WASHINGTON, D.C.--A drug used to protect U.S. troops in case of a nerve gas attack may be the cause of the Gulf War Syndrome, according to a study released by the Department of Defense today. Although conclusive evidence is still lacking, the report marks the first time that the Pentagon has offered a plausible cause for the symptoms that ail tens of thousands of Gulf War veterans. Previous studies had only ruled out possible culprits, such as stress, uranium, and oil-well fires.
Before and during the Gulf War in 1990 and 1991, an estimated 250,000 soldiers were given pyridostigmine bromide (PB) tablets as a protective measure against soman, a nerve gas. By latching onto an enzyme called AChE, soman prevents the natural breakdown of the neurotransmitter acetylcholine, leading to twitches, muscle cramps, and respiratory failure. PB can prevent this by temporarily binding to AChE itself, but because soman acts so fast, the PB tablets have to be swallowed before exposure to soman takes place.
PB has long been used to treat a rare autoimmune disease called myasthenia gravis, and officials had presumed it to be relatively safe. But when veterans started coming down with dizzyness, rashes, and problems with movement, sleep, and memory, PB came under suspicion. According to one theory, the drug may cause nerve cells to permanently tone down their acetylcholine production, which could lead to some of the symptoms.
After combing through roughly 1000 scientific papers about PB and conducting 80 interviews, physician and biologist Beatrice Golomb of the San Diego Veterans Affairs Medical Center concludes that this theory is "scientifically viable," but that further animal and human studies are needed. One problem for epidemiologists, however, is that the Pentagon doesn't have good records of who took PB during the Gulf War and who didn't.
"It's an uncommonly good review of a very large body of literature," says epidemiologist Robert Haley of the University of Texas Southwestern Medical Center in Dallas. "This report is an indication that there really is something in this theory," he adds. "Hopefully it will stimulate others to study the problem."
Meanwhile, the work hasn't led officials to rule out the use of PB in the future, says Sue Bailey, assistant secretary of defense for health affairs, because it's still the only known prophylactic against soman. But Bailey says the Pentagon will be "very judicious" about future use, and will improve its medical record-keeping during deployments.