Brains don’t give up their secrets easily. An enlarged heart is self-evidently sick; a cirrhotic liver may look nothing like a healthy one. But a scrambled, damaged, degenerating brain may look perfectly fine — at least until you turn a microscope to it.
Dave Duerson, two-time Super Bowl-winning safety for the Chicago Bears and New York Giants, knew that. That’s why he shot himself in the chest last week instead of in the head; that’s why he texted his ex-wife first; and that’s why he left a note that said essentially the same thing his cellphone message had said: “Please, see that my brain is given to the NFL’s brain bank.”
The brain bank is a cooperative facility recently established by the National Football League and Boston University to conduct post-mortem analyses of players’ brains. There is a very real need for that kind of research — a need that has become painfully clear in the past few years. (More on Time.com: Former NFL Players Are Popping Painkillers and in ‘Poor Health’)
In 2010, University of Pennsylvania football player Owen Thomas committed suicide in his off-campus apartment. In 2009, Cincinnati Bengal star Chris Henry died in a domestic incident after he tumbled from the back of his wife’s moving pick-up truck during an argument. In 2004, former Pittsburgh Steeler Justin Strzelczyk died when he drove his car into a tractor trailer while fleeing police. All three suffered from chronic traumatic encephalopathy (CTE) a degenerative brain condition that can be caused by concussions and other brain trauma and can lead to erratic, violent and self-destructive behavior. Twenty other NFL retirees have have been posthumously diagnosed with CTE, and Duerson, who had worked with the NFL committee that oversees the league’s disability plan and had himself been experiencing head pain and blurred vision, suspected he might be another.
As I reported in a story in the January 31, 2011 issue of TIME, concussions and sub-concussive injuries are problems that affect more than just football players. Americans now suffer up to 3.8 million diagnosed concussions per year, a figure that doubled from 1997 to 2005. And since those are only the cases that make it to emergency rooms, there are many millions more that go entirely unreported — often because they cause few or no symptoms, even as they do microscopic damage to the brain all the same.
Athletes do suffer more traumatic brain injury than other people, and football players can suffer most of all. About 100,000 high school football players are concussed per year, and a recent study at the University of North Carolina found that college players suffer a stunning 950 to 1,100 sub-concussive injuries every season. (More on Time.com: Can Football Finally Tackle Its Injury Problem?)
“We’ve been collecting data at the collegiate level using accelerometers [in helmets] for about six years,” U.N.C. neuroscientist Kevin Guskiewicz told me when I was reporting my story. “There’s a three-fold increase in risk of depression among ex-NFL players if they’ve had three or more concussions during their careers and a five-fold increase in risk of mild cognitive impairment.”
Not all of those retirement problems are attributable to CTE — depression in particular is not uncommon when athletes have to leave the sport they love — but it’s becoming undeniable that many are. Worse, it’s not even necessary for a player to suffer a full-blown concussion for brain damage to be done. Thomas had never been diagnosed with a concussion at any point in his playing career, and yet his brain showed all of the telltale signs of long-term injury.
Those signs — which scientists at the Boston brain bank will now look for in Duerson’s brain — principally involve what are known as tau proteins, which are key structural components of brain tissue. When the head is violently shaken, connecting fibers among neurons are torn. The brain tries to repair the injury, but often it can’t keep up, particularly when the blows keep coming. This leads to sludge-like tau deposits which are detectable only by slicing and staining samples of brain tissue and examining them under a microscope. (More on Time.com: The Problem with Football: How to Make It Safer)
“Any concussion can lead to taus, but what we’ve learned is that it’s the repetitive nature of what used to be called mild brain injury that often causes CTE,” says neurosurgeon Julian Bailes of West Virginia University, who conducted the post-mortem study on Chris Henry’s brain.
More troublingly, says Bailes, it’s not just neurobiology that is working against players; it’s physics too. Football players colliding on the line of scrimmage are the worst kind of immovable forces, and as they’ve gotten both bigger and — significantly — faster, the energy they pack has increased exponentially. “The kinetic energy of a moving body is equal to one half its mass times the velocity squared,” is how Bailes and other scientists put it. That might be opaque, but here’s another way to think of it: When a player is running at a top speed of 18 mph, it’s the equivalent of 324 mph (18 times 18) for the purposes of determining how much energy his body and brain sustain on impact. Increase running speed to just 24 mph and your computational velocity goes up to 576 mph. (More on Time.com: Kids Competing Too Soon After Concussions)
“In youth football, concussions are not a big problem because they don’t get that velocity,” Bailes says. “[In college and the pros,] the velocity and the big battering ram helmets do the damage.”
And damage done at any time can be damage for life. “CTE is a progressive, degenerative disease,” says professor of neurology Robert Stern of Boston University, who will be part of the team analyzing Duerson’s brain. “It is our expectation that if someone has the disease it will progress over time regardless of additional trauma.”
Duerson played fast and played hard like every other pro — and he died violently like too many others as well. The final determination of CTE in his brain will await the studies in Boston. But even as the NFL does battle with its players over the league’s expiring labor contract and the possibility of a lockout, both sides ought to remember that the sport’s most fragile asset is not its TV revenue or ticket sales, but the very destructible men who play the game, and sometimes die for it.