Steph called it the scariest fall of his career. “You’re in the air for a long time,” he said after the game, “not knowing how you’re going to hit the floor, knowing that it’s inevitable.” Curry’s taken harder hits—and come away with worse symptoms—but that second-and-a-half or so of unexpected flight was the scariest. For the Warriors, that fear likely extended through the 15 or so minutes Curry returned to play in the second half, or at least it should have, because even though Curry passed the NBA’s concussion protocol, the team didn’t know for sure that Curry didn’t have a concussion—because it couldn’t have.

In November of 2012, the 4th International Conference on Concussion in Sport was held in Zurich, where a collection of researchers made their recommendations for research and standardization of brain injuries in sports. Among other things, they differentiated the term “concussion” from “mild traumatic brain injury” (mTBI), since they functionally describe two different things. (The researchers slipped a nerd-burn on the U.S. into the text, noting that the conflation happens most “in the sporting context and particularly in the U.S. literature.” Yeah, well, suck one, Zurich dweebs.) You know the difference between a full blown CONCUSSION and the structural degradation of the brain from the NFL’s adventures in medical misdirection, and it isn’t too surprising that the same remedial reading is applied to other leagues’ rulebooks, albeit less perniciously.

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A concussion, as it’s clinically diagnosed, is about symptoms; it’s a subset of the broader traumatic brain injury family. This definition encompasses trauma to the head area that “typically results in the rapid onset of short-lived impairment of neurological function that resolves spontaneously.” Rapid is a useful word here, because in everyday parlance it’s understandable as the minutes following an accident. As it’s used here, though, it describes the window in which symptoms can present themselves, which quite commonly can be hours later, or even the next day. Definitionally, a test taken in time to determine whether or not a player can return to action can’t take into account symptoms that haven’t presented themselves yet.

So when Curry says that he wasn’t suffering concussion symptoms—or actually, that they were “minor” compared to what previous blows to the head did to him—all he’s saying, all the test is saying, is that as far as anyone could tell, Curry didn’t seem to be suffering a worrying amount of ill effects from falling six feet or so backwards and cracking his skull on the hardwood. (At least, none beyond staring dead-eyed into the distance whenever the camera caught him between plays in the second half.) This is good news obviously, and much better than Steph leaking gray matter down the back of his away uni, but it says something specific about the limitations of concussion and brain trauma tests as they exist in sports. Specifically, it says they’re very hard, and also suck.

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At the podium after the game, Curry repeated over and over that the important thing was for him to make sure everything was okay before re-entering the game, and that nothing had gotten any worse since the incident. He said he went through some agility drills, rode the bike, and did some sprints in the hallway to make sure that symptoms didn’t crop up while he was running around. These are a good baseline. Protocols like the SCAT3 tests will require testing the eyes, cognitive response (e.g. reciting a set of random digits backwards), and a variety of other things like range of motion in the neck or coordination. They’re pretty good tests, just rushed.

They’re also eminently gameable. I took one of these tests a few years back, and cognitive response time was judged by a simple test using a yardstick-like instrument with a weight at the bottom. The administrator would hold the stick in front of your open hand, and drop it suddenly; your grade was how much length you let pass before you caught it. Ideally, you’d take a baseline of your un-concussed brain, to be referred to after you slam dunk your frontal lobe. The response (for me at least) was shockingly consistent, but it was also consistent when I tried to game it and wait a half-beat longer to catch it.

Around the NFL’s research, we’d call this the “criminal players are undermining our righteous scientists” line of defense. In the NBA, where crushing institutional pressure to play through serious injury to ruinous long-term effect isn’t as prevalent, it seems more like a matter of course. Naturally some players will want to maximize the odds they can keep playing, particularly in a sport where impacts and collisions are more voluntary than they are in football. This isn’t to say Steph did this—again, he at least sounded like he wanted to be sure he was okay before trudging back into a game the Warriors were losing by 20 in a series they were winning 3-0—but to put a point on the limitations of the “concussion protocol” run out by sports.

Now take the widespread credulity with which these tests are reported. Here’s Woj at Yahoo endowing them with sentient roster management capabilities:

For 45 minutes – through the end of the second quarter, halftime and into the third quarter – the Warriors doctors and trainers examined Curry. The NBA has a concussion protocol, a battery of tests that must be administered and aced before a player can be cleared for a return. Had there been a concussion, Curry would’ve been sidelined until he shed those symptoms – and who knows how long that could’ve extended?

That isn’t to pick on Woj, or even Mike Breen, who spent last night reciting “head contusion” enough times that it almost sounded like he began to believe it meant something—it’s a tricky distinction. So why not just get a better test? Because the clinical trauma and symptoms don’t match neuropathological definition, necessarily.

A brain injury has to be borderline catastrophic to show up on traditional “brain tests” like a CT or MRI—tests that look at blood flow and swelling and physical, spatial differences in the brain. (The fMRI, for example, observes cerebral blood flow, but minor inflammation won’t necessarily cause any difference in the flow of blood.) Remember: symptoms vs. brain structure. While a clinical diagnosis is about showing symptoms, the actual underlying damage to your brain is much harder to detect.

Using this structural set of criteria, a concussion is a rotational injury to the brainstem (caused by torsional impact) in which some the connective tissue snaps off, causing trauma to the brain. The instability of the brainstem then leads to the metaphor you’ve probably heard, of a brain with no seat belt smacking into the inside of your skull, causing damage that isn’t much different from a bruise. The important thing to remember here, though, is that the snapped tissue in your brain stem doesn’t grow back, which is why previous brain injuries are a serious risk factor for the future. No one wants Steph Curry to be Sid Crosby in a tank top.


So structural problems are hard to see, and symptoms don’t always present until after the window during which a player is being evaluated. This is why a review of current literature on brain injuries suggests that even players who aren’t showing symptoms should probably be held out of play, due to the compounded structural risk as well as the risk of unrelated injuries if a guy’s balance gives out all of a sudden after he’s returned to the court.

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These are all real concerns with valid medical backing. But in a sport like basketball, where brain injuries are more faint risk than cover fee, sending a player back onto the court when he’s showing no clinical symptoms (but who looked to all the world like a drunk guy trying very hard to look sober) is a risk born from medical reality, and no more provably unethical than shooting a knee full of cortisone so it can drag your small forward through a series before being surgically repaired in the offseason, and replaced in a decade or two, and cause a lifetime of chronic pain thereafter.

Photos via Getty Images Sport

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