Late NFL wide receiver Demaryius Thomas had the degenerative brain disease known as chronic traumatic encephalopathy, or CTE, Boston University researchers revealed Tuesday.

Thomas was found dead at his home in Georgia on Dec. 9 at age 33, but the Fulton County coroner has not released a cause of death. His family suspected seizures resulting from a 2019 car accident might have caused his death.

The former Denver Broncos star began displaying erratic behavior, including mood changes and isolation, in 2020, according to his family.

“His mood would change, and he would also isolate himself sometimes,” said Katina Stuckey Smith, Thomas’ mother, in an interview with ABC. “He was, like, ‘Mom, I don’t know what’s going on with my body. You know, I gotta get myself together,’ and he said, ‘I don’t feel like myself anymore.'”

Neuropathologist Dr. Ann McKee, part of the Boston University brain research team, told ABC that Thomas most likely died after having a seizure. The condition isn’t commonly associated with CTE.

A four-time Pro Bowl selection, Thomas played eight-plus seasons with the Broncos, who drafted him in the first round in 2010 and traded him to Houston in October 2018.

He won Super Bowl 50 with Denver and recorded 724 catches for 9,763 yards and 63 touchdowns in 143 career games with the Broncos, Texans (2018) and New York Jets (2019). He signed with New England in 2019 but never appeared in a game for the Patriots.

–Field Level Media