BOSTON -- Veterans of the first Gulf War who returned with multiple health symptom complaints show significant differences in brain structures from their fellow returnees without high numbers of health symptoms, according to research that will be presented at the American Academy of Neurologys 59th Annual Meeting in Boston, April 28 May 5, 2007.

The study involved 36 veterans of the first Gulf War (1990-1991). Half of the veterans had a high number (more than five) of symptoms, such as joint pain, fatigue, forgetfulness, headaches, skin rash, nausea, and difficulty concentrating. The other half of the veterans had a lower number (five or fewer) of symptoms.

Researchers found that two areas of the brain involved in thinking and memory were significantly smaller in the veterans with a high number of symptoms than in the veterans with fewer symptoms. The overall cortex was five percent smaller in those with more symptoms, and the rostral anterior cingulated gyrus was six percent smaller.

Those with more symptoms also did not perform as well on tests of learning and memory. On one test, those with more symptoms scored 15 percent lower than those with fewer symptoms; the score was 12 percent lower on another test. The researchers found that the smaller the brain volume was in those areas, the worse the veterans performed on the memory tests.

"We dont know the cause of these differences in the veterans brain volumes, but the hypothesis is that they are related to exposure to hazardous substances during the first Gulf War," said study author Roberta White, PhD, of Boston University School of Public Health. "Many troops were exposed to hazardous substances such as pesticides, and other studies have shown that exposures to these substances affect the central nervous system."