A new study published in the journal Brain Communications suggests that Gulf War Illness can be categorized into two distinct subtypes.
Gulf War Illness (GWI) is a chronic, multi-symptom condition affecting about 25-35% of military veterans who returned from the 1990-91 Persian Gulf War. Symptoms may include fatigue, muscle pain, insomnia, cognitive problems (often described as brain fog) and exhaustion after exercise. Many of these symptoms are similar to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).
Through functional magnetic resonance imaging (fMRI), researchers at Georgetown University Medical Center have demonstrated that GWI patients have one of two different types of changes after exercise when compared to healthy patients.
The results clarify that the illness leads to measurable physiological changes in the brain, suggesting multiple strategies for future treatments of these patients.
For the study, researchers in the laboratory of James Baraniuk, M.D., professor of medicine at Georgetown University Medical Center, imaged the brains of veterans with Gulf War illness before and after moderate exercise. The next day, the participants completed a second stress test and a memory test during brain imaging.
No differences were found in fMRI scans between the veterans before exercise. The veterans were then divided into those who had previously shown racing heart rates after standing up and those who did not.
According to Stuart Washington, Ph.D., a postdoctoral fellow and lead author on the study, both groups of GWI veterans had differences in brain activity compared to healthy patients, but the type of abnormal brain activity could be broken down even further between the two GWI groups.
After exercise, the veterans prone to racing heart rates had a significant decrease in brain activity in the cerebellum, the part of the brain responsible for fine motor control, cognition, pain, and emotion.
On the other hand, the group not prone to racing heart rates had a significant increase in brain activity in a different part of the brain that is responsible for planning of body movements and is also associated with chronic pain.
The healthy patients showed no changes at all.
“Gulf War illness remains a debilitating disease, but we are getting a better handle on the cognitive dysfunction,” said Baraniuk. “Now that different regions of the brain have been associated with two subtypes of GWI, we can study these regions through imaging and other techniques to improve diagnosis and, perhaps, to study future treatments.
“We are grateful to the veterans who participated in this research because they are providing the answers to medical questions and leading the charge to new therapies for GWI.”