The vast bulk of this magazine’s coverage at the annual RSNA Conference, held every year the week after Thanksgiving at Chicago’s vast McCormick Place Convention Center, and sponsored by the Radiological Society of North America, revolves around either imaging informatics coverage, or healthcare policy coverage related to diagnostic imaging practice, or both. But very occasionally, something that is a bit different piques our interest.
That was the case at a press conference held on Monday, December 1. The title of the presentation given was “Head Impacts and White Matter Changes in High School Football: A TBSS Analysis.”A scientific paper was presented by Christopher T. Whitlow, M.D., Ph.D., associate professor of radiology at the Wake Forest School of Medicine at Wake Forest University in Winston-Salem, North Carolina. He and several colleagues had prepared a paper, which Dr. Whitlow presented on that day, on a study of brain impacts of playing high school football.
As noted in the abstract, “The purpose of this study is to determine if head impacts acquired over a season of high school football produce diffusion tensor imaging (DTI) white matter changes in the absence of clinically diagnosed concussion. We hypothesize,” the study’s authors wrote, “that players with greater levels of head impact exposure (heavy hitters) compared to those with lower levels of impact exposure (light hitters), will have decreases in fractional anisotropy (FA) that have been associated with white matter injury.” Translated into lay language, what Dr. Whitlow and his colleagues were trying to determine was whether, even in the absence of diagnosed concussion, playing heavy tackle football might have impacts on the brains of high school players.
As the abstract noted, “24 high school football players (mean age = 16.7; age range = 16-18) were instrumented with the Head Impact Telemetry System (HITs) during all practices and games DTI images were acquired pre- and post-season at 2 mm isotropic resolution in accordance with the NINDS Common Data Elements… Both groups demonstrated a main effect of time, with global increases in FA [functional anisotropy—a measure of the movement of particles within the brain] (post- vs/ pre-season) likely reflecting effects of brain development. Between group analyses revealed widely distributes statistically significant areas of decreased delta FA (post-pre season for HH compared to LH [heavy hitters, light hitters]. These areas included the splenium of the corpus callosum and deep white matter tracts.”
As he noted, “There are areas in the brain where there was a statistically significant difference between players with the highest and lowest cumulative head impact exposure. What you’re seeing,” he said, “is changes that are a little concerning, because often, in other studies, decreases in FA and increases in MD [mean diffusivity (MD)—a measure of brain function] have been associated with micro abnormalities in the white matter."
Ultimately, Dr. Whitlow and his fellow study authors concluded that “This study adds to the growing body of literature providing evidence that a season of play in a contact sport can show brain MRI changes in the absence of concussion or clinical findings.”
During the question-and-answer portion of the press conference, Dr. Whitlow elaborated for the assembled press, “These are preliminary results, and among a relatively small number of subjects. The results are statistically significant, but we don’t yet know whether they’re clinically significant. So this raises questions. Do these changes go away? When you play contact sports, you can get bruises and small injuries that just resolve over time. So do these changes go away, or persist? Are they associated with subtle cognitive or behavioral changes? The pathophysiology behind this is unknown.”
He added that, “In future studies, we’ll start to delve into longitudinal changes associated with behavioral, cognitive changes.”
What’s fascinating here is that Dr. Whitlow indicated to me immediately after the press conference, as he had referenced during the press conference, that this is one of the very few clinical studies, as far as he and his colleagues are aware, of high school football players, even though numerically speaking, they make up the vast majority of all football players by sheer numbers (clearly, they dwarf the numbers of professional and college football players), and despite the fact that high school players are by definition younger, and, as Dr. Whitlow pointed out, considerably more vulnerable to potential brain injury than are adult-aged players.
“The takeaway message,” Dr. Whitlow told the assembled press in December, “is that we have this huge group of youth athletes. And in that age stage, the brain is developing over time. And these youth athletes really represent an enormous group of people. Most studies have looked at collegiate and professional players. But we need to study youth players to evaluate them for risks and potentially intervene.”
The potential societal impact of studies like this could be quite considerable. And, moving forward, it will be interesting to see whether a slightly larger number of scientific sessions, including press conferences, at the annual RSNA conference, will touch on societally relevant topics. Of course, it all depends on the scientific researchers. But this press conference was a reminder that the RSNA Conference may be able to offer up relevant sessions worth covering that are both clinical and that have policy implications.