Sports-Related Head Injuries Linked to Serious Brain Condition Chronic Traumatic Encephalopathy (CTE)

Sports-Related Head Injuries Linked to Serious Brain Condition Chronic Traumatic Encephalopathy (CTE) Diffusion tensor imaging (DTI) of fiber tracts in the brain (image courtesy of Wikipedia) In 2009, Ann C. McKee, MD et al. published a scientific paper in the Journal of Neuropathology and Experimental Neurology entitled Chronic Traumatic Encephalopathy in Athletes: Progressive Tauopathy following Repetitive Head Injury.  Dr. McKee and her research team at The Center for the Study of Traumatic Encephalopathy had done (and still do) some of the world’s leading work in brain trauma research in athletes. The paper was a review of 47 verified cases of chronic traumatic encephalopathy (CTE). There are a great many neurological and behavioral symptoms listed by the paper that define CTE, making the claim that the condition is its own form of tauopathy. (Tauopathy is a form of brain degeneration caused by the build-up of tau proteins. We’ll talk a little bit more about tau proteins later.) Isolating CTE as a unique brain condition is perhaps the paper’s achievement: We demonstrate that although CTE shares many features of other neurodegenerative disorders, including Alzheimer disease, progressive supranuclear palsy, post-encephalitic Parkinsonism, and the amyotrophic lateral sclerosis/Parkinson’s-dementia complex of Guam (ALS/PDC), CTE is a neuropathologically distinct, progressive tauopathy with a clear environmental etiology. CTE is not unique to athletes, but it is certainly prevalent in contact sports. Traumatic brain injuries (TBIs) suffered on the field can eventually lead to CTE. In the 2006 scientific paper entitled The Epidemiology and Impact of Traumatic Brain Injury: A Brief Overview published in the Journal of Head Trauma Rehabilitation, Jean A. Langlois, Sc.D., M.P.H., Wesley Rutland-Brown, M.P.H. and Marlena M. Wald, MLS, M.P.H. reported that current data on TBIs around the country are probably underestimating the actual number of cases: Sports and recreation activities are also a major cause of TBI, including concussions, and are severely underestimated using existing national data sets. Although a previous Centers for Disease Control and Prevention study estimated that approximately 300,000 such injuries occur each year, it included only TBIs for which the person reported a loss of consciousness. Other studies suggest that injuries involving loss of consciousness may account only for between 8% and 19.2% of sports-related TBIs. Taking this into account, a more accurate approximation may be that 1.6 million to 3.8 million sports-related TBIs occur each year. CT scan of brain with cerebral contusions, hemorrhage within hemispheres, subdural hematoma and skull fractures (image courtesy of Wikipedia) The article also made it clear that people who suffer these TBIs are at a much higher risk of developing other health conditions including epilepsy and Alzheimers disease. There are, however, non-physical cognitive ailments that pose a unique problem for recognition. CTE and depression, for example, may not reveal obvious physical problems and can thus go undetected until it is too late. Such was the case for Dave Duerson, Junior Seau and Derek Boogaard, just three of the many athletes who suffered from the condition. Duerson, a former Chicago Bear and New York Giant, killed himself in 2011. He shot himself in the heart. Before doing so, he requested through multiple avenues to have his brain preserved for research. He left it in his suicide note and in a text to his ex-wife. This reinforces what writer Ed Pilkington noted in an article for The Guardianthat Duerson knew he had a problem. In the article, Pilkington interviewed Dr. McKee (the same Dr. McKee from the 2009 paper cited earlier) at the NFLs brain bank (The Center for the Study of Traumatic Encephalopathy) in the Bedford VA medical center in Massachusetts as she was examining a brain that used to belong to a very skilled NFL player, but whose identity would remain anonymous. Her evaluation of said brain was that repeated blows to the head had reduced its size and removed key filaments. Later, she pulled up slides of Duersons brain on her laptop. They showed the buildup of tau, that abnormal protein that is formed in the brain after repeated trauma. Tau proteins essentially block the function of neurons and can spread to surrounding areas, eventually destroying functionality. Although tau is a damaging characteristic of brain trauma and can be detected in the blood and cerebrospinal fluid, it does not necessarily correlate with CTE and cannot, therefore, serve as a dependable diagnostic. In an NBC News article centered on former NFL linebacker Junior Seau, more of the same was found. Seau committed suicide in 2012 just like Duerson: a gunshot to the chest, preserving his brain for research. As the article by Maggie Fox stated, an autopsy showed he had CTE. Seau, like others before and after him, died young. One can’t help but wonder what would happen to these former-athletes if they went on living with CTE into later ages. And, if they did, what sort of psychological and behavioral challenges they would face on day-to-day basis. Would the tauopathy completely destroy their cognitive capacity? Hall of Fame running back Tony Dorsett underwent brain scans