1
|
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] [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.
Collapse
|
2
|
Gean EG, Ayers CK, Winchell KA, Freeman M, Press AM, Paynter R, Kansagara D, Nugent SM. Biological measures and diagnostic tools for Gulf War Illness - A systematic review. Life Sci 2021; 275:119360. [PMID: 33741418 DOI: 10.1016/j.lfs.2021.119360] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 02/22/2021] [Accepted: 03/07/2021] [Indexed: 10/21/2022]
Abstract
AIMS Gulf War Illness (GWI) is a chronic multisymptom illness with debated etiology and pathophysiology. This systematic review catalogues studies of validated biological tests for diagnosing GWI and of associations between biological measures and GWI for their promise as biomarkers. MAIN METHODS We searched multiple sources through February 2020 for studies of diagnostic tests of GWI and of associations between biological measures and GWI. We abstracted data on study design, demographics, and outcomes. We assessed the risk of bias of included studies. KEY FINDINGS We did not identify any studies validating tests of biomarkers that distinguish cases of GWI from non-cases. We included the best-fitting studies, 32 completed and 24 ongoing or unpublished studies, of associations between GWI and biological measures. The less well-fitting studies (n = 77) were included in a Supplementary Table. Most studies were of the central nervous and immune systems and indicated a significant association of the biological measure with GWI case status. Biological measures were heterogeneous across studies. SIGNIFICANCE Our review indicates that there are no existing validated biological tests to determine GWI case status. Many studies have assessed the potential association between a variety of biological measures and GWI, the majority of which pertain to the immune and central nervous systems. More importantly, while most studies indicated a significant association between biological measures and GWI case status, the biological measures across studies were extremely heterogeneous. Due to the heterogeneity, the focus of the review is to map out what has been examined, rather than synthesize information.
Collapse
Affiliation(s)
- Emily G Gean
- Scientific Resource Center for the Agency for Healthcare Research and Quality Evidence-based Practice Center, Portland VA Research Foundation, United States of America.
| | - Chelsea K Ayers
- VA Portland Health Care System Evidence Synthesis Program, United States of America
| | - Kara A Winchell
- VA Portland Health Care System Evidence Synthesis Program, United States of America
| | - Michele Freeman
- VA Portland Health Care System Evidence Synthesis Program, United States of America
| | - Ashlyn M Press
- Cooperative Studies Program Epidemiology Center-Durham, Durham Veterans Affairs Health Care System, Durham, NC, United States of America
| | - Robin Paynter
- VA Portland Health Care System Evidence Synthesis Program, United States of America
| | - Devan Kansagara
- VA Portland Health Care System Evidence Synthesis Program, United States of America
| | - Shannon M Nugent
- VA Portland Health Care System Evidence Synthesis Program, United States of America
| |
Collapse
|
3
|
Afek A, Ben-Avraham R, Davidov A, Berezin Cohen N, Ben Yehuda A, Gilboa Y, Nahum M. Psychological Resilience, Mental Health, and Inhibitory Control Among Youth and Young Adults Under Stress. Front Psychiatry 2020; 11:608588. [PMID: 33584372 PMCID: PMC7874000 DOI: 10.3389/fpsyt.2020.608588] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 12/21/2020] [Indexed: 01/18/2023] Open
Abstract
Psychological resilience allows one to cope successfully with adversities occurring during stressful periods, which may otherwise trigger mental illness. Recent models suggest that inhibitory control (IC), the executive control function which supports our goal-directed behavior and regulates our emotional response, may underlie resilience. However, the ways in which this is manifested during stressful situations in real life is still unclear. Here, we examined the relationship between IC, psychological resilience, psychological distress, and anxiety among 138 female and male participants in a stressful situation: during their initial combat training in the military. Using a mobile app, we assessed IC using emotional and non-emotional variations of the Go/No-Go task. Psychological resilience, psychological distress, and anxiety were assessed using mobile versions of self-report questionnaires. We found that psychological resilience is significantly correlated with non-emotional IC (r = 0.24, p < 0.005), but not with emotional IC; whereas, psychological distress and anxiety are correlated with emotional IC (r = -0.253, p < 0.005 and r = -0.224, p < 0.01, for psychological distress and anxiety, respectively), but not with non-emotional IC. A regression model predicting emotional IC confirmed non-emotional IC and distress as unique contributors to the variance, but not psychological distress. In addition, associations between psychological distress and emotional IC were found only for female participants. Collectively, the results clarify the link between IC, resilience, and mental health in real-life stressful situations, showing separate mechanisms of IC involved in resilience on the one hand, and mental health on the other hand. These results have implications for building mobile resilience interventions for youth and young adults facing stressful situations.
Collapse
Affiliation(s)
- Anat Afek
- School of Occupational Therapy, Faculty of Medicine, Hebrew University, Jerusalem, Israel
| | - Rina Ben-Avraham
- School of Occupational Therapy, Faculty of Medicine, Hebrew University, Jerusalem, Israel
| | | | - Noa Berezin Cohen
- Mental Health Department, Medical Corps, Israel Defense Forces, Haifa, Israel
| | - Ariel Ben Yehuda
- Mental Health Department, Medical Corps, Israel Defense Forces, Haifa, Israel
| | - Yafit Gilboa
- School of Occupational Therapy, Faculty of Medicine, Hebrew University, Jerusalem, Israel
| | - Mor Nahum
- School of Occupational Therapy, Faculty of Medicine, Hebrew University, Jerusalem, Israel
| |
Collapse
|
4
|
Gopinath KS, Sakoglu U, Crosson BA, Haley RW. Exploring brain mechanisms underlying Gulf War Illness with group ICA based analysis of fMRI resting state networks. Neurosci Lett 2019; 701:136-141. [DOI: 10.1016/j.neulet.2019.02.041] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 02/16/2019] [Accepted: 02/26/2019] [Indexed: 11/24/2022]
|
5
|
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] [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.
Collapse
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
| |
Collapse
|
6
|
Cue-dependent inhibition in posttraumatic stress disorder and attention-deficit/hyperactivity disorder. J Anxiety Disord 2017; 51:1-6. [PMID: 28818658 DOI: 10.1016/j.janxdis.2017.08.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 07/18/2017] [Accepted: 08/01/2017] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Attention-deficit/hyperactivity disorder (ADHD) and posttraumatic stress disorder (PTSD) are common among military veterans, but the comorbidity of these two psychiatric disorders remains largely unstudied. Evaluating response inhibition and cue-dependent learning as behavioral and neurocognitive mechanisms underlying ADHD/PTSD can inform etiological models and development of tailored interventions. METHOD A cued go/no-go task evaluated response inhibition in 160 adult males. Participants were recruited from the community and a Veterans Administration medical center. Four diagnostic groups were identified: ADHD-only, PTSD-only, ADHD+PTSD, controls. RESULTS Group differences were observed across most indices of inhibitory functioning, reaction time, and reaction time variability, whereby PTSD-only and ADHD+PTSD participants demonstrated deficits relative to controls. No cue dependency effects were observed. CONCLUSION Finding complement prior work on neurocognitive mechanisms underlying ADHD, PTSD, and ADHD+PTSD. Lack of expected group differences for the ADHD-only group may be due to limited power. Additional work is needed to better characterize distinctions among clinical groups, as well as to test effects among women and youth.
Collapse
|
7
|
Nguyen LT, Mudar RA, Chiang HS, Schneider JM, Maguire MJ, Kraut MA, Hart J. Theta and Alpha Alterations in Amnestic Mild Cognitive Impairment in Semantic Go/NoGo Tasks. Front Aging Neurosci 2017; 9:160. [PMID: 28588479 PMCID: PMC5440918 DOI: 10.3389/fnagi.2017.00160] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 05/08/2017] [Indexed: 12/29/2022] Open
Abstract
Growing evidence suggests that cognitive control processes are impaired in amnestic mild cognitive impairment (aMCI); however the nature of these alterations needs further examination. The current study examined differences in electroencephalographic theta and alpha power related to cognitive control processes involving response execution and response inhibition in 22 individuals with aMCI and 22 age-, sex-, and education-matched cognitively normal controls. Two Go/NoGo tasks involving semantic categorization were used. In the basic categorization task, Go/NoGo responses were made based on exemplars of a single car (Go) and a single dog (NoGo). In the superordinate categorization task, responses were made based on multiple exemplars of objects (Go) and animals (NoGo). Behavioral data showed that the aMCI group had more false alarms during the NoGo trials compared to controls. The EEG data revealed between group differences related to response type in theta (4–7 Hz) and low-frequency alpha (8–10 Hz) power. In particular, the aMCI group differed from controls in theta power during the NoGo trials at frontal and parietal electrodes, and in low-frequency alpha power during Go trials at parietal electrodes. These results suggest that alterations in theta power converge with behavioral deterioration in response inhibition, whereas alterations in low-frequency alpha power appear to precede behavioral changes in response execution. Both behavioral and electrophysiological correlates combined provide a more comprehensive characterization of cognitive control deficits in aMCI.
