BOSTON -- Some veterans of the first Gulf War are only now starting to show functional and structural brain changes that may be related to wartime exposures to neurotoxic substances, according to a small study.
BOSTON, May 1 -- Some veterans of the first Gulf War are only now starting to show functional and structural brain changes that may be related to wartime exposures to neurotoxic substances, according to a small study.
Regions of the brain involved in cognition, attention, and memory were significantly smaller in Gulf War vets who complained of five or more symptoms than in those who had fewer, reported Frederick Powell, M.D., of Boston University, and colleagues, at the American Academy of Neurology meeting here.
The symptoms of 36 Gulf War vets, followed for 16 years as part of a longitudinal study, included arthralgias, fatigue, memory problems, headaches, skin rash, nausea, and problems with concentration. About half the vets had five or more symptoms.
The investigators performed volumetric MRI scans of the brains of the 36 vets. The researchers also conducted a battery of neuropsychological function tests.
They compared those showing fewer than five symptoms with those showing five or more to see whether there was a relationship between functional symptoms and structural brain changes.
Using multivariate analysis of variance (MANOVA) to evaluate the MRI scans, they found that the veterans with at least five symptoms had a 6% reduction in the volume of the rostral anterior cingulate gyrus, and a 5% reduction in volume of the overall cortex. Both of these differences were significant compared with the patients with fewer than five symptoms (P <0.05%).
They also detected non-significant trends toward smaller volumes of the posterior cingulate gyrus and caudate nucleus among the high-symptom patients.
The authors also found that the posterior cingulate volume on the structural MRI scans correlated in a linear fashion with performance on the California Verbal Learning Test (CVLT) Short Delay, with highly symptomatic patients scoring 15% lower. Cererbral cortex volume was also correlated with performance on the California Verbal Learning B list, with the most symptomatic patients scoring 12% lower on the test.
"Previous research has shown that exposure to neurotoxins can alter the integrity of the central nervous system, including the gray matter," the authors wrote in their poster presentation. "It is unclear whether the volumetric differences in the brain reported here are attributable to some type of Gulf War exposure, or represent long-standing differences in brain morphology between high- and low-symptom individuals."
"The fact that we found a relationship between the anatomical and the functional findings suggest that these are robust findings," said co-author Roberta White, Ph.D., a professor of neurology at the BU School of Public Health, in an interview.
Dr. White said that the investigators suspect that exposure of Gulf War vets to hazardous substances such as pesticides and other neurotoxin may account for the central nervous system changes they observed, as suggested by other studies.