Multiple Sclerosis Centers of Excellence
Combat-Related Chemical Exposure and the Link to Multiple Sclerosis and Other Neurological Diseases
William J. Culpepper II, PhD, MA
There are numerous studies about the effects of war on illnesses experienced by military personnel. Currently, there are several research studies that are examining whether there is a relationship between war and illnesses. Web links to several resources regarding combat-related illness and injury are given at the end of this article.
This type of research is challenging. Typically, there is an observation that there seems to be a group of service members or Veterans with a disease or condition that have a similar military history. Then someone asks the question is this disease somehow related to that military history. Now the challenge begins as we must look back in time to try to determine the nature of the military history (and the exposures) of the affected individuals, often having to rely upon questionnaires and military records that were not designed for doing this type of research. Next, we must be able to accurately determine those with and without the disease in question; define what the suspected exposures are; ensure that the disease did not occur prior to military-related exposure; and determine who was exposed and who wasn’t.
In general, to determine whether an exposure causes a disease, it must be shown that those exposed have a higher rate (incidence) of the disease than those not exposed. For example, when Gulf War Veterans were evaluated for a number of neurological diseases, ALS was slightly increased compared to those not serving in the Gulf War however, MS was not more common in Gulf War Veterans (Barth et al. Am J Ind Med. 2009 Sep;52(9):663-70).
There are only two studies that have specifically investigated the possible link between combat or combat-related exposures and the risk of developing MS. The first used a large cohort of Gulf War era Veterans that were service connected for MS (Wallin et al. Neuroepidemiology. 2014;42(4):226-34). Department of Defense data on service members exposure to the oil well fires and destruction of chemical munitions was obtained and medical records reviewed to identify those that developed MS sometime after deployment. Veterans deployed to regions with exposure to the oil well fires and destruction of chemical weapons sites had less MS than those not deployed. However, we believe that this finding may have resulted from the “healthy soldier effect” whereby soldiers are screened and only those that are the fittest (and least likely to develop MS) are selected for deployment.
The second study, was an incidence (newly diagnosed cases) study of MS in active duty personnel and evaluated whether deployment to a combat zone was associated with higher rates of MS compared to those not deployed (Williams et al. MSMR. 2017 Aug;24(8):2-11). While this study did not evaluate any specific exposure, they did find that active duty service members that were deployed to a combat zone had a 22.4% higher rate of MS compared to those that were not deployed. The findings from these two studies, as well as others, offer conflicting results that do not provide any conclusive evidence that combat-related exposure are related to an increased risk of developing MS.
Thus, at present, there is no evidence to support a link between MS and Agent Orange, MS and radiation exposure, MS and exposure to depleted uranium, or MS and serving during the Gulf War. However, if you feel you might have been exposed to Agent Orange and are experiencing other health related symptoms we recommend you contact the Agent Orange hotline at 800-749-8387 or visit the VA Agent Orange website.
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