Brain damage, not excessive steroid use, may have been what led Chris Benoit to kill his wife and son and then himself, a medical expert said Wednesday.
Neurologists with the Sport Legacy Institute who examined the WWE star's brain found it riddled with evidence of chronic traumatic encephalopathy (CTE), a form of brain damage likely caused by concussions Benoit sustained in his years as a professional wrestler.
Symptoms of the condition, which is believed to afflict some 20 percent of professional boxers, include depression, dementia and erratic behavior.
Dr. Julian Bailes, chairman of the Department of Neurosurgery at West Virginia University and a founding member of the Sports Legacy Institute, told ABC's Good Morning America on Wednesday that what they found in Benoit's brain tissue was "striking and maybe shocking."
He said the brain damage was "enough to very likely explain aberrant behavior including suicide and even homicide."
"This is something you should never see in a 40-year-old," Bailes added of the brain tissue's condition.
Benoit killed his wife, Nancy, and seven-year-old son Daniel before hanging himself at the family's home in Atlanta in June.
Steroids were found both on the scene and in Benoit's bloodstream, leading to speculation that " 'roid rage" was a factor in the double murder-suicide.
However, Bailes said that steroids would not have caused Benoit's brain damage.
"There is no consensus in the medical community that the syndrome of ' 'roid rage' even occurs," Bailes said.
Benoit's father granted permission for the Sports Legacy Institute to perform the tests on his son's brain tissue, because he found the murder-suicide to be completely out of character for the man he knew.
He also denounced the theatrics in modern-day wrestling, which he indicated led to his son's brain injury.
"I think it's the extreme that is in the wrestling industry today," Michael Benoit told reporters. "The human skull is not built to get hit by a chair or something."