“Concussions as we know them involve a hit that rattles a part of the brain involved in language processing or motor skills. Hits to the forehead that might be every bit as damaging hide their nefarious effects in the frontal lobe, a part of the brain involved in visual memory and not motor or sensory function, and thus not taxed by sideline concussion exams. Indeed, it’s possible that all along, while brain trauma questions have focused on concussions, the real damage is being inflicted by minor impacts that chip away at the brain.”By Bob DeMarco
Penn State Clips
“The Damage Done” is part of a special report on football concussions in this week’s November 1 issue of Sports Illustrated.
Purdue University researchers put sensors into the helmets of 23 players from Jefferson High in Lafayette, Ind., and gave players the ImPACT test—a computerized neurocognitive exam that tests memory and concentration—and tests of working memory while their brains were monitored with magnetic resonance imaging (MRI) during the 2009 football season.
The results suggested that, while concussive hits dominate the debate, minor blows—of which there are hundreds each game—can be just as traumatic.
At midseason, researchers had 11 players who had never suffered concussions retake the ImPACT test and have their brains scanned with functional MRIs (fMRI) during working memory tests of increasing difficulty to pinpoint active areas in the brain.
The results:
- ImPACT test: “Of 11 players who took midseason testing, three had suffered concussions during the season and eight had never had concussions. Of those eight, four showed significant declines in visual memory. The players with the most impaired visual memory skills were not coming from the concussed group but from a group that in the week preceding the test had taken a large numbers of hits—around 150 a week—mostly in the 40 to 80 G range.”
- fMRI and working memory tests: “All of the players were able to complete the test with relative accuracy, but the brain activity of the four players who took a lot of middling hits—but suffered no concussions—changed dramatically. When each one took the harder version of the test, there was an unmistakable decline in activity in an area of the brain just behind the forehead called the dorsolateral prefrontal cortex, which is critical to visual memory.”
The collisions that caused these declines in visual memory were hardly violent. Rather it was a matter of frequency and location, and it may very well be the frontal lobe—a part of the brain involved in navigating social situations—that pays the price:
“Concussions as we know them involve a hit that rattles a part of the brain involved in language processing or motor skills. Hits to the forehead that might be every bit as damaging hide their nefarious effects in the frontal lobe, a part of the brain involved in visual memory and not motor or sensory function, and thus not taxed by sideline concussion exams. Indeed, it’s possible that all along, while brain trauma questions have focused on concussions, the real damage is being inflicted by minor impacts that chip away at the brain.”
Here is a link to the PDF of the story that will appear in Sports Illustrated -- The Damage Done.
This following is an abstract from Functionally-Detected Cognitive Impairment in High School Football Players Without Clinically-Diagnosed Concussion.
Source: Journal of Neurotrauma
Head trauma and concussion in football players has recently received considerable attention.
Postmortem evidence suggests that accrual of damage to the brain may occur with repeated blows to the head, even when individual blows fail to produce clinical symptoms. There is an urgent need for improved detection and characterization of head trauma to reduce future injury risk and promote development of new therapies.
This study examined neurologic performance and health in the presence of head collision events in high school football players, using longitudinal measures of collision events (HITTM system), neurocognitive testing (ImPACTTM), and functional MRI (fMRI).
Longitudinal assessment (including baseline) was conducted in 11 males (ages 15-19) participating on the varsity and junior varsity football teams at a single high school.
We expected and observed subjects in two previously described categories: (1) no clinically-diagnosed concussion and no changes in neurological behavior and (2) clinically-diagnosed concussion with changes in neurological behavior.
Additionally, we observed players in a previously undiscovered third category who exhibited no clinically observed symptoms associated with concussion, but who demonstrated measurable neurocognitive (primarily visual working memory) and neurophysiologic (altered activation in dorsolateral prefrontal cortex, DLPFC) impairments.
This new category was associated with significantly higher numbers of head collision events to the top-front of the head, directly above DLPFC.
Observation of this category suggests that more players are suffering neurologic injury than are presently detected via traditional concussion-assessment mechanisms.
These individuals are unlikely to undergo clinical evaluation and thus continue to participate in football-related activities even when changes in brain physiology (and potential brain health) are present, likely increasing risk of future neurologic injury.
Also see:
Brain changes found in football players thought to be concussion-free
Original content Bob DeMarco Penn State Clips
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