Iraq war: Epidemic of invisible brain damage?

The Washington Post published an article on April 8 by on the invisible head trauma created by the high-powered explosives being used by the U.S. military in Iraq. Forensic psychologists who evaluate combat veterans should be on the alert for neurological sequelae, as described in the following article by pediatric nephrologist Ronald Glasser:

This is the new physics of war. Three 155mm shells, linked together and combined with 100 pounds of Semtex plastic explosive, covered by canisters of butane or barrels of gasoline, can upend a 70-ton tank, destroy a Humvee or blow an engine block through the hood of a truck. Those deadly ingredients form the signature weapon of the war in Iraq: improvised explosive devices, known by anybody who watches the news as IEDs.

Some of the impact of these roadside bombs is brutally clear: Troops are maimed by projectiles, poisoned by clouds of bacteria-laced debris and burned by post-blast flames. But the IEDs have added a new dimension to battlefield injuries: wounds and even deaths among troops who have no external signs of trauma but whose brains have been severely damaged. Iraq has brought back one of the worst afflictions of World War I trench warfare: shell shock. The brain of a soldier exposed to a roadside bomb is shocked, truly.

About 1,800 U.S. troops, according to the Department of Veterans Affairs, are now suffering from traumatic brain injuries (TBIs) caused by penetrating wounds. But neurologists worry that hundreds of thousands more -- at least 30 percent of the troops who've engaged in active combat for four months or longer in Iraq and Afghanistan -- are at risk of potentially disabling neurological disorders from the blast waves of IEDs and mortars, all without suffering a scratch….

Here's why IEDS carry such hidden danger. The detonation of any powerful explosive generates a blast wave of high pressure that spreads out at 1,600 feet per second from the point of explosion and travels hundreds of yards. The lethal blast wave is a two-part assault that rattles the brain against the skull. The initial shock wave of very high pressure is followed closely by the "secondary wind": a huge volume of displaced air flooding back into the area, again under high pressure. No helmet or armor can defend against such a massive wave front.

It is these sudden and extreme differences in pressures -- routinely 1,000 times greater than atmospheric pressure -- that lead to significant neurological injury. Blast waves cause severe concussions, resulting in loss of consciousness and obvious neurological deficits such as blindness, deafness and mental retardation. Blast waves causing TBIs can leave a 19-year-old private who could easily run a six-minute mile unable to stand or even to think….

Almost as daunting as treating TBI is the volume of such injuries coming out of Iraq. Macedo cited the estimates, gleaned at seminars with VA doctors, that as many as one-third of all combat forces are at risk of TBI. Military physicians have learned that significant neurological injuries should be suspected in any troops exposed to a blast, even if they were far from the explosion. Indeed, soldiers walking away from IED blasts have discovered that they often suffer from memory loss, short attention spans, muddled reasoning, headaches, confusion, anxiety, depression and irritability….

The unseen damage can be long-lasting. Most of the families of our wounded that I have interviewed months, if not years, after the injury say the same thing: "Someone should have told us that with these closed-head injuries, things would not really get all that much better."