March 24 (HealthDay News) -- Exposure to certain chemicals during the 1991 Gulf War appears to have triggered abnormal responses in the brains of some U.S. veterans, researchers have found.
They say the discovery could lead to new diagnostic tests and treatments for veterans with so-called Gulf War syndrome.
The study, from the University of Texas Southwestern Medical Center at Dallas, pinpointed brain function problems in veterans exposed to certain toxic chemicals, such as sarin gas, during the war.
"Before this study, we didn't know exactly what parts of the brain were damaged and causing the symptoms in these veterans," Dr. Robert Haley, chief of epidemiology and lead author of the study, said in a UT Southwestern news release. "We designed an experiment to test areas of the brain that would have been damaged if the illness was caused by sarin or pesticides, and the results were positive."
The study included 21 chronically ill Gulf War veterans and 17 healthy veterans. They were given small doses of physostigmine, a substance that briefly stimulates cholinergic receptors on brain cells. The researchers then used brain scans to observe levels of cell response in different areas of the brain.
"What we found was that some of the brain areas we previously suspected responded abnormally to the cholinergic challenge," Haley said. "Those areas were in the basal ganglia, hippocampus, thalamus and the amygdala.
"Changes in functioning of these brain structures can certainly cause problems with concentration and memory, body pain, fatigue, abnormal emotional responses and personality changes that we commonly see in ill Gulf War veterans," he said.
The study also gave researchers what Haley described as an added bonus: "a statistical formula combining the brain responses in 17 brain areas that separated the ill from the well veterans, and three different Gulf War syndrome variants from each other with a high degree of accuracy."
If further study in a larger group of veterans can replicate that finding, "we might have an objective test for Gulf War syndrome and its variants," he said.
That would help determine why some people are affected by chemical exposure and others are not, Haley said, and also would help in the design of studies that could lead to better treatments.
Haley was to present the findings March 24 to the House of Lords in England at a symposium on Gulf War research. The study is published in the March issue of Psychiatry Research: Neuroimaging.
SOURCE: University of Texas Southwestern Medical Center at Dallas, news release, March 20, 2009