The Relationship Between Traumatic Brain Injury and Rates of Chronic Symptomatic Illness in 202 Gulf War Veterans.

Abstract

Although not a "signature injury" of Operation Desert Shield/Desert Storm (i.e., Gulf War, GW), some GW veterans have a history traumatic brain injury (TBI). For example, a previous study found that 12.2% of the GW veterans from the Fort Devens Cohort Study had self-reported TBIs. The present study sought to build upon this finding by examining the relationship between TBI and chronic symptomatic illness in a different sample of GW veterans. Participants were 202 GW veterans recruited from 2014 to 2018 at the San Francisco Veterans Affairs Medical Center as part of a VA-funded study on the effects of predicted exposure to low levels of sarin and cyclosarin on brain structure and function. The Ohio State University TBI identification method was used to determine lifetime history of TBI. The Kansas Gulf War Military History and Health Questionnaire was used to assess symptoms and to determine cases of Kansas Gulf War Illness (GWI) and Centers for Disease Control and Prevention (CDC) Chronic Multisymptom Illness (CMI). Nearly half (47%) the sample had a history of TBI, but only 7% of the TBIs were sustained in injuries that occurred during the GW. Most of the TBIs were sustained in injuries that occurred prior to (73%) or after (34%) the GW. History of TBI was not associated with higher rates of symptomatic illness when it was narrowly defined (i.e., Kansas GWI cases or cases of severe CMI). History of TBI was only associated with higher rates of symptomatic illness when it is broadly defined (i.e., CDC CMI or mild-moderate CMI). There was suggestive evidence that veterans who sustained TBIs during the GW (only seven in the present sample) have poorer functional outcomes compared with GW veterans with non-GW related TBIs. While TBIs were uncommon during the GW, many GW veterans sustained TBIs prior or after the GW. Because TBI and GWI/CMI share some overlapping symptoms, history of TBI may appear to be associated with increased rates of chronic symptomatic illness in GW veterans if chronic symptomatic illness is defined broadly (i.e., CDC CMI or mild-moderate CMI). History of pre-GW TBI did not affect the veterans' response to exposures/experiences from the GW; however, there was suggestive evidence that veterans who sustained TBIs during the GW may have poorer functional outcomes that GW veterans without TBI or even GW veterans with non-GW-related TBIs. Future, better powered studies with randomly and systematically select participants from the larger population of GW veterans will need to confirm this finding.