MIT's Technology Review looks at military TBI.

Here's a telling comment:

"With IEDs, the insurgents have by dumb luck developed a weapon system that targets our medical weakness: treating brain injury," says Kevin "Kit" Parker, a U.S. Army Reserve captain and assistant professor of biomedical engineering at Harvard University who served in southern Afghanistan in 2002.

The article goes on to conclude:

Military doctors are only beginning to get a grasp on the number of soldiers who have suffered mild traumatic brain injury, the medical term for a concussion. Mild injuries are by far the most common type of brain trauma, but they are more easily missed than moderate and severe injuries (they typically don't show up on standard brain scans), and the lasting effects, especially of repeated concussions, are not yet clear. Surveys of troops to be redeployed in Iraq suggest that 20 to 40 percent still had symptoms of past concussions, including headaches, sleep problems, depression, and memory difficulties. "We don't know what it means in terms of long-term functional ability," says William Perry, past president of the National Academy of Neuropsychology.

In young children, the brain possesses great plasticity and can recover from enormous insults. Recovery will be much harder for these folks. Hopefully, much of what we belatedly learn about the mechanism of injury and the nature of mild TBI wil not only help advance their rehabilitation from those injuries, but transfer to children who were victims of inflicted head injuries.