Ninety-nine percent of former NFL football players tested in a recent study were diagnosed with a progressive neurological disorder, commonly known as CTE, or Chronic traumatic encephalopathy.
That's a stunning statistic recently published in The Journal of the American Medical Association, whose findings explored the prevalence of CTE in American football at all levels of play--from high school to professional. More generally, the research suggests that players' neuropathological severity correlates to the number of years spent on the field. Of the 202 brains sampled in the study, a very small percentage of former high school football players were diagnosed with mild pathology, while the majority of former college, semiprofessional, and professional players exhibited signs of severe pathology.
The study, however, noted that CTE risk is based on a myriad of factors, including, but not limited to, duration of play, player position, cumulative hits, as well as the linear and rotational acceleration of blows sustained to the head.
The study resonated with many, particularly with now former Baltimore Ravens' offensive lineman and PhD candidate in applied mathematics at MIT John Urschel, who unexpectedly announced his retirement from the sport at the precocious age of 26 on Thursday. He'll end his NFL career with three seasons under his belt.
Dr. Ann McKee, a neuropathologist who studies brain trauma out of the CTE Center at the Boston University School of Medicine, examined the donated brains of former football players. She said linemen, like Urschel, tend to make up the largest share of her testing because nearly half of the players on the field serve in that position.
Former Washington Redskins' defensive lineman Brandon Noble knows that world all too well, having sustained repeated blows after more than two decades of play. He said, despite widely-held assumptions, it's not the "Tweety Bird" moments that are necessarily most responsible for the build up of a protein called Tau, which spreads slowly to other parts of the brain, killing other brain cells in its path.
"CTE isn't from that one big knockout. It's not from two or three concussions. It's from the fact that I hit my head 60 times a day for 20 years."
The 43-year-old player retired relatively early, too. At the age of 31, he called it quits, though, he continues to coach football camps. Despite the fact that he hasn't been an active NFL player for nearly a decade, he doesn't know if he has CTE. That's because the neurodegenerative disease, which leads to dementia, confusion, memory loss, and erratic behavior, can only be diagnosed posthumously.
"The CTE, the brain stuff, is scary because you don't know," he told Circa. "I could be fine. I could live until I'm 100. I could go left next week."
In fact, Noble said he's begun to notice an uptick in his forgetfulness, recalling a moment from December.
"I remember around Christmas time, being out and driving, and just being like, 'Where in the hell am I going right now?' [I was] literally just at an intersection. I stopped and I called my wife. I was like, 'Where was I going?' But, you don't know. That could just be being busy, too."
Despite the first CTE diagnosis surfacing in 2002, the NFL didn't acknowledge the correlation between repetitive head trauma and the disease until March 2016. Jeff Miller, the NFL's senior vice president for health and safety, made the admission before a group of House Representatives in a watershed moment.
"Well, certainly Dr. McKee's research shows that a number of retired NFL players were diagnosed with CTE, so the answer to that question is certainly yes," Miller said. "But there's also a number of questions that come with that."
According to the CTE Center, the neuropathological disease doesn't have a cure, but researchers are conducting clinical trials to discover how it develops and progresses.