The prevalence of repeated closed head injury in sports has gained a lot of attention in the past decade. The National Football League (NFL), in particular, has received criticism for their practices surrounding brain safety. In 2011, a federal lawsuit was filed against the NFL for withholding information on the harmful effects of repetitive head injury among participants of organized football. This practice was said to put players at risk of the neurodenegerative disease chronic traumatic encephalopathy (CTE) following multiple traumatic brain injuries, making them highly susceptible to early onset of Alzheimer’s Disease, depression, cognitive deficits, and other consequences of CTE that impact functional outcomes.
In the midst of the lawsuit, former players like Ray Easterling, Dave Duerson, and Junior Seau committed suicide. Autopsies revealed that they all suffered from CTE. Dave Duerson reportedly decided to die of a gunshot wound to the chest in order for researchers to examine his brain. These and other cases like it have launched a number of investigations to assess the link between contact sports and CTE.
The case eventually reached a settlement where the NFL paid $765 million to provide medical help to former players. The league responded with great haste, mandating neurological consultants for every team, revising protocols for examinations and treatment, and revisiting rules surrounding excessive contact. The NFL has even teamed up with Heads Up, the national initiative to raise awareness for concussions and other football-related health risks too.
The response is welcomed in light of new data regarding CTE in former NFL players. The Department of Veterans’ Affairs in Bedford reported that 76 of 79 deceased former NFL players showed evidence of a neurodegenerative disease. Of 128 deceased football players (who played professionally [in the NFL] or semi-professionally [in college or high school]) examined, 101 were found to have CTE. Although the sample may be skewed, since the players that tend to donate their brains are likely those who suspect they had the disease, the data is still a testament to the prevalence of repeated brain injury in contact sports. Interestingly, the prevalence seems to increase with the level of football played: as Dr. Ann McKee, the director of the Bedford VA brain bank, concluded, “the longer you play football, the higher your risk [of CTE].”
Notice that in the previously mentioned study, CTE could only be definitively identified posthumously. Only a year ago, tracking tau protein accumulation and neuronal degeneration in-vivo was thought to be impossible. A recent development by UCLA researchers, however, has paired a chemical marker called FDDNP (binds to amyloid beta plaques and tau neurofibrillary tangles) with the PET scan technique to compare the brains of CTE subjects (14 retired NFL players) with those of healthy and Alzheimer’s subjects. The study revealed that the three types of brains in question show markedly different expression of FDDNP binding proteins (see image below). Although the method cannot yet replace posthumous study of the brain in definitive identification of CTE, its application for tracking disease trajectory and its implications as a diagnostic tool are unparalleled. With developments like these, the future of CTE research is bright!
UCLA FDDNP + PET scan technique: