Mild Brain Trauma May Raise Long-Term Alzheimer’s Risk

WASHINGTON — Impro­vised explo­sive devices and mul­ti­ple deploy­ments to Iraq and Afghanistan are boost­ing the inci­dence of mild trau­mat­ic brain injury, a con­di­tion that some ear­ly stud­ies indi­cate may increase a soldier’s future risk for Alzheimer’s dis­ease, a researcher said yes­ter­day.

National Veterans Summer Sports Clinic in San Diego
Car­los Figueroa, a Marine Corps vet­er­an who suf­fered a trau­mat­ic brain injury, post-trau­mat­ic stress dis­or­der and nerve injuries to his left leg dur­ing oper­a­tions in Afghanistan, tries his hand at kayak­ing at the Nation­al Vet­er­ans Sum­mer Sports Clin­ic in San Diego last sum­mer.
Army pho­to by Robert Tur­til
Click to enlarge

Dr. Elaine Peskind spoke at the 3rd Annu­al Trau­ma Spec­trum Con­fer­ence held today and yes­ter­day at the Nation­al Insti­tutes of Health in Bethes­da, Md.

The con­fer­ence — spon­sored by the Defense Cen­ters of Excel­lence for Psy­cho­log­i­cal Health and Trau­mat­ic Brain Injury, the Nation­al Insti­tutes of Health and the Depart­ment of Vet­er­ans Affairs — tar­get­ed emerg­ing research on poly­trau­ma, recov­ery and rein­te­gra­tion for ser­vice­mem­bers, vet­er­ans and their fam­i­lies.

Trau­mat­ic brain injury severe enough to cause loss of con­scious­ness — from a sports con­cus­sion, an auto­mo­bile acci­dent or an IED — “is the best-estab­lished envi­ron­men­tal risk fac­tor for Alzheimer’s, the late-life dement­ing dis­or­der occur­ring in up to 50 per­cent of peo­ple over age 85,” she said.

Peskind is a geri­atric psy­chi­a­trist and a research pro­fes­sor of psy­chi­a­try and behav­ioral sci­ences at the Uni­ver­si­ty of Wash­ing­ton School of Med­i­cine in Seat­tle. She also is a Vet­er­ans Admin­is­tra­tion doc­tor who is cre­den­tialed at Joint Base Lewis McChord. There, since 2007, she and a col­league have con­duct­ed a clin­i­cal tri­al to eval­u­ate the drug Pra­zosin for active-duty sol­diers with post-trau­mat­ic stress dis­or­der.

It was dur­ing the Lewis McChord study that Peskind noticed the link between PTSD and mild trau­mat­ic brain injury, or mTBI, and mem­o­ry prob­lems. Dur­ing study vis­its, she noticed that sol­diers reg­u­lar­ly took lit­tle note­books out of their shoul­der pock­ets and wrote down every­thing she said — so they wouldn’t for­get, they told her. And study coor­di­na­tors had to call and remind the sol­diers to come to their appoint­ments.

Peskind, who once con­sid­ered mTBI a prob­lem of reha­bil­i­ta­tion rather than men­tal health, called it a “clas­sic light bulb moment.” “I said, wow, maybe we do have a prob­lem here,” she added, “and I became very inter­est­ed in TBI research.” The nature of the wars in Iraq and Afghanistan is con­tribut­ing to the mTBI prob­lem, she said.

“As of this month, some­thing in the vicin­i­ty of 2 mil­lion sol­diers and Marines have been deployed to the wars in Iraq and Afghanistan — OIF and OEF — and near­ly 800,000 have been deployed more than once,” she said.

And the weapon of choice for insur­gents in both war zones is a range of impro­vised explo­sive devices, she said.

“The esti­mate of the num­ber who returned with symp­to­matic mild trau­mat­ic brain injury due to blast expo­sure has var­ied from the offi­cial VA num­ber of 9 per­cent offi­cial­ly diag­nosed with mTBI to over 20 per­cent,” she said, “and I think, ulti­mate­ly, it will be high­er than that.”

