Gulf War illness, with its many and varied many symptoms, isn’t a psychological ailment. It causes neurological damage in two different parts of the brain, affecting pain regulation and heart rates, according to a study by Georgetown University Medical Center (GUMC).
Researchers found that Gulf War illness has two different forms, depending on which brain regions have atrophied. Their study of Gulf War veterans, published online last week in PLOS ONE, “may help explain why clinicians have consistently encountered veterans with different symptoms and complaints,” according to a press release from GUMC.
Using brain imaging before and after exercise tests, researchers studied the effects of physical stress on the veterans and a control group.
“Following exercise, subgroups were evident,” the release said. “In 18 veterans, they found that pain levels increased after completion of the exercise stress tests; fMRI scans in these participants showed loss of brain matter in adjacent regions associated with pain regulation.”
During cognitive tasks, these vets showed an increased use of the basal ganglia — a compensatory strategy the brain uses that is also seen in neurodegenerative disorders such as Alzheimer’s disease, according to George. Following exercise, this group lost the ability to employ its basal ganglia, suggesting an adverse response to a physiological stressor.
In addition, “a separate group of 10 veterans had a very different clinical alteration,” lead author Dr. James Baraniuk, a GUMC professor of medicine, said in a statement.
These 10 veterans had substantial increases in their heart rate, and researchers also determined that this subgroup had atrophy in the brain stem, which regulates heart rate.
In addition, brain scans during a cognitive task performed prior to exercise showed increased compensatory use of the cerebellum, again a trait seen in neurodegenerative disorders.
“Like the other group, this cohort lost the ability to use this compensatory area after exercise,” the press release said.
Changes in cognition, brain structure and exercise-induced symptoms found in the veterans were absent in the 10-participant matched control group.
“The use of other brain areas to compensate for a damaged area is seen in other disorders, such as Alzheimer’s disease, which is why we believe our data show that these veterans are suffering from central nervous system dysfunction,” Rayhan said.
However, just because such changes are similar to other neurodegenerative states doesn’t mean that veterans will progress to Alzheimer’s or other diseases, according to Rayhan.
The findings — a surprise to researchers — follow a study in Gulf War veterans published in March in PLOS ONE that reported abnormalities in the bundle of nerve fibers connecting the brain areas involved in the processing and perception of pain and fatigue.
Gulf War Illness is the mysterious malady believed to have affected more than 200,000 military personnel who served in the 1990-1991 Operation Desert Shield and Desert Storm.
Although veterans were exposed to nerve agents, pesticides and herbicides (among other toxic chemicals), no one has definitively linked any single exposure or underlying mechanism to Gulf War illness.
The symptoms of Gulf War illness — which have not been widely accepted by the public or medical professionals — range from mild to debilitating and can include widespread pain, fatigue and headache, as well as cognitive and gastrointestinal dysfunctions.
“Our findings help explain and validate what these veterans have long said about their illness,” Rayhan said.