Chronic traumatic encephalopathy, the brain disease known as CTE, has been found in 99 percent of deceased NFL players’ brains that were donated for scientific research, according to a new study.
The study, published this week in the medical journal JAMA, found that the neurodegenerative disease, found in individuals exposed repeatedly to head trauma, is pathologically marked by a buildup of abnormal tau protein in the brain that can lead to a variety of clinical symptoms.
“There’s no question that there’s a problem in football. That people who play football are at risk for this disease,” Dr. Ann McKee, director of Boston University’s CTE Center and coauthor of the new study, said in a statement. “And we urgently need to find answers for not just football players, but veterans and other individuals exposed to head trauma.”
McKee added that the group of players posthumously tested by her is far from a random sample of NFL retirees.
“There’s a tremendous selection bias,” McKee said, noting that many families donated brains specifically because the former player showed symptoms of CTE.
CTE symptoms include memory loss, confusion, impaired judgment, aggression, depression, anxiety, impulse control issues and sometimes suicidal behavior.
The disease can only be formally diagnosed with an autopsy. The brain of former New England Patriots tight end Aaron Hernandez, who committed suicide while serving a life sentence for first-degree murder, will be examined, for CTE.
The study comprises the largest of its kind. The criteria for submitting a brain was based on exposure to repetitive head trauma, regardless of whether that individual exhibited symptoms during their lifetime.