A Shock Wave of Brain In­juries

The Washington Post Sunday - - Outlook - By Ron­ald Glasser

“We can save you. But you might not be what you were.”

TNeu­ro­sur­geon, Com­bat Sup­port Hospi­tal, Balad, Iraq

his 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.

For the first time, the U.S. mil­i­tary is treat­ing more head in­juries than chest or ab­dom­i­nal wounds, and it is ill-equipped to do so. Ac­cord­ing to a July 2005 es­ti­mate from Wal­ter Reed Army Med­i­cal Cen­ter, two-thirds of all sol­diers wounded in Iraq who don’t im­me­di­ately re­turn to duty have trau­matic brain in­juries.

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 twopart 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.

An­other prob­lem is that th­ese blast-re­lated brain

in­juries dif­fer from other se­vere head trau­mas, and the com­plex­ity of treat­ing re­turn­ing troops with “closed-head” in­juries is tax­ing an al­ready over­bur­dened mil­i­tary health-care sys­tem. There is not a neu­ro­sur­geon who works in a trauma unit any­where in the United States who doesn’t know what to do when an am­bu­lance brings in a biker who has suf­fered a se­vere head in­jury in a high­way ac­ci­dent. The stan­dard care in­volves us­ing cal­cium chan­nel block­ers to pro­tect dam­aged nerve cells against fur­ther in­jury, in­tra­venous di­uret­ics to con­trol brain swelling and, if the swelling be­comes too great, re­moval of the top of the skull to al­low the brain to swell with­out in­creas­ing neu­ro­log­i­cal dam­age. This is what sur­geons did in the case of ABC News an­chor Bob Woodruff, who suf­fered se­vere brain in­juries from an IED blast in Bagh­dad last year.

All this works with the com­mon types of se­vere head in­juries, but it does not work with brains dam­aged by shock waves. De­spite the usual in­ter­ven­tions and treat­ments, the ma­jor­ity of blastin­jury pa­tients who have neu­ro­log­i­cal dam­age do not fully re­cover. There is a grow­ing un­der­stand­ing within the neu­ro­sur­gi­cal com­mu­nity that blast in­juries are dif­fer­ent from those caused by pen­e­trat­ing or skull-frac­ture trauma. It is thought that shock waves dam­age the brain at a mi­cro­scopic, sub-cel­lu­lar level.

That’s why sur­geons who are quite ca­pa­ble of re­con­struct­ing the skull of a mo­tor­cy­cle crash vic­tim — some­thing for which they have been well trained — strug­gle to come up with treat­ment and re­ha­bil­i­ta­tion tech­niques for the ex­plo­sion­dam­aged brains of troops.

“TBIs from Iraq are dif­fer­ent,” said P. Steven Macedo, a neu­rol­o­gist and for­mer doc­tor at the Vet­er­ans Ad­min­is­tra­tion. Con­cus­sions from mo­tor­cy­cle ac­ci­dents in­jure the brain by stretch­ing or tear­ing it, he noted. But in Iraq, some­thing else is go­ing on. “When the sound wave moves through the brain, it seems to cause lit­tle gas bub­bles to form,” he said. “When they pop, it leaves a cav­ity. So you are lit­ter­ing peo­ple’s brains with th­ese lit­tle holes.”

Al­most as daunt­ing as treat­ing TBI is the vol­ume of such in­juries com­ing out of Iraq. Macedo cited 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.

What’s baf­fling is the Pen­tagon’s fail­ure to work with Congress to pro­vide a steady stream of fund­ing for re­search on TBIs. Mean­while, the high-profile fir­ings of top com­man­ders at Wal­ter Reed have shed light on the woe­fully in­ad­e­quate treat­ment for troops. In th­ese cir­cum­stances, sol­diers face a strug­gle to get the long-term re­ha­bil­i­ta­tion nec­es­sary for a TBI. At Wal­ter Reed, Macedo said, doc­tors have cho­sen to med­i­cate most TBI pa­tients, even though cog­ni­tive re­ha­bil­i­ta­tion, in­clud­ing brain teasers and me­mory ex­er­cises, seems to hold the most prom­ise for deal­ing with the dis­or­der.

Oddly enough, hav­ing more mil­i­tary pa­tients than can be ad­e­quately treated is, in terms of war­fare, a grue­some kind of suc­cess. Th­ese are the war in­jured who once would have been the war dead. And it is the un­ex­pected num­ber of ca­su­al­ties who in a pre­vi­ous med­i­cal era would have been fa­tal­i­ties that has sunk the out­pa­tient clin­ics at Wal­ter Reed and left those in the VA sys­tem lost and adrift.

