Chronic traumatic encephalopathy in sports

Study of CTE's relationship with American football began in 2002. Since then, hundreds of players have been diagnosed posthumously with CTE, including a number of players who committed suicide. CTE has affected not only professional football players, but players who only played in college and in high school.

In 2002, Bennet Omalu, a forensic pathologist and neuropathologist in Pittsburgh, Pennsylvania, found CTE in the brains of Mike Webster, Terry Long, Andre Waters, Justin Strzelczyk, and Tom McHale.[3] Omalu, initially a medical examiner, then associate adjunct professor in California, was a co-founder of the Brain Injury Research Institute[3] and reportedly in 2012 participated in the autopsy of Junior Seau.[4] Omalu's participation was halted during the autopsy after son Tyler Seau, under pressure from the NFL, revoked previously provided oral permission. Tyler Seau had received received telephone calls from NFL management denouncing Omalu's professional ethics, qualifications, and motivation when the league asked him to revoke Dr. Omalu's research.[5]

Research into football players with CTE has continued with neuropathologist Ann McKee of Boston University's CTE Center, who diagnosed the bodies of twelve former professional American football players with CTE postmortem between 2008 and 2010.[6] An autopsy McKee conducted in 2010 on the brain of Owen Thomas, a 21-year-old junior lineman at the University of Pennsylvania who died of suicide, showed early stages of CTE, making him the second youngest person at the time to be diagnosed with the condition. Thomas was also the second amateur football player diagnosed with CTE; Mike Borich, who died at 42, was also diagnosed by McKee.[7] The doctors who performed the autopsy indicated that they found no causal connection between the early stage CTE and Thomas's suicide. There was no indication that Thomas missed playing time due to concussions; however, as a player who played hard and "loved to hit people", Thomas may have played through concussions and received thousands of subconcussive impacts on the brain.[8]

On May 2, 2012, retired twelve time Pro Bowler Junior Seau died of suicide with a gunshot wound to the chest.[9] There was speculation that he had brain damage due to CTE.[4][10][11][12][13] Seau's family donated his brain tissue to the National Institute of Neurological Disorders and Stroke.[14] On January 10, 2013, the brain pathology report was released, and Seau's brain showed evidence of CTE.[15] Seven months after Seau's death, on December 1, 2012, Kansas City Chiefs linebacker Jovan Belcher killed his girlfriend and drove to Arrowhead Stadium and killed himself in front of then GM Scott Pioli and then head coach Romeo Crennel. A year later, on behalf of Belcher's minor daughter, a family lawyer filed a wrongful death lawsuit against the Chiefs, alleging that the team deliberately ignored warning signs of CTE, possibly leading to Belcher's suicide. The lawyer also hired a medical examiner to examine Belcher's brain for signs of CTE. On September 29, 2014, it was confirmed that he had CTE.[16] Coverage of Belcher's murder-suicide, combined with the suicide of Junior Seau, drew national attention to CTE and its effects on the brains of football players.

In September 2015, researchers with the United States Department of Veterans Affairs and Boston University announced that they had identified CTE in 96 percent of National Football League players that they had examined and in 79 percent of all football players.[17] By November 2016, 90 of 94 former NFL players were diagnosed post-mortem with CTE by McKee.[18] Professional players diagnosed included eight-time Pro Bowler Lou Creekmur,[19] Cookie Gilchrist[20] and Wally Hilgenberg.[21]

In March 2016, former NFL running back for the New England Patriots, and Philadelphia Eagles, Kevin Turner died at age 46. In 2010 he was diagnosed with amyotrophic lateral sclerosis (ALS). After donating his brain to Boston University Brain CTE Center they diagnosed Turner with CTE. He had a severe case with CTE which killed him, not ALS.[22]

In April 2017, former New England Patriots tight end Aaron Hernandez died by suicide in prison at age 27. On September 21, 2017, an autopsy report from Boston University identified Stage 3 CTE in Hernandez's brain.[23] Until Hernandez's autopsy, researchers had never seen Stage 3 CTE in a brain younger than 46 years old.[24]

The Journal of the American Medical Association released an updated study in July 2017 reporting that out of 111 brains of deceased former NFL players studied, 110 (99%) had CTE.[25] This also led to players retiring very early in their career. As of December 2018, 87% of the 202 American football players' brains that have been donated to Boston University tested positive for CTE.[26]

O.J. Simpson is suspected to have chronic traumatic encephalopathy.[27][28][29]

Athletes from other sports have also been identified as having CTE, such as hockey player Bob Probert.[40] Neuropathologists at Boston University diagnosed Reg Fleming as the first hockey player known to have the disease. This discovery was announced in December 2009, six months after Fleming's death.[41]

Rick Martin, best known for being part of the Buffalo Sabres' French Connection, was diagnosed with CTE after his brain was posthumously analyzed.[42] Martin was the first documented case of an ice hockey player not known as an enforcer to have developed CTE; Martin was believed to have developed the disease primarily as a result of a severe concussion he received in 1977 while not wearing a helmet. The disease was low-grade and asymptomatic in his case, not affecting his cognitive functions. He died of a heart attack in March 2011 at the age of 59.[43]

Also within a few months in 2011, the deaths of three hockey "enforcers"—Derek Boogaard from a combination of too many painkillers and alcohol, Rick Rypien, an apparent suicide, and Wade Belak, who, like Rypien, was reportedly depressed; and all with a record of fighting, blows to the head and concussions—led to more concerns about CTE. Boogaard's brain was examined by BUSM, which in October 2011 determined the presence of CTE.[44] One National Hockey League player known in part for leading "the thump parade", former Boston Bruin right winger Shawn Thornton mulled over the "tragic coincidence" of the three recent league deaths and agreed that their deaths were due to the same cause, yet still defended the role of fighting on the rink.[45]

In 2016, Stephen Peat, then 36 years old and formerly an enforcer for the Washington Capitals during his professional career, was reported to be suffering severe symptoms of CTE. His father Walter was reported to worry that his son would join the "dead before turning 50 ... since 2010" list of enforcers including Boogaard, Rypien, Belak, Steve Montador.[46]

In December 2017 Zarley Zalapski died, at the age of 49, after complications related to a viral infection.[47][48][49] Following his death, his sister wanted to know if he had any brain issues and was confirmed to have CTE.[50] In 1989, Merril Hoge was a Pittsburgh Steeler when Zalapski was a Pittsburgh Penguin. The two were part of a civic helmet-safety campaign and posed for photos. A few years before Zalapski's death, his sister Kyla had reached out to Hoge to assist her brother who was struggling with his health to transition into retirement.[50]

In January 2018 former hockey player and captain for the Minnesota-Duluth Bulldogs Andrew Carroll, committed suicide, at the age of 32. He was only officially diagnosed with a few concussions. After looking at Andrew's lab results, researchers at Boston University estimated that number was closer to 20. A little over a year later Andrew Carroll was diagnosed with CTE.[51]

In 2011, USA hockey, which controls the rules surrounding youth hockey in the United States banned body checking along with checking at the head or neck for kids who are ages 13-14 or younger. This is supposed to help prevent youth hockey players get concussions, and other injuries in youth hockey.[52]

In February 2015, Steve Montador died unexpectedly, and the subsequent examination of Montador's brain by doctors at Krembil Neuroscience Centre at Toronto Western Hospital found a "widespread presence" of CTE.[53] Montador joins the growing list of former ice hockey players discovered to have CTE which includes Rick Martin, Derek Boogaard, and Reg Fleming.[54]

Some researchers have argued that prospective longitudinal studies, following subjects over time, are needed to completely understand the causes and progression of CTE. [55]

In 2007, neuropathologists from the Sports Legacy Institute (an organization co-founded by Christopher Nowinski, himself a former professional wrestler) examined the brain of Chris Benoit, a professional wrestler with WWE, who killed his wife and son before committing suicide. The suicide and double murder were originally attributed to anabolic steroid abuse, but a brain biopsy confirmed pathognomonic CTE tissue changes: large aggregations of tau protein as manifested by neurofibrillary tangles and neuropil threads, which cause neurodegeneration.[56][57]

In 2009, Bennet Omalu discovered CTE in recently retired wrestler Andrew "Test" Martin, who died at age 33 from an accidental drug overdose.[58]

On February 9, 2016, Daniel Bryan was forced to retire early due to signs of CTE and post-concussion seizures.[59] He was medically cleared to wrestle again on March 20, 2018.[60]

After their deaths in February and April 2016 respectively, former ECW wrestlers Axl Rotten and Balls Mahoney were found to have had CTE.[61]

In July 2016, 53 professional wrestlers, represented by Konstantin Kyros, filed a lawsuit against WWE, looking to hold the organization accountable for their "long-term neurological injuries" due to multiple concussions and CTE.[62] In November 2017, as part of filing an amended version of the lawsuit, Kelli Sloan and Shirley Fellows were added to the class-action documents, as they represented deceased wrestlers diagnosed with CTE, with Sloan representing her father Harry (Mr. Fuji) Fujiwara and Fellows her son Timothy Well. Carole Snuka, initially part of the first filing, also used the second filing to note her husband, whom she represented in the litigation, subsequently died and was also diagnosed with CTE.[63] The lawsuit was dismissed on September 14, 2018 by US district judge Vanessa Lynne Bryant.[64] The appeal is pending, jointly from three cases, currently involving 67 professional wrestlers combined. According to a July 2019 appeal filed, six deceased wrestlers represented in the case were found to have CTE. Kyros noted Ashley Massaro, a seventh wrestler who has since died after she joined his class-action lawsuit, requested her brain be studied for CTE.[65]

