ABC INTERVIEW: Demaryius Thomas brain scans reveal Stage 2 CTE

The parents of Super Bowl champion Demaryius Thomas have revealed circumstances surrounding their son’s death at the age of 33.

In an ABC exclusive interview that aired on “Good Morning America” Tuesday, Bobby Thomas and Katina Stuckey Smith said postmortem brain scans revealed that Demaryius Thomas was suffering from Stage 2 CTE, a degenerative disease that is currently being studied but has already shown up hundreds of NFL players’ brains.

The Mayo Clinic says CTE, short for chronic traumatic encephalopathy, is diagnosed only during autopsy and “has a complex relationship with head traumas such as persistent post-concussive symptoms and second impact syndrome that occur earlier in life.”

Mayo lists cognitive impairment, impulsive or aggressive behavior, mental health struggles, substance abuse, and motor issues as possible effects of CTE.

Although medical experts claim CTE does not cause death, they say it is an invisible injury that may contribute to a wide range of medical problems.

Demaryius’ parents say he started having violent seizures in 2021, when he retired. His death on Dec. 9, 2021 is believed to be the result of one of those seizures.

RELATED: Pro Bowler, Super Bowl champ Demaryius Thomas dies at 33

Boston University CTE Center Dr. Ann McKee believes the former football player’s case of CTE stemmed from severe injuries he sustained off the field in a car crash and a fall down a stone staircase.

Bobby Thomas and Smith tell ABC they expected Demaryius Thomas to struggle from physical injuries after 10 NFL seasons, but they also started noticing symptoms like paranoia, headaches and memory loss.

The diagnosis has led to some guilt for the former star receiver’s family.

“When they started explaining … side effects, warning signs, and that’s when the bell started ringing,” Bobby Thomas told ABC. “When they said it, I was like, ‘Man, he was doing that. He did that, too. And I faulted myself, ’cause I said, ‘I know I coulda done more.'”

Smith tells ABC her son expressed not feeling like himself anymore in the period before his death.

Demaryius was known for his kind personality, the Denver Broncos said in a statement following his death.

His contributions to the community went beyond the playing field, the team said, noting his work with the Broncos Boys and Girls Club, hospital visits, his annual football camp and “many other genuine interactions.”

“Demaryius’ humility, warmth, kindness and infectious smile will always be remembered by those who knew him and loved him,” the Broncos said. “We have lost an incredible player and a special person in Demaryius Thomas.”

McKee tells ABC there is hope that within five years, doctors will be able to diagnose CTE in living players.

Smith tells ABC she had a conversation where her son expressed the desire to have his body help other players if anything ever happened to him.

Watch the full interview at the top of this article.