In our last post we discussed the basic science of concussion. In this post we’ll discuss some of the current ways that concussion is diagnosed. We’ll also discuss some of the ways players with sports concussions are treated.
As we mentioned in the last post I think it’s useful to frame this discussion in reference to sports concussions as this is the most likely place where we’d encounter concussion in our day-to-day lives. The CDC originally estimated that 300,000 sports concussion occur a year. More recent estimates suggest that this number could be much higher at nearly 4 million a year. Even this number may be too low as athletes are known to underreport concussion symptoms (either because they don’t recognize the often fleeting symptoms, or because they purposefully don’t mention the symptoms to avoid being taken out of an important game.) While the exact number may not be known, what is known is that sports concussion is not an uncommon occurrence. Finally, while sports concussion can occur in many sports (see Figure 1) it is most common in football. This is in part due to the fact that football is the most commonly played sports in the US with over 5 million players (including 3.5 million youth football players) annually.
Figure 1: Concussion rates in various high school and college sports (Source: Saigal et al, 2014).
The wide variation in symptoms of concussion demonstrates how just about every part of the brain is affected by concussion. A player who sustains a concussion may have symptoms of a concussion such as headache, nausea, or fogginess. A player may also have signs of concussion such as amnesia or loss of consciousness. It’s important to realize though that a player does NOT have to lose consciousness to have a concussion as this will happen in less than 10% of cases. Players may have behavioral changes such as irritability or impulsiveness. Players may also have cognitive impairment such as decreased concentration, slowed reaction time or memory problems. Finally players may have balance difficulties.
If a player is hit in the head and afterwards demonstrates 1 or more of the above signs or symptoms, you should assume that player has a concussion and begin a more in-depth evaluation of the player. In the past such an evaluation, often having to occur rapidly on the sidelines in the heat of battle of a game, would have been quite time consuming. Since the mid 90’s much work has gone into streamlining this evaluation in order to more rapidly and accurately diagnose concussion. The result of that work is the Sports Concussion Assessment Tool, now in its 3rd iteration (SCAT-3). SCAT-3 is the gold standard for concussion evaluation in sports today and is present in one form or another on the sidelines of most college and pro sports contests. SCAT-3 and other similar sideline tools combine assessments for the various signs and symptoms of concussion into a compact format that is rapidly administered, often in an easy to use electronic form. In NFL games if a player is suspected of having a concussion the SCAT-3 is immediately administered on an iPad (see figure 2) and test results are compared to preseason baseline scores. If concussion is suspected the player must be immediately removed from the contest and is not to return. SCAT-3 can then be repeated serially over the subsequent days to a) be sure that the player isn’t worsening and b) track recovery.
Figure 2: SCAT assessment iOS app (Source: Okonkwo et al, 2014).
Again, a concussed player is to be immediately removed from the game and is not to return to play until cleared. Typically the player is cleared by a physician using a graduated return to play protocol that gradually increases the player’s activities as long as they remain asymptomatic. Thankfully the symptoms of concussion typically resolve by 7-10 days as glucose levels as well as blood flow to the brain normalize.
Figure 3: Graduated return-to-play protocol (Source: www.concussiontreatment.com).
I recently spoke with retired orthopedic surgeon who used to sidelines assessments for concussions. He told me that he often faced quite a backlash from coaches and parents if he removed a player from a game. Thankfully these days it’s not just a physician recommendation that a player be removed from play, it’s the law. In 2006 a high school football player in Washington State named Zach Lystedt suffered a concussion during a game. He was quickly cleared and put back into the game a few minutes after the concussion. When he suffered a second blow to the head in the same game he almost died of a brain hemorrhage. By 2009 Washington State had passed “Zach’s Law” mandating the following after concussion: mandatory removal of play, mandatory bench time until the player is asymptomatic, required medical clearance from a physician prior to returning to play, consent from parents to return to play and finally various programs to educate players, parents and coaches about concussion. By 2013 a version of Zach’s Law had been passed in all 50 states.
In the next post in this series we’ll discuss the dangers of repeat concussion.
Thanks for reading.
J. Alex Thomas, M.D.
Daneshevar, D. H., Nowinksi, C., McKee, A., & Cantu, R. (2012). The Epidemiology of Sport-Related Concussion. Clinics in Sports Medicine, 29(1), 997–1003.
McCrory, P., Meeuwisse, W. H., Aubry, M., Cantu, R. C., Dvořák, J., Echemendia, R. Engebretsen, L. et al, (2013). Consensus statement on concussion in sport: The 4th international conference on concussion in sport, Zurich, November 2012. Journal of Athletic Training, 48(4), 554–575.
Okonkwo, D. O., Tempel, Z. J., & Maroon, J. (2014). Sideline Assessment Tools for the Evaluation of Concussion in Athletes: A Review. Neurosurgery, 75(4), 82–95.
Saigal, R., & Berger, M. (2014). The Long-term Effects of Repetitive Mild Head Injuries in Sports. Neurosurgery, 75(4), 149–155.