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Concussions: let’s get the diagnosis right!
Caralyn Baxter explores the topic of incorrect concussion diagnosis and argues that clinicians must avoid falling into the ‘head hit plus symptoms equal concussion’ mindset.
Concussion, once contact sport’s dirty little secret, is today’s injury buzzword. In the last 15 years, lawsuits filed against several large organizations, including the National Football League, spread awareness of concussion injuries among the general population. Media coverage of the topic also increased, making concussion the fear of every young football player. Why? Because concussion has become such a high-profile issue that even those slightly suspected of ‘getting their bell rung’ will assuredly be pulled out of play. While this increased awareness has led to positive legislative changes, and decreased the incidence of concussion injuries in many sports (including professional football), has the pendulum swung too far the other way (1)?
The risks related to repeated head trauma and concussions are real. What seems less apparent in the mainstream media (but is perhaps just as important) are the adverse effects seen with decreased sport participation and decreased physical activity as a result of fear of concussive injury. Concussion diagnosis is complex; there is no single objective test or measure that a clinician can use to diagnose or rule out this injury. Therefore, it is necessary to apply a comprehensive and thoughtful approach to all athletes to avoid a concussion misdiagnosis, which may lead to the unnecessary loss of sport participation and physical activity.
Not every hit to the head leads to a concussion
How often are we getting the diagnosis right? The increasing awareness and chance of concussion in contact sport risk an ‘autopilot approach’ to an athlete’s neurological status and brain health. That is, rather than taking a comprehensive medical history, including a review of the mechanism of injury, baseline health status, and family history, clinicians are all too often assuming that ‘head hit plus symptoms equals concussion’.
The problem with this approach is that the constellation of symptoms seen post-concussion are non-specific and may result in complex overlays with other neurological processes. For example, student-athletes with no known developmental or health problems and no prior history of concussion frequently report non-specific concussion-like symptoms in their daily lives, related to stress, depression or insufficient sleep(2).
Voormolen et al in 2019 surveyed 11,759 healthy subjects and found that 49.9% experienced fatigue regularly, 42.4% experienced sleep disturbance, and an estimated 30% of respondents reported forgetfulness or poor memory(3). Knowing that the general population experiences non-specific, concussion-like symptoms on a routine basis, habitually attributing symptoms following a head impact to concussion without first considering other variables may be detrimental to athletes in our care.
Headaches, in particular, can muddy the waters when evaluating an athlete’s neurological readiness to play. Up to 95% of sports-related concussions result in complaints of headaches(4); yet the presence of a headache should never automatically lead to a concussion diagnosis. As Eckner et al described in 2016(5):
“Given the significant overlap between symptoms of concussion and those of migraine headache, it is possible that in some cases, an athlete experiencing a migraine headache could be misdiagnosed with concussion. It is possible that the misclassification of posttraumatic headaches as concussion may spuriously inflate the strength of their association.”
To further muddy the waters, headaches can be attributed to a multitude of other conditions athletes routinely face, such as emotional distress, dehydration, and poor sleep. In fact, the diagnosis of ‘footballer’s migraine’ has been described in the medical literature for over 40 years(6). In a 2017 study, Kamins et al observed that patients frequently experience more persistent symptoms including, but not limited to, chronic migraines, anxiety, posttraumatic stress disorder, attention problems and sleep dysfunction(7). The researchers concluded that
“clinicians must determine whether these are premorbid maladies, downstream effects of concussion, unrelated phenomena or a true representation of ongoing concussion pathophysiology”.
This cautions clinicians not to pull athletes out of play and enroll in a concussion protocol just because headache symptoms present themselves.
Getting the diagnosis right
To avoid automatic attribution of neurological symptoms to a concussion injury, clinicians must first have an understanding of the foundational definition of a concussion. For a concussion to merit serious consideration, two things have to happen:
- There needs to be enough biomechanical force present to cause an injury to the brain.
- Symptoms need to be present(8).
The determination of these factors is meant to assist in the go/no-go decision-making process only – not to immediately diagnosis a concussion. In the presence of one or both of these factors, the athlete should be removed from the field of play and undergo an in-depth evaluation while also allowing sufficient time for a clinical presentation to clarify itself.
As Kutcher et al stated in a 2014 study,
“It is often impossible to diagnose concussion immediately following the biomechanical insult(9). The signs and symptoms of concussion may take several hours to develop or may not be noted by the patient until further cognitive or physical exertion is experienced.”
Thus, it is imperative to remain vigilant throughout the entire evaluation process, be attentive to confounding variables and comorbidities, and allow for diagnostic certainty to evolve along with the athlete’s presentation.
In the same study, Kutcher proposed a categorization to aid with the evolving diagnostic process and subsequent management (see table 1). This classification system helps clinicians avoid the reflexive approach of entering an athlete who reports neurological symptoms into a concussion protocol – a protocol that neither considers comorbidities nor adapts to reflect other possible diagnoses. This system allows for flexibility and consideration of confounding variables, resulting in a tailored rehabilitation strategy that prevents unnecessary loss of physical activity or athletic participation.
Table 1: Classification of concussion*(9)
*Used with permission.
Preventing activity loss
Preventing unnecessary loss of physical activity, fitness loss, and athletic participation averts the development of secondary symptoms and complications. The benefits of continued athletic activity far outweight the rapid deconditioning process that occurs when someone stops playing sports. In addition, athletic participation aids in the management of depression, anxiety, and ADHD(10, 11, 12).Moreover, routine physical activity enhances cognitive function and prosocial behavior(13).
When an athlete stops playing sport, even temporarily, the effects can be dramatic. After as little as three days of bed rest regularly exercising endurance athletes experience reductions in peak exercise performance and impaired neuroendocrine responses to graded exercise(14). In short, cessation of physical activity alone has adverse downstream social, cognitive, and physical effects – effects that are arguably as impactful to an athlete’s quality of life as a concussion injury diagnosis.
Given the harmful effects of removing an athlete from sport, an accurate concussion diagnosis is essential. As clinicians, we must ‘first, do no harm’ to athletes in our care, while also recognizing the dangers of sport participation when concussed. This means developing a comprehensive differential diagnosis and abandoning the linear approach that a hit head plus symptoms equal a concussion. Consider all variables that may contribute to an athlete’s neurological presentation and raise the bar on athlete brain health management.
- Concussion2016;1(4):CNC23. Published 2016 Sep 23. doi:10.2217/cnc-2016-0007
- Br J Sports Med 2017;51:941-948
- Brain Injury 2019, 33(8), 1078–1086
- J Athl Train. 2017;52(3):175–185
- Clin J Sport Med. 2017;27(3):266–270
- Br Med J. 1972;2(5809):326–327.
- Br J Sports Med.(2017) 51:935–40
- Br J Sports Med. (2017) 51:838–47
- Continuum Minneap Minn. 2014;20(6 sports neurology)1552–69
- Cochrane Database Syst Rev. 2013;(9):CD004366
- Ann Behav Med. 2015;49(4):542–556
- J Atten Disord. 2012;16(1):71-80.
- BMC Public Health. 2018;18(1):702
- Front Neurol. 2018;9:1115