It is believed that former mixed martial artists Gary Goodridge[66] and James Leahy have CTE, as a result of repeated head trauma from their fighting careers. Delayed onset is becoming increasingly common as with Leahy, whose symptoms developed many years after any sporting activity.[67]

In October 2016, Bennet Omalu announced that CTE had been detected in the brain of Jordan Parsons, a MMA fighter who had been killed the previous day by a drunk driver.[68]

In 2018, Wanderlei Silva admitted that he has been bearing symptoms consistent with CTE, and has expressed a wish to donate his brain for research.[69]

In 2012, Patrick Grange, a semi-professional footballer, was diagnosed in an autopsy with Stage 2 CTE with motor neuron disease. "The fact that Patrick Grange was a prolific header is important", Christopher Nowinski, co-founder of the Sports Legacy Institute, said in an e-mail. "We need a larger discussion around at what age we introduce headers, and how we set limits to exposure once it is introduced."[70] Grange played soccer in high school; college at Illinois-Chicago and New Mexico; in the Premier Development League; for Albuquerque Asylum; and for Chicago Fire Premier. He died of ALS at age 29 in 2012 with a posthumous diagnosis of CTE.[71]

In 2014, Brazilian footballer Bellini was posthumously diagnosed with CTE. Bellini, along with Pelé, led Brazil to FIFA World Cup victories in 1958 and 1962.[72]

In 2017, a study identified CTE in four former association footballers known to be skilled headers.[73]

Researchers found Australian rugby union player Barry "Tizza" Taylor died in 2013 of complications of severe CTE with dementia at age 77. Taylor played for 19 years in amateur and senior leagues before becoming a coach.[70]

In 2013, Willie Stewart, Consultant Neuropathologist at the Institute of Neurological Sciences at the Southern General Hospital in Glasgow, identified CTE in the brain of a former amateur rugby player in his 50s which is believed to be the first confirmed case of early onset dementia caused by CTE in a rugby player.[74]

An Australian study of 25 retired NRL players showed they suffered impaired reaction times and concentration compared to the general population.[75][76]

This included Kangaroos player Ian Roberts who had been knocked unconscious 14 times over his professional career.[77][78]

Australian rules football player Greg Williams is thought to have CTE as a result of concussions over a 250-game career.[79]

In March 2016 Justin Clarke of the Australian Football League (AFL) team the Brisbane Lions was forced to retire at just 22 years of age due to a serious concussion sustained during off-season training two months earlier.[80] He was the fifth AFL player in the previous ten months to retire with concussion related injuries, with Sam Blease (25 yo, Melbourne and Geelong), Jack Fitzpatrick (26 yo, Hawthorn and Melbourne Football Club), Leigh Adams (27 yo, North Melbourne), Matt Maguire (32 yo, Brisbane and St Kilda), and Brent Reilly (32 yo, Adelaide) all having retired since May 2015. All the retirements were linked to a crackdown on head injuries by the AFL and fears of CTE associated with local and international sportspeople, especially American footballers.[81] On January 10, 2011, former AFL and Canadian football player through the years of 1956 to 1967 Cookie Gilchrist died. Gilchrist was diagnosed with stage four CTE by Boston University.[82]

In 2012, the brain tissue of Ryan Freel was tested after his death. It was found that he had Stage 2 CTE. Freel was the first Major League Baseball player to be diagnosed with chronic traumatic encephalopathy.[83] After the 2012 season, the MLB instituted the Buster Posey rule. The rule is supposed to help prevent the amount of concussions there are in baseball each year, and to also help stop unnecessary harm to the players.[84]

In 2016, BMX biker and extreme sport icon Dave Mirra was diagnosed post-mortem with CTE. He died of suicide by gunshot on February 4, 2016, and his brain was examined by Lili-Naz Hazrati of the University of Toronto, who confirmed the diagnosis.[85]

In 2017, Ty Pozzobon, who at the age of 25 years also committed suicide, became the first professional bull rider diagnosed with the disease.[86][87] Within ten years, he had received 15 head injuries and his first concussion at the age of 16.

• McGrath, Ben, "The N.F.L. and the concussion crisis", The New Yorker, January 31, 2011. Includes an account of The New York Times' and Alan Schwarz's editorial focus on CTE.
• Ward Joe, Williams Josh, Manchester Sam, "110 N.F.L. Brains", The New York Times, July 25, 2017.
• PBS Frontline, "League of Denial", October 9, 2013.