Researchers in Chicago report that they have detected evidence of chronic traumatic encephalopathy, more commonly known as CTE, in a living patient for the first time. 
 
 Currently, CTE, a degenerative brain disease found in those with a history of repetitive brain trauma, can only be formally diagnosed after an autopsy. But a new study indicates researchers may be one step closer to being able to diagnose the disease while a patient is still alive by detecting deposits of tau proteins. 
 
 Scans performed on 14 retired NFL players while they were still alive indicated the presence of tau, a type of protein that clumps up over neural cells that have been damaged, according to a study published in the Journal of Neurosurgery. The protein slowly spreads throughout the brain, killing brain cells, according to the Concussion Legacy Foundation. 
 
 Eric Gay/AP 
 
 When one of the former players died, doctors were able to determine whether the "distinctive CTE pattern" that resulted in his scan actually indicated the presence of the disease. 
 
 Once the man's brain was examined after his death, doctors made the official CTE diagnosis, according to the study. 
 
 The man was 59 when his brain was scanned, according to the study. Two years later, at age 61, the man's wife noticed that he had been experiencing progressive motor deficits, such as the inability to button his shirts, zip his pants or tie his shoes. Eventually, he was no longer able to feed himself. He had also developed muscle twitching in his arms and decreased muscle mass in his shoulders and arms, the study states, and in addition to what doctors presumed was CTE he also suffered from amyotrophic lateral sclerosis, often called ALS or Lou Gehrig’s Disease. 
 
 In the final months of his life, the man was admitted to a nursing home for dehydration, failure to thrive, progressive dysphagia, incontinence, progressive neck and limb weakness, and slurred speech, according to the study. 
 
 The man began playing football at 11 years old and continued until he retired from the league at 33, which placed his "cumulative lifetime risk exposure" at 22 years, according to the study. 
 
 While more research is needed to corroborate the result of the exam, the ability to identify CTE in the brain of a living patient is the first step toward understanding the development of the disease and developing a cure, the researchers said. 
 
 The findings from the study also confirmed that a "fingerprint" signature of CTE that was previously reported exists, according to the study. 
 
 One of the researchers, Julian Bailes, M.D., director of neurosurgery and co-director of NorthShore University HealthSystem Neurological Institute, told ABC News that his team was "pleased " with the study. 
 
 “The importance of this one today is that this is the first time to have a scan which shows brain degeneration of CTE in a living person and then to have that person die and it correlates with the autopsy,” Bailes said, adding it’s the first such case to his knowledge. 
 
 “We realize and always want to acknowledge that this is only one and more work needs to be done to verify the correlation,” he said, adding that for now the team is “very, very pleased.” 
 
 CTE is often found in athletes, military veterans and others with a "history of repetitive brain trauma," according to the Concussion Legacy Foundation. 
 
 ABC News' Michael DelMoro contributed to this report. ||||| Four years ago, researchers from Evanston’s NorthShore University HealthSystem and other scientific organizations announced they had used brain scans to detect the hallmark of chronic traumatic encephalopathy, or CTE, in ex-NFL players while they were still alive — a technique that promised to spur more accurate diagnoses, and possibly new treatments. 
 
 The scans indicated the presence of tau, a protein that builds up over damaged brain cells. But the scientists cautioned that the results needed to be confirmed, because CTE, a dementia-like disease linked to repetitive head trauma, can be definitively diagnosed only by examining brain tissue after a person’s death. 
 
 Dr. Julian Bailes, a NorthShore neurosurgeon, said Wednesday that confirmation has arrived. 
 
 In a paper published last week in the journal Neurosurgery, Bailes and other researchers reported that one of the former players who underwent a scan had his brain examined after he died — and sure enough, the tissue revealed he had been suffering from CTE. 
 
 More research is needed to corroborate the result, but if it holds up, Bailes said it could be a pivotal step in finding a way to help people with the condition. 
 
 “If there’s ever a treatment developed, you can test the response to it,” he said. “If you can trust the scans, you can tell a football player he shouldn’t keep playing, or tell someone in the military he can’t (be exposed to) explosions.” 
 
 The paper does not name the ex-NFL player, but his family confirmed it was Fred McNeill, a former linebacker for the Minnesota Vikings who died in 2015. 
 
