SOURCES: Ann C. McKee, M.D., professor of neurology and professor of pathology, department of neurology, Boston University School of Medicine, Boston; James M. Noble, M.D., assistant professor, neurology, department of neurology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Neurological Institute of New York, Columbia University Medical Center, New York City; Associated Press; Jan. 4, 2016, JAMA Neurology, online
MONDAY, Jan. 4, 2016 (HealthDay News) -- Former Missouri State linebacker Michael Keck quit football after three years of Division 1 play and might have faded into obscurity.
But his death at age 25, in 2013, has opened a window on a poorly understood but increasingly scrutinized brain disorder.
In death, Keck joined a tragic gridiron group, including once-great pro players Mike Webster and Junior Seau, all of whom developed chronic traumatic encephalopathy (CTE) -- a devastating disease caused by repeated blows to the head.
"This is a relatively understudied disease," said Dr. Ann McKee, a professor of pathology at Boston University School of Medicine. "But the loss of memory, the behavioral problems, the depression, the difficulties with learning and planning can and do affect all kinds of athletes, both professional and amateur."
McKee is co-author of a new case study, based on Keck's experience, published online Jan. 4 in JAMA Neurology.
Keck was knocked unconscious during fall practice in 2009. "After that, things changed for him," his wife, Cassandra Keck, later told the Associated Press.
Keck's memory, vision and ability to sleep suffered, she said, adding that he started taking medication for head pain. He became moody and, later, prone to bouts of violent behavior, she told the news service.
"He told one of the trainers there's something wrong with his head. They gave him a concussion test and told him to count backward from 20 by threes," Cassandra Keck said in the interview. "Some other players couldn't do it, either. So they just said football players are dumb."
But debilitating headaches and falling grades caused Keck to leave school in his junior year.
Keck's death several years later was originally attributed to an unrelated heart condition, but post-mortem testing revealed CTE.
Although the disease is known to result from repeated head injuries, CTE confirmation can only come upon examination of a patient's brain after death.
Suspecting CTE, Keck volunteered to undergo neuropsychological evaluation at age 24.
"His wife will tell you that he thought he had CTE," said McKee. "It turns out he was right."
Results of the neuropsychological tests documented a list of mental health struggles that had long plagued the athlete who had suffered more than 10 concussions.
This provided researchers a rare chance to stack symptoms alongside actual brain pathology. More research is essential to gain a better understanding of CTE, McKee said, noting "this will certainly help."
Keck started playing football at age 6, and suffered his first concussion two years later. But even without concussions, athletes are at risk of CTE, McKee said.
"It's a widespread misperception that CTE is about concussions," said McKee. "About 20 percent of patients have no history of concussion at all. A lot of the time it's really about exposure to sub-concussive routine hits that don't give rise to any immediate symptoms."
Such hits occur hundreds, even thousands, of times in the course of a year of football. "It's about long-term exposure to repeated head trauma," she said.
Investigators are approaching Keck's case cautiously, hoping to learn what they can from the information he left behind, while acknowledging that the early onset of symptoms could mean his experience was not the norm.
Dr. James Noble, an assistant professor of neurology at Columbia University Medical Center in New York City, said the Keck case should serve as "a call to responsibility, concerning everybody involved in sports, to better understand this disease."
Parents, players, sports leagues, schools, and conferences -- "everybody who has an interest in the academic, mental and physical health of these players" -- must take an interest in their neurological health, said Noble, author of an accompanying journal editorial.
Noble pointed out that the first case of football-associated CTE appeared only about 10 years ago.
That was when Pittsburgh forensic pathologist Dr. Bennet Omalu autopsied the brain of "Iron Mike" Webster, the star center for the Pittsburgh Steelers of the 1970s who died at age 50 after years of dementia had left him penniless and intermittently homeless. Omalu -- portrayed by Will Smith in the movie "Concussion" -- discovered that Webster's brain was riddled with large clumps of tau protein, which generally is considered a hallmark of Alzheimer's disease. Omalu published his findings in the journal Neurosurgery in 2005.
And 12-time Pro Bowl NFL linebacker Junior Seau, who died by suicide at age 43 two years after leaving the league following the 2009 season, was also subsequently diagnosed with CTE. He was inducted into the NFL Hall of Fame last summer.
Greater awareness has brought scrutiny and improved safety provisions to football, but much is still unknown, Noble said.
"While it's encouraging that awareness about the dangers of head trauma has increased over the last 10 years, there are still so many unresolved questions in this field," he added.
There's more on CTE at Boston University.