Kimberly A. Sullivan, Ph.D.; Boston University Medical Center, GWI Investigator-Initiated Research Award

Roughly 25% of the veterans from the Gulf War, they include nearly 700,000 veterans, have reported a constellation of health systems that have been called Gulf War Illness. These symptoms include fatigue, cognitive complaints of concentration and attention problems, as well as memory issues, joint pain, gastrointestinal distress, and headaches. There have been questions whether multiple chemical exposures may be related to these chronic health effects in Gulf War Veterans and these multiple exposures include a similar class of chemicals called acetylcholine esterase inhibitors. And these include different types of pesticides.

Recent reports from the Department of Defense and the Rand Corporation have suggested that nearly 41,000 Gulf War Veterans could have been overexposed to these particular chemicals. And so our study, the Pesticide MRI Study, was designed to assess these brain behavior relationships in a group of Gulf War Veterans with known pesticide exposures based on the Military Occupational Specialties, Pesticide Applicators, or Preventative Medicine Personnel. In this small pilot study of 24 study participants, we performed brain MRIs as well as cognitive functioning and health symptom reports in order to assess brain behavior relationships. So we were looking at patterns of structural and functional changes in these veterans. In this way, we were looking to see whether central nervous system deficit from these chemical exposures may be related to health symptom report and cognitive functioning.

We found that particular central nervous system deficits appeared present when we looked at different parts of the brain. So when we looked at brain volumes of white matter in the brain, we found that correlated with health symptom report in these Gulf War Veterans. So that as white matter decreased, health symptom reporting increased in these Gulf War Veterans. And the other finding that we had was that when we looked at specific combinations of pesticide exposures, we found that individuals who had high exposure to delousing agents including-that was called lindane as well as pest strips in enclosed areas called dichlorvos had lower brain volumes on not only white matter but also grey matter of the brain, suggesting that this is a group that should be followed over time as well.

And lastly we found that in veterans who had high exposures to the insect repellent DEET combined with high intake of anti-nerve gas pills called pyridostigmine bromide, this group showed lower volumes on a measure of the brain called the hippocampus. So they had lower hippocampo volumes, which is associated with memory functioning. And this group also showed lower performance on cognitive measures of visual memory processing where they were asked to draw a complex figure. So in this particular effect, we found a structural and functional pattern.

I think what these results are showing us is that specific chemical exposures during the Gulf War seem to be correlated with central nervous system deficits that appear to correlate with health symptom effects and cognitive effects. And what we'd like to do in future research is to try and really further understand this mechanism of what's happening in Gulf War Illness and also to identify treatment options for that.

The reason why some veterans may be ill chronically and some may not, may have a lot to with genetic predisposition and the ability to clear some of these chemicals out of their system; and so future research that we may be interested in conducting down the line also would look at those particular genetic predispositions to clearing these chemicals out of your system. Gulf War Illness is not only a multisymptom illness, it also appears to be a multisystem illness so it really does require multiple disciplines to really tackle the problem in the most expedient way. And the CDMRP has a mechanism for that and consortiums for some other programs and now recently for the Gulf War Illness program, which I think is the exact way to tackle this issue. What I'd like to say to Gulf War Veterans is that the researchers who are continuing in this field are really starting to put the pieces together in what is going on with Gulf War Illness and we're trying to devise treatments that will be helpful to you. The best thing for veterans who are interested in helping this research is to please participate in research studies because we're really trying to help figure this puzzle out.