Though it’s not the only sport in which concussions frequently occur (see “Heads Up,” below), football has been under heightened scrutiny since 2005. That’s when scientists at the University of Pittsburgh revealed that they had discovered a brain disease called chronic traumatic encephalopathy (C.T.E.) in the brains of former National Football League (N.F.L.) players. C.T.E. is caused by repeated hits to the head, and its symptoms include confusion, memory loss, dementia, depression, and suicidal thoughts. (C.T.E. can be definitively diagnosed only after death, though it may be suspected in a living patient.)
The findings forced the N.F.L. in 2009 to acknowledge publicly that football-related concussions can lead to long-term negative health effects. A rash of suicides of former players, including Hall of Famer Junior Seau in 2012, called increased attention to the issue. An autopsy on Seau’s brain revealed he had severe C.T.E.
The N.F.L. has since stated that it expects nearly a third of retired players to develop permanent brain impairments, such as Alzheimer’s disease or other forms of dementia. And a study released last year by researchers at Boston University and the VA Boston Healthcare System painted an even starker picture: It examined the brains of 111 former N.F.L. players, and all but one had C.T.E.
It’s not only N.F.L. players who are at risk of brain damage. The study showed that 76 percent of the 67 former high school and college football players’ brains examined had C.T.E. too.
High school players are particularly vulnerable to damage from blows to the head, especially if they’ve had concussions before (see “Inside a Concussion,” below). A teenage brain can begin to show C.T.E.-related symptoms if another blow to the head is sustained soon after a concussion, according to a 2018 Boston University study.
There can also be a more immediate consequence to these hits. Last month, a 16-year-old high school football player in Georgia died two days after sustaining a head injury in a game. A 17-year-old high school football player in Washington State died in 2015 after a routine collision following a concussion. And a 16-year-old player in Oklahoma died in 2015 shortly after sustaining a head injury while making a tackle.
“A teenager’s brain is still developing,” says Martha Shenton, director of the neuroimaging lab at Harvard Medical School. “Even a moderate hit to the head following a concussion can be fatal because the brain hasn’t healed from the previous blow.”