The U.S. Department of Defense is seeking portable brain scanning devices, so that troops with head trauma, can be detected as soon as possible. It's become increasingly clear that head trauma, from roadside bombs, traffic accidents or explosions encountered in combat, are a cause of PTSD (post-traumatic stress disorder), especially cases that do not manifest themselves for years.
In recognition of this, the army and marines have been limiting troops to only three incidents of concussion, from roadside bombs, per combat tour. Troops that reach this limit, are given a non-combat job for the rest of their tour. The marine criteria is more complex than the one used by the army, taking into account all sources of concussion. However, most of the troops exposed to combat injury are army.
What spurred this idea is the discovery that physical injuries (to the brain) can now be detected (with more precise instruments like MRI), and often treated. There are now more portable brain scanning devices coming out of the laboratory, and the military wants to hustle some of these devices to the combat zone, where troops with minor brain trauma (which shows no immediate ill effects), can be detected and treated.
In the last few years, it has become clear that there are several sources of PTSD, and concussions from explosions is more of a factor than previously thought. Many troops, because of exposure to roadside bombs, and battlefield explosions in general, have developed minor concussions that, like sports injuries, could turn into long term medical problems. Often these concussions were accompanied by some PTSD. Medical experts believe that the proposed policy would have long term benefits, in that it would prevent permanent brain injuries and PTSD, including cases that could require a soldier or marine to be retired early on medical disability.
Some combat commanders, and many of the troops pulled out of combat, are opposed to the "three strikes and you�re out" approach. The commanders feel that sending units into action with fewer troops makes it more likely that they will suffer still more casualties. Infantrymen tend to be reluctant to leave their buddies in the lurch, unless physically unable to continue fighting. The military may change this by convincing troops that, like boxers, hockey or football players, too many concussions will lead to serious problems down the line, or even sooner. The portable scanners would enable medics to actually measure any brain trauma from bombs or other battlefield damage. Thus, only those troops who definitely had brain trauma, would be pulled out of combat and treated. The troops would be more amenable to this.
The portable scanners would also enable medical researchers to determine which kinds of battlefield abuse is most likely to cause brain trauma. That's because roadside bombs are only one of several sources of concussions. Currently, the military medicine experts believe that roadside bombs are, by far, the biggest source of these concussions, and the resulting brain injuries. The proposed "three bombs and you're out" (of combat) rule, is not expected to pull more than one or two percent of troops out of action. But this would have a higher impact on combat units, which always suffer most of the casualties. Thus infantry units might lose another 5-10 percent of their troops.
The army has, over the years, developed a set of guidelines for how to recognize the symptoms of combat fatigue (or PTSD). With all the attention PTSD has gotten in the media of late, troops are more willing to seek treatment, or at least admit there is a problem. While extreme cases of PTSD are pretty obvious, it's the more subtle ones that army wants to catch now. These are easier to cure if caught early.