April 18th, 2012
04:15 PM ET
Years ago, a mysterious disease process – characterized by viscous tangles lodged in parts of the brain responsible for decision-making and mood – was an undefined phenomenon occurring among professional football players, and others exposed to repetitive brain trauma.
What scientists could piece together: Something in the brain was causing profound memory problems, and self-destructive, even suicidal, behavior among them. Since then, posthumous brain studies have shed light on that something - Chronic traumatic encephalopathy, or CTE - but little is known about when or how CTE begins.
However, data from the first year of a longitudinal study, called the Professional Fighters Brain Health Study, released Wednesday, suggests a possible starting point for problems with cognition and memory - both hallmarks of CTE.
"Chronic brain conditions, like Parkinson's and Alzheimer's disease, they begin years before any symptoms develop," said Dr. Charles Bernick, lead study author and associate director of the Cleveland Clinic Lou Ruvo Center for Brain Health. "We thought maybe that's the case with CTE."
The study group comprised 109 fighters for whom brain trauma is customary - boxers and mixed martial artists - and separated them based on the length of time in the sport, and the approximate number of bouts they participated in, according to published records and self-reports.
One group had fought for fewer than six years, another for between six and 12 years and the third group fought for more than 12 years. Study authors were looking for a relationship between the number of fights participants had and the size of certain areas of the brain.
According to Bernick, among those who fought for more than six years, there was some shrinking in brain areas like the thalamus and caudate, and the hippocampus, which is associated with memory. The more fights they had, the more pronounced the shrinkage. But when he examined cognitive test scores among the group that fought more than 12 years, their performance was worse, implying a progression: Damage to the brain that in some cases leads to CTE, may begin years before any symptoms show up.
What the study cannot yet account for is what makes one fighter more susceptible to CTE than another. Findings in the Professional Fighters Brain Health Study will later include factors such as genetics, proteins in the blood, speech analysis, educational level, and other factors that could paint a more vivid picture of the disease.
"This is a very exciting study and really one of the first of its kind anywhere," said Robert Stern, a professor of neurology and neurosurgery, and co-Director, Center for the Study of Traumatic Encephalopathy at the Boston University School of Medicine. "Scientific study of CTE is really in its infancy, with almost everything to be learned ahead of us."
Stern, along with colleagues at Brigham and Women's Hospital, also are trying to learn more about the genesis of CTE. According to Stern, the study will compare 100 former National Football League players - aged 40 to 69 - exposed to repetitive brain trauma, with a control group of athletes not exposed to brain trauma.
The study will include neuroimaging and other brain studies, neuropsychological examinations, EEG and genetic studies, and spinal taps measuring for proteins like tau, which collects in the brain of those diagnosed with CTE.
Work undertaken by both Bernick and Stern represent an early glimpse into the complex disease processes which characterize CTE, with the goal of identifying and suspending the disease before it gets worse.
"If you're going to protect athletes, looking later in the disease doesn't help you," said Bernick. "If we're going to protect them, we need measures to detect the earliest changes that reflect damage to the brain."
Bernick and colleagues' data will be presented this week at the American Academy of Neurology's 64th Annual Meeting.
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