"We found that two regions of the brain had significant shrinking compared with other soldiers who have lower levels of symptoms," Roberta White, chairman of environmental health at the Boston University School of Public Health, said at the 59th annual meeting of the American Academy of Neurology in Boston.

The two regions of the brain -- the rostral anterior cingulate gyrus and the overall cortex -- are involved in thinking and memory. The rostral anterior cingulate gyrus was 6 percent smaller and the overall cortex was 5 percent smaller in the brains of veterans who complained of at least five symptoms, when compared with veterans who returned from the Gulf with fewer than five complaints.

The measurements were derived using magnetic resonance imaging scans of the 18 patients with more than five medical issues and scans of 18 soldiers with fewer complaints. Overall, White said her study will eventually include 62 veterans, with 31 in each category.

The soldiers complained of fatigue, memory loss, joint pain, headaches, respiratory infections and skin rashes that were severe enough to cause disruption in their activities of daily living, White said Tuesday in her presentation at the meeting of 12,000 specialist in ailments of the brain and central nervous system.

White told United Press International that the changes she recorded on the imaging scans correlated with delayed recall and learning on standard memory tests.

"The question of whether there is anything to these complaints continues to be controversial," Robert Haley, professor of internal medicine at the University of Texas Southwestern Medical School at Dallas, told UPI.

"These results are part of the mosaic that appears to show that there is something to these complaints. It doesn't nail it down, but adds to the evidence that something happened to these men that has caused physical changes in their brain structure."

Haley did not participate in the study presented at the AAN meeting but has also studied effects of Gulf War syndrome in his patients. "These findings suggest there is a loss of brain cells due to a toxic effect of pesticides and nerve gas, which then causes brain volume shrinkage," he said.

Last year the Institute of Medicine convened a panel of experts to review Gulf War syndrome. That panel determined that even though soldiers who served in Iraq and Kuwait suffer increased rates of many ailments, it could find no evidence that the syndrome existed.

Haley said that the changes in the brain could have occurred from exposure to some sort of chemical and would not have been caused by the mental stress of fighting a war as suggested by those who doubt the syndrome.

White said that many of the men in her study served across Iraq and in the area of Khamisiyah when U.S. forces destroyed a munitions dump that contained chemical weapons including nerve agents sarin and cyclosarin.

"These are really important findings given that the Institute of Medicine has stated that the Gulf War syndrome is imaginary and has no physical basis," White said. "When you combine these findings with greater rates of amyotrophic lateral sclerosis in the vets, it is pretty clear something happened to the Gulf War veterans' brains, and we're just beginning to see what these effects are," she said. Studies suggest that serving in the first Gulf War doubles veterans' risk of amyotrophic lateral sclerosis, a rare, progressive and fatal illness also known as Lou Gehrig's disease.

"It took us 20 years to find out about Agent Orange and the Vietnam War. Now, 16 years later, we are beginning to find out about central nervous system ailments in Gulf War veterans," White said in a news briefing.