CHICAGO (AP) -- After thousands of hits to his head and confronted with troubling symptoms, NFL Hall of Famer Joe DeLamielleure is sure he has the devastating brain disease CTE -- even though the strongest scientific evidence says it can only be diagnosed in the dead.
He is certain because researchers trying to develop a test for CTE have essentially told him so, based on preliminary and unproven results.
To the 62-year-old DeLamielleure, the results are reassuring, offering a potential explanation for his sudden anger, depression and sleeplessness.
"They're absolutely positive I have it. You can see it on the X-ray," DeLamielleure said by telephone from his home in Charlotte, N.C.
The former Buffalo Bills offensive lineman and several other retired players were tested last year at UCLA by researchers who told them that changes seen on the scans are consistent with CTE. They were told their brains resemble those of retired players who killed themselves and were diagnosed with CTE during autopsies.
Dr. Julian Bailes, co-director of the NorthShore Neurological Institute in Evanston, Ill., is part of that research team -- one of many groups racing to develop methods to diagnose and eventually treat CTE. Bailes and co-researchers at UCLA think they're leading the pack with a PET scan technique to detect abnormal brain buildup of a protein called tau. The test involves injecting a special chemical marker that is designed to bind to tau deposits in the brain; those areas light up on the imaging scans.
Their first results in living patients -- five former NFL players, including DeLamielleure -- were published last year. Research involving about a dozen more former athletes and others with multiple concussions is expected to be published later this year.
For many skeptics, including doctors, neuroscientists and researchers working on developing different detection methods, CTE testing in the living is too preliminary to make any kind of diagnosis and raises serious ethical questions. The disease is progressive and can't be cured.
Robert Stern, a scientist with Boston University's Center for the Study of Traumatic Encephalopathy, has a National Institutes of Health grant to do that kind of research; his team has examined more than 70 former NFL players so far. He said results so far are promising, and medical ethicists have been consulted for guidance on what to tell players about the findings.
"This is a very complex issue, because, No. 1, we don't truly know what many of the tests might mean. No. 2, this is a very vulnerable group of people who are scared to death about seeing their brothers have such significant cognitive and behavioral and mood changes," Stern said.
"There has been so much hype about this issue," he added. "The awareness and the attention to CTE has grown so tremendously in the last three to four years, but it has grown much, much faster than the science could possibly grow. We're still in the early infancy of our scientific knowledge of this disease."
Several former NFL stars have been diagnosed with the disease after death in recent years, including Junior Seau, Dave Duerson and Ray Easterling. All of them had troubling symptoms and committed suicide. Thousands of former players have sued the NFL, claiming the league withheld information about damaging effects of repeated head blows and concussions. DeLamielleure is among them, and he is also among those who have agreed to donate their brains to CTE researchers.
DeLamielleure estimates he endured more than 200,000 head blows during his 13-year NFL career -- "dings" that made him see stars but didn't worry him much -- until word started spreading about CTE. When he learned last year about the experimental test, DeLamielleure eagerly volunteered.
"When I read what happened to Junior Seau and Dave Duerson -- they didn't sleep, had wild mood swings, and shot themselves in the chest -- I wanted to know what I was going through before something happened," he said.
There is much that isn't known about CTE, including why some athletes with a history of head blows never get dementia or other debilitating symptoms, who is most prone and whether genes or other health conditions increase the risk. Some of the symptoms occur in many people who never played contact sports, and in other diseases, including Alzheimer's.
And some of the symptoms in former NFL stars may have nothing to do with head blows.
Leonard Glantz, a bioethicist at Boston University's School of Public Health, said CTE tests in the living should be billed as experimental and that participants should understand they are research subjects, not patients.