Com­pared with the wars in Viet­nam and Korea, she said, a sig­nif­i­cant improve­ment in body armor and bat­tle­field med­i­cine have altered the ratio of wound­ed to killed in bat­tle from 4 to 1 in pre­vi­ous wars to 10 to 1 today.

“So we have a lot more sol­diers and Marines and oth­er ser­vice­mem­bers sur­viv­ing blast expo­sure,” Peskind said. News reports high­light the dam­age that can result from head injuries expe­ri­enced by some col­le­giate and pro­fes­sion­al foot­ball play­ers, she said.

John Grim­s­ley, a for­mer Hous­ton Oil­ers line­backer, devel­oped a dement­ing dis­or­der in his mid-40s, Peskind said. After his death at age 45 in 2008 from an acci­den­tal gun­shot wound, a brain autop­sy showed mul­ti­ple neu­rofib­ril­lary tan­gles, one of the two major indi­ca­tors of Alzheimer’s dis­ease.

Sim­i­lar cas­es include Cincin­nati Ben­gals wide receiv­er Chris Hen­ry, who died in a 2009 acci­dent at age 26, and 21-year-old Uni­ver­si­ty of Penn­syl­va­nia defen­sive end Owen Thomas, who com­mit­ted sui­cide in 2010.

Autop­sies of both young brains showed neu­rofib­ril­lary tan­gles, she said.

“There is a grow­ing con­cern that mul­ti­ple con­cus­sive and sub­con­cus­sive events — you know, head injuries — may set in motion path­o­gen­ic process­es that may lat­er emerge as these neu­rode­gen­er­a­tive dement­ing dis­or­ders,” Peskind said.

But for ser­vice­mem­bers with mTBI, the con­cern is that mTBI could even­tu­al­ly lead to Alzheimer’s dis­ease lat­er in life, she said. “There has been live­ly con­tro­ver­sy regard­ing the eti­ol­o­gy, course and treat­ment of the per­sis­tent post-con­cus­sive somat­ic, cog­ni­tive and behav­ioral symp­toms in OIF/OEF vet­er­ans fol­low­ing a blast expo­sure and TBI,” Peskind said.

An epi­demi­o­log­ic study in active-duty sol­diers at Wal­ter Reed found that many of the chron­ic post-con­cus­sive symp­toms, except headache, were more cor­re­lat­ed with PTSD and depres­sion than with mTBI, she added.

“But I and many oth­er skilled clin­i­cians are pret­ty well con­vinced that for warfight­ers these chron­ic, post-con­cus­sive symp­toms fol­low­ing a blast con­cus­sion and TBI reflect real but rea­son­ably sub­tle per­sis­tent brain dam­age,” Peskind said.

To find out whether the chron­ic symp­toms rep­re­sent struc­tur­al or func­tion­al brain changes, Peskind said she and her col­leagues are involved in an ongo­ing study that involves four dif­fer­ent kinds of brain imag­ing tech­nolo­gies and mul­ti­ple phys­i­o­log­i­cal and neu­ropsy­cho­log­i­cal tests.

In pre­lim­i­nary results of the work, which she called a “snap­shot in time,” Peskind said the imag­ing is begin­ning to show a “pat­tern of func­tion­al deficits [that] is some­what rem­i­nis­cent of the very, very ear­li­est changes seen in Alzheimer’s dis­ease.”

But, she added, “cau­tion is need­ed … We need more data, we need more analy­sis and of course repli­ca­tion [of these results] by oth­er [research] groups is need­ed … We real­ly need to fig­ure out what the long-term risk is for this group of vet­er­ans.”

Source:
U.S. Depart­ment of Defense
Office of the Assis­tant Sec­re­tary of Defense (Pub­lic Affairs)

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