In the first study of its kind, researchers at Georgetown University Medical Center have found evidence that veterans who suffer from Gulf War Illness have physical changes in their brains involved in the processing of pain and fatigue. The results could lead to a potential biomarker for Gulf War Illness, along with a possible target for therapy aimed at regenerating brain neurons.
“Pain and fatigue are perceptions, just like other sensory input, and Gulf War Illness could be due to extensive damage to the structures that facilitate them,” said lead author Rakib Rayhan, a researcher at Georgetown University Medical Center. “Some of the veterans we studied feel pain when doing something as simple as putting on a shirt. Now we have something to tell them about why their lives have been so greatly affected.”
In their study, published in the peer-reviewed, open access journal PLOS ONE, the brain scans of 31 veterans with Gulf War Illness were compared to 20 control subjects, revealing anomalies in the bundles of nerve fibers that connect brain areas.
Specifically, researchers discovered significant axonal damage in areas of the brain associated with the severity of pain, fatigue, emotions and reward processing. Bundles of axons form the brain’s white matter, carrying nerve impulses between different parts of the brain.
“This bundle also supports activity in the ventral attention network, which searches for unexpected signals in the surrounding environment that may be inappropriately interpreted as causing pain or being dangerous.” said Rayhan. “Altered function in this tract may explain the increased vigilance and distractibility observed in veterans.”
Researchers hope the study will provide insight into the mysterious medical symptoms reported by more than one-fourth of the 697,000 veterans deployed to the 1990-1991 Persian Gulf War.
These symptoms range from mild to debilitating and can include widespread pain, fatigue, and headache, as well as cognitive and gastrointestinal problems. Although the vets were exposed to toxic chemicals like nerve agents, pesticides and herbicides, no one has definitively linked any single exposure or underlying mechanism to Gulf War Illness.
Using a form of functional magnetic resonance imaging (MRI) called diffusion tensor imaging, researchers examined patterns of water diffusion in the brain, looking for changes in the integrity of white matter not seen on regular MRI scans.
“This provides a completely new perspective on Gulf War Illness,” said study senior investigator, James Baraniuk, MD, a professor of medicine at Georgetown University Medical Center. “While we can’t exactly tell how this tract is affected at the molecular level, the scans tell us these axons are not working in a normal fashion.”
Although the results are preliminary, researchers said the changes appear distinct from multiple sclerosis, major depression, Alzheimer’s disease and other neurodegenerative diseases. The findings could also provide validation for veterans who have long said no one believes them.
Many veterans have had difficulties getting benefits and treatment for the service-connected condition because some doctors assumed they were suffering from post-traumatic stress that was all inside their head, or they were faking it.