Recent studies [1–6] have given us a much clearer understanding of the natural history of concussion. We have begun to realize the need to individualize treatment and move away from rote category, guideline, and management strategies.
We now know more completely what we agree upon and what we disagree with. By applying evidence-based information and outcome data, we are beginning to think independently again, yet base return-to-play decisions on more than just our experience.
Many head injuries are easily managed and are not controversial. Others, unfortunately, can be conundrums. It becomes more important to highlight common problematic areas, as illustrated by the case that follows.
This case involves an 18-year-old high school football quarterback, an all-state candidate, and a member of his school's National Honor Society. This young athlete has played football all of his life, and, with the exception of a sprained ankle in 8th grade, has never been injured. He desires to attend medical school eventually and is expected to become a first-year student at an Ivy League school next fall.
It should be noted that although there has been no significant past medical history, the patient was briefly treated for attention deficient hyperactive disorder as an 8-year-old until the age of 9.5 years, when therapy was discontinued. In the 10th football game of the current season, the team's first state playoff game (regular season record 9-0), the head injury occurs.
With 8 minutes to play in the second quarter of the football game, the athlete is tackled while setting up to pass (blind-sided by a linebacker blitz). He is hit hard and unable to protect his helmeted head, which hits the natural grass turf. The referee calls an injury time out when the player fails to get up after the play. This allows the medical doctor and the high school trainer to attend to him on the playing field. There apparently was brief loss of consciousness, the athlete “awakening” as the doctor arrives at his side. The examination on the field shows immediate disorientation and disequilibrium to the point of needing assistance to get off the football field.
There is no evidence of retrograde amnesia. The follow-up examination on the sidelines continues to show disorientation with the loss of the ability to remember plays and an inability to successfully perform the “months of the year in reverse” test. There is also a loss of immediate memory using a three-word recall. The patient complains of a slight headache, but there are no vision changes. Other questions asked of him simply validate his disorientation.
A second examination conducted 5 minutes later is basically unchanged. At 10 minutes following the injury, a third examination shows evidence of nearly complete resolution of all symptoms and signs. However, on a “head shake” test, headache and vertigo occur. At this point, with 2 minutes remaining before the half, he is benched through half-time. The score at half-time is 17-10 in favor of the opponent.
This athlete's skills are clearly missed by his team. The examination at half-time (approximately 20 minutes after the onset of injury) results in a conclusion that he is once again clear of all signs and symptoms. A repeat head shake test is normal and he is allowed to return to play.
With his return to play, he leads his team to victory in spite of a below-average performance in the third quarter. Signs and symptoms do not return during any serial examinations, including a postgame examination.
The next day, he is seen in the training room where he complains of a slight headache and some photophobia. Neuropsychologic [NP] testing is performed at this time (less than 24 hours after the injury). Results are significant for decreased memory composite score and executive function. He is not allowed to practice on Monday (postinjury day 3). Repeat NP testing is conducted, which shows a complete return to normal based upon his personal preseason baseline. He is cleared to practice with no restrictions for Tuesday.
There is nothing particularly profound in this case presentation. This was not a trick case or a “zebra.” Rather, we have a rather plain looking “horse” to examine.
What this case does represent is one of the common presentations of a concussed athlete where controversy concerning the disposition of this athlete and his return to play continues. For many sports clinicians, the presence of any loss of consciousness precludes further participation in that contest . This is based upon experiential data and is independent of other signs and symptoms. Obviously, the most prominent sign in the presentation of this case is the transitory period of loss of consciousness.
Why did loss of consciousness become the basis and centerpiece of concussion management strategies [8–12]? Call it fear. Fear of the unknown; we simply didn't know any better, so extrapolations made from inappropriate sources (eg, hospital emergency rooms treating motor vehicle accidents) became the only source of data on this subject [13,14]. Until recently, no one had taken an organized systematic approach in studying mild traumatic brain injury in sports [15,16].
We over-generalized and probably over-simplified a very complicated subject. How else can you explain drafting a guideline document based upon one case ? We interpreted something, named it, then used it to justify our decisions, all without much scientific rigor. The product of this exercise is second impact syndrome .
Loss of consciousness is always a serious sign, a sign of insult to the reticular activating system of the brain stem. Prolonged loss of consciousness (however you wish to define it) should be treated as a neurologic and possibly neurosurgical emergency.
Brief loss of consciousness probably represents an instantaneous insult to the reticular activating system, a transient shock without structural damage. It does not appear to portend bad things to come .
Studying the concussion databases has revealed a more ominous and specific sign of poor outcome: amnesia, either post-traumatic or retrograde. The presence of amnesia represents injury to the hippocampus and temporal lobe of the brain and correlates well with poor outcome measures .
Although guidelines for the immediate disposition of a head-injured athlete continue to be unclear and controversial (due to the heavy “background noise” of opinion), an examination of the following tables should help the practitioner in a case such as this. Table 1 represents one perspective summarizing the general opinion of most researchers in this area .
Box A roughly corresponds to the characteristics of this case. Based upon data and the literature, the sports clinician could safely allow this athlete to return to play, as was the case. Many physicians may still feel uncomfortable with this decision. However, nothing in the literature would indicate a need to pull this individual from the game.
Likewise, if we change the presentation of this case slightly by eliminating the brief loss of consciousness and extending the other signs and symptoms past the 20 minutes outlined, the case then seems to be best represented by Box B.
This presentation is also problematic with advocates on both sides. I take a position that based upon the recent data , the presentation represented by Box B represents more of a reason to withdraw an athlete from the contest than the scenario of Box A, especially if amnesia of any type is involved.
Some evidence-based points to consider:
- No symptomatic athlete should be returned to play for any reason. Although there is general agreement to this statement, is our sideline assessment of concussion sophisticated enough to make this determination? The answer is “yes.”
- Does brief loss of consciousness preclude any further participation in a contest? Based upon existing data, the answer is “no.”
- The younger the brain, the more vulnerability to head injury recurrence or poor outcome exists. This statement would appear to be true.
- Treat each sports induced mild traumatic brain injury individually. There appear to be many, many variables to consider. It is not appropriate to use strict inflexible criteria in this setting. The more we learn about concussion, the more these statements are true.
Consider carefully these at risk groups of athletes: those who have suffered previous mild traumatic brain injury, those with learning disabilities, those with a lower baseline mental status, and those who possess genetic predeterminance to brain vulnerability—apolipoprotein E4 .
Although information that would identify athletes into one of these categories may not always be present, it is the role of the team physician to collect as much data as possible to identify these groups. When in doubt always err on the conservative side. This homily has served team physicians for many, many years. I believe it is important to restate it here.
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