The McHale case was announced Tuesday afternoon at a news conference in Tampa — where McHale had lived and where the Super Bowl will take place Sunday — held by Boston University’s Center for the Study of Traumatic Encephalopathy.  “This is a medically significant finding,” said Dr. Daniel P. Perl, the director of neuropathology at the Mount Sinai School of Medicine in New York who is not affiliated with the Boston University group. “I think with a sixth case identified, out of six, for a condition that is incredibly rare in the general population, there is more than enough evidence that football is clearly strongly related to the presence of this pathology.”  Dr. Ira Casson, a co-chairman of the N.F.L. committee that has studied concussions since 1994, said he could have no reaction until the McHale case and other recent C.T.E. findings appear in a peer-reviewed scientific journal.  “It’s very hard to react to things and to case studies that are not presented in appropriate, scientific form and have not gone through peer review,” said Casson, a neurologist at Long Island Jewish Medical Center. He added: “I think that there are many questions that still are out there as to whether there is a kind of traumatic encephalopathy associated with football. I think we don’t know. I think that there is not enough scientific evidence to say that there is.”  Dr. Ann C. McKee, a co-director of the Boston University group, said that she was completing a paper on the football C.T.E. cases that could be published as early as May. She added that the presence of C.T.E. in McHale and in a previous case, the former Houston Oilers linebacker John Grimsley, were confirmed by Dr. E. Tessa Hedley-Whyte, the director of neuropathology at Massachusetts General Hospital.  McHale played on N.F.L. offensive lines for nine seasons, most of them with the Buccaneers, before retiring and running several Tampa-area restaurants. According to his widow, Lisa, he developed such chronic pain in his shoulders and other joints that in 2005 he began taking improperly large doses of the painkiller OxyContin, which exacerbated his lethargy and depression and led him to take cocaine occasionally to offset those effects.  McHale spiraled downward, went through drug rehabilitation three times, and died on May 25, 2008, of a lethal — and deemed by the police, accidental — combination of oxycodone and cocaine. His death shocked many former teammates and players, several of whom remembered him as an intelligent and responsible man.  Lisa McHale said she did not recall her husband’s having any concussions in college, he attended Cornell University, or in the N.F.L. McKee said the brain damage Tom McHale developed — which drug abuse cannot cause, doctors added — probably played a role in his self-destruction in his final years.  “You would expect the symptoms of lack of insight, poor judgment, decreased concentration and attention, inability to multitask and memory problems,” McKee said of the damage she found in McHale.  Lisa McHale said that the finding of C.T.E. in her husband’s brain gave her some solace by offering a more tangible explanation for his emotional demise, and perhaps sparing him from a bleak future. According to Dr. Robert A. Stern of Boston University, who conducted the McHale investigation with McKee, had McHale lived, he probably would have had full-blown dementia by age 60.  “I really was just overwhelmed with sadness for Tom, that his brain was in that state,” Lisa McHale said. “All of our efforts that I had been witnessing the last couple of years, where he was putting all of himself into trying to get better and trying to regain his former self and working so hard and being so frustrated, it hit me hard.”  Only one N.F.L. player examined for C.T.E. has not shown the condition — running back Damien Nash, who collapsed in 2007 while playing basketball at age 24. The progressive disease is virtually never found in anyone that young.  “I’m hoping that six of six is finally going to turn people’s heads,” Lisa McHale said of the 36-to-50 age group, which included Grimsley; the former Philadelphia Eagles defensive back Andre Waters; and the former Pittsburgh Steelers Mike Webster, Terry Long and Justin Strzelczyk. “We’re not talking about turf toe — we’re talking about a significant brain injury that has huge implications in terms of people’s health. If they can finally let players know what the risks are, it won’t bring Tom back, but it would make his death a great deal less meaningless.”  An N.F.L. pamphlet given to all players, emphasizing the seriousness of concussions and the procedures regarding them, says that “current research with professional athletes” has not shown that multiple concussions have long-term effects “if each injury is managed properly.” It does not say that that research was conducted by the N.F.L.’s own committee, and that outside published research on N.F.L. retirees has shown increased risk for cognitive impairment, depression and dementia. The pamphlet also makes no mention of the C.T.E. cases, whose increasing number is convincing many experts that subconcussive brain trauma can have cumulative effects.  Jeff Pash, the N.F.L.’s executive vice president for labor, said the league committee was continuing its own study of retired players, which began in 2007 and will probably not be published until 2011 or 2012. Regarding the McHale finding and the reported link between C.T.E. and cognitive decline, Pash said: “I look forward to seeing this report. It’s something we’re paying a lot of attention to.”  Pash added, in defense of the league’s wait-and-see approach: “There are a great many people who have played football and other contact sports for many years and at high levels who do not appear to have suffered these types of deficits. Whether it’s President Ford or major business leaders, whether it’s people on television.”  Perl said that many members of a group not having a condition is irrelevant to the question of how many do have it, and why.  “Let’s say 20 percent are susceptible to something — 80 percent are not going to show anything,” he said. “But if 20 percent have what should otherwise be a very rare condition, and that could be the case here, you can’t rely on the 80 percent to suggest there is no problem.”  A version of this article appears in print on , on Page B11 of the New York edition with the headline: Sixth N.F.L. Player’s Brain Is Found to Have Damage. Order Reprints| Today's Paper|Subscribe
Damage found in the brain of former N.F.L. lineman Tom McHale further stokes the debate over the significance of such findings.