Former NFL star wide receiver Demaryius Thomas had CTE when he died, parents say

By Kevin Dotson, CNN

Updated 0411 GMT (1211 HKT) July 6, 2022

Demaryius Thomas (88), a former wide receiver for the Denver Broncos, seen with his parents, Katina Stuckey Smith and Bobby Thomas.

(CNN)Former NFL player Demaryius Thomas was suffering from stage 2 CTE when he died late last year, according to his parents.

Katina Stuckey Smith and Bobby Thomas said the diagnosis came after an examination of their son's brain following his death in December, according to a news release from the Concussion Legacy Foundation.Smith and Thomas said told ABC News their 33-year-old son died of cardiac arrest caused by a seizure disorder that led to his retirement from football in June of 2021.Denver Broncos honor Demaryius Thomas with memorial and tribute CTE, known as chronic traumatic encephalopathy, occurs when the brain starts to degenerate likely due to repeated head traumas, according to the Mayo Clinic. It has been found in the brains of people who play football and other contact sports, the clinic said, and diagnosis is currently only possible through autopsy by studying sections of the brain.Dr. Ann McKee, a professor of neurology and pathology at Boston University's CTE Center, studied Thomas' brain and made the diagnosis.Read More«We found what we've seen in so many other players under the age of 34,» McKee told ABC News. «On the basis of multiple lesions in the frontal lobes and temporal lobe are beginning degeneration of deeper areas of the brain. He was diagnosed with CTE, stage two.»She added: «CTE itself does not cause death. You don't die from CTE. ...What CTE does is it changes your behavior and your personality.»Thomas' parents told ABC News they saw their son dealing with many CTE symptoms in the months leading up