The Risk Of Brain Injuries Shifts As Children Grow Up

As children grow, they learn to crawl, to walk and then to drive. It turns out, the way they get hurt, and in particular their heads, evolves as as their forms of motion change.

Small children suffer head injuries from falling, while teenagers are at risk from car accidents, assaults and sports injuries, according to a paper published Wednesday in the New England Journal of Medicine.

The authors, all part of the Pediatric Emergency Care Applied Research Network, analyzed data from 43,000 children admitted to emergency rooms for blunt force head trauma between 2004 and 2006.

In children under 2 years old, the top three causes of head injuries were all fall-related: from a height, down the stairs, or from standing, walking or running. For children between 2 and 12 years, the top causes were falls from a height, falls from standing, walking or running, and being accidentally bopped on the head.

But as children become teens, the causes of head injuries change radically. Assault topped the list, causing 24 percent of blunt force trauma injuries in children 13 to 17 years. Sports injuries accounted for 19 percent, and motor vehicle accidents were linked to 18 percent for the age group.

"It really just is the developmental stages that children are in," Dr. Kimberly Quayle , a pediatrician at the Washington University School of Medicine and an author of the study, tells Shots.

It's important to understand, because head trauma can cause traumatic brain injury, the leading cause of death and disabilities for children over one year. The data from Quayle and her colleagues shows seat belts and bike helmets work to reduce that risk.

The prevalence of TBIs verified by CT scans for children in car accidents dropped from 5 percent to 2 percent if the child was wearing a seat belt or was in an infant carrier. Similarly, only 5 percent of children wearing a bike helmet when hit by a car showed a TBI on their CT scan compared to 8 percent without a helmet.

"If you look at the younger kids, the fact that motor vehicle accidents are not showing up as significant causes [of head injuries] probably means we're doing a pretty good job on car seats and adequate infant car protection," say Dr. Mark Proctor, a neurosurgeon at Boston Children's Hospital who was unaffiliated with the study.

Although, he adds, the car seats can lead to falls when not used in a car. "We see a lot of injuries from a car seat being used as a carrier. They're great for cars; They're not great for carriers." The carriers easily slip and fall off tables or counters leading to head injuries, says Proctor.

Quayle and colleagues say the data can help pinpoint age-specific injury-prevention measures, like reminding teens to buckle up before they drive. We don't need to invent new tools, says Quayle, it's just a matter of "continuing to be vigilant about the things we already know are there."