Characterizing 1991 Gulf War women veterans from the Boston Biorepository and Integrative Network for Gulf War Illness: demographics, exposures, neuroimaging and cognitive outcomes

Objective: Gulf War Illness (GWI) is a debilitating multisymptom condition that affects nearly a third of 1990-91 Gulf War (GW) veterans. Symptoms include pain, fatigue, gastrointestinal issues, and cognitive decrements. Our work has shown that GWI rates and potential causes for symptoms vary between men and women veterans. Studies have documented neuropsychological and neuroimaging findings mostly in men or combined sex datasets. Data are lacking for women veterans due to lack of power and repositories of women veteran samples. Methods: We characterized GW women veterans in terms of demographics, exposures, neuropsychological and neuroimaging outcomes from the newly collated Boston, Biorepository and Integrative Network (BBRAIN) for GWI. Results: BBRAIN women veterans are highly educated with an average age of 54 years. 81% met GWI criteria, 25% met criteria for current PTSD, 78% were white, and 81% served in the Army. Exposure to combined acetylcholinesterase inhibitors (AChEi) including skin pesticides, fogs/sprays and/or pