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Collier CA, Salikhova A, Sabir S, Foncerrada S, Raghavan SA. Crisis in the gut: navigating gastrointestinal challenges in Gulf War Illness with bioengineering. Mil Med Res 2024; 11:45. [PMID: 38978144 PMCID: PMC11229309 DOI: 10.1186/s40779-024-00547-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 06/26/2024] [Indexed: 07/10/2024] Open
Abstract
Gulf War Illness (GWI) is characterized by a wide range of symptoms that manifests largely as gastrointestinal symptoms. Among these gastrointestinal symptoms, motility disorders are highly prevalent, presenting as chronic constipation, stomach pain, indigestion, diarrhea, and other conditions that severely impact the quality of life of GWI veterans. However, despite a high prevalence of gastrointestinal impairments among these veterans, most research attention has focused on neurological disturbances. This perspective provides a comprehensive overview of current in vivo research advancements elucidating the underlying mechanisms contributing to gastrointestinal disorders in GWI. Generally, these in vivo and in vitro models propose that neuroinflammation alters gut motility and drives the gastrointestinal symptoms reported in GWI. Additionally, this perspective highlights the potential and challenges of in vitro bioengineering models, which could be a crucial contributor to understanding and treating the pathology of gastrointestinal related-GWI.
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Affiliation(s)
- Claudia A Collier
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA
| | - Aelita Salikhova
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA
| | - Sufiyan Sabir
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA
| | - Steven Foncerrada
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA
| | - Shreya A Raghavan
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA.
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Carpenter JM, Brown KA, Veltmaat L, Ludwig HD, Clay KB, Norberg T, Harn DA, Wagner JJ, Filipov NM. Evaluation of delayed LNFPIII treatment initiation protocol on improving long-term behavioral and neuroinflammatory pathology in a mouse model of Gulf War Illness. Brain Behav Immun Health 2022; 26:100553. [DOI: 10.1016/j.bbih.2022.100553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 10/29/2022] [Accepted: 11/06/2022] [Indexed: 11/09/2022] Open
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Chan A, Gao J, Houston M, Willett T, Farhadian B, Silverman M, Tran P, Jaradeh S, Thienemann M, Frankovich J. Children With PANS May Manifest POTS. Front Neurol 2022; 13:819636. [PMID: 35557616 PMCID: PMC9086964 DOI: 10.3389/fneur.2022.819636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 02/09/2022] [Indexed: 11/22/2022] Open
Abstract
Objectives Pediatric acute-onset neuropsychiatric syndrome (PANS) is characterized by an abrupt-onset of severe psychiatric symptoms including OCD, anxiety, cognitive difficulties, and sleep issues which is thought to be a post-infection brain inflammatory disorder. We observed postural orthostatic tachycardia syndrome (POTS) which resolved with immunomodulation in a patient with Pediatric acute-onset neuropsychiatric syndrome (PANS). Here, we aim to present a case of POTS and to examine the prevalence of (POTS) in our PANS cohort, and compare the clinical characteristics of patients with and without POTS. Study Design We conducted this cohort study of patients meeting PANS criteria who had at least three clinic visits during the study period. We included data from prospectively collected questionnaires and medical record review. We present a case followed by statistical comparisons within our cohort and a Kaplan-Meier analysis to determine the time-dependent risk of a POTS diagnosis. Results Our study included 204 patients: mean age of PANS onset was 8.6 years, male sex (60%), non-Hispanic White (78%). Evidence of POTS was observed in 19/204 patients (9%) with 5/19 having persistent POTS defined as persistent abnormal orthostatic vitals, persistent POTS symptoms, and/or continued need for pharmacotherapy for POTS symptoms for at least 6 months). In this PANS cohort, patients with POTS were more likely to have comorbid joint hypermobility (63 vs 37%, p = 0.04), chronic fatigue (42 vs 18%, p = 0.03), and a family history of chronic fatigue, POTS, palpitations and syncope. An unadjusted logistic regression model showed that a PANS flare (abrupt neuropsychiatric deterioration) was significantly associated with an exacerbation of POTS symptoms (OR 3.3, 95% CI 1.4–7.6, p < 0.01). Conclusions Our study describes a high prevalence of POTS in patients with PANS (compared to the general population) and supports an association between POTS presentation and PANS flare within our cohort.
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Affiliation(s)
- Avis Chan
- Division of Allergy, Immunology and Rheumatology, Department of Pediatrics, Stanford University School of Medicine, Palo Alto, CA, United States.,Stanford PANS/Immune Behavioral Health Clinic and PANS Research Program at Lucile Packard Children's Hospital, Palo Alto, CA, United States
| | - Jaynelle Gao
- Division of Allergy, Immunology and Rheumatology, Department of Pediatrics, Stanford University School of Medicine, Palo Alto, CA, United States.,Stanford PANS/Immune Behavioral Health Clinic and PANS Research Program at Lucile Packard Children's Hospital, Palo Alto, CA, United States
| | - Madison Houston
- Stanford PANS/Immune Behavioral Health Clinic and PANS Research Program at Lucile Packard Children's Hospital, Palo Alto, CA, United States.,Department of Human Biology, Stanford University School of Humanities and Sciences, Stanford, CA, United States
| | - Theresa Willett
- Division of Allergy, Immunology and Rheumatology, Department of Pediatrics, Stanford University School of Medicine, Palo Alto, CA, United States.,Stanford PANS/Immune Behavioral Health Clinic and PANS Research Program at Lucile Packard Children's Hospital, Palo Alto, CA, United States
| | - Bahare Farhadian
- Division of Allergy, Immunology and Rheumatology, Department of Pediatrics, Stanford University School of Medicine, Palo Alto, CA, United States.,Stanford PANS/Immune Behavioral Health Clinic and PANS Research Program at Lucile Packard Children's Hospital, Palo Alto, CA, United States
| | - Melissa Silverman
- Stanford PANS/Immune Behavioral Health Clinic and PANS Research Program at Lucile Packard Children's Hospital, Palo Alto, CA, United States.,Division of Child and Adolescent Psychiatry and Child Development, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Paula Tran
- Stanford PANS/Immune Behavioral Health Clinic and PANS Research Program at Lucile Packard Children's Hospital, Palo Alto, CA, United States.,Division of Child and Adolescent Psychiatry and Child Development, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Safwan Jaradeh
- Autonomic Disorders Program, Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Margo Thienemann
- Stanford PANS/Immune Behavioral Health Clinic and PANS Research Program at Lucile Packard Children's Hospital, Palo Alto, CA, United States.,Division of Child and Adolescent Psychiatry and Child Development, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Jennifer Frankovich
- Division of Allergy, Immunology and Rheumatology, Department of Pediatrics, Stanford University School of Medicine, Palo Alto, CA, United States.,Stanford PANS/Immune Behavioral Health Clinic and PANS Research Program at Lucile Packard Children's Hospital, Palo Alto, CA, United States
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Avery TJ, Mathersul DC, Schulz-Heik RJ, Mahoney L, Bayley PJ. Self-Reported Autonomic Dysregulation in Gulf War Illness. Mil Med 2021; 188:usab546. [PMID: 34966941 DOI: 10.1093/milmed/usab546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 11/30/2021] [Accepted: 12/22/2021] [Indexed: 11/14/2022] Open
Abstract
INTRODUCTION Autonomic nervous system dysregulation is commonly observed in Gulf War illness (GWI). Using a new sample, we sought to replicate and extend findings from a previous study that found autonomic symptoms predicted physical functioning in Veterans with GWI. MATERIALS AND METHODS A linear regression model was used to predict physical functioning (36-item Short Form Health Survey (SF-36); n = 73, 75% male). First, we examined the predictive value of independent variables individually in the model including: the 31-item Composite Autonomic Symptom Score (COMPASS-31) total score, body mass index (BMI), mental health burden (i.e., post-traumatic stress disorder [PTSD] and/or depression), and COMPASS-31 subscales: orthostatic intolerance, vasomotor, secretomotor, gastrointestinal, bladder, and pupillomotor. Next, we estimated linear regression models containing the three variables (autonomic symptoms, BMI, and mental health burden) identified as predictors of physical functioning from the prior study. RESULTS These linear regression models significantly predicted physical functioning and accounted for 15% of the variance with COMPASS-31, 36.6% of variance with COMPASS-31 and BMI, and 38.2% of variance with COMPASS-31, BMI, and mental health burden. Then, forward step-wise linear regressions were applied to explore new models including COMPASS-31 subscales. Two new models accounted for more of the variance in physical functioning: 39.3% with added gastrointestinal symptoms (β = -2.206, P = .001) and 43.4% of variance with both gastrointestinal (β = -1.592, P = .008) and secretomotor subscales (β = -1.533, P = .049). Unlike the previous study we intended to replicate, mental health burden was not a significant predictor in any of our models. CONCLUSIONS Treatments that address autonomic dysregulation should be prioritized for research and clinical recommendations for Veterans with GWI who experience chronic pain.
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Affiliation(s)
- Timothy J Avery
- U.S. Department of Veterans Affairs, War Related Illness and Injury Study Center, VA Palo Alto Heath Care System, Palo Alto, CA 94301, USA
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
- National Center for PTSD, Veterans Affairs Palo Alto Health Care System, Menlo Park, CA 94025, USA
| | - Danielle C Mathersul
- U.S. Department of Veterans Affairs, War Related Illness and Injury Study Center, VA Palo Alto Heath Care System, Palo Alto, CA 94301, USA
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
- Discipline of Psychology, Murdoch University, Murdoch, WA 6150, Australia
| | - R Jay Schulz-Heik
- U.S. Department of Veterans Affairs, War Related Illness and Injury Study Center, VA Palo Alto Heath Care System, Palo Alto, CA 94301, USA
| | - Louise Mahoney
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Peter J Bayley
- U.S. Department of Veterans Affairs, War Related Illness and Injury Study Center, VA Palo Alto Heath Care System, Palo Alto, CA 94301, USA
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
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Zhang Y, Vakhtin AA, Dietch J, Jennings JS, Yesavage JA, Clark JD, Bayley PJ, Ashford JW, Furst AJ. Brainstem damage is associated with poorer sleep quality and increased pain in gulf war illness veterans. Life Sci 2021; 280:119724. [PMID: 34144059 DOI: 10.1016/j.lfs.2021.119724] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 06/01/2021] [Accepted: 06/07/2021] [Indexed: 11/19/2022]
Abstract
AIMS Gulf War Illness (GWI) is manifested as multiple chronic symptoms, including chronic pain, chronic fatigue, sleep problems, neuropsychiatric disorders, respiratory, gastrointestinal, and skin problems. No single target tissue or unifying pathogenic process has been identified that accounts for this variety of symptoms. The brainstem has been suspected to contribute to this multiple symptomatology. The aim of this study was to assess the role of the brainstem in chronic sleep problems and pain in GWI veterans. MATERIALS AND METHODS We enrolled 90 veterans (Age = 50 ± 5, 87% Male) who were deployed to the 1990-91 Gulf War and presented with GWI symptoms. Sleep quality was evaluated using the global Pittsburgh Sleep Quality Index. Pain intensities were obtained with the Brief Pain Inventory sum score. Volumes in cortical, subcortical, brainstem, and brainstem subregions and diffusion tensor metrics in 10 bilateral brainstem tracts were tested for correlations with symptom measures. KEY FINDINGS Poorer sleep quality was significantly correlated with atrophy of the whole brainstem and brainstem subregions (including midbrain, pons, medulla). Poorer sleep quality also significantly correlated with lower fractional anisotropy in the nigrostriatal tract, medial forebrain tract, and the dorsal longitudinal fasciculus. There was a significant correlation between increased pain intensity and decreased fractional anisotropy in the dorsal longitudinal fasciculus. These correlations were not altered after controlling for age, sex, total intracranial volumes, or additional factors, e.g., depression and neurological conditions. SIGNIFICANCE These findings suggest that the brainstem plays an important role in the aberrant neuromodulation of sleep and pain symptoms in GWI.
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Affiliation(s)
- Yu Zhang
- War Related Illness & Injury Study Center (WRIISC), VA Palo Alto Health Care System, Palo Alto, CA, United States.
| | | | - Jessica Dietch
- War Related Illness & Injury Study Center (WRIISC), VA Palo Alto Health Care System, Palo Alto, CA, United States; Stanford University, Stanford, CA, United States
| | - Jennifer S Jennings
- War Related Illness & Injury Study Center (WRIISC), VA Palo Alto Health Care System, Palo Alto, CA, United States
| | - Jerome A Yesavage
- War Related Illness & Injury Study Center (WRIISC), VA Palo Alto Health Care System, Palo Alto, CA, United States; Stanford University, Stanford, CA, United States
| | - J David Clark
- War Related Illness & Injury Study Center (WRIISC), VA Palo Alto Health Care System, Palo Alto, CA, United States; Stanford University, Stanford, CA, United States
| | - Peter J Bayley
- War Related Illness & Injury Study Center (WRIISC), VA Palo Alto Health Care System, Palo Alto, CA, United States; Stanford University, Stanford, CA, United States
| | - J Wesson Ashford
- War Related Illness & Injury Study Center (WRIISC), VA Palo Alto Health Care System, Palo Alto, CA, United States; Stanford University, Stanford, CA, United States
| | - Ansgar J Furst
- War Related Illness & Injury Study Center (WRIISC), VA Palo Alto Health Care System, Palo Alto, CA, United States; Stanford University, Stanford, CA, United States
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Jaquess KJ, Allen N, Chun TJ, Crock L, Zajdel AA, Reinhard MJ, Costanzo ME. The relationship between Gulf War Illness symptom severity and heart rate variability: A pilot study. Life Sci 2021; 280:119663. [PMID: 34087286 DOI: 10.1016/j.lfs.2021.119663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 05/20/2021] [Accepted: 05/21/2021] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Gulf War Illness (GWI) is a chronic multisymptom illness affecting 250,000+ veterans of the '90-'91 Gulf War which remains under-explored in terms of its physiological characteristics. We investigated whether subjective GWI symptom severity scores were related to objective measures of autonomic nervous system activity. METHODS We estimated activity in the two major branches of the autonomic nervous system (the parasympathetic nervous system [PNS] and the sympathetic nervous system [SNS]) via metrics of heart rate variability in a sample of Veterans who met established criteria for GWI with varying degrees of self-reported symptom severity. We hypothesized that subjective symptom severity scores would be inversely related to PNS activity and positively related to SNS activity. RESULTS Significant negative relationships were observed between the root mean square of successive differences of beat-to-beat intervals (a measure of PNS activity) and symptom severity, both overall and across specific GWI symptom categories (sp. fatigue [r = -0.574], gastrointestinal [r = -0.544]). Furthermore, significant positive relationships were observed between the cardiac sympathetic index and symptom severity, both overall and across specific symptom categories (sp. cognitive [r = 0.721], fatigue [r = 0.560], gastrointestinal [r = 0.694], skin [r = 0.686]). CONCLUSIONS Metrics of PNS activation revealed a negative relationship with self-reported symptom severity, while metrics of SNS activation revealed a positive relationship. The present results improve our understanding of the physiology of GWI and provide a new window from which to consider this medically unexplained illness.
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Affiliation(s)
- Kyle J Jaquess
- War Related Illness and Injury Study Center, Department of Veterans Affairs Washington, DC, United States of America; Department of Kinesiology, University of Maryland, College Park, MD, United States of America; Department of Psychology, Juniata College, Huntingdon, PA, United States of America.
| | - Nathaniel Allen
- War Related Illness and Injury Study Center, Department of Veterans Affairs Washington, DC, United States of America
| | - Timothy J Chun
- War Related Illness and Injury Study Center, Department of Veterans Affairs Washington, DC, United States of America
| | - Lucas Crock
- War Related Illness and Injury Study Center, Department of Veterans Affairs Washington, DC, United States of America
| | - Alexander A Zajdel
- War Related Illness and Injury Study Center, Department of Veterans Affairs Washington, DC, United States of America
| | - Matthew J Reinhard
- War Related Illness and Injury Study Center, Department of Veterans Affairs Washington, DC, United States of America; Department of Psychiatry, Georgetown University School of Medicine, Washington, DC, United States of America
| | - Michelle E Costanzo
- War Related Illness and Injury Study Center, Department of Veterans Affairs Washington, DC, United States of America
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Mathersul DC, Dixit K, Avery TJ, Schulz-Heik RJ, Zeitzer JM, Mahoney LA, Cho RH, Bayley PJ. Heart rate and heart rate variability as outcomes and longitudinal moderators of treatment for pain across follow-up in Veterans with Gulf War illness. Life Sci 2021; 277:119604. [PMID: 33984356 DOI: 10.1016/j.lfs.2021.119604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 05/05/2021] [Accepted: 05/07/2021] [Indexed: 10/21/2022]
Abstract
AIMS Accumulating evidence suggests Gulf War illness (GWI) is characterised by autonomic nervous system dysfunction (higher heart rate [HR], lower heart rate variability [HRV]). Yoga - an ancient mind-body practice combining mindfulness, breathwork, and physical postures - is proposed to improve autonomic dysfunction yet this remains untested in GWI. We aimed to determine (i) whether HR and HRV improve among Veterans with GWI receiving either yoga or cognitive behavioural therapy (CBT) for pain; and (ii) whether baseline autonomic functioning predicts treatment-related pain outcomes across follow-up. MAIN METHODS We present secondary analyses of 24-hour ambulatory cardiac data (mean HR, square root of the mean squared differences between successive R-R intervals [RMSSD], high frequency power [HF-HFV], and low-to-high frequency ratio [LF/HF] extracted from a 5-min window during the first hour of sleep) from our randomised controlled trial of yoga versus CBT for pain among Veterans with GWI (ClinicalTrials.govNCT02378025; N = 75). KEY FINDINGS Veterans who received CBT tended towards higher mean HR at end-of-treatment. Better autonomic function (lower mean HR, higher RMSSD/HF-HRV) at baseline predicted greater reductions in pain across follow-up, regardless of treatment group. Better baseline autonomic function (mid-range-to-high RMSSD/HF-HRV) also predicted greater pain reductions with yoga, while worse baseline autonomic function (higher mean HR, lower RMSSD/HF-HRV) predicted greater pain reductions with CBT. SIGNIFICANCE To our knowledge, this is the first study to suggest that among Veterans with GWI, HR may increase with CBT yet remain stable with yoga. Furthermore, HR and HRV moderated pain outcome across follow-up for yoga and CBT.
