Brain study reveals late Broncos receiver Demaryius Thomas had CTE
The family of late Broncos receiver Demaryius Thomas announced Tuesday that Boston University researchers have diagnosed him with stage 2 of chronic traumatic encephalopathy (CTE), a degenerative brain disease caused by repetitive head trauma.
Thomas died on Dec. 9, 2021, at age 33 when he was found unresponsive in a shower of his home in Georgia. His parents, Bobby Thomas and Katina Smith, donated his brain to BU’s CTE Center for examination.
Led by neuropathologist Dr. Ann McKee, director of the BU CTE Center, Thomas’ brain was found to have several lesions, leading to a stage 2 conclusion. Symptoms include progressive cognitive and mood abnormalities.
“In the years before he died, Thomas developed depression, anxiety, panic attacks and trouble with his memory,” said a statement released by the Concussion Legacy Foundation (CLF) on behalf of Thomas’ family.
CTE is judged on a scale of stages 1-4. Stage 4 is the most severe and associated with dementia.
“Once I became aware of CTE and began to familiarize myself with the symptoms, I noticed that Demaryius was isolating himself and I saw other changes in him,” Katina Smith said. “He was just so young and it was horrible to see him struggle.”
Although the Fulton County Medical Examiner has not released autopsy results, Thomas’ death has been speculated as seizure-related. The CTE Center said epileptic seizures can be associated with late-stage CTE, but “it is far more likely that he developed post-traumatic epilepsy after a motor vehicle accident and fall he experienced several years before his death.”
In February 2019, Thomas was involved in a single-vehicle rollover crash in downtown Denver. He and two passengers sustained injuries when Thomas, driving 70 mph in a 30 mph zone, lost control of his car on Auraria Parkway. Thomas pled guilty to a charge of careless driving; a charge of felony vehicular assault was dismissed.
According to the CLF, Thomas is one of more than 300 former NFL players who have been diagnosed with CTE by McKee and the BU CTE Center research team.
CTE can only be diagnosed after the person is deceased. Families then donate the person’s brain to BU.
In its statement, the BU CTE Center said Thomas’ brain showed “multiple CTE lesions … throughout the frontal and temporal lobes.”
The frontal lobe controls decision making and attention and the temporal lobe controls memory processing and emotion.
“The question I keep asking myself is, ‘When will enough be enough?’” McKee said in a statement. “When will athletes, parents and the public at-large stop ignoring the risks of American football and insist that the game be changed to reduce sub-concussive hits?”
The CTE Center at BU is an independent academic research center that is a part of the school’s Alzheimer’s Disease Research Center, which was established in 1996. The center’s “brain bank” includes more than 1,200 brains, including over 700 that have been diagnosed with CTE.
The Concussion Legacy Foundation was founded in 2007 by Chris Nowinski, who played football at Harvard and was a professional wrestler who was forced to retire due to concussions. The CLF’s stated mission is to support all impacted by concussions and CTE, promote smarter and safer sports through education and innovation, and CTE prevention and research.
After Thomas’ death, Nowinski contacted Bobby Thomas and Katina Smith to discuss donating their son’s brain for research.
“The football community would have no idea why so many former players struggle with neurological disorders after their career without the families who say yes to brain donation so I want to thank Bobby Thomas and Katina Smith — and all families — for their trust in Dr. McKee and this team,” Nowinski said.
Last year, two NFL players were diagnosed with stage 2 CTE: Former Northern Colorado receiver Vincent Jackson, who died due to chronic alcohol use, and former defensive back Phillip Adams, who committed suicide after killing six people.
Other former NFL players who have been diagnosed with CTE include Junior Seau, Aaron Hernandez, Mike Webster, Dwight Clark and Andre Waters. Seau, Hernandez and Waters committed suicide; Webster was the first NFL player diagnosed with CTE following a fatal heart attack in 2002; and Clark died in 2018 because of ALS.
Last month, Scott Vermillion became the first former Major League Soccer player to be diagnosed with CTE of any stage. He died from an accidental overdose in December 2020.
In 2019, BU analyzed the brains of 266 deceased amateur and pro football players and estimated a person’s risk of developing CTE doubles for every 2.6 years playing the sport.
The Thomas family statement said Demaryius played 16 years of tackle football, including three seasons for Georgia Tech and a decade in the NFL.
A first-round pick by the Broncos in 2010, Thomas caught 665 passes for 9,055 yards and 60 touchdowns for the team, was a member of the 2015 Super Bowl-winning club and was named to four Pro Bowls. He was traded to Houston in ’18 and finished his career with the Jets in ’19. Thomas announced his retirement last summer.
“(Thomas’) father and I hope all families learn the risk of playing football,” Katina Smith said. “We don’t want other parents to have to lose their children like we did.”
Said Nowinski: “I hope this is a wake-up call for high-profile current and former NFL players that CTE is rampant among them and they need to get involved in creating real solutions. CTE should be their No. 1 off-the-field issue.”
