The University of Texas team's work, summarized in the October issue of the American Journal of Medicine, found that damage to the parasympathetic nervous system may account for nearly half of the typical symptoms, including gallbladder disease, unrefreshing sleep, depression, joint pain, chronic diarrhea and sexual dysfunction, that afflict those with Gulf War syndrome.
"The high rate of gallbladder disease in these men, reported in a previous study, is particularly disturbing because typically women over 40 get this. It's singularly rare in young men," said Dr. Robert Haley, lead author of the study.
The parasympathetic system regulates primitive, automatic bodily functions such as digestion and sleep, while the sympathetic nervous system controls the "fight or flight" instinct.
The research was supported by the U.S. Army Medical Research and Materiel Command, the U.S. Public Health Service and the Perot Foundation.