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Haley RW, Kramer G, Xiao J, Dever JA, Teiber JF. Evaluation of a Gene-Environment Interaction of PON1 and Low-Level Nerve Agent Exposure with Gulf War Illness: A Prevalence Case-Control Study Drawn from the U.S. Military Health Survey's National Population Sample. Environ Health Perspect 2022; 130:57001. [PMID: 35543525 PMCID: PMC9093163 DOI: 10.1289/ehp9009] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
BACKGROUND Consensus on the etiology of 1991 Gulf War illness (GWI) has been limited by lack of objective individual-level environmental exposure information and assumed recall bias. OBJECTIVES We investigated a prestated hypothesis of the association of GWI with a gene-environment (GxE) interaction of the paraoxonase-1 (PON1) Q192R polymorphism and low-level nerve agent exposure. METHODS A prevalence sample of 508 GWI cases and 508 nonpaired controls was drawn from the 8,020 participants in the U.S. Military Health Survey, a representative sample survey of military veterans who served during the Gulf War. The PON1 Q192R genotype was measured by real-time polymerase chain reaction (RT-PCR), and the serum Q and R isoenzyme activity levels were measured with PON1-specific substrates. Low-level nerve agent exposure was estimated by survey questions on having heard nerve agent alarms during deployment. RESULTS The GxE interaction of the Q192R genotype and hearing alarms was strongly associated with GWI on both the multiplicative [prevalence odds ratio (POR) of the interaction=3.41; 95% confidence interval (CI): 1.20, 9.72] and additive (synergy index=4.71; 95% CI: 1.82, 12.19) scales, adjusted for measured confounders. The Q192R genotype and the alarms variable were independent (adjusted POR in the controls=1.18; 95% CI: 0.81, 1.73; p=0.35), and the associations of GWI with the number of R alleles and quartiles of Q isoenzyme were monotonic. The adjusted relative excess risk due to interaction (aRERI) was 7.69 (95% CI: 2.71, 19.13). Substituting Q isoenzyme activity for the genotype in the analyses corroborated the findings. Sensitivity analyses suggested that recall bias had forced the estimate of the GxE interaction toward the null and that unmeasured confounding is unlikely to account for the findings. We found a GxE interaction involving the Q-correlated PON1 diazoxonase activity and a weak possible GxE involving the Khamisiyah plume model, but none involving the PON1 R isoenzyme activity, arylesterase activity, paraoxonase activity, butyrylcholinesterase genotypes or enzyme activity, or pyridostigmine. DISCUSSION Given gene-environment independence and monotonicity, the unconfounded aRERI>0 supports a mechanistic interaction. Together with the direct evidence of exposure to fallout from bombing of chemical weapon storage facilities and the extensive toxicologic evidence of biochemical protection from organophosphates by the Q isoenzyme, the findings provide strong evidence for an etiologic role of low-level nerve agent in GWI. https://doi.org/10.1289/EHP9009.
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Affiliation(s)
- Robert W. Haley
- Division of Epidemiology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Gerald Kramer
- Division of Epidemiology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Junhui Xiao
- Division of Epidemiology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jill A. Dever
- RTI International, Washington, District of Columbia, USA
| | - John F. Teiber
- Division of Epidemiology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Brady CB, Robey I, Stein TD, Huber BR, Riley J, Abdul Rauf N, Spencer KR, Walt G, Adams L, Averill JG, Walker S, McKee AC, Thomson SP, Kowall NW. The Department of Veterans Affairs Gulf War Veterans' Illnesses Biorepository: Supporting Research on Gulf War Veterans' Illnesses. Brain Sci 2021; 11:1349. [PMID: 34679413 PMCID: PMC8533803 DOI: 10.3390/brainsci11101349] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 10/09/2021] [Accepted: 10/11/2021] [Indexed: 12/27/2022] Open
Abstract
AIMS To introduce a resource supporting research on Gulf War illness (GWI) and related disorders, the Gulf War Veterans' Illnesses Biorepository (GWVIB). METHODS Gulf War era veterans (GWVs) are recruited nationally and enrolled via telephone and email/postal mail. Enrolled veterans receive annual telephone and mail follow-up to collect health data until their passing. A postmortem neuropathological examination is performed, and fixed and frozen brain and spinal cord samples are banked to support research. Investigators studying GWI and related disorders may request tissue and data from the GWVIB. RESULTS As of September 2021, 127 GWVs from 39 states were enrolled; 60 met the criteria for GWI, and 14 met the criteria for chronic multisymptom illness (CMI). Enrollees have been followed up to six years. Postmortem tissue recoveries were performed on 14 GWVs. The most commonly found neuropathologies included amyotrophic lateral sclerosis, chronic traumatic encephalopathy, and Lewy body disease. Tissue was of good quality with an average RNA integrity number of 5.8 (SD = 1.0) and ≥4.8 in all of the cases. DISCUSSION The availability of health data and high-quality CNS tissue from this well-characterized GWV cohort will support research on GWI and related disorders affecting GWVs. Enrollment is ongoing.
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Affiliation(s)
- Christopher B. Brady
- Research and Development Service, VA Boston Healthcare System, Boston, MA 02130, USA; (J.R.); (N.A.R.); (K.R.S.); (G.W.); (L.A.)
- Department of Neurology, Boston University School of Medicine, Boston, MA 02118, USA; (B.R.H.); (N.W.K.)
- Harvard Medical School, Boston, MA 02115, USA
| | - Ian Robey
- Southern Arizona VA Healthcare System, Tucson, AZ 85723, USA; (I.R.); (J.G.A.); (S.W.); (S.P.T.)
- Department of Endocrinology, University of Arizona, Tucson, AZ 85724, USA
| | - Thor D. Stein
- Pathology Service, VA Boston Healthcare System, Boston, MA 02130, USA; (T.D.S.); (A.C.M.)
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA 02118, USA
- Department of Veterans Affairs Medical Center, Bedford, MA 01730, USA
| | - Bertrand R. Huber
- Department of Neurology, Boston University School of Medicine, Boston, MA 02118, USA; (B.R.H.); (N.W.K.)
- Pathology Service, VA Boston Healthcare System, Boston, MA 02130, USA; (T.D.S.); (A.C.M.)
- National Center for Posttraumatic Stress Disorder, VA Boston Healthcare System, Boston, MA 02130, USA
| | - Jessica Riley
- Research and Development Service, VA Boston Healthcare System, Boston, MA 02130, USA; (J.R.); (N.A.R.); (K.R.S.); (G.W.); (L.A.)
| | - Nazifa Abdul Rauf
- Research and Development Service, VA Boston Healthcare System, Boston, MA 02130, USA; (J.R.); (N.A.R.); (K.R.S.); (G.W.); (L.A.)
| | - Keith R. Spencer
- Research and Development Service, VA Boston Healthcare System, Boston, MA 02130, USA; (J.R.); (N.A.R.); (K.R.S.); (G.W.); (L.A.)
| | - Gabriel Walt
- Research and Development Service, VA Boston Healthcare System, Boston, MA 02130, USA; (J.R.); (N.A.R.); (K.R.S.); (G.W.); (L.A.)
| | - Latease Adams
- Research and Development Service, VA Boston Healthcare System, Boston, MA 02130, USA; (J.R.); (N.A.R.); (K.R.S.); (G.W.); (L.A.)
| | - James G. Averill
- Southern Arizona VA Healthcare System, Tucson, AZ 85723, USA; (I.R.); (J.G.A.); (S.W.); (S.P.T.)
| | - Sean Walker
- Southern Arizona VA Healthcare System, Tucson, AZ 85723, USA; (I.R.); (J.G.A.); (S.W.); (S.P.T.)
| | - Ann C. McKee
- Pathology Service, VA Boston Healthcare System, Boston, MA 02130, USA; (T.D.S.); (A.C.M.)
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA 02118, USA
| | - Stephen P. Thomson
- Southern Arizona VA Healthcare System, Tucson, AZ 85723, USA; (I.R.); (J.G.A.); (S.W.); (S.P.T.)
- Department of Endocrinology, University of Arizona, Tucson, AZ 85724, USA
| | - Neil W. Kowall
- Department of Neurology, Boston University School of Medicine, Boston, MA 02118, USA; (B.R.H.); (N.W.K.)
- Neurology Service, VA Boston Healthcare System, Boston, MA 02130, USA
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Kodali M, Mishra V, Hattiangady B, Attaluri S, Gonzalez JJ, Shuai B, Shetty AK. Moderate, intermittent voluntary exercise in a model of Gulf War Illness improves cognitive and mood function with alleviation of activated microglia and astrocytes, and enhanced neurogenesis in the hippocampus. Brain Behav Immun 2021; 97:135-149. [PMID: 34245811 PMCID: PMC9885810 DOI: 10.1016/j.bbi.2021.07.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 06/28/2021] [Accepted: 07/04/2021] [Indexed: 02/01/2023] Open
Abstract
Persistent cognitive and mood impairments in Gulf War Illness (GWI) are associated with chronic neuroinflammation, typified by hypertrophied astrocytes, activated microglia, and increased proinflammatory mediators in the brain. Using a rat model, we investigated whether a simple lifestyle change such as moderate voluntary physical exercise would improve cognitive and mood function in GWI. Because veterans with GWI exhibit fatigue and post-exertional malaise, we employed an intermittent voluntary running exercise (RE) regimen, which prevented exercise-induced stress. The GWI rats were provided access to running wheels three days per week for 13 weeks, commencing ten weeks after the exposure to GWI-related chemicals and stress (GWI-RE group). Groups of age-matched sedentary GWI rats (GWI-SED group) and naïve rats were maintained parallelly. Interrogation of rats with behavioral tests after the 13-week RE regimen revealed improved hippocampus-dependent object location memory and pattern separation function and reduced anxiety-like behavior in the GWI-RE group compared to the GWI-SED group. Moreover, 13 weeks of RE in GWI rats significantly reversed activated microglia with short and less ramified processes into non-inflammatory/antiinflammatory microglia with highly ramified processes and reduced the hypertrophy of astrocytes. Moreover, the production of new neurons in the hippocampus was enhanced when examined eight weeks after the commencement of RE. Notably, increased neurogenesis continued even after the cessation of RE. Collectively, the results suggest that even a moderate, intermittent physical exercise has the promise to improve brain function in veterans with GWI in association with suppression of neuroinflammation and enhancement of hippocampal neurogenesis.
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Affiliation(s)
- Maheedhar Kodali
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, United States,Research Service, Olin E. Teague Veterans Affairs Medical Center, Central Texas Veterans Health Care System, Temple, TX, United States
| | - Vikas Mishra
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, United States,Research Service, Olin E. Teague Veterans Affairs Medical Center, Central Texas Veterans Health Care System, Temple, TX, United States
| | - Bharathi Hattiangady
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, United States,Research Service, Olin E. Teague Veterans Affairs Medical Center, Central Texas Veterans Health Care System, Temple, TX, United States
| | - Sahithi Attaluri
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, United States
| | - Jenny Jaimes Gonzalez
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, United States
| | - Bing Shuai
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, United States,Research Service, Olin E. Teague Veterans Affairs Medical Center, Central Texas Veterans Health Care System, Temple, TX, United States
| | - Ashok K. Shetty
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, United States,Research Service, Olin E. Teague Veterans Affairs Medical Center, Central Texas Veterans Health Care System, Temple, TX, United States,Corresponding author at: Institute for Regenerative Medicine, Texas A&M Health Science Center, College of Medicine, 1114 TAMU, 206 Olsen Boulevard, College Station, TX 77843, United States. (A.K. Shetty)
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Moffet EW, Jones SG, Snyder T, Riedner B, Benca RM, Juergens T. Gulf War veterans exhibit broadband sleep EEG power reductions in regions overlying the frontal lobe. Life Sci 2021; 280:119702. [PMID: 34111462 DOI: 10.1016/j.lfs.2021.119702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 05/17/2021] [Accepted: 06/02/2021] [Indexed: 11/23/2022]
Abstract
AIMS Nearly a third of U.S. veterans who deployed in support of the 1990-1991 Persian Gulf War are affected by Gulf War illness (GWI). Here we aimed to characterize whether subjective sleep complaints in GWI veterans are associated with objective sleep EEG disturbances relative to healthy veterans and controls; and whether Gulf War veterans show alterations in neural activity during sleep that differentiate them from healthy subjects. MAIN METHODS We used high-density EEG (HDEEG) to assess regional patterns of rapid eye movement (REM) sleep and non-REM (NREM) sleep between three groups: Gulf War male veterans with fatigue and GWI, Gulf War male veterans without fatigue or GWI, and control males. The groups were matched relative to age, sex and obstructive sleep apnea. Topographic comparisons of nocturnal NREM and REM sleep were made between groups for all frequency bands. KEY FINDINGS Topographic analysis revealed a broadband reduction in EEG power in a circumscribed region overlying the frontal lobe in both groups of Gulf War veterans, regardless of GWI and fatigue. This frontal reduction in neural activity was present, to some extent, across all frequency bands in NREM and REM sleep. SIGNIFICANCE Given that our findings were observed in all Gulf War veterans, it appears unlikely that frontal sleep HDEEG power reductions prove wholly responsible for fatigue symptoms. These results provide avenues for research which may someday contribute to improved clinical care of formerly deployed veterans of the Persian Gulf War.
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Madhu LN, Kodali M, Attaluri S, Shuai B, Melissari L, Rao X, Shetty AK. Melatonin improves brain function in a model of chronic Gulf War Illness with modulation of oxidative stress, NLRP3 inflammasomes, and BDNF-ERK-CREB pathway in the hippocampus. Redox Biol 2021; 43:101973. [PMID: 33933884 PMCID: PMC8105671 DOI: 10.1016/j.redox.2021.101973] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 04/05/2021] [Accepted: 04/09/2021] [Indexed: 02/07/2023] Open
Abstract
Persistent cognitive and mood dysfunction is the primary CNS symptom in veterans afflicted with Gulf War Illness (GWI). This study investigated the efficacy of melatonin (MEL) for improving cognitive and mood function with antioxidant, antiinflammatory, and pro-cognitive effects in a rat model of chronic GWI. Six months after exposure to GWI-related chemicals and stress, rats were treated with vehicle or MEL (5, 10, 20, 40, and 80 mg/kg) for eight weeks. Behavioral tests revealed cognitive and mood dysfunction in GWI rats receiving vehicle, which were associated with elevated oxidative stress, reduced NRF2, catalase and mitochondrial complex proteins, astrocyte hypertrophy, activated microglia with NLRP3 inflammasomes, elevated proinflammatory cytokines, waned neurogenesis, and synapse loss in the hippocampus. MEL at 10 mg/kg alleviated simple and associative recognition memory dysfunction and anhedonia, along with reduced oxidative stress, enhanced glutathione and complex III, and reduced NLRP3 inflammasomes, IL-18, TNF-α, and IFN-γ. MEL at 20 mg/kg also normalized NRF2 and catalase and increased microglial ramification. MEL at 40 mg/kg, in addition, reduced astrocyte hypertrophy, activated microglia, NF-kB-NLRP3-caspase-1 signaling, IL-1β, MCP-1, and MIP-1α. Moreover, MEL at 80 mg/kg activated the BDNF-ERK-CREB signaling pathway, enhanced neurogenesis and diminished synapse loss in the hippocampus, and improved a more complex hippocampus-dependent cognitive function. Thus, MEL therapy is efficacious for improving cognitive and mood function in a rat model of chronic GWI, and MEL's effect was dose-dependent. The study provides the first evidence of MEL's promise for alleviating neuroinflammation and cognitive and mood impairments in veterans with chronic GWI. A low dose of Melatonin alleviated recognition memory dysfunction and anhedonia in a model of chronic GWI. A moderate dose of Melatonin improved more complex cognitive function in a model of chronic GWI. Melatonin treatment reduced oxidative stress and enhanced mitochondrial complex proteins in the GWI brain. Melatonin inhibited NLRP3 inflammasomes and proinflammatory cytokines in the GWI brain. Melatonin activated the BDNF-ERK-CREB signaling pathway and enhanced neurogenesis in the GWI brain.
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Affiliation(s)
- Leelavathi N Madhu
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, USA
| | - Maheedhar Kodali
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, USA
| | - Sahithi Attaluri
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, USA
| | - Bing Shuai
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, USA
| | - Laila Melissari
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, USA
| | - Xiaolan Rao
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, USA
| | - Ashok K Shetty
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, USA.
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Parrish RR, Haley RW. Resolving whether inhalation of depleted uranium contributed to Gulf War Illness using high-sensitivity mass spectrometry. Sci Rep 2021; 11:3218. [PMID: 33602963 DOI: 10.1038/s41598-021-82535-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 01/18/2021] [Indexed: 11/08/2022] Open
Abstract
Of the hypothesized causes of Gulf War Illness (GWI), a chronic multi-symptom illness afflicting approximately 25% of military personnel deployed to the 1991 Gulf War, exposure to depleted uranium (DU) munitions has attracted international concern. Past research has not tested the potential association of GWI with inhaled DU nor used isotope mass spectrometry of sufficient sensitivity to rigorously assess prior DU exposure. We applied a standard biokinetic model to predict the urinary concentration and uranium isotopic ratios for a range of inhalation exposures. We then applied sensitive mass spectrometry capable of detecting the predicted urinary DU to 154 individuals of a population-representative sample of U.S. veterans in whom GWI had been determined by standard case definitions and DU inhalation exposures obtained by medical history. We found no difference in the 238U/235U ratio in veterans meeting the standard case definitions of GWI versus control veterans, no differences by levels of DU inhalation exposure, and no 236U associated with DU was detected. These findings show that even the highest likely levels of DU inhalation played no role in the development of GWI, leaving exposure to aerosolized organophosphate compounds (pesticides and sarin nerve agent) as the most likely cause(s) of GWI.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Alshelh Z, Albrecht DS, Bergan C, Akeju O, Clauw DJ, Conboy L, Edwards RR, Kim M, Lee YC, Protsenko E, Napadow V, Sullivan K, Loggia ML. In-vivo imaging of neuroinflammation in veterans with Gulf War illness. Brain Behav Immun 2020; 87:498-507. [PMID: 32027960 DOI: 10.1016/j.bbi.2020.01.020] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 01/27/2020] [Accepted: 01/30/2020] [Indexed: 12/11/2022] Open
Abstract
Gulf War Illness (GWI) is a chronic disorder affecting approximately 30% of the veterans who served in the 1991 Gulf War. It is characterised by a constellation of symptoms including musculoskeletal pain, cognitive problems and fatigue. The cause of GWI is not definitively known but exposure to neurotoxicants, the prophylactic use of pyridostigmine bromide (PB) pills, and/or stressors during deployment have all been suspected to play some pathogenic role. Recent animal models of GWI have suggested that neuroinflammatory mechanisms may be implicated, including a dysregulated activation of microglia and astrocytes. However, neuroinflammation has not previously been directly observed in veterans with GWI. To measure GWI-related neuroinflammation in GW veterans, we conducted a Positron Emission Tomography (PET) study using [11C]PBR28, which binds to the 18 kDa translocator protein (TSPO), a protein upregulated in activated microglia/macrophages and astrocytes. Veterans with GWI (n = 15) and healthy controls (HC, n = 33, including a subgroup of healthy GW veterans, HCVET, n = 8), were examined using integrated [11C]PBR28 PET/MRI. Standardized uptake values normalized by occipital cortex signal (SUVR) were compared across groups and against clinical variables and circulating inflammatory cytokines (TNF-α, IL-6 and IL-1β). SUVR were validated against volume of distribution ratio (n = 13). Whether compared to the whole HC group, or only the HCVET subgroup, veterans with GWI demonstrated widespread cortical elevations in [11C]PBR28 PET signal, in areas including precuneus, prefrontal, primary motor and somatosensory cortices. There were no significant group differences in the plasma levels of the inflammatory cytokines evaluated. There were also no significant correlations between [11C]PBR28 PET signal and clinical variables or circulating inflammatory cytokines. Our study provides the first direct evidence of brain upregulation of the neuroinflammatory marker TSPO in veterans with GWI and supports the exploration of neuroinflammation as a therapeutic target for this disorder.
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Zhang Y, Avery T, Vakhtin AA, Mathersul DC, Tranvinh E, Wintermark M, Massaband P, Ashford JW, Bayley PJ, Furst AJ. Brainstem atrophy in Gulf War Illness. Neurotoxicology 2020; 78:71-79. [PMID: 32081703 DOI: 10.1016/j.neuro.2020.02.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 01/30/2020] [Accepted: 02/16/2020] [Indexed: 01/02/2023]
Abstract
BACKGROUND Gulf War Illness (GWI) is a condition that affects about 30 % of veterans who served in the 1990-91 Persian Gulf War. Given its broad symptomatic manifestation, including chronic pain, fatigue, neurological, gastrointestinal, respiratory, and skin problems, it is of interest to examine whether GWI is associated with changes in the brain. Existing neuroimaging studies, however, have been limited by small sample sizes, inconsistent GWI diagnosis criteria, and potential comorbidity confounds. OBJECTIVES Using a large cohort of US veterans with GWI, we assessed regional brain volumes for their associations with GWI, and quantified the relationships between any regional volumetric changes and GWI symptoms. METHODS Structural magnetic resonance imaging (MRI) scans from 111 veterans with GWI (Age = 49 ± 6, 88 % Male) and 59 healthy controls (age = 51 ± 9, 78 % male) were collected at the California War Related Illness and Injury Study Center (WRIISC-CA) and from a multicenter study of the Parkinson's Progression Marker Initiative (PPMI), respectively. Individual MRI volumes were segmented and parcellated using FreeSurfer. Regional volumes of 19 subcortical, 68 cortical, and 3 brainstem structures were evaluated in the GWI cohort relative to healthy controls. The relationships between regional volumes and GWI symptoms were also assessed. RESULTS We found significant subcortical atrophy, but no cortical differences, in the GWI group relative to controls, with the largest effect detected in the brainstem, followed by the ventral diencephalon and the thalamus. In a subsample of 58 veterans with GWI who completed the Chronic Fatigue Scale (CFS) inventory of Centers for Disease Control and Prevention (CDC), smaller brainstem volumes were significantly correlated with increased severities of fatigue and depressive symptoms. CONCLUSION The findings suggest that brainstem volume may be selectively affected by GWI, and that the resulting atrophy could in turn mediate or moderate GWI-related symptoms such as fatigue and depression. Consequently, the brain stem should be carefully considered in future research focusing on GWI pathology.
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Affiliation(s)
- Yu Zhang
- War Related Illness and Injury Study Center (WRIISC), Veterans Affairs Palo Alto Health Care System, USA.
| | - Timothy Avery
- War Related Illness and Injury Study Center (WRIISC), Veterans Affairs Palo Alto Health Care System, USA; Psychiatry and Behavioral Sciences, Stanford University School of Medicine, USA
| | - Andrei A Vakhtin
- War Related Illness and Injury Study Center (WRIISC), Veterans Affairs Palo Alto Health Care System, USA; Psychiatry and Behavioral Sciences, Stanford University School of Medicine, USA
| | - Danielle C Mathersul
- War Related Illness and Injury Study Center (WRIISC), Veterans Affairs Palo Alto Health Care System, USA; Psychiatry and Behavioral Sciences, Stanford University School of Medicine, USA
| | - Eric Tranvinh
- Neuroradiology, Stanford University School of Medicine, USA
| | - Max Wintermark
- War Related Illness and Injury Study Center (WRIISC), Veterans Affairs Palo Alto Health Care System, USA; Neuroradiology, Stanford University School of Medicine, USA
| | - Payam Massaband
- Radiology, VA Palo Alto Health Care System, USA; Radiology, Stanford University School of Medicine, USA
| | - J Wesson Ashford
- War Related Illness and Injury Study Center (WRIISC), Veterans Affairs Palo Alto Health Care System, USA; Psychiatry and Behavioral Sciences, Stanford University School of Medicine, USA
| | - Peter J Bayley
- War Related Illness and Injury Study Center (WRIISC), Veterans Affairs Palo Alto Health Care System, USA; Psychiatry and Behavioral Sciences, Stanford University School of Medicine, USA
| | - Ansgar J Furst
- War Related Illness and Injury Study Center (WRIISC), Veterans Affairs Palo Alto Health Care System, USA; Psychiatry and Behavioral Sciences, Stanford University School of Medicine, USA; Neurology and Neurological Sciences, Stanford University, USA; Polytrauma System of Care (PSC), VA Palo Alto Health Care System, USA
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Tillman GD, Spence JS, Briggs RW, Haley RW, Hart J, Kraut MA. Gulf War illness associated with abnormal auditory P1 event-related potential: Evidence of impaired cholinergic processing replicated in a national sample. Psychiatry Res Neuroimaging 2019; 283:7-15. [PMID: 30453127 DOI: 10.1016/j.pscychresns.2018.11.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 10/05/2018] [Accepted: 11/09/2018] [Indexed: 10/27/2022]
Abstract
Our team previously reported event-related potential (ERP) and hyperarousal patterns from a study of one construction battalion of the U.S. Naval Reserve who served during the 1991 Persian Gulf War. We sought to replicate these findings in a sample that was more representative of the entire Gulf War-era veteran population, including male and female participants from four branches of the military. We collected ERP data from 40 veterans meeting Haley criteria for Gulf War syndromes 1-3 and from 22 matched Gulf War veteran controls while they performed an auditory oddball task. Reports of hyperarousal from the ill veterans were significantly greater than those from the control veterans, and P1 amplitudes in Syndromes 2 and 3 were significantly higher than P1 amplitudes in Syndrome 1, replicating our previous findings. Many of the contributors to the generation of the P1 potential are also involved in the regulation of arousal and are modulated by cholinergic and dopaminergic systems-two systems whose dysfunction has been implicated in Gulf War illness. These differences among the three syndrome groups where their means were on either side of controls is a replication of our previous ERP study and is consistent with previous imaging studies of this population.
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Affiliation(s)
- Gail D Tillman
- Center for BrainHealth, The University of Texas at Dallas
| | - Jeffrey S Spence
- Departments of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Richard W Briggs
- Departments of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Robert W Haley
- Departments of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - John Hart
- Center for BrainHealth, The University of Texas at Dallas; Departments of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, United States.
| | - Michael A Kraut
- Center for BrainHealth, The University of Texas at Dallas; Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
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11
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Falvo MJ, Lindheimer JB, Serrador JM. Dynamic cerebral autoregulation is impaired in Veterans with Gulf War Illness: A case-control study. PLoS One 2018; 13:e0205393. [PMID: 30321200 PMCID: PMC6188758 DOI: 10.1371/journal.pone.0205393] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 09/25/2018] [Indexed: 02/03/2023] Open
Abstract
Neurological dysfunction has been reported in Gulf War Illness (GWI), including abnormal cerebral blood flow (CBF) responses to physostigmine challenge. However, it is unclear whether the CBF response to normal physiological challenges and regulation is similarly dysfunctional. The goal of the present study was to evaluate the CBF velocity response to orthostatic stress (i.e., sit-to-stand maneuver) and increased fractional concentration of carbon dioxide. 23 cases of GWI (GWI+) and 9 controls (GWI) volunteered for this study. Primary variables of interest included an index of dynamic autoregulation and cerebrovascular reactivity. Dynamic autoregulation was significantly lower in GWI+ than GWI- both for autoregulatory index (2.99±1.5 vs 4.50±1.5, p = 0.017). In addition, we observed greater decreases in CBF velocity both at the nadir after standing (-18.5±6.0 vs -9.8±4.9%, p = 0.001) and during steady state standing (-5.7±7.1 vs -1.8±3.2%, p = 0.042). In contrast, cerebrovascular reactivity was not different between groups. In our sample of Veterans with GWI, dynamic autoregulation was impaired and consistent with greater cerebral hypoperfusion when standing. This reduced CBF may contribute to cognitive difficulties in these Veterans when upright.
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Affiliation(s)
- Michael J. Falvo
- War Related Illness and Injury Study Center, Department of Veterans Affairs, East Orange, New Jersey, United States of America
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey, United States of America
- Department of Physical Medicine and Rehabilitation, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey, United States of America
| | - Jacob B. Lindheimer
- William S. Middleton Memorial Veterans Hospital, Department of Veterans Affairs, Madison, Wisconsin, United States of America
- Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Jorge M. Serrador
- War Related Illness and Injury Study Center, Department of Veterans Affairs, East Orange, New Jersey, United States of America
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey, United States of America
- Department of Cardiovascular Electronics, National University of Ireland Galway, Galway, Connacht, IRE
- * E-mail:
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12
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Naughton SX, Hernandez CM, Beck WD, Poddar I, Yanasak N, Lin PC, Terry AV. Repeated exposures to diisopropylfluorophosphate result in structural disruptions of myelinated axons and persistent impairments of axonal transport in the brains of rats. Toxicology 2018; 406-407:92-103. [DOI: 10.1016/j.tox.2018.06.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 05/02/2018] [Accepted: 06/08/2018] [Indexed: 01/17/2023]
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13
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Cooper BY, Flunker LD, Johnson RD, Nutter TJ. Behavioral, cellular and molecular maladaptations covary with exposure to pyridostigmine bromide in a rat model of gulf war illness pain. Toxicol Appl Pharmacol 2018; 352:119-31. [PMID: 29803855 DOI: 10.1016/j.taap.2018.05.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 05/16/2018] [Accepted: 05/20/2018] [Indexed: 12/12/2022]
Abstract
Many veterans of Operation Desert Storm (ODS) struggle with the chronic pain of Gulf War Illness (GWI). Exposure to insecticides and pyridostigmine bromide (PB) have been implicated in the etiology of this multisymptom disease. We examined the influence of 3 (DEET (N,N-diethyl-meta-toluamide), permethrin, chlorpyrifos) or 4 GW agents (DEET, permethrin, chlorpyrifos, pyridostigmine bromide (PB)) on the post-exposure ambulatory and resting behaviors of rats. In three independent studies, rats that were exposed to all 4 agents consistently developed both immediate and delayed ambulatory deficits that persisted at least 16 weeks after exposures had ceased. Rats exposed to a 3 agent protocol (PB excluded) did not develop any ambulatory deficits. Cellular and molecular studies on nociceptors harvested from 16WP (weeks post-exposure) rats indicated that vascular nociceptor Nav1.9 mediated currents were chronically potentiated following the 4 agent protocol but not following the 3 agent protocol. Muscarinic linkages to muscle nociceptor TRPA1 were also potentiated in the 4 agent but not the 3 agent, PB excluded, protocol. Although Kv7 activity changes diverged from the behavioral data, a Kv7 opener, retigabine, transiently reversed ambulation deficits. We concluded that PB played a critical role in the development of pain-like signs in a GWI rat model and that shifts in Nav1.9 and TRPA1 activity were critical to the expression of these pain behaviors.
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Abstract
Several studies have implicated immune system disruption in the pathophysiology of GWI. In addition, alterations in brain structure and functioning have been associated with specific exposures in theater, including pyridostigmine bromide and nerve gas agents. Recent studies conducted up to 25 years after the 1991 conflict have examined factors associated with the continuation or worsening of GWI. Drawing upon published studies of neural and immune system abnormalities in veterans with GWI, this paper proposes a model of GWI that takes into account neurologic and immunologic pathways, neuroimmune mechanisms of disease pathophysiology, individual predisposition due to sex and genetic background, and comorbid factors including neurological conditions such as neuritis/neuralgia and epilepsy that may occur along a continuum with GWI. The proposed neuroimmune model of GWI is likely to be useful for designing new research studies, clarifying factors involved in the continuation or worsening of GWI, and identifying biomarker screening algorithms for the illness. The proposed model goes beyond previously proposed frameworks for GWI by taking into account potential differences in risk based upon female vs. male sex, time elapsed since exposure to neurotoxicants, duration and severity of illness, comorbid conditions, and genotype.
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Affiliation(s)
- Steven S Coughlin
- Department of Clinical and Digital Health Sciences, Augusta University, Augusta, GA.,Research Service, Charlie Norwood VA Medical Center, Augusta, GA
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15
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Van Riper SM, Alexander AL, Koltyn KF, Stegner AJ, Ellingson LD, Destiche DJ, Dougherty RJ, Lindheimer JB, Cook DB. Cerebral white matter structure is disrupted in Gulf War Veterans with chronic musculoskeletal pain. Pain 2017; 158:2364-75. [DOI: 10.1097/j.pain.0000000000001038] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Christova P, James LM, Engdahl BE, Lewis SM, Carpenter AF, Georgopoulos AP. Subcortical brain atrophy in Gulf War Illness. Exp Brain Res 2017; 235:2777-86. [DOI: 10.1007/s00221-017-5010-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Turner MP, Hubbard NA, Himes LM, Faghihahmadabadi S, Hutchison JL, Bennett IJ, Motes MA, Haley RW, Rypma B. Cognitive Slowing in Gulf War Illness Predicts Executive Network Hyperconnectivity: Study in a Population-Representative Sample. Neuroimage Clin 2016; 12:535-541. [PMID: 27672557 PMCID: PMC5030369 DOI: 10.1016/j.nicl.2016.08.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Revised: 06/06/2016] [Accepted: 08/24/2016] [Indexed: 12/30/2022]
Abstract
Cognitive slowing is a prevalent symptom observed in Gulf War Illness (GWI). The present study assessed the extent to which functional connectivity between dorsolateral prefrontal cortex (DLPFC) and other task-relevant brain regions was predictive of GWI-related cognitive slowing. GWI patients (n = 54) and healthy veteran controls (n = 29) were assessed on performance of a processing speed task (the Digit Symbol Substitution Task; DSST) while undergoing functional magnetic resonance imaging (fMRI). GWI patients were slower on the DSST relative to controls. Bilateral DLPFC connectivity with task-relevant nodes was altered in GWI patients compared to healthy controls during DSST performance. Moreover, hyperconnectivity in these networks predicted GWI-related increases in reaction time on the DSST, whereas hypoconnectivity did not. These results suggest that GWI-related cognitive slowing reflects reduced efficiency in cortical networks.
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Affiliation(s)
- Monroe P. Turner
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Nicholas A. Hubbard
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Lyndahl M. Himes
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | | | - Joanna L. Hutchison
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Ilana J. Bennett
- Center for the Neurobiology of Learning and Memory, University of California-Irvine, Irvine, CA, USA
| | - Michael A. Motes
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Robert W. Haley
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Bart Rypma
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
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Cooper CM, Briggs RW, Farris EA, Bartlett J, Haley RW, Odegard TN. Memory and functional brain differences in a national sample of U.S. veterans with Gulf War Illness. Psychiatry Res Neuroimaging 2016; 250:33-41. [PMID: 27017423 DOI: 10.1016/j.pscychresns.2016.03.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 01/29/2016] [Accepted: 03/12/2016] [Indexed: 01/07/2023]
Abstract
Roughly 26-32% of U. S. veterans who served in the 1991 Persian Gulf War report suffering from chronic health problems. Memory complaints are regularly reported by ill Gulf War veterans (GWV), but limited data verify their complaints. This study investigated episodic memory and brain function in a nationally representative sample of GWV, using a face-name memory task and functional magnetic resonance imaging during encoding. A syndrome classification system was used to subdivide ill GWV into the three major Gulf War Illness syndrome types, "impaired cognition" (GWV-1), "confusion ataxia" (GWV-2), and "central pain" (GWV-3). Memory and brain function of ill GWV were contrasted to deployed and nondeployed well GWV controls (GWV-C). Ill GWV exhibited impaired memory function relative to GWV-C but the patterns of functional brain differences varied. Brain activation differentiated the GWV-C from the ill GWV. The different syndrome types also differed from one another in several brain regions. Additionally, the current study was the first to observe differences in brain function between deployed and nondeployed GWV-C. These results provide (1) evidence of memory impairment in ill GWV and differentiate the syndrome types at a functional neurobiological level, and (2) the role of deployment in the war on brain function.
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Affiliation(s)
- Crystal M Cooper
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Richard W Briggs
- Department of Aging and Geriatric Research, University of Florida, Gainesville, FL, USA
| | - Emily A Farris
- Department of Psychology, University of Texas Permian Basin, Odessa, TX, USA
| | - James Bartlett
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Robert W Haley
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Timothy N Odegard
- Department of Psychology, Middle Tennessee State University, Murfreesboro, TN, USA
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White RF, Steele L, O'Callaghan JP, Sullivan K, Binns JH, Golomb BA, Bloom FE, Bunker JA, Crawford F, Graves JC, Hardie A, Klimas N, Knox M, Meggs WJ, Melling J, Philbert MA, Grashow R. Recent research on Gulf War illness and other health problems in veterans of the 1991 Gulf War: Effects of toxicant exposures during deployment. Cortex 2015; 74:449-75. [PMID: 26493934 PMCID: PMC4724528 DOI: 10.1016/j.cortex.2015.08.022] [Citation(s) in RCA: 278] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 08/19/2015] [Accepted: 08/28/2015] [Indexed: 11/01/2022]
Abstract
Veterans of Operation Desert Storm/Desert Shield - the 1991 Gulf War (GW) - are a unique population who returned from theater with multiple health complaints and disorders. Studies in the U.S. and elsewhere have consistently concluded that approximately 25-32% of this population suffers from a disorder characterized by symptoms that vary somewhat among individuals and include fatigue, headaches, cognitive dysfunction, musculoskeletal pain, and respiratory, gastrointestinal and dermatologic complaints. Gulf War illness (GWI) is the term used to describe this disorder. In addition, brain cancer occurs at increased rates in subgroups of GW veterans, as do neuropsychological and brain imaging abnormalities. Chemical exposures have become the focus of etiologic GWI research because nervous system symptoms are prominent and many neurotoxicants were present in theater, including organophosphates (OPs), carbamates, and other pesticides; sarin/cyclosarin nerve agents, and pyridostigmine bromide (PB) medications used as prophylaxis against chemical warfare attacks. Psychiatric etiologies have been ruled out. This paper reviews the recent literature on the health of 1991 GW veterans, focusing particularly on the central nervous system and on effects of toxicant exposures. In addition, it emphasizes research published since 2008, following on an exhaustive review that was published in that year that summarizes the prior literature (RACGWI, 2008). We conclude that exposure to pesticides and/or to PB are causally associated with GWI and the neurological dysfunction in GW veterans. Exposure to sarin and cyclosarin and to oil well fire emissions are also associated with neurologically based health effects, though their contribution to development of the disorder known as GWI is less clear. Gene-environment interactions are likely to have contributed to development of GWI in deployed veterans. The health consequences of chemical exposures in the GW and other conflicts have been called "toxic wounds" by veterans. This type of injury requires further study and concentrated treatment research efforts that may also benefit other occupational groups with similar exposure-related illnesses.
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Affiliation(s)
- Roberta F White
- Department of Environmental Health, Boston University School of Public Health, Boston, MA, United States.
| | - Lea Steele
- Baylor University Institute of Biomedical Studies, Waco, TX, United States.
| | - James P O'Callaghan
- Molecular Neurotoxicology, Toxicology & Molecular Biology Branch (MS-3014), Health Effects Laboratory Division, Centers for Disease Control and Prevention - NIOSH, Morgantown, WV, United States.
| | - Kimberly Sullivan
- Boston University School of Public Health, Department of Environmental Health, Boston, MA, United States.
| | - James H Binns
- Research Advisory Committee on Gulf War Veterans' Illnesses, Phoenix, AZ, United States.
| | | | - Floyd E Bloom
- Molecular & Integrative Neuroscience Department, The Scripps Research Institute, La Jolla, CA, United States.
| | - James A Bunker
- National Gulf War Resource Center, Topeka, KS, United States.
| | - Fiona Crawford
- Director, TBI Research Program, Roskamp Institute, Sarasota, FL, United States.
| | - Joel C Graves
- Captain, U.S. Army, Retired, Crestview, FL, United States.
| | - Anthony Hardie
- Veterans for Common Sense, Bradenton, FL, United States.
| | - Nancy Klimas
- Institute for Neuro-Immune Medicine, Nova Southeastern University, Miami, FL, United States.
| | - Marguerite Knox
- McEntire Joint National Guard Base, Eastover, SC, United States.
| | - William J Meggs
- Department of Emergency Medicine, 3ED311, The Brody School of Medicine, East Carolina University School of Medicine, Greenville, NC, United States.
| | - Jack Melling
- U.S. Government Accountability Office, Salisbury, Wiltshire, UK.
| | | | - Rachel Grashow
- Northeastern University, Department of Civil and Environmental Engineering, Boston, MA, United States.
