A Magnetoencephalographic (MEG) Study of Gulf War Illness (GWI)

Abstract

Background

Gulf War Illness (GWI) has affected many Gulf War veterans. It involves several organs, most notably the brain. Neurological-cognitive-mood-related symptoms frequently dominate and are at the root of chronic ill-health and disability in GWI. Here we investigated the neural mechanisms underlying brain dysfunction in GWI in the absence of mental health disorders.

Methods

Eighty-six veterans completed diagnostic interviews to establish the presence of GWI and assess mental health status. Participants diagnosed with GWI met both Center for Disease Control and Kansas criteria. We studied 46 healthy controls and 40 veterans with GWI without mental illness. They all underwent a resting-state magnetoencephalographic (MEG) scan to assess brain communication based on synchronous neural interactions (SNI; Georgopoulos et al., 2007).

Findings

We found substantial differences in SNI between control and GWI groups centered on the cerebellum and frontal cortex. In addition, using the maxima and minima of SNI per sensor as predictors, we successfully classified 94.2% of the 86 participants (95% sensitivity, 93.5% specificity).

Interpretation

These findings document distinct differences in brain function between control and GWI in the absence of mental health comorbidities, differences that are excellent predictors of GWI.

Funding

U.S. Department of Veterans Affairs and University of Minnesota.

Highlights

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  This is the first study of brain mechanisms in Gulf War Illness using magnetoencephalography.

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  Substantial differences in brain synchronicity were found in veterans with Gulf War Illness compared to control Gulf War veterans.

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  These differences involved mainly the cerebellum and frontal cortex.

Gulf War Illness is a debilitating disorder of unknown etiology that has affected a substantial number of veterans who served in the 1990–91 Gulf War. A prominent feature of the disease is the presence of neurological, cognitive and mood disorders. Here we assessed dynamic brain function in veterans suffering from Gulf War Illness (in the absence of mental illness) using magnetoencephalography, a high-fidelity method that measures brain activity. We found neural miscommunication in Gulf War Illness (as compared to control participants) entered mainly on the cerebellum and frontal cortex. These results document dynamic brain anomalies in Gulf War Illness and pave the way for further investigations to elucidate the mechanisms leading to those anomalies.