As most readers are probably aware, the past few years have seen considerable media and clinical interest in chronic traumatic encephalopathy (CTE), a progressive, neurodegenerative condition linked to, and thought to result from, concussions, blasts, and other forms of brain injury (including, importantly, repeated but milder sub-concussion-level injuries) that can lead to a variety of mood and cognitive disorders, including depression, suicidality, memory loss, dementia, confusion, and aggression. Once thought mostly to afflict only boxers, CTE has more recently been acknowledged to affect a potentially much larger population, including professional and amateur contact sports players and military personnel.
CTE is diagnosed by the deterioration of brain tissue and tell-tale patterns of accumulation of the protein tau inside the brain. Currently, CTE can be diagnosed only posthumously, by staining the brain tissue to reveal its concentrations and distributions of tau. According to Wikipedia, as of December of 2012, some thirty-three former NFL players have been found, posthumously, to have suffered from CTE. Non-professional football players are also at risk; in 2010, 17-year-old high school football player Nathan Styles became the youngest person to be posthumously diagnosed with CTE, followed closely by 21-year-old University of Pennsylvania junior lineman Owen Thomas. Hundreds of active and retired professional athletes have directed that their brains be donated to CTE research upon their deaths. More than one of these players died by their own hands, including Thomas, Atlanta Falcons safety Ray Easterling, Chicago Bears defensive back Dave Duerson, and, most recently, retired NFL linebacker Junior Seau. In February 2011, Duerson shot himself in the chest, shortly after he texted loved ones that he wanted his brain donated to CTE research. In May 2012, Seau, too, shot himself in the chest, but left no note. His family decided to donate his brain to CTE research in order “to help other individuals down the road.” Earlier this month, the pathology report revealed that Seau had indeed suffered from CTE. Many other athletes, both retired and active, have prospectively directed that their brains be donated to CTE research upon their death. Some 4,000 former NFL players have reportedly joined numerous lawsuits against the NFL for failure to protect players from concussions. Seau’s family, following similar action by Duerson’s estate, recently filed a wrongful death suit against both the NFL and the maker of Seau’s helmet.
The fact that CTE cannot currently be diagnosed until after death makes predicting and managing symptoms and, hence, studying treatments for and preventions of CTE, extremely difficult. Earlier this month, retired NFL quarterback Bernie Kosar, who sustained numerous concussions during his twelve-year professional career — and was friends with both Duerson and Seau — revealed both that he, too, has suffered from various debilitating symptoms consistent with CTE (but also, importantly, with any number of other conditions) and also that he believes that many of these symptoms have been alleviated by experimental (and proprietary) treatment provided by a Florida physician involving IV therapies and supplements designed to improve blood flow to the brain. If we could diagnose CTE in living individuals, then they could use that information to make decisions about how to live their lives going forward (e.g., early retirement from contact sports to prevent further damage), and researchers could learn more about who is most at risk for CTE and whether there are treatments, such as the one Kosar attests to, that might (or might not) prevent or ameliorate it.
Last week, UCLA researchers reported that they may have discovered just such a method of in vivo diagnosis of CTE. In their very small study, five research participants — all retired NFL players — were recruited “through organizational contacts” “because of a history of cognitive or mood symptoms” consistent with mild cognitive impairment (MCI). Participants were injected with a novel positron emission tomography (PET) imaging agent that, the investigators believe, uniquely binds to tau. All five participants revealed “significantly higher” concentrations of the agent compared to controls in several brain regions. If the agent really does bind to tau, and if the distributions of tau observed in these participants’ PET scans really are consistent with the distributions of tau seen in the brains of those who have been posthumously-diagnosed CTE, then these participants may also have CTE.
That is, of course, a lot of “ifs.” The well-known pseudomymous neuroscience bloggerNeurocritic recently asked me about the ethics of this study. He then followed up with his own posts laying out his concerns about both the ethics and the science of the study. Neurocritic has two primary concerns about the ethics. First, what are the ethics of telling a research participant that they may be showing signs of CTE based on preliminary findings that have not been replicated by other researchers, much less endorsed by any regulatory or professional bodies? Second, what are the ethics of publishing research results that very likely make participants identifiable? I’ll take these questions in order.