In Iraq and Afghanistan, the ra­tio of wounded ser­vice mem­bers to fa­tal­i­ties is 16 to 1, if the def­i­ni­tion of “wounded” is any­one evac­u­ated from a com­bat zone. Dur­ing the Viet­nam War, ac­cord­ing to the VA, the ra­tio was 2.6 to 1. U.S. troops no longer die from the kind of in­juries that killed many thou­sands in Viet­nam. The ma­jor­ity of com­bat deaths there oc­curred right where the sol­dier was hit. If you were go­ing to die, you were dead be­fore there was any need of a mede­vac chop­per. If you’d had an arm or leg blown off, the chances were that you had also suf­fered a pen­e­trat­ing chest or ab­dom­i­nal wound and would bleed to death wait­ing to be taken to the near­est sur­gi­cal hospi­tal.

But if the bleed­ing could be staunched and you were still breath­ing when the medics got to you, the odds on sur­vival were in your fa­vor. The mil­i­tary medicine prac­ticed in Viet­nam wasn’t so dif­fer­ent from what World War II medics prac­ticed: Stop the bleed­ing and hope for the best un­til the he­li­copter shows up.

It wasn’t un­til Oc­to­ber 1993, when a U.S. com­bat as­sault team rap­pelled down from a he­li­copter into a 72-hour gun­fight in the streets of Mo­gadishu, So­ma­lia, that the no­tion of mil­i­tary medicine changed from ba­sic life sup­port to in­ten­sive care. In that siege sit­u­a­tion, medics had no choice but to care for a grow­ing num­ber of wounded on their own, be­cause evac­u­a­tion was im­pos­si­ble. But with­out clear in­ten­sive-care pro­ce­dures, they ran out of med­i­ca­tions and flu­ids to treat the most se­verely in­jured.

In the civil­ian world, trauma medicine had pro­gressed through­out the 1970s and ’80s, well past the sim­ple ex­pe­di­ents of tourni­quet, plasma and keep­ing an air­way open. Mo­gadishu forced the mil­i­tary to aban­don the last of its med­i­cal prac­tices from Viet­nam. It was time to teach the medics a new trade.

Pen­tagon of­fi­cials in­creased the train­ing pe­riod for a 91W, or com­bat medic, from 10 to 16 weeks. Medics now trained on pa­tient sim­u­la­tors that would “bleed to death” if blood loss was not stopped or “suf­fo­cate” if chest tubes weren’t cor­rectly placed or a tra­cheotomy wasn’t per­formed within three min­utes. Medics learned the new in­ten­sive-care the­ory of “hy­poten­sive re­sus­ci­ta­tion,” in which in­tra­venous flu­ids are given only in min­i­mal amounts solely to keep the heart pump­ing, as op­posed to the old Viet­nam method of keep­ing blood pres­sure el­e­vated, which only added to blood loss. Medics to­day use bet­ter­de­signed tourni­quets and hemo­static ban­dages — dress­ings that act to stop bleed­ing for bet­ter hem­or­rhage con­trol. They ad­min­is­ter the latest non-opi­ate painkillers, which, un­like mor­phine and De­merol, do not slow breath­ing. This is the first war in which troops are very un­likely to die if they’re still alive when a medic ar­rives.

An­other large part of the 16-to-1 wounded-to­fa­tal­ity ra­tio has to do with ad­vances in body ar­mor. To­day’s body ar­mor is dra­mat­i­cally ef­fec­tive in pre­vent­ing fa­tal wounds of the chest and up­per ab­domen. There is not an or­tho­pe­dic or gen­eral sur­geon in Iraq or Afghanistan who hasn’t been as­ton­ished the first time a trooper with two miss­ing limbs and a trau­matic brain in­jury is car­ried off in a chop­per and the sur­geon re­mov­ing the ar­mor can­not find a scratch from the chin to the groin.

But the un­seen dam­age can be long-last­ing. Most of the fam­i­lies of our wounded 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.”

Now in its fifth year, the Iraq con­flict is not a war of death for U.S. troops nearly so much as it is a war of dis­abil­i­ties. The sym­bol of this bat­tle is not the ceme­tery but the or­tho­pe­dic ward and the neu­ro­sur­gi­cal unit. The men and women inside those units have come home alive but miss­ing arms and legs, many un­able to see or hear or re­mem­ber who they were be­fore be­ing hit by a road­side bomb. Sur­vival clearly rep­re­sents as much of a revo­lu­tion in mil­i­tary medicine as does the dom­i­nance of the sui­cide bomber and the road­side bomb in the age of “shock and awe.” But now both the med­i­cal pro­fes­sion and the coun­try are left to play a ter­ri­ble game of catch-up.


» Ron­ald Glasser will dis­cuss his ar­ti­cle at 11 a.m. Mon­day at www.wash­ing­ton­post.com/liveon­line


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