WASHINGTON - They served their country two decades ago, and more than 200,000 Gulf War vets are still dealing with the mysterious symptoms they brought home.
These vets say their wide-ranging problems -- from cognitive impairment to debilitating fatigue -- are the result of exposure to dangerous chemicals during their service in the war from 1990 to 1991.
Getting to the bottom of their complaints has been a two-year mission for a research team at Georgetown University Medical Center. Now, these researchers say they have found the missing piece of the puzzle.
Results published in the journal PLOS ONE show there are two different forms of Gulf War illness, each linked to damage in a different part of the brain.
Gulf War illness is believed to have affected roughly one-third of the 700,000 military personnel who served in Operation Desert Shield and Desert Storm.
Researchers on the project studied 28 sick veterans. They first looked at the blood pressure and heart rate of each individual, and then conducted MRIs to determine the response to physical stress.
The study's results were shocking. The researchers found the veterans' symptoms were split into two groups.
One group showed signs of atrophy in the part of the brain that regulates blood pressure and heart rate. The other group of veterans displayed atrophy in the area that processes pain.
The research does not try to determine what caused the damage.
But the study helps to explain why the symptoms of Gulf War illness are so broad.
The researchers say they hope their work will lead to better forms of treatment.
In March, the Georgetown researchers reported finding the first physical evidence of Gulf War illness in sick veterans, disputing the notion that the symptoms were the result of combat stress.
That earlier study used magnetic resonance imaging to uncover physical changes to the brain that were likely to result in changes in the way the body perceives both pain and fatigue.
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