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Moffett K, Crosson B, Spence JS, Case K, Levy I, Gopinath K, Shah P, Goyal A, Fang Y, Briggs RW, Hart J, Moore A, Haley RW. Word-finding impairment in veterans of the 1991 Persian Gulf War. Brain Cogn 2015; 98:65-73. [PMID: 26114921 DOI: 10.1016/j.bandc.2015.05.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 04/15/2015] [Accepted: 05/27/2015] [Indexed: 11/25/2022]
Abstract
Approximately one quarter of 1991 Persian Gulf War Veterans experience cognitive and physiological sequelae that continue to be unexplained by known medical or psychological conditions. Difficulty coming up with words and names, familiar before the war, is a hallmark of the illness. Three Gulf War Syndrome subtypes have been identified and linked to specific war-time chemical exposures. The most functionally impaired veterans belong to the Gulf War Syndrome 2 (Syndrome 2) group, for which subcortical damage due to toxic nerve gas exposure is the suspected cause. Subcortical damage is often associated with specific complex language impairments, and Syndrome 2 veterans have demonstrated poorer vocabulary relative to controls. 11 Syndrome 1, 16 Syndrome 2, 9 Syndrome 3, and 14 age-matched veteran controls from the Seabees Naval Construction Battalion were compared across three measures of complex language. Additionally, functional magnetic resonance imaging (fMRI) was collected during a covert category generation task, and whole-brain functional activity was compared between groups. Results demonstrated that Syndrome 2 veterans performed significantly worse on letter and category fluency relative to Syndrome 1 veterans and controls. They also exhibited reduced activity in the thalamus, putamen, and amygdala, and increased activity in the right hippocampus relative to controls. Syndrome 1 and Syndrome 3 groups tended to show similar, although smaller, differences than the Syndrome 2 group. Hence, these results further demonstrate specific impairments in complex language as well as subcortical and hippocampal involvement in Syndrome 2 veterans. Further research is required to determine the extent of language impairments in this population and the significance of altered neurologic activity in the aforementioned brain regions with the purpose of better characterizing the Gulf War Syndromes.
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Affiliation(s)
- Kristin Moffett
- Department of Clinical and Health Psychology, University of Florida, 1225 Center Drive, Room 3151, Gainesville, FL 32611, USA.
| | - Bruce Crosson
- Department of Veterans Affairs Rehabilitation Research and Development, Brain Rehabilitation Research Center of Excellence, Malcolm Randall VA Medical Center, 1601 S.W. Archer Road, Gainesville, FL 32608-1197, USA; Department of Veterans Affairs Rehabilitation Research and Development, Center of Excellence for Visual and Neurocognitive Rehabilitation, 1670 Clairmont Rd., Decatur, GA 30033, USA; Departments of Neurology and Radiology, Emory University, 101 Woodruff Circle, Suite 6000, Atlanta, GA 30322, USA; Department of Psychology, Georgia State University, PO Box 5010, Atlanta, GA 303025010, USA.
| | - Jeffrey S Spence
- Departments of Internal Medicine (Epidemiology Division) and Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-8874, USA.
| | - Kimberly Case
- Department of Clinical and Health Psychology, University of Florida, 1225 Center Drive, Room 3151, Gainesville, FL 32611, USA.
| | - Ilana Levy
- Department of Clinical and Health Psychology, University of Florida, 1225 Center Drive, Room 3151, Gainesville, FL 32611, USA.
| | - Kaundinya Gopinath
- Departments of Internal Medicine (Epidemiology Division) and Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-8874, USA.
| | - Parina Shah
- Departments of Internal Medicine (Epidemiology Division) and Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-8874, USA.
| | - Aman Goyal
- Departments of Internal Medicine (Epidemiology Division) and Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-8874, USA.
| | - Yan Fang
- Departments of Internal Medicine (Epidemiology Division) and Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-8874, USA.
| | - Richard W Briggs
- Departments of Internal Medicine (Epidemiology Division) and Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-8874, USA; Department of Physics & Astronomy, Georgia State University, Atlanta, GA 30302-5060, USA.
| | - John Hart
- Departments of Internal Medicine (Epidemiology Division) and Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-8874, USA.
| | - Anna Moore
- Center for Rehabilitation Medicine, Emory University, 101 Woodruff Circle, Suite 6000, Atlanta, GA 30322, USA.
| | - Robert W Haley
- Departments of Internal Medicine (Epidemiology Division) and Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-8874, USA.
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21
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Hattiangady B, Mishra V, Kodali M, Shuai B, Rao X, Shetty AK. Object location and object recognition memory impairments, motivation deficits and depression in a model of Gulf War illness. Front Behav Neurosci 2014; 8:78. [PMID: 24659961 PMCID: PMC3952084 DOI: 10.3389/fnbeh.2014.00078] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Accepted: 02/24/2014] [Indexed: 12/31/2022] Open
Abstract
Memory and mood deficits are the enduring brain-related symptoms in Gulf War illness (GWI). Both animal model and epidemiological investigations have indicated that these impairments in a majority of GW veterans are linked to exposures to chemicals such as pyridostigmine bromide (PB, an antinerve gas drug), permethrin (PM, an insecticide) and DEET (a mosquito repellant) encountered during the Persian Gulf War-1. Our previous study in a rat model has shown that combined exposures to low doses of GWI-related (GWIR) chemicals PB, PM, and DEET with or without 5-min of restraint stress (a mild stress paradigm) causes hippocampus-dependent spatial memory dysfunction in a water maze test (WMT) and increased depressive-like behavior in a forced swim test (FST). In this study, using a larger cohort of rats exposed to GWIR-chemicals and stress, we investigated whether the memory deficiency identified earlier in a WMT is reproducible with an alternative and stress free hippocampus-dependent memory test such as the object location test (OLT). We also ascertained the possible co-existence of hippocampus-independent memory dysfunction using a novel object recognition test (NORT), and alterations in mood function with additional tests for motivation and depression. Our results provide new evidence that exposure to low doses of GWIR-chemicals and mild stress for 4 weeks causes deficits in hippocampus-dependent object location memory and perirhinal cortex-dependent novel object recognition memory. An open field test performed prior to other behavioral analyses revealed that memory impairments were not associated with increased anxiety or deficits in general motor ability. However, behavioral tests for mood function such as a voluntary physical exercise paradigm and a novelty suppressed feeding test (NSFT) demonstrated decreased motivation levels and depression. Thus, exposure to GWIR-chemicals and stress causes both hippocampus-dependent and hippocampus-independent memory impairments as well as mood dysfunction in a rat model.
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Affiliation(s)
- Bharathi Hattiangady
- Research Service, Olin E. Teague Veterans' Medical Center, Central Texas Veterans Health Care System Temple, TX, USA ; Institute for Regenerative Medicine, Texas A&M Health Science Center College of Medicine at Scott and White Temple, TX, USA ; Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine College Station, TX, USA
| | - Vikas Mishra
- Research Service, Olin E. Teague Veterans' Medical Center, Central Texas Veterans Health Care System Temple, TX, USA ; Institute for Regenerative Medicine, Texas A&M Health Science Center College of Medicine at Scott and White Temple, TX, USA ; Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine College Station, TX, USA
| | - Maheedhar Kodali
- Research Service, Olin E. Teague Veterans' Medical Center, Central Texas Veterans Health Care System Temple, TX, USA ; Institute for Regenerative Medicine, Texas A&M Health Science Center College of Medicine at Scott and White Temple, TX, USA ; Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine College Station, TX, USA
| | - Bing Shuai
- Research Service, Olin E. Teague Veterans' Medical Center, Central Texas Veterans Health Care System Temple, TX, USA ; Institute for Regenerative Medicine, Texas A&M Health Science Center College of Medicine at Scott and White Temple, TX, USA ; Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine College Station, TX, USA
| | - Xiolan Rao
- Research Service, Olin E. Teague Veterans' Medical Center, Central Texas Veterans Health Care System Temple, TX, USA ; Institute for Regenerative Medicine, Texas A&M Health Science Center College of Medicine at Scott and White Temple, TX, USA ; Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine College Station, TX, USA
| | - Ashok K Shetty
- Research Service, Olin E. Teague Veterans' Medical Center, Central Texas Veterans Health Care System Temple, TX, USA ; Institute for Regenerative Medicine, Texas A&M Health Science Center College of Medicine at Scott and White Temple, TX, USA ; Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine College Station, TX, USA
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Nutter T, Jiang N, Cooper BY. Persistent Na+ and K+ channel dysfunctions after chronic exposure to insecticides and pyridostigmine bromide. Neurotoxicology 2013; 39:72-83. [DOI: 10.1016/j.neuro.2013.08.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 08/07/2013] [Accepted: 08/11/2013] [Indexed: 12/15/2022]
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23
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Hubbard NA, Hutchison JL, Motes MA, Shokri-Kojori E, Bennett IJ, Brigante RM, Haley RW, Rypma B. Central Executive Dysfunction and Deferred Prefrontal Processing in Veterans with Gulf War Illness. Clin Psychol Sci 2013; 2:319-327. [PMID: 25767746 DOI: 10.1177/2167702613506580] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Gulf War Illness is associated with toxic exposure to cholinergic disruptive chemicals. The cholinergic system has been shown to mediate the central executive of working memory (WM). The current work proposes that impairment of the cholinergic system in Gulf War Illness patients (GWIPs) leads to behavioral and neural deficits of the central executive of WM. A large sample of GWIPs and matched controls (MCs) underwent functional magnetic resonance imaging during a varied-load working memory task. Compared to MCs, GWIPs showed a greater decline in performance as WM-demand increased. Functional imaging suggested that GWIPs evinced separate processing strategies, deferring prefrontal cortex activity from encoding to retrieval for high demand conditions. Greater activity during high-demand encoding predicted greater WM performance. Behavioral data suggest that WM executive strategies are impaired in GWIPs. Functional data further support this hypothesis and suggest that GWIPs utilize less effective strategies during high-demand WM.
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Affiliation(s)
- Nicholas A Hubbard
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Joanna L Hutchison
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA ; Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Michael A Motes
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA ; Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Ehsan Shokri-Kojori
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Ilana J Bennett
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Ryan M Brigante
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Robert W Haley
- Epidemiology Division, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Bart Rypma
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA ; Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
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Abstract
Roughly 26-32% of US veterans, who served in the first Gulf War, report suffering from chronic health problems ( Golomb, 2008 , Proceedings of the National Academies of Science, 105, 4295). The present study investigated the memory deficits reported by these ill Gulf War veterans (GWV) using a face-name associative memory paradigm administered during functional magnetic resonance imaging (fMRI). The fMRI data confirmed memory performance on the memory task to be related to the amount of activation in the left hippocampus observed during the study. In addition, ill-GWV demonstrated decreased memory performance relative to unaffected GWV on this memory test, providing evidence of memory deficits using an objective measure of memory.
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Affiliation(s)
- Timothy N Odegard
- Department of Psychology, University Texas Arlington, Arlington, TX 76019-0528, USA.
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Tillman GD, Calley CS, Green TA, Buhl VI, Biggs MM, Spence JS, Briggs RW, Haley RW, Kraut MA, Hart J Jr. Visual event-related potentials as markers of hyperarousal in Gulf War illness: evidence against a stress-related etiology. Psychiatry Res 2013; 211:257-67. [PMID: 23149040 DOI: 10.1016/j.pscychresns.2012.08.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 08/14/2012] [Accepted: 08/16/2012] [Indexed: 11/20/2022]
Abstract
An exaggerated response to emotional stimuli is among the many symptoms widely reported by veterans of the 1991 Persian Gulf War. These symptomologies have been attributed to damage and dysfunction associated with deployment-related exposures. We collected event-related potential data from 22 veterans meeting Haley criteria for Gulf War (GW) Syndromes 1-3 and from 8 matched GW veteran controls, who were deployed but not symptomatic, while they performed a visual three-condition oddball task where images authenticated to be associated with the 1991 Persian Gulf War were the distractor stimuli. Hyperarousal reported by ill veterans was significantly greater than that by control veterans, but this was not paralleled by higher amplitude P3a in their ERP responses to GW-related distractor stimuli. Whereas previous studies of PTSD patients have shown higher amplitude P3b responses to target stimuli that are placed amid trauma-related nontarget stimuli, ill veterans in this study showed P3b amplitudes to target stimuli - placed amid GW-related nontarget stimuli - that were significantly lower than those of the control group. Hyperarousal scores reliably predicted P3b, but not P3a, amplitudes. Although many factors may contribute to P3b amplitude differences - most notably depression and poor sleep quality, symptoms that are prevalent in the GW syndrome groups - our findings in context of previous studies on this population are consistent with the contention that dysfunction in cholinergic and dopaminergic neurotransmitter systems, and in white matter and basal ganglia may be contributing to impairments in GW veterans.
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Broderick G, Ben-Hamo R, Vashishtha S, Efroni S, Nathanson L, Barnes Z, Fletcher MA, Klimas N. Altered immune pathway activity under exercise challenge in Gulf War Illness: an exploratory analysis. Brain Behav Immun 2013. [PMID: 23201588 DOI: 10.1016/j.bbi.2012.11.007] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Though potentially linked to the basic physiology of stress response we still have no clear understanding of Gulf War Illness (GWI), a debilitating illness presenting with a complex constellation of immune, endocrine and neurological symptoms. Here we compared male GWI (n=20) with healthy veterans (n=22) and subjects with chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) (n=7). Blood was drawn during a Graded eXercise Test (GXT) prior to exercise, at peak effort (VO2 max) and 4-h post exercise. Affymetrix HG U133 plus 2.0 microarray gene expression profiling in peripheral blood mononuclear cells (PBMCs) was used to estimate activation of over 500 documented pathways. This was cast against ELISA-based measurement of 16 cytokines in plasma and flow cytometric assessment of lymphocyte populations and cytotoxicity. A 2-way ANOVA corrected for multiple comparisons (q statistic <0.05) indicated significant increases in neuroendocrine-immune signaling and inflammatory activity in GWI, with decreased apoptotic signaling. Conversely, cell cycle progression and immune signaling were broadly subdued in CFS. Partial correlation networks linking pathways with symptom severity via changes in immune cell abundance, function and signaling were constructed. Central to these were changes in IL-10 and CD2+ cell abundance and their link to two pathway clusters. The first consisted of pathways supporting neuronal development and migration whereas the second was related to androgen-mediated activation of NF-κB. These exploratory results suggest an over-expression of known exercise response mechanisms as well as illness-specific changes that may involve an overlapping stress-potentiated neuro-inflammatory response.
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Affiliation(s)
- Gordon Broderick
- Department of Medicine, University of Alberta, Edmonton, Canada.
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Haley RW, Tuite JJ. Epidemiologic Evidence of Health Effects from Long-Distance Transit of Chemical Weapons Fallout from Bombing Early in the 1991 Persian Gulf War. Neuroepidemiology 2013; 40:178-89. [DOI: 10.1159/000345124] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 10/03/2012] [Indexed: 11/19/2022] Open
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28
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Gopinath K, Gandhi P, Goyal A, Jiang L, Fang Y, Ouyang L, Ganji S, Buhner D, Ringe W, Spence J, Biggs M, Briggs R, Haley R. FMRI reveals abnormal central processing of sensory and pain stimuli in ill Gulf War veterans. Neurotoxicology 2012; 33:261-71. [PMID: 22327017 DOI: 10.1016/j.neuro.2012.01.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 01/26/2012] [Accepted: 01/26/2012] [Indexed: 11/17/2022]
Abstract
Many veterans chronically ill from the 1991 Gulf War exhibit symptoms of altered sensation, including chronic pain. In this study of 55 veterans of a Construction Battalion previously examined in 1995-1996 and 1997-1998, brain activation to innocuous and noxious heat stimuli was assessed in 2008-2009 with a quantitative sensory testing fMRI protocol in control veterans and groups representing three syndrome variants. Testing outside the scanner revealed no significant differences in warm detection or heat pain threshold among the four groups. In the fMRI study, Syndrome 1 and Syndrome 2, but not Syndrome 3, exhibited hypo-activation to innocuous heat and hyper-activation to noxious heat stimuli compared to controls. The results indicate abnormal central processing of sensory and painful stimuli in 2 of 3 variants of Gulf War illness and call for a more comprehensive study with a larger, representative sample of veterans.
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Affiliation(s)
- Kaundinya Gopinath
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States.
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Iannacchione VG, Dever JA, Bann CM, Considine KA, Creel D, Carson CP, Best H, Haley RW. Validation of a research case definition of Gulf War illness in the 1991 US military population. Neuroepidemiology 2011; 37:129-40. [PMID: 21986258 DOI: 10.1159/000331478] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Accepted: 08/03/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND A case definition of Gulf War illness with 3 primary variants, previously developed by factor analysis of symptoms in a US Navy construction battalion and validated in clinic veterans, identified ill veterans with objective abnormalities of brain function. This study tests prestated hypotheses of its external validity. METHODS A stratified probability sample (n = 8,020), selected from a sampling frame of the 3.5 million Gulf War era US military veterans, completed a computer-assisted telephone interview survey. Application of the prior factor weights to the subjects' responses generated the case definition. RESULTS The structural equation model of the case definition fit both random halves of the population sample well (root mean-square error of approximation = 0.015). The overall case definition was 3.87 times (95% confidence interval, 2.61-5.74) more prevalent in the deployed than the deployable nondeployed veterans: 3.33 (1.10-10.10) for syndrome variant 1; 5.11 (2.43-10.75) for variant 2, and 4.25 (2.33-7.74) for variant 3. Functional status on SF-12 was greatly reduced (effect sizes, 1.0-2.0) in veterans meeting the overall and variant case definitions. CONCLUSIONS The factor case definition applies to the full Gulf War veteran population and has good characteristics for research.
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Li X, Spence JS, Buhner DM, Haley RW, Briggs RW. Dynamic physostigmine effects on hippocampus perfusion. J Magn Reson Imaging 2011; 35:280-6. [DOI: 10.1002/jmri.22821] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Accepted: 08/30/2011] [Indexed: 11/07/2022] Open
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31
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Torres-Altoro MI, Mathur BN, Drerup JM, Thomas R, Lovinger DM, O'Callaghan JP, Bibb JA. Organophosphates dysregulate dopamine signaling, glutamatergic neurotransmission, and induce neuronal injury markers in striatum. J Neurochem 2011; 119:303-13. [PMID: 21848865 DOI: 10.1111/j.1471-4159.2011.07428.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The neurological effects of organophosphate (OP) pesticides, commonly used on foods and in households, are an important public health concern. Furthermore, subclinical exposure to combinations of organophosphates is implicated in Gulf War illness. Here, we characterized the effects of the broadly used insecticide chlorpyrifos (CPF) on dopamine and glutamatergic neurotransmission effectors in corticostriatal motor/reward circuitry. CPF potentiated protein kinase A (PKA)-dependent phosphorylation of the striatal protein dopamine- and cAMP-regulated phosphoprotein of M(r) 32 kDa (DARPP-32) and the glutamate receptor 1 (GluR1) subunit of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in mouse brain slices. It also increased GluR1 phosphorylation by PKA when administered systemically. This correlated with enhanced glutamate release from cortical projections in rat striatum. Similar effects were induced by the sarin congener, diisopropyl fluorophosphate, alone or in combination with the putative neuroprotectant, pyridostigmine bromide and the pesticide N,N-diethyl-meta-toluamide (DEET). This combination, meant to mimic the neurotoxicant exposure encountered by veterans of the 1991 Persian Gulf War, also induced hyperphosphorylation of the neurofibrillary tangle-associated protein tau. Diisopropyl fluorophosphate and pyrodostigmine bromide, alone or in combination, also increased the aberrant activity of the protein kinase, Cdk5, as indicated by conversion of its activating cofactor p35 to p25. Thus, consistent with recent findings in humans and animals, organophosphate exposure causes dysregulation in the motor/reward circuitry and invokes mechanisms associated with neurological disorders and neurodegeneration.
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Affiliation(s)
- Melissa I Torres-Altoro
- Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
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32
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Li X, Spence JS, Buhner DM, Hart J, Cullum CM, Biggs MM, Hester AL, Odegard TN, Carmack PS, Briggs RW, Haley RW. Hippocampal dysfunction in Gulf War veterans: investigation with ASL perfusion MR imaging and physostigmine challenge. Radiology 2011; 261:218-25. [PMID: 21914840 DOI: 10.1148/radiol.11101715] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To determine, with arterial spin labeling (ASL) perfusion magnetic resonance (MR) imaging and physostigmine challenge, if abnormal hippocampal blood flow in ill Gulf War veterans persists 11 years after initial testing with single photon emission computed tomography and nearly 20 years after the 1991 Gulf War. MATERIALS AND METHODS The local institutional review board approved this HIPAA-compliant study. Veterans were screened for contraindications and gave written informed consent before the study. In a semiblinded retrospective protocol, veterans in three Gulf War illness groups-syndrome 1 (impaired cognition), syndrome 2 (confusion-ataxia), and syndrome 3 (central neuropathic pain)-and a control group received intravenous infusions of saline in an initial session and physostigmine in a second session, 48 hours later. Each infusion was followed by measurement of hippocampal regional cerebral blood flow (rCBF) with pulsed ASL. A mixed-effects linear model adjusted for age was used to test for differences in rCBF after the cholinergic challenge across the four groups. RESULTS Physostigmine significantly decreased hippocampal rCBF in control subjects (P < .0005) and veterans with syndrome 1 (P < .05) but significantly increased hippocampal rCBF in veterans with syndrome 2 (P < .005) and veterans with syndrome 3 (P < .002). The abnormal increase in rCBF was found to have progressed to the left hippocampus of the veterans with syndrome 2 and to both hippocampi of the veterans with syndrome 3. CONCLUSION Chronic hippocampal perfusion dysfunction persists or worsens in veterans with certain Gulf War syndromes. ASL MR imaging examination of hippocampal rCBF in a cholinergic challenge experiment may be useful as a diagnostic test for this condition.
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Affiliation(s)
- Xiufeng Li
- Departments of Radiology, Division of Neuroradiology, Internal Medicine, Clinical Sciences, Psychiatry, and Neurology, University of Texas Southwestern Medical Center, Dallas, TX 75390-8874, USA
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Liu P, Aslan S, Li X, Buhner DM, Spence JS, Briggs RW, Haley RW, Lu H. Perfusion deficit to cholinergic challenge in veterans with Gulf War Illness. Neurotoxicology 2010; 32:242-6. [PMID: 21147163 DOI: 10.1016/j.neuro.2010.12.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Revised: 12/02/2010] [Accepted: 12/06/2010] [Indexed: 10/18/2022]
Abstract
A highly plausible etiology for Gulf War Illness (GWI) is that the neural damage and cognitive deficits are associated with excessive exposure to cholinesterase-inhibiting cholinergic stimulants. Our previous SPECT study provided strong indication that cerebral blood flow (CBF) in veterans with GWI may be different from those of unaffected control veterans. The present study confirmed and extended previous findings that patients with GWI have abnormal response to an inhibitory cholinergic challenge, physostigmine infusion, when compared to age-gender-education matched control veterans. The MRI-based arterial spin labeling (ASL) and phase-contrast techniques have several key advantages over SPECT, including shorter experiment duration, complete non-invasiveness, and higher spatial and temporal resolutions, and therefore may provide a cost-effective biomarker for characterization of GWI.
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Affiliation(s)
- Peiying Liu
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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