Julianne Maisano

On Tuesday, February 16, 2016 Dr. John P. DiFiori, Chief of the Division of Sports Medicine at UCLA, held a lecture entitled, “The Vulnerable Window in Concussion: A Challenge in Determining Return to Play”. Dr. DiFiori discussed the process by which a concussion is diagnosed on the sideline of a game, the pathophysiology of a concussion, and some of the most recent research studies that have examined the consequences of concussions on a cellular and physiological level. In his lecture, Dr. DiFiori the average time (10 days) that it takes for a collegiate athlete’s concussion symptoms to resume, the fact that most athletes are not willing to report a concussion, and that one is most vulnerable to endure long-term cognitive function problems if they receive a second concussion three days after they receive their first one. However, one of the most important things he mentioned was protocol that details the length of time a player should sit out before they are allowed to return to play (RTP), a process that is not only vital to the patient’s immediate well-being, but for their long-term well-being as well.

A concussion can be defined as a traumatic brain injury induced by a disruption in the anatomical structures and pathophysiological processes of the brain (Harmon et al., 2013). Classified as a traumatic brain injury (TBI), concussion severity can range from a mild to severe depending upon the patient’s symptoms. According to the Center for Disease Control (CDC), approximately 1.6-3.2 million people endure concussion a year within the United States, and of those concussions endured, most as classified as mild (Choe et al., 2012). While many people are under the impression that concussions are primarily caused by direct head to head contact, this predisposed notion is not completely true. Dr. DiFiori mentioned, that while most concussions occur as a result of physical contact, most concussions are a result of head to ground or wall contact (DiFiori, 2016).

According to Dr. DiFiori, there is a decline in participation in youth football, as children as being swayed away from participating in contact sports. This decision can be attributed to the increase of knowledge about the symptoms, severity, and long-term effects of concussions, such as chronic traumatic encephalopathy (CTE). It is known that children’s brain heals more slowly than a mature adult brain. Children’s skulls are not proportional to their neck, which makes them susceptible to concussions. This lack of maturity, allows for the brain to move around significantly during a collision due the weight of the head overwhelming the neck. Likewise, a child’s brain is not completely myelinated and numerous neuronal connections and synapses have yet to be formed. When the brain becomes concussed, it endures an electrical shock and smacks against the inside of the skull. This rapid movement causes axons to tear and disrupt numerous neural connections. As a result, an influx of the protein tau is found within the axons is released into the cerebral spinal fluid (Semple et al., 2015). On average, it takes collegiate athlete cerebral blood flow between nine and ten days to normalize. This is not to say that it takes approximately ten days for all athletes to get back on the field and return to play, but this time point gives the brain a longer rest time and allows it to reset itself, something which is found to be longer in children (DiFiori, 2016).

Dr. DiFiori also discussed the vulnerable window, a period of time after someone receives a concussion, that if they continue to play and received another concussion are at a greater risk to encounter long-term cognition issues, such as chronic traumatic encephalopathy (CTE), as well as psychological disorders. Serious long-term consequences such as CTE could result in depression and/or anxiety, and could possible lead athletes to commit suicide. Dr. DiFiori detailed the various consequences of an athlete retuning to play before they are physically, mentally, and emotionally ready. Subsequently, to explained the differences in and importance of neurological tests prior to athletes beginning a season to determine their baseline score, which will be used to evaluate the athlete’s progress while they have a concussion and post concussion. To express the significance of the vulnerable window, Dr. DiFiori discussed Huang et al. (2013) research study, which analyzed the impact of concussions on animal models and found that of the time points at which concussions were given to mice after they received their first surgery, three days post concussion number one resulted in the worst long-term cognitive functions for the animal.

To conclude his lecture, Dr. DiFiori stated that the best practice for treating a concussion is to remove an athlete immediately from a sporting event if they are expressing concussion symptoms, properly evaluate their symptoms and document them, and to inform the athlete how to rest while they have concussion, as well as to limit their use of light and brain stimulating devices and activities. Dr. DiFiori mentioned that it is important to gradually integrate stimulation while treating a concussion, and to always keep in mind the best interest of the athlete for both the short-term and most especially the long-term, when developing a treatment plan.



Choe, M. C., Babikian, T., Difiori, J., Hovda, D. A., & Giza, C. C. (2012). A pediatric perspective

on concussion pathophysiology. Current Opinion in Pediatrics, 24(6), 689-695.


DiFiori, J. P. (2016, February 22). The Vulnerable Window in Concussion: A Challenge in

Determining Return to Play. Lecture presented at Concussion Awareness Day in McCook Auditorium, Hartford, CT.


Harmon, K. G., Drezner, J., Gammons, M., Guskiewicz, K., Halstead, M., Herring, S., . . . Roberts,

  1. (2013). American Medical Society for Sports Medicine Position Statement. Clinical Journal of Sport Medicine, 23(1), 1-18.


Semple, B. D., Lee, S., Sadjadi, R., Fritz, N., Carlson, J., Griep, C., . . . Noble-Haeusslein, L. J.

(2015). Repetitive Concussions in Adolescent Athletes – Translating Clinical and Experimental Research into Perspectives on Rehabilitation Strategies. Frontiers in Neurology Front. Neurol., 6, 1-16.


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