The massive legal action brought by former players against the National Football League has been known as a concussion lawsuit.
But make no mistake, experts say. The brain degeneration known as CTE is at the heart of the civil suits by more than 5,000 former players and surviving family members that are now pending in U.S. District Court in Philadelphia.
Bob Fitzsimmons, a Wheeling, W.Va., lawyer who helped found the Pittsburgh-based Brain Injury Research Institute to study the disorder, said that "whether you call it CTE or permanent damage to the brain, it's a key factor in the proceedings."
"If a person had a concussion and they had no residual damage, in my opinion, why are they involved in the lawsuit? You had your concussion, you're healed, you're OK. I think it's the risk of development of permanent damage" that is the key issue for many former players.
The significance of chronic traumatic encephalopathy is reflected in the formal language of the complaint.
"The NFL defendants have known or should have known for many years," the complaint says, "that neuropathology studies, brain imaging tests, and neuropsychological tests on many former football players have established that ... players who sustain repetitive head impacts ... have suffered and continue to suffer brain injuries that result in any one or more of the following conditions: early-onset of Alzheimer's Disease, dementia, depression, deficits in cognitive functioning, reduced processing speed, attention and reasoning, loss of memory, sleeplessness, mood swings, personality changes, and the debilitating and latent disease known as" CTE.
CTE also is implicated in the suicides of several of the plaintiffs, including former linebacker Junior Seau and former defensive backs David Duerson, Ray Easterling and Andre Waters. In an unusual pattern, Seau, Duerson and Easterling shot themselves in the chest, and both Duerson and Easterling left suicide notes asking that their brains be donated for study.
While those cases are especially emotional, CTE's impact on potential damage awards in the lawsuit will be even more important for the players who will go on living for years and may need long-term medical and daily living assistance.
Right now, both sides are waiting for a critical ruling by U.S. District Judge Anita Brody on the league's argument that all health and safety issues, including head injuries, are covered under the league's collective bargaining agreement with the players association.
If she agrees, it would shift the cases to individual arbitration by each team.
If she rejects that argument, the high-powered lawyers on each side will begin arguments on three critical issues.
First, how much did the NFL know about the risk of brain injuries from playing the game, and for how long?
Second, did the players contribute to the problem by concealing concussions or lobbying to return to play too soon?
And third, if the league knew or should have known about the risks, how big should the monetary damages be?
That last issue will be heavily shaped by the research on CTE and whether there is a direct connection between head trauma and the protein deposits associated with the disorder.
If the court does decide that head injuries lead to CTE, it could escalate potential damages by millions of dollars by requiring long-term monitoring and care of former players.
Some brain experts, including those advising the NFL, have cast doubt on the link between blows to the head and CTE, while others who are studying the disorder say there is no other reasonable explanation.
Ann McKee, a Boston University pathologist and leading CTE researcher, said she is convinced the disorder comes from brain impacts. "In all my years of looking at brains, I've never had anyone come to me and say, I think I'm seeing this same thing without a history of head trauma."
But the lack of an alternative explanation is not proof, others say.
William Meehan, a Harvard University concussion expert, said the research done over the last decade by Dr. McKee and Bennet Omalu, a pathologist affiliated with Pittsburgh's brain injury institute, is "great work. They have made an observation and developed hypotheses that explain that observation, and what we're starting to do now is check those hypotheses to get at the truth."
Dr. Meehan is part of a Harvard group that recently received a $100 million grant from the NFL Players Association to do a long-term study of what factors lead to brain damage in football players.
Matthew Mitten, director of the National Sports Law Institute at Marquette University, said another key issue in the NFL lawsuit is whether the league engaged in fraud.
If the NFL merely "should have known" about the risks of brain injuries, then anything the players did to conceal risks -- returning to the field even though they were still suffering symptoms, for instance -- could be seen as "contributory negligence" that would reduce the league's liability, Mr. Mitten said.
But if the league knew for sure about brain damage risks and concealed that information from players, the contributory negligence argument goes out the window, and the league could be found guilty of fraud, he said.
No matter which way Judge Brody rules, both sides are expected to appeal, which could drag the case out for years.
From a financial and public image standpoint, though, there might be pressure on both sides to settle out of court.
In a recent overview of the case in BloomsburgBusinessweek, writer Paul Barrett noted that even if the league settled for $5 billion, if that was paid out over 25 years and divided among the 32 teams, it would cost each team $6.25 million a year -- "a meaningful tax ... but one the franchises could absorb without much distraction."
William Gibbs, a Chicago attorney representing Duerson's family in the lawsuits, said last year that he actually thinks NFL Commissioner Roger Goodell is "a good man" who is trying to reduce head injuries in the pro game.
"But I just don't understand why the league won't take care of the guys who were so critically affected by this. It just seems that instead of litigating thousands of lawsuits over the next 10 years, the money they will spend in that litigation could be utilized to take care of those guys."
Wheeling's Mr. Fitzsimmons is also dismayed by the lawsuits.
"What I want to say to all the parties is, 'everybody just stop.' The bottom line is safety, and that's not just the safety of professional football players but of our children and all the millions of people who engage in activities that potentially involve contact to the head.
"So let's get the most independent research we can, better identify the problem, make the measurements more reliable, and see if we can't come up with rules, regulations or medication -- anything that would potentially stop this condition or treat it. Everybody needs to step back and do the right thing."
Mark Roth: email@example.com or 412-263-1130.