 Four years ago, researchers announced that they had used brain scans to detect the hallmark of CTE. (Nov. 16, 2017) Four years ago, researchers announced that they had used brain scans to detect the hallmark of CTE. (Nov. 16, 2017) SEE MORE VIDEOS 
 
 Dr. Bennet Omalu, the pioneering CTE researcher portrayed by actor Will Smith in the 2015 movie “Concussion,” is the lead author on the Neurosurgery paper. Last year Omalu told CNN that McNeill underwent the tau-detecting brain scan. After McNeill’s death, Omalu said he found signs of CTE in the athlete’s brain tissue. 
 
 Omalu is part of a company called TauMark that is trying to commercialize the brain scan technology (Bailes said he is not involved). 
 
 The Neurosurgery paper says its subject played football for 22 years, including 12 in the NFL. He had only one reported concussion, suffered when he was in college, and didn’t even have his “bell rung” very often. 
 
 When he was done playing, he went through law school, joined a firm and became partner. A few years after that, though, he was dismissed for poor performance. The same thing happened at least twice more until he finally stopped practicing law and filed for bankruptcy. 
 
 Jim Mone / AP Green Bay Packers tight end Paul Coffman, left, is pursued by Vikings linebacker Fred McNeill on Nov. 29, 1981. Green Bay Packers tight end Paul Coffman, left, is pursued by Vikings linebacker Fred McNeill on Nov. 29, 1981. (Jim Mone / AP) (Jim Mone / AP) 
 
 By the time he was 59, he was showing distressing behavioral traits researchers believe are signs of CTE: memory loss, depression, a lack of impulse control and a bad temper. Two years later, his motor skills deteriorated until he couldn’t feed himself. 
 
 Toward the end of his life, McNeill was diagnosed with amyotrophic lateral sclerosis, a disease that causes muscles to weaken and waste away, along with presumptive CTE. He died at 63. 
 
 Brain scans are just one diagnostic tool scientists are trying to develop to combat CTE. Researchers at Boston University announced in September they had found higher levels of a protein called CCL11 in the brains of people diagnosed with CTE, and that it might be possible to use that as a biomarker to detect the disease in the living. 
 
 But Dr. Lili-Naz Hazrati, a neuroscience researcher at Toronto’s Hospital for Sick Children, said no matter the technology, reliable CTE detection still appears far away. 
 
 She said the tissue images included in the Neurosurgery paper did not convince her that the ex-NFL player actually was suffering from CTE. Tau is associated with other neurological diseases, including Alzheimer’s, and can also be present in healthy brains, she said. 
 
 Figuring out a way to definitively diagnose the disease in living people is important because early detection improves the odds of successful treatment, she said. But she said scientists have yet to find biomarkers that identify Alzheimer’s — a disease that has been studied for more than a century — and CTE will likely prove no easier. 
 
 “When there’s such a diversity (of diagnostic techniques) and no one seems to be finding the same thing, it’s really hard to validate the findings,” she said. 
 
 jkeilman@chicagotribune.com 
 
 Twitter @JohnKeilman
– In a potentially groundbreaking first, doctors say they detected chronic traumatic encephalopathy, the degenerative brain disease associated with repeated head injuries, in a living patient. Just weeks after Boston University researchers announced CCL11 proteins in the brain could indicate CTE in living patients, researchers in Chicago say they identified CTE in a retired NFL player before he died by detecting different proteins. Initially, they performed brain exams on 14 former NFL players in 2012 while all were living. Over damaged neural cells, they found clumps of tau proteins—which are believed to kill brain cells, per ABC News—with a "specific topographic signature" doctors believed indicated a CTE finding, lead author Bennet Omalu tells CNN. Their suspicion was confirmed when former Minnesota Vikings linebacker Fred McNeill, who played football for 22 years but suffered only one reported concussion, died in 2015, allowing doctors to formally diagnose CTE during an autopsy, reports the Chicago Tribune. McNeill's wife later told researchers he'd started having trouble with simple motor skills two years after his brain was initially scanned. He was soon unable to feed himself and suffered from ALS, slurred speech, progressive dysphagia, and other health issues at his time of death, researchers write in the Neurosurgery journal. Though more work is needed to confirm the link between tau proteins and CTE, Omalu is optimistic and hopes a commercial test for CTE might be available in "less than five years." (Here's what Aaron Hernandez's brain revealed.)