last year that showed he had signs of CTE. Dorsett, now 59, had recalled bouts of memory loss and admitted that his “quality of living has changed drastically and it deteriorates every day.” Derek Boogaard (image courtesy of Wikipedia) In a 2011 article for Time, Jeffrey Kluger reviewed yet another victim of sports-related brain damage: hockey player Derek Boogaard. His death was not directly caused by CTE as Duerson’s and Seau’s were, but Boogaard was diagnosed postmortem. He died from an overdose of alcohol and oxycodone, taken, perhaps, in an effort to alleviate some of his suffering. Kluger defines CTE in his own words: a brain condition similar to Alzheimers disease but caused by nothing more mysterious than getting hit too much. Kluger later reiterated the hardest part about brain disorders such as CTEnamely that the condition cannot be properly diagnosed until the patients brain can be sliced open after their death. Those afflicted may experience any number of symptoms including memory loss, intense depression and general cognitive distress. The University of Rochester Medical Center is working on multiple projects on traumatic brain injury, but interestingly, one project is looking at non-concussion-causing head blows. It is well-known at this point that repeated concussions cause serious cognitive issues, yet with this other project, Jeffrey J. Bazarian, M.D., M.P.H. wants to look at the everyday, seemingly harmless hits that football players experience. Using special sensors inside the helmets of University of Rochester football players, Dr. Bazarian could compare readings before and after the players season. This study is vastly important because, as the lab says on their site, while the neurologic risks of concussion are just beginning to be appreciated, the risks posed by cumulative sub-concussive head blows are potentially much larger, as they affect virtually every athlete involved in contact sports on an almost daily basis. The findings could call for more preventative actions in contact sports and likely freak out parents of young athletes everywhere. Practically, you may not be able to take the hits out of the games, but there may be ways to manage potential trauma. After all, as we’ve just learned from Dr. Bazarian, multiple seemingly minor head blows can add up to irreversible, life-changing damage. Even a concussion, something that used to be treated as a laughable incident (how many fingers am I holding up?), is now seen as a serious injury. Even the world of medicine is seeing them in a whole new light. “Scientifically, what were seeing is there is actually a change in the electrical activity of the brain that can last weeks or months,” says Dr. Neil Martin, chairman of neurosurgery at the David Geffen School of Medicine at UCLA. It seems, then, sitting out for the rest of the game is not treatment enough for even the simplest of concussions. Risking another hit, in the long run, may prove fatal. UFC logo (image courtesy of Wikipedia) The danger is real, especially since many head injuries in contact sports go undiagnosed and untreated, as current UFC light heavyweight champion Jon Jones reflected on in a Fox Sports article from last week. “I saw those lights,” Jones said. “Now that I’m older I realize that those lights were probably some type of concussion.” This is the threat Dr. McKee and other brain trauma experts are talking about. Concussions are dangerous on their own, but if gone unnoticed or are not treated properly they can develop into CTE and other serious brain conditions. In an interview with Jeffrey Brown of PBS, Dr. McKee admitted there are still a lot of questions out there regarding CTE. And when working in a field (science) that demands overwhelming evidence to accept alternative hypotheses, questions leave room for doubt and further studies: A key question remains, what’s the incidence and prevalence? How common is this disorder? And that, we will never establish from an autopsy study. For that, we really need to be able to identify this disease in living individuals. And that’s a huge focus of our more recent research. How can we identify this in people that are living? And that might be through MRI scans or PET scans and especially the ones that might peg the [tau] protein that develops. But we are really going to need those tests to be able to determine if a living person has this disease and then be able to measure that person’s exposure to head trauma. And that will be the defining moment. And that will probably take a longitudinal prospective study involving probably thousands of subjects. These are the questions that Dr. McKee and her peers in brain trauma research are faced with. The next logical step, it seems, would be working towards preventative measures. After all, we cant very well cancel sports Well, Reebok might have made a step in the right direction with a new product called the Checklight. It is a skullcap worn under the helmet but has force detectors attached and will light yellow for a moderate hit and red for a severe hit. Although they make it clear that the product is not a concussion diagnostic, the light indicators can give players, parents and coaches more information about the severity of hits and allow them to make the best decisions with that new information. Today, over 400 living athletes have promised to give their brain up for trauma research.