Hall of Fame defensive tackle Steve McMichael, a key member of the Super Bowl XX champion Chicago Bears, has been diagnosed posthumously with Stage 3 chronic traumatic encephalopathy, the Concussion & CTE Foundation said Tuesday.

McMichael died April 23, 2025, after a five-year battle with ALS, also known as Lou Gehrig’s disease. He was 67.

“By sharing Steve’s diagnosis, we want to raise awareness of the clear connection between CTE and ALS,” McMichael’s wife Misty said in a statement released by the Concussion & CTE Foundation.

“Too many NFL players are developing ALS during life and diagnosed with CTE after death. I donated Steve’s brain to inspire new research into the link between them.”

ALS — amyotrophic lateral sclerosis — is a neurological disorder that destroys motor neurons. CTE is a degenerative brain disease that has been found in people exposed to repetitive head trauma; it can be diagnosed only after death.

McMichael’s CTE diagnosis was made by researchers at the Boston University CTE Center, which has found that several other former NFL players suffered from both ALS and CTE. According to the center’s director, neurologist Dr. Ann McKee, about 6% of people with CTE also have ALS.

“There is strong evidence linking repetitive brain trauma and ALS,” McKee said.

Michael kept up with the research, according to the Concussion & CTE Foundation, and pledged to donate his brain to be studied after his death.

“Steve McMichael was known for his strength, toughness, and larger-than-life presence,” said Dr. Chris Nowinski, co-founder and chief executive of the Concussion & CTE Foundation, “but his final act was to give a piece of himself back to the sports community so we might have a chance to save ourselves.”

McMichael spent 13 of his 15 NFL seasons in Chicago, earning Pro Bowl honors in 1986 and 1987. He set a Bears record playing in 191 consecutive games from 1981 to 1993 and is second on the team’s all-time sacks list with 92.5 (he had 95 total in his career).

After football, McMichael spent several years as a professional wrestler with World Championship Wrestling.

Bedridden in the advanced stages of ALS, McMichael was inducted into the Pro Football Hall of Fame in a ceremony from his Homer Glen, Ill., home in 2024.

The Associated Press contributed to this report.