Veterans of the 1990-91 Persian Gulf War suffering from mysterious medical symptoms, termed Gulf War Illness, have physical changes in their brains not seen in unaffected individuals, according to a study published March 20 in PLOS ONE.

Specifically, veterans with the illness have anomalies in the bundles of nerve fibers that connect brain areas involved in the processing and perception of pain and fatigue, according to Rakib Rayhan, MS, of Georgetown University Medical Center in Washington, D.C., and colleagues.

“The right inferior fronto-occipital fasciculus may be a potential biomarker for Gulf War Illness,” wrote the authors.

Findings were based on diffusion tensor imaging scans of 31 veterans with the illness and 20 control subjects. White matter diffusivity properties were correlated with dolorimetery and subjective reports of pain and fatigue to identify tracts associated with Gulf War Illness symptoms.

Results showed significant correlation between severity of symptoms and axonal damage in the right inferior fronto-occipital fasciculus. While the findings are preliminary, the changes appear distinct from other neurodegenerative diseases, such as multiple sclerosis or Alzheimer's disease, and may offer a target for therapy, according to the authors.

"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," Rayhan said in a release. "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."

More than one-fourth of the 697,000 veterans deployed during the first Gulf War reported symptoms of Gulf War Illness, including pain, fatigue, headache, cognitive dysfunction and gastrointestinal issues.