Concussions: Introduction of Overlapping Concussion Syndrome
A 13 year old female soccer player collides with another player falls and hits her head on the ground. She immediately appears dazed and confused. She reports a severe global headache and mild photophobia. Her coach appropriately suspects concussion and removes her from the game. Her parents then take her to the emergency room where over the next couple hours she improves slightly. She is diagnosed with a concussion and sent home to rest and follow up with her primary care physician. Follow up with her primary care doctor occurs two days later where she demonstrates continued improvement with a mild headache, dizziness, and fatigue. She is advised to rest the remainder of the week and stay out of school. She follows the instructions and in a week reports she is doing well, therefore her parents allow her to return to school. Since she is doing well in school, she is allowed to return to soccer activities.
Sound familiar? This scenario is estimated to occur 150,000 times per year nationally for athlete’s ages14-18 years old (Bakhos, Lockhart et al. 2010).
Two weeks following her concussion, she was playing soccer again. During a game she jumps for a header and hits her head on another player’s head and immediately has a return of her symptoms. Again, she is taken out of the game and again she is diagnosed with a concussion. Unfortunately, now her symptoms are more severe and the duration significantly longer. Due to the severity of her symptoms she misses a significant portion of the school year and ultimately has to receive tutoring over the summer to catch up and stay with her grade. It was noted upon further questioning that she really was never back to normal after the first concussion. Although her headache, dizziness, and photophobia resolved, she still had subtle symptoms such as mild fatigue, difficulty concentrating in class, and homework taking longer to complete.
Sound familiar? If not think again. Although the numbers are unknown, this scenario occurs quite frequently. I personally have seen this scenario on a weekly basis. What is happening here is another concussion occurs on the tail end of a concussion where complete resolution has not yet occurred. Unfortunately, when this occurs the symptoms are often amplified and prolonged.
The medical literature is very aware of Second Impact Syndrome (SIS) where a second blow on top of a previous head injury with continuing symptoms leads to a loss of regulation of cerebral blood flow resulting in brain swelling and herniation commonly resulting in death. Second impact syndrome although catastrophic, is very rare, with estimates of less than 1 case per year (Thomas, Haas et al. 2011).
What happened in this described case is not SIS, rather a much more common injury where a concussion occurs while the athlete is still symptomatic from a previous concussion. This scenario often results in more severe symptoms that last longer. I believe this scenario deserves proper terminology. I have previously referred to this condition as Overlapping Concussion Syndrome (OCS). Patients with overlapping concussion syndrome may also be labeled as post concussive syndrome. Clinically these syndromes may be similar but there is a big difference as OCS can be prevented. In OCS there is a previous event, whether it was recognized or not. The proper recognition and management of the first event is the opportunity to prevent OCS or some of those injuries labeled as PCS.
Overlapping concussion syndrome emphasizes the need to properly manage concussions. We have to be diligent in following concussions to a resolution. The difficulty is that some of the residual symptoms can be more difficult to detect and the clinician must be carefully looking for the more subtle signs of concussions. These subtle signs may be seen in school performance, mild headaches, fatigue, personality changes, vestibular impairment, or neurocognitive testing changes, to name a few. In addition, as the child feels better, there may be pressure to return to sporting activity that leads them to hide or underestimate these mild symptoms, making them even more difficult to detect.
As we move forward, we need to improve the detection of these subtle symptoms. Neurocognitive testing is one of the mechanisms by which this is being done. We are currently looking at vestibular measurements to help as well. Some of our current research is in the area of eye motion and balance changes. Still many of the subtle symptoms can be identified by the athlete, parents, and teachers.
I believe that if we remain diligent in the diagnosis of concussions and continue this diligence to the management of concussions, we will better prevent the more severe condition of OCS as well as the rare yet catastrophic SIS.
David Wang MD, MS
Elite Sports Medicine
Connecticut Children’s Medical Center
Bakhos, L. L., G. R. Lockhart, et al. (2010). “Emergency department visits for concussion in young child athletes.” Pediatrics 126(3): e550-556.
Thomas, M., T. S. Haas, et al. (2011). “Epidemiology of sudden death in young, competitive athletes due to blunt trauma.” Pediatrics 128(1): e1-8
Dave H. Wang, MD, MS
David is a sports medicine physician with over 15 years of specialized care for athletes of all abilities, from the novice to the Olympian. He has served as a team physician for the University of Minnesota for over a decade, which is also where he received his M.D. in 1989. Most recently he has been the director of the Sports Medicine department in a large multispecialty clinic in Minnesota where he has continued to work with non surgical techniques for musculoskeletal ailments as well as medical conditions affecting the athlete. He holds a Masters degree in Exercise Physiology and has interest and experience with sports performance issues. He is a former collegiate track athlete, who has accumulated a deep understanding of the specifics of most sports and their unique training regimes. In 2009 David and his family made the decision to move to Connecticut and join the outstanding staff at Elite Sports Medicine.