If neuropathologist Ann McKee finds that the brain of Dave Duerson is atrophied and stained with brown, it will be a sign the former Bears safety is the latest NFL player to be linked to a disease formerly associated mainly with boxers taking repeated punches to the head.
McKee has 67 donated brains from those at risk of head injury waiting to be examined for signs of chronic traumatic encephalopathy, or CTE. And the list of donors is growing rapidly, reflecting growing concern in the NFL and the public over the ramifications of repeated concussions and head trauma experienced on the field.
Duerson, 50, who died from a self-inflicted gunshot wound last week, aimed at his chest rather than the head. Just before this last act, Duerson asked his family via text message to donate his brain to the NFL, which works with the Center for the Study of Traumatic Encephalopathy (CSTE) at the Boston University School of Medicine. The results of the analysis, which will come back in three to six months, may provide a window into his actions.
Bears linebacker Hunter Hillenmeyer is one of just a handful of active players who have pledged to donate their brains to the center, which currently has more than 370 people on the living donor registry. Football players make up the vast majority, followed by hockey players and wrestlers.
So far, McKee has analyzed the brains of more than 45 athletes; more than 30 have shown evidence of CTE, including 13 of 14 former NFL players.
Earlier this month, former Bears quarterback Jim McMahon agreed to donate his brain to the school. Now 51, McMahon has been having short-term memory issues and said he often feels dazed.
"I believe in being proactive," said McMahon, who also will be participating in clinical trials at the center, a partnership between Boston University and the Sports Legacy Institute, a concussion education program. While he can remember events in his past — including Super Bowl XX — "I can't remember why I walked into a room or what I was going to do in there," he wrote in an e-mail to the Tribune. "Occasionally while driving I forget where I am going or why I am going to that place."
The critical question is whether Duerson was suffering from CTE, which is linked to memory impairment, emotional instability, erratic behavior, depression and problems with impulse control. Eventually, CTE, a chronic neurodegenerative disease, progresses to full-blown dementia, though it's distinct from Alzheimer's.
"There's a long latent period between the time the individual has the brain trauma and the time the symptoms develop," said McKee, a co-director of the CSTE and the Director of Neuropathology at the Bedford VA Medical Center, where the lab work will take place.
Normal brains, when specially prepared with a dye, appear blue. McKee will be looking for evidence showing that the brain has shrunken or atrophied. These areas of the brain would appear brown because of buildup of a protein called tau.
Initially, CTE was called "dementia pugilistica" because it was thought to affect only boxers. While most cases are athletes, about 10 percent are not; of those, the largest affected population is military veterans. Others who are susceptible include those who have been physically abused, epileptics and developmentally challenged children who bang their heads, said McKee.
While most brain injury research is concussion-related, overall brain trauma that didn't necessarily cause a concussion may be more important, said Dr. Robert Cantu, a co-director of the CSTE and a senior adviser to the NFL's head, neck and spine committee.
"We know college football linemen, on average, take over 1,000 hits to the head a season over 20 G-force," Cantu said. "That's not a concussion, that's just helmet to helmet contact."
One way to gather more precise scientific data would be to scan a player's brain before he dies to possibly detect CTE in living athletes. At Brigham and Women's Hospital in Boston, a team is recruiting volunteers for "virtual biopsies" using advanced MRI technology. Volunteers spend 45 minutes in an extra-wide scanner; the results allow the scientists to see biochemical changes in the brain that may be related to CTE, said Dr. Alexander Lin, the principal investigator of a pilot study conducted at the Center for Clinical Spectroscopy at Harvard Medical School.
Former NFL player Brent Boyd, 50, was one of five former athletes with a history of concussions who participated in Lin's study. His results showed significant changes in his brain biochemistry that may be related to CTE, Lin said, though nothing can be officially declared until after his death when his brain tissue can be sampled.
Boyd and Duerson testified before a congressional committee in 2007 about brain injuries. Boyd, a former All-America lineman at UCLA who played professionally for the Vikings, attributed his suffering from depression, brain damage and homelessness to playing football. Duerson was unconvinced.
Boyd is the founder of the NFL retired players advocacy group Dignity After Football and was one of the first living athletes to join the brain registry. He has been trying to raise awareness about brain trauma since 2006.
He graduated with honors from college and was planning to go to law school, but he said his brain was so changed by concussions that he knew he couldn't withstand the workload. Boyd said he never would have played if he had known what was going to happen to his brain.
"I spent decades being ashamed of my mental and financial condition," he said. "It's one thing to break your leg. But break your brain, and it takes away your life."