TWO STUDIES SHOW GULF WAR VETS
HAVE DOUBLE ALS RISK

Two new studies appearing in the journal Neurology, one privately funded, the other federally supported, both report an above-average occurrence of amyotrophic lateral sclerosis among Persian Gulf War-deployed veterans. In the same Sept. 23 issue, the statistical significance of the studies is called into question in an editorial.

A privately funded study by Robert W. Haley of the University of Texas Southwestern Medical Center in Dallas and a government-funded study by Ronnie D. Horner of the National Institute of Neurological Disorders and Stroke in Bethesda, Md., both depict a roughly twofold risk of ALS development for U.S. veterans who were actively deployed in the Persian Gulf between Aug. 2, 1990, and July 31, 1991, when compared with nondeployed U.S. military personnel.

With deployed troops developing ALS more frequently and, maybe more importantly, much earlier in life than average, the two studies raise the question of whether an environmental factor could have triggered an early onset of the disease.

The criteria classifying a person as actively deployed included being stationed for at least one month within the studied time frame in the Gulf War theater of operations (Saudi Arabia, Kuwait and the other Arab Emirates, Turkey, Diego Garcia, or on the Red Sea).

The Horner study found varying risk levels within branches of the military. Deployed Air Force and Army personnel had the highest risks, at 2.68 and 2.04 times the rate of nondeployed personnel, respectively. The study showed an overall average of 1.92 times the ALS incidence for deployed troops, compared to nondeployed troops. This indicates the strong possibility that an environmental agent specific to the area and time frame of the Gulf War may have caused or prematurely triggered ALS.

But an editorial in the journal by Michael Rose of the Department of Neurology at King’s College Hospital in London, while praising the studies for their hard work, calls into question the solidity of their findings.

“There is still the concern that this degree of excess risk is not convincing, especially given the small number of ALS cases,” Rose writes.

However, Yadollah Harati, a co-author of the Horner study and neurologist at the Vicki Appel MDA Neuromuscular Clinic at Baylor College of Medicine in Houston, says the agreement between the two studies “tells us that there may be some validity to both studies … despite the fact that the number of patients is small.”

Originally skeptical himself about a Gulf War-ALS tie, Harati says he changed his mind after reviewing the two new studies.

In addition to a higher incidence of ALS in Gulf War vets, the studies both show a higher than average occurrence of ALS onset in people in their 20s and 30s. Because ALS typically occurs in middle age, the studies hint at the possibility of an environmental agent that triggers ALS prematurely.

When it comes to determining what the environmental factor(s) in question might be, Harati is uncertain.

“My feeling is that the stress of war itself, or the stress of the training in the military, or the makeup of these individuals — the fact that certain people are being selected for service — could all be factors, but that is the purest speculation.”

The notion that U.S. troops currently in Iraq might be experiencing similar risks as those faced in the 1990s is one Harati doesn’t support.

“If you say the Gulf War findings had something to do with toxins, with fumes from burning oil, with depleted uranium, then these are probably not happening this time,” Harati says.

The two studies’ funding comes from sources with possibly conflicting interests: The federal government, which would be responsible for providing health care benefits to affected veterans, funded the Horner study, and the (Ross) Perot Foundation, which Harati says would have political motivation to find fault in the Gulf War agenda of the George H.W. Bush presidency, supported the other study.

Harati adds, “Just the fact that two groups have been in disagreement in the past and came up with the same conclusion is a strong statement.”

Rose agrees with the studies’ significance because any unidentified clusters of rare diseases can offer promising clues to the possible causes if studied carefully and comprehensively. This is an important factor for ALS because of its still unknown causes.

Rose also maintains that the two-times normal risk factor, if accurate, would only place the incidence of ALS at one in 150,000, making it still a highly rare occurrence among Gulf War veterans.

As of 2002, veterans of the Gulf War who develop ALS are eligible for service-connected benefits from the Veterans Administration. For more information, go to
www.va.gov/health_benefits or call (877) 222-VETS.

Subscribers to Neurology can view the full studies at www.neurology.org.