Chronic Traumatic Encephalopathy from Contact Sports

Research Highlight by Kurtis Chien

Chronic traumatic encephalopathy (CTE) is a degenerative brain disease found in people who suffer repeated head trauma (1). CTE is most commonly observed in football players, boxers, and other athletes who participate in contact sports. The disease can only be diagnosed during autopsy, since the person’s brain tissue must be examined (2). However, it is possible to retroactively gather information about their condition prior to death. One case study was done on a college football player who played football for 16 years (2). He suffered more than 10 concussions during that period, the earliest of which occurred when he was 8 years old. After a concussion during his freshman year of college, the player reported lingering headaches, neck pain, memory loss, and difficulty concentrating. The symptoms were so debilitating that he eventually failed his courses and dropped out of college.

            Though the repeated concussions almost certainly lead to the football player’s CTE, the amount of trauma necessary to bring about the development of CTE has yet to be determined (1). The type of sport played and the player’s position in their team seem to play a role as well. For example, in football, receivers and cornerbacks suffer the most concussions during their careers (3). The increased impact frequency and intensity may contribute to a greater risk for CTE. In addition to this, a range of auxiliary factors are suspected of putting a person at greater risk for CTE. People with at least one copy of APOE e4, an allele of the gene APOE, represent 57% of the victims of CTE (1). The population baseline for the allele is 28%. Alcohol and tobacco use may also exacerbate the probability of developing the disease (1). More case studies on victims of CTE as well as control data of healthy athletes and non-athletes would be needed to support these conclusions. Further research may also give a better idea on the causes of CTE and methods to prevent it.



  1. Rettner, R. (2017, September 29). Aaron Hernandez's 'Severe' CTE: How Does It Progress So Quickly? Retrieved September 29, 2017, from
  2. The JAMA Network Journals. (2016, January 4). Chronic traumatic encephalopathy in 25-year-old former football player. ScienceDaily. Retrieved September 30, 2017 from
  3. Breslow, J. M. (2014, February 4). What We've Learned From Two Years of Tracking NFL Concussions. Retrieved September 29, 2017, from