ROSEMONT, Ill. -- At the outset of the NFL's "concussion summit" Tuesday morning, directors of the symposium distributed two pink index cards on which each participant could submit any questions that they wanted to pose to any of the medical experts gathered here to discuss what has become a hot-button issue for the league.
The reaction of 15-year veteran defensive back Troy Vincent, who is president of the NFL Players Association, and who has suffered seven documented concussions in his career?
"I asked for more cards," Vincent said.
That pretty much synopsized the problem which confronted the researchers, team doctors and trainers who came here to exchange ideas and opinions on how to manage concussions in the league. During a day-long series of presentations that commissioner Roger Goodell called "an important day for the National Football League," and even with the participation of some of the country's leading experts, including four researchers who have prominently dissented from the league's stance on concussions, there were still more concerns than there were pink index cards.
And, at least for now, there remain considerably more questions than answers.
In that the conference was the first one ever in the NFL devoted solely to the discussion of mild traumatic brain injury, and the first time the league has invited longtime dissenters such as Dr. Robert Cantu and Dr. Kevin Guskiewicz, the ambitious undertaking was certainly a unique one. It brought together men of divergent and passionate opinions but, as Goodell noted, with one purpose: further protecting the well-being of NFL players.
"We have no other agenda, and vigorous debate is part of advancing that agenda," said the commissioner, who emphasized that the NFL has been conducting concussion research for 14 years, in his opening remarks to the participants.
Long a critic of the NFL's concussion analyses, Guskiewicz, the lead author of a study by the University of North Carolina which concluded from surveys that players who sustained multiple concussions during their careers were more susceptible to mental impairment, said he was "very encouraged" by Tuesday's session. And Cantu called the Tuesday symposium a "great scientific exchange."
Yet for all the good work accomplished Tuesday, there were no league standards that were adopted to ascertain when players should or shouldn't be permitted to return to play. Many of the participants here acknowledged that the most notable revelation was that, even with the increased focus on concussions, there is still much more research needed to understand what Dr. Michael L.J. Apuzzo called "the most exquisite part of the body."
"People talk about so-called 'mind games,' but we don't want to be playing games, really, with the minds, the brains of people," Vincent said. "This was a tremendous event and, in the long run, it will mean a lot to players. But after listening to all the experts, I'm still not sure I even know what a concussion is. So the debate goes on."
Fueling the debate, and clearly providing the impetus for Tuesday's sessions, were the four fairly recent deaths of former league players. In the cases of all four -- safety Andre Waters and offensive linemen Mike Webster, Terry Long and Justin Strzelczyk -- pathologists found evidence of chronic traumatic encephalopathy, more commonly known as punch-drunkeness.
One problem: The body of work is small, in general because, practically speaking, a person must be deceased in order to conduct such invasive research on the brain. It is difficult, then, to make sweeping conclusions about the scope of such brain damage. And as Dr. Apuzzo pointed out, to draw far-reaching assertions would take extensive study and the ability to compare the population of NFL players over a given period to the population at large over the same time span.
Still, there is legitimate concern and, Goodell, who has quickly championed a number of causes in his first year as commissioner, has made the concussion research a priority. A six-year study by the NFL revealed an incidence of .48 concussions per game, but even that number may be somewhat arbitrary, since players are loathe to report the symptoms of concussions and even more reluctant to be sidelined by what appear as mild head injuries.
"Guys don't ever want to admit they're dinged," said 11-year veteran tight end Ernie Conwell, one of three players who sat in on the discussions. "In that regard, we're our own worst enemies. Sometimes we have to be protected from ourselves."
Noted Vincent: "To ask a player with a head injury if he wants to go back into a game, that's not exactly the best thing. Most players are going to make the emotional decision. They're going back onto the field."
The league's answer for that is a whistle-blower system that will be introduced in camps. It allows anyone to anonymously report when doctors are pressured to clear players or players are pressured to play with concussions. Also, rules requiring players to properly buckle
their chin strap will be enforced. And a brochure will be distributed to players to help educate them and their families about concussions.
Both Goodell and Apuzzo stressed that, while the recent deaths of the four players so often cited in concussion debates seem to indicate an inherent danger of long-term brain injury for players, head injuries and their incidence must be viewed in a bigger picture. A player's entire medical history, said Goodell -- who mandated that every team send its physician and trainer here and who has ordered that every player in the league undergo neuropsychological testing in training camp, to determine baseline measurements -- must be considered.
"We need to determine the genetic profile of people who will be at risk," Apuzzo said.
What may have been accomplished on Tuesday was a greater understanding by team doctors and trainers of how diligent they must be, and how essential it is for them to err on the side of caution before returning a player to a game. Because the brain is such a complicated but fragile thing, one trainer said, each case is an individual puzzle. But doctors and trainers, who spend the entire season with a team, come to know players well, and should be able to discern in many cases even subtle changes.
"I think we will, somewhere down the road, have very stringent standards, especially after we get the baseline testing done," Conwell said. "But for now, it's still a case-by-case thing. I mean, I listened really closely to everything being said in the presentations, because player health issues have really become a passion for me. And the general message was, like, 'In conclusion, there are no hard-and-fast conclusions that apply across the board.' So while this was a great thing, there's still a long way to go."
Len Pasquarelli is a senior writer for ESPN.com. The Associated Press contributed to this report.