE in professional athletes may be confounded by multiple medical comorbidities that impact the phenotypic expression of this disorder [29]. In addition, prior studies have suggested that a dose or exposure effect may exist [30], [, 31]. While the neuropathologic features of CTE are progressively becoming more well defined, the clinical features of CTE have yet to evolve to the same level of specificity [26, 32, 33]. To quote the Berlin consensus statement on concussion, “There is much more to learn about the potential cause and effect relationships of repetitive head impact exposure and concussions.” [3] Such work on the clinical picture of CTE-Traumatic Encephalopathy Syndrome is ongoing, including discussions of proposed research criteria.

This Commentary is not meant to replace or contradict the consensus statements referenced herein. Those statements and guidelines are considered the gold standard for diagnosis and management of SRC. Rather, this Commentary is meant to be a brief, noncomprehensive summary of the available evidence to better inform healthcare providers in the management of SRC and allow them to recognize the better resources available to them.