Researchers Look for Geographical Ties to ALS Cases Among 1991 Gulf War Veterans

CINCINNATI—Researchers at the University of Cincinnati are working with Duke University and the Durham Veterans Affairs Medical Center to uncover where Persian Gulf War veterans with Amyotrophic Lateral Sclerosis (ALS) were first exposed to factors that may have caused the illness.

This is the third branch of an ongoing study looking at ALS outbreaks among veterans who were deployed to the Gulf War in 1991.

ALS is a fatal neurological disease caused by the degeneration of nerve cells in the central nervous system that control voluntary muscle movement. It is commonly known as Lou Gehrig’s Disease after the baseball Hall of Famer who died of it in 1941.

Researchers are using computer-assisted geographical technology and are layering military records to find specific areas within the war zone with elevated risk.

This work is published in the online edition of the journal NeuroToxicology.

Ronnie Horner, PhD, senior author of the study and director of the department of public health sciences at UC, is working with colleagues to explore possible exposures veterans might have had in the Gulf region that could explain higher ALS rates.

“As one of the largest contemporary set of cases, it presents a real opportunity to identify clues as to the cause of ALS, not only for the veterans of the first Gulf War but, perhaps, for ALS generally,” says Horner.

A recent UC study published in the July issue of Neuroepidemiology says that cases of ALS among soldiers who served in the first Gulf War were caused by certain events during their deployment to the war zone from August 1990 to July 1991.

“The outbreak was time-limited,” Horner says. “We actually saw a declining risk after 1996; therefore, the risk is not continual. If the array of possible environmental exposures could be reduced, it may be possible to identify or at least focus on specific potential causes for these ALS outbreaks.”

To narrow down the possibilities, the teams at UC, Duke and the Durham VA are using geographic information systems (GIS) analysis, which allows researchers to layer different kinds of information onto maps to find potential risks.

Researchers began by searching Department of Veterans Affairs and Department of Defense records as well as other sources to identify military personnel diagnosed with ALS after 1991.

They also identified the military units in which veterans with ALS served during their period of deployment to the Persian Gulf region.

The researchers identified troop units that were exposed to chemicals from a munitions storage area at Khamisiyah, Iraq, which was destroyed by U.S. forces in March 1991. A United Nations commission later found that many rockets in storage had been loaded for chemical warfare.

Researchers used statistical methods to compute the likelihood of a specific place being important for each grid of Gulf territory. The likelihood went as high as 91 percent in some grid cells, most notably in a region southeast of Khamisiyah.

However, researchers say they will need to do additional analysis, adding time and place to the mix, before they can be more specific.

In addition, scientists will examine other environmental exposures that may be associated with ALS onset, such as oil well fire smoke plumes.

“With this information, we may be able to discover what caused the ALS outbreak and hopefully prevent similar instances from occurring in the future,” Horner says.