Collapse
Affiliation(s)
- Lydia T Nguyen
- Neuroscience Program, University of Illinois at Urbana-ChampaignChampaign, IL, United States
| | - Raksha A Mudar
- Neuroscience Program, University of Illinois at Urbana-ChampaignChampaign, IL, United States.,Department of Speech and Hearing Science, University of Illinois at Urbana-ChampaignChampaign, IL, United States
| | - Hsueh-Sheng Chiang
- School of Behavioral and Brain Sciences, The University of Texas at DallasRichardson, TX, United States
| | - Julie M Schneider
- School of Behavioral and Brain Sciences, The University of Texas at DallasRichardson, TX, United States
| | - Mandy J Maguire
- School of Behavioral and Brain Sciences, The University of Texas at DallasRichardson, TX, United States
| | - Michael A Kraut
- Department of Radiology, The Johns Hopkins University School of MedicineBaltimore, MD, United States
| | - John Hart
- School of Behavioral and Brain Sciences, The University of Texas at DallasRichardson, TX, United States
| |
Collapse
|
8
|
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] [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.
Collapse
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
| |
Collapse
|
9
|
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: 282] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [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.
Collapse
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.
| |
Collapse
|
10
|
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 PMCID: PMC3578115 DOI: 10.1016/j.pscychresns.2012.08.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [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.
Collapse
|
11
|
Tillman GD, Calley CS, Green TA, Buhl VI, Biggs MM, Spence JS, Briggs RW, Haley RW, Hart J, Kraut MA. Event-related potential patterns associated with hyperarousal in Gulf War illness syndrome groups. Neurotoxicology 2012; 33:1096-105. [PMID: 22691951 DOI: 10.1016/j.neuro.2012.06.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 05/14/2012] [Accepted: 06/03/2012] [Indexed: 12/29/2022]
Abstract
An exaggerated response to emotional stimuli is one of the several symptoms widely reported by veterans of the 1991 Persian Gulf War. Many have attributed these symptoms to post-war stress; others have attributed the symptoms to deployment-related exposures and associated damage to cholinergic, dopaminergic, and white matter systems. We collected event-related potential (ERP) data from 20 veterans meeting Haley criteria for Gulf War Syndromes 1-3 and from 8 matched Gulf War veteran controls, who were deployed but not symptomatic, while they performed an auditory three-condition oddball task with gunshot and lion roar sounds as the distractor stimuli. Reports of hyperarousal from the ill veterans were significantly greater than those from the control veterans; different ERP profiles emerged to account for their hyperarousability. Syndromes 2 and 3, who have previously shown brainstem abnormalities, show significantly stronger auditory P1 amplitudes, purported to indicate compromised cholinergic inhibitory gating in the reticular activating system. Syndromes 1 and 2, who have previously shown basal ganglia dysfunction, show significantly weaker P3a response to distractor stimuli, purported to indicate dysfunction of the dopaminergic contribution to their ability to inhibit distraction by irrelevant stimuli. All three syndrome groups showed an attenuated P3b to target stimuli, which could be secondary to both cholinergic and dopaminergic contributions or disruption of white matter integrity.
Collapse
Affiliation(s)
- Gail D Tillman
- Center for BrainHealth, The University of Texas at Dallas, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
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] [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.
Collapse
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
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|