Nonconcussive Head Blows in Football Also Damaging
The rising interest in brain injury among American football players has spilled over into Sports Illustrated. In the November 1 issue, out today, writer David Epstein profiles a complex study conducted by Purdue researchers, who fitted 11 Indiana highschoolers' helmets with impact sensors. Using the NFL-endorsed ImPACT neurocognitive test and fMRI, the researchers determined, to their surprise, that repetitive nonconcussive* head blows are not without consequence. The visual memory scores of some players who sustained these types of hits,** usually frontal and often exceeding 100 Gs, dropped significantly and appeared to correlate with changes in fMRI brain activity (in the dorsolateral prefrontal cortex).
The disturbing finding: On the sidelines and off the field, these players were clinically asymptomatic, at least by crude measures. They could carry on conversations, did not demonstrate memory impairment, and appeared to be fine by their parents' observations.
The reassuring finding: These players' ImPACT scores returned to baseline off-season.
The remaining uncertainty: No one really knows what the long-term toll of repetitive, nonconcussive, frontal head blows is, season after season. The Purdue researchers hope to follow up their subjects throughout their high school athletic careers and perhaps into college.
In addition to SI coverage, the Purdue study was published in the peer-reviewed Journal of Neurotrauma last month.
fMRI = functional MRI.
* Meaning, not impairing consciousness.
** Frontal head blows can be distinguished from the brainstem-torquing side blows associated with concussion.