Several research studies indicate the presence of an association between traumatic brain injury (TBI) and the development of brain damage due to sports-related injuries and neurological diseases later in life.[1] [2] Currently, the number of sports and activity-related cases of TBI is significant at 1.6 to 3.8 million per year. [3] News reports about hard head impacts in sports as well as a high-profile, multimillion-dollar legal settlement negotiation over compensating current and retired injured players, has highlighted the problem of TBI in sports. [4] [5] [6] [7]

According to a “Frontline: Concussion Watch” report, 152 NFL players sustained concussions in the 2013-2014 football season, which is down from the prior season which saw 171 players with concussions. [8] [9] In fact, the risk of developing Alzheimer’s is increased for NFL players, with risk of death from the disease at four times that of the general population. ALS and Parkinson’s disease are also notable for increased morbidity and mortality risk in NFL players later in life.[10] Linemen and players in positions such as guard, center, tackle, defensive, and offensive end sustain fewer concussions with potential for future neurodegenerative disease than quarterbacks, wide receivers, and running backs.[11] [12] [13] Cornerbacks and wide receivers sustained the highest number of concussions for the 2013-2014 season at 23 and 20, respectively.[14] [15] This is attributed to the fact that players in the latter category collide with other players at higher rates of speed, therefore increasing their risk for head trauma. The prevalence of MTBI was associated with increased concussion rates in retired players, with 3- to 5-fold rates of mild cognitive and memory disorder prevalence, respectively. [16]

While this issue often arises concerning football, recent studies have shown that young women are more susceptible to severe and long-lasting cognitive and visual memory deficits and may take longer to recover after sustaining head injuries than young men.[17] [18] [19] Females make up 29% of all of those aged 19 and under who require a trip to the emergency room to treat traumatic brain injury. [20] While nearly half of injuries sustained recreationally by females aged 15-19 are not attributed to any particular sport, the most common sports-related TBI injuries can be attributed to soccer (making up 16% of all TBI injuries among 15-19 year old females), with other sports including gymnastics, basketball, softball, and horseback riding.[21] The significant prevalence of head injuries in soccer can be attributed to plays such as head impact with the ball traveling at an excessively high rate of speed, head collisions with other players, impact with the goalpost, and head-ground impact.[22]

There have been efforts by athletic organizations to improve safety. For example, the National Collegiate Athletic Association partnered with the Centers for Disease Control and Prevention in issuing a set of safety guidelines for student athletes that emphasized taking all possible measures to avoid hard contacts with other players. [23] However, one recent study called even these precautions into doubt: the study showed that even football players who do not sustain concussions may be at increased risk for later cognitive deficits (e.g. decreased reaction time, verbal memory, visual memory, motor speed, and impulse control) compared with demographically matched peers who never played football at all. [24]

Dorkina Myrick, MD, PhD, MPP, is a physician-scientist and pathologist trained at the National Institutes of Health. Dr. Myrick also previously served as a Senior Health Policy Advisor on the United States Senate Special Committee on Aging in Washington, DC. Dr. Myrick conducted this research during her time in the United States Senate. She is currently a JD candidate at the Boston University School of Law.

References:

[1] Guskiewicz et al. “Association Between Recurrent Concussion and Late-Life Cognitive Impairment in Retired Professional Football Players.” Neurosurgery vol. 57. no. 4. pp. 719-726. October 2005.

[2] DeKosky, Steven et al. “Acute and chronic traumatic encephalopathies: pathogenesis and biomarkers.” Nature Reviews Neurology 9, 192-200 (April 2013). http://www.nature.com/nrneurol/journal/v9/n4/full/nrneurol.2013.36.html. Retrieved January 19, 2014.

[3] “Heads Up: Facts for Physicians About Mild Traumatic Brain Injury (MTBI).” U.S. Department of Health and Human Services. Centers for Disease Control and Prevention. p.2. Website: http://www.cdc.gov/concussion/headsup/pdf/Facts_for_Physicians_booklet-a.pdf . Retrieved January 19, 2014.

[4] “League of Denial: The NFL’s Concussion Crisis.” October 8, 2013. http://www.pbs.org/wgbh/pages/frontline/league-of-denial/. Retrieved January 19, 2014.

[5] Belson, Ken. “N.F.L. Agrees to Settle Concussion Suit for $765 Million.” New York Times. August 29, 2013. Website: http://www.nytimes.com/2013/08/30/sports/football/judge-announces-settlement-in-nfl-concussion-suit.html?pagewanted=1. Retrieved January 19, 2014.

[6] Belson, Ken. “Judge Rejects N.F.L. Settlement, for Now.” New York Times. January 14, 2014. Website: http://www.nytimes.com/2014/01/15/sports/football/judge-questions-whether-sum-of-nfl-settlement-is-enough.html?hpw&rref=sports. Retrieved January 19, 2014.

[7] Munson, Lester. “Players Contest NFL Concussion Deal.” ESPN.com. May 5, 2014. Website: http://espn.go.com/espn/otl/story/_/id/10886620/new-court-filing-players-says-most-seriously-injured-ex-nfl-players-not-benefit-nfl-concussion-settlement. Retrieved May 21, 2014.

[8] “Frontline: Concussion Watch.” Website: http://www.pbs.org/wgbh/pages/frontline/concussion-watch/ Retrieved January 21, 2014.

[9] “About Concussion Watch.” Online: http://www.pbs.org/wgbh/pages/frontline/sports/concussion-watch/about-concussion-watch/. Retrieved May 21, 2014.

[10] “Brain and Nervous System Disorders among Retired NFL Players.” National Institute for Occupational Safety and Health. January 2013. Online: https://www.cdc.gov/niosh/pgms/worknotify/pdfs/NFL_Notification_02.pdf. Retrieved February 18, 2019.

[11] Id. at “Neurodegenerative Causes of Death among Retired National Football League Players.”

[12] Id. at “Traumatic Brain Injury: Hope Through Research.”

[13] “Diseases and Conditions: Traumatic Brain Injury – Complications (Degenerative Brain Diseases).” Mayo Clinic Website. http://www.mayoclinic.org/diseases-conditions/traumatic-brain-injury/basics/treatment/con-20029302. Retrieved May 23, 2014.

[14] Brandt, Gil. “At NFL Scouting Combine, Speed is King for Cornerbacks.” NFL CFB 24/7. Website: http://www.nfl.com/news/story/0ap2000000325547/article/at-nfl-scouting-combine-speed-is-king-for-cornerbacks. February 13, 2014. Retrieved May 21, 2014.

[15] See “Frontline: Concussion Watch.” http://www.pbs.org/wgbh/pages/frontline/concussion-watch/. Retrieved January 21, 2014.

[16] Id. at “Neurodegenerative Causes of Death among Retired National Football League Players.”

[17]  Covassin et al. “Are There Differences in Neurocognitive Function and Symptoms Between Male and Female Soccer Players After Concussions?” The American Journal of Sports Medicine. December 1, 2013 41 (12) 2890-2895. Website: http://ajs.sagepub.com/content/41/12/2890.abstract. Retrieved January 17, 2013.

[18] Covassin et al. “The Role of Age and Sex in Symptoms, Neurocognitive Performance, and Postural Stability in Athletes After Concussion.” The American Journal of Sports Medicine. June 2012 vol. 40 no. 6 1303-1312. Website: http://ajs.sagepub.com/content/40/6/1303.abstract?ijkey=d872f279796c3435a99c6a528d96b8a42aef5565&keytype2=tf_ipsecsha. Retrieved January 17, 2014.

[19] “Evidence of Cognitive Dysfunction after Soccer Playing with Ball Heading Using a Novel Tablet-Based Approach.” PLoSOne. Volume 8. Issue 2. pp. 1-4. February 2013. Web: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3583826/pdf/pone.0057364.pdf. Retrieved January 17, 2014.

[20] Table 3. “Five most common activities associated with emergency department visits for nonfatal traumatic brain injuries related to sports or recreation activities, by age group and sex —– National Electronic Injury Surveillance System—All Injury Program, United States, 2001-“Nonfatal Traumatic Brain Injuries Related to Sports and Recreation Activities Among Persons Aged ≤19 Years — United States, 2001—2009.” Morbidity and Mortality Weekly Report (MMWR). October 7, 2011 / 60 (39); 1337-1342. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6039a1.htm?s_cid=mm6039a1_w . Website page last updated October 07, 2011. Retrieved January 16, 2013.

[21] Table 3. “Five most common activities associated with emergency department visits for nonfatal traumatic brain injuries related to sports or recreation activities, by age group and sex —– National Electronic Injury Surveillance System—All Injury Program, United States, 2001-“Nonfatal Traumatic Brain Injuries Related to Sports and Recreation Activities Among Persons Aged ≤19 Years — United States, 2001—2009.” Morbidity and Mortality Weekly Report (MMWR). October 7, 2011 / 60 (39); 1337-1342.

[22] Patlak, Margie and Joy, Janet. “Is Soccer Bad for Children’s Heads? Summary of the IOM Workshop on Neuropsychological Consequences of Head Impact in Youth Soccer (2002).” Board on Neuroscience and Behavioral Health. National Academy Press. Institute of Medicine. Washington, D.C. p. 3. Website: http://www.nap.edu/openbook.php?record_id=10362&page=3 . Retrieved January 17, 2014.

[23] “Concussion – A Fact Sheet for Student Athletes.” National Collegiate Atheltic Association and the Centers for Disease Control and Prevention. Website: http://fs.ncaa.org/Docs/health_safety/ConFactSheetsa.pdf. May 20, 2014.

[24]   Singh et al. “Relationship of Collegiate Football Experience and Concussion with Hippocampal Volume and Cognitive Outcomes.” Journal of the Americam Medical Association. 311 (18):1883-1888. 2014.   The paper correlated hippocampal sizes (a part of the brain that is associated with memory) as inversely related to cognitive deficits. The largest hippocampi were found in non-players. Football players without diagnosed concussions had smaller hippocampi, and football players with diagnosed concussions had the smallest hippocampi. Non-players with the largest hippocampi had minimal to no cognitive deficits. Players without concussions had fewer cognitive deficits than those with concussions, but more cognitive deficits than the non-players. However, additional studies must be done, as this study was limited by a small sample size. Other factors that may have impacted the results include variances in the way that concussions are diagnosed, increased levels of stress hormones – glucocorticoids (which impact hippocampal size), and differences in genetics, environment, and hormone levels.