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Affiliation(s)
- Danielle C Mathersul
- War Related Illness and Injury Study Center (WRIISC), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, United States of America; Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, United States of America; Discipline of Psychology, Murdoch University, Murdoch, WA 6150, Australia.
| | - Kamini Dixit
- War Related Illness and Injury Study Center (WRIISC), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, United States of America
| | - Timothy J Avery
- War Related Illness and Injury Study Center (WRIISC), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, United States of America; Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, United States of America; National Centre for Posttraumatic Stress Disorder (NCPTSD), Veterans Affairs Menlo Park Health Care System, Menlo Park, CA 94025, United States of America
| | - R Jay Schulz-Heik
- War Related Illness and Injury Study Center (WRIISC), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, United States of America
| | - Jamie M Zeitzer
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, United States of America; Mental Illness Research, Education and Clinical Center (MIRECC), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, United States of America
| | - Louise A Mahoney
- War Related Illness and Injury Study Center (WRIISC), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, United States of America
| | - Rachael H Cho
- War Related Illness and Injury Study Center (WRIISC), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, United States of America
| | - Peter J Bayley
- War Related Illness and Injury Study Center (WRIISC), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, United States of America; Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, United States of America
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Dickey B, Madhu LN, Shetty AK. Gulf War Illness: Mechanisms Underlying Brain Dysfunction and Promising Therapeutic Strategies. Pharmacol Ther 2020; 220:107716. [PMID: 33164782 DOI: 10.1016/j.pharmthera.2020.107716] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 10/19/2020] [Indexed: 12/13/2022]
Abstract
Gulf War Illness (GWI), a chronic multisymptom health problem, afflicts ~30% of veterans served in the first GW. Impaired brain function is among the most significant symptoms of GWI, which is typified by persistent cognitive and mood impairments, concentration problems, headaches, chronic fatigue, and musculoskeletal pain. This review aims to discuss findings from animal prototypes and veterans with GWI on mechanisms underlying its pathophysiology and emerging therapeutic strategies for alleviating brain dysfunction in GWI. Animal model studies have linked brain impairments to incessantly elevated oxidative stress, chronic inflammation, inhibitory interneuron loss, altered lipid metabolism and peroxisomes, mitochondrial dysfunction, modified expression of genes relevant to cognitive function, and waned hippocampal neurogenesis. Furthermore, the involvement of systemic alterations such as the increased intensity of reactive oxygen species and proinflammatory cytokines in the blood, transformed gut microbiome, and activation of the adaptive immune response have received consideration. Investigations in veterans have suggested that brain dysfunction in GWI is linked to chronic activation of the executive control network, impaired functional connectivity, altered blood flow, persistent inflammation, and changes in miRNA levels. Lack of protective alleles from Class II HLA genes, the altered concentration of phospholipid species and proinflammatory factors in the circulating blood have also been suggested as other aiding factors. While some drugs or combination therapies have shown promise for alleviating symptoms in clinical trials, larger double-blind, placebo-controlled trials are needed to validate such findings. Based on improvements seen in animal models of GWI, several antioxidants and anti-inflammatory compounds are currently being tested in clinical trials. However, reliable blood biomarkers that facilitate an appropriate screening of veterans for brain pathology need to be discovered. A liquid biopsy approach involving analysis of brain-derived extracellular vesicles in the blood appears efficient for discerning the extent of neuropathology both before and during clinical trials.
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Affiliation(s)
- Brandon Dickey
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center College of Medicine, College Station, TX, USA; Texas A&M University Health Science Center College of Medicine, Temple, TX, USA
| | - Leelavathi N Madhu
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center College of Medicine, College Station, TX, USA
| | - Ashok K Shetty
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center College of Medicine, College Station, TX, USA.
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