ADVERTISEMENT
latest stories:
This article is from the In-Depth Report The Science of Concussion and Brain Injury

A Generation Loses Consciousness, and Grows More Conscious of Headbanging

New data suggests blows to the head are on the rise among U.S. adults and kids, but definitive diagnosis remains elusive


Football helmet of the late Owen Thomas, a former University of Pennsylvania football player.
Image: House Committee on Education and the Workforce Democrats

Blows to the head that were once considered a relatively harmless result of rough-and-tumble play appear to be sending more kids than ever before to U.S. emergency rooms.
 
New work published in the May 13 issue of JAMA The Journal of the American Medical Association finds that head injuries led an estimated 2.5 million people to visit a U.S. emergency room in 2010. About one third of the cases were children, with most ER visits sparked by falls or some collision involving the head. The study adds to a growing body of data that suggests mild traumatic brain injury (TBI) is a larger public health problem than physicians previously knew.
 
U.S. emergency room visits for TBIs shot upward by almost 30 percent between 2006 and 2010. The majority of these incidents were coded in medical records as either concussion or unspecified head injury. The incidence of these TBIs climbed upward in every age group but children under three years old and adults over 60 showed the largest increases in TBI rates during that period, according to the study.
 
The authors note that the rapid increase in these injuries is likely due to increased public awareness of TBI exposure, better diagnosis or both. This study did not tease out if the head blows came from athletic or nonathletic activity (such as falls around the house) but other findings have noted the alarming incidence of such injuries in youth playing sports.
 
Most of the head injuries included in this study were listed as relatively minor and patients were typically discharged quickly. Unfortunately, that does not mean patients’ problems ended when they left the hospital. Diagnosing concussion remains a struggle for clinicians because brain scans are often inconclusive. Unraveling how potential preexisting genetic or environmental conditions could elevate concussion risk or affect how scans should be interpreted also remains a significant problem. “We still don’t have many objective measures, at least in the emergency department, to help us say you did sustain a mild TBI even though your CT scan is negative,” says study author Jennifer Marin, a pediatric emergency physician at Children’s Hospital of Pittsburgh. “Explaining the concept of cognitive rest [for recovering from injury] is difficult when you can’t show an image of how the brain has been injured.” Months after a concussion, patients may still have lingering symptoms including headaches and inability to concentrate—even when initial brain scans reveal nothing. Moreover, suffering just one concussion elevates the risk of suffering another and may make it more challenging to recover from future jolts to the head.
 
The work was released alongside another study in JAMA that found that National Collegiate Athletic Association Division I football players, irrespective of their concussion diagnosis, have shrunken hippocampal volume on average compared with healthy nonplayers. Football players with a longer history of play (and presumably more opportunities for blows to the head) showed even more reduced hippocampal volume. The hippocampus, located inside the brain, helps with such mental work as memory and spatial reasoning. But the study co-authors, led by Rashmi Singh of the Laureate Institute for Brain Research, Tulsa, Okla., note that they still cannot discern what the reduced volumes mean for long-term cognitive function in these individuals.
 
Compared with 25 nonathletes with no history of concussion, players with a history of concussion had hippocampal volumes in both hemispheres of their brains that appeared about 25 percent smaller than those of healthy nonathletes. Meanwhile, players without a history of diagnosed concussion also had hippocampal volumes about 15 percent smaller than those healthy nonathletes. (This is noteworthy because players tend to underreport concussion symptoms.) More football experience also generally correlated with slower reaction time on cognitive tests. Exactly how to interpret the implications of the reduced brain mass or connect the dots to respective head injuries remains uncertain because there was little available baseline data for the studied players. So, the “snapshots” of these brains fail to provide a time line of football experience and hippocampal damage.
 
Still, it’s clear that none of this is good news. At the hospital, Marin says, “we stabilize patients but then they go home and a lot of them will experience complications down the line.”
 

Rights & Permissions
Share this Article:

Comments

You must sign in or register as a ScientificAmerican.com member to submit a comment.
Scientific American Holiday Sale

Give a Gift &
Get a Gift - Free!

Give a 1 year subscription as low as $9.99

Subscribe Now! >

X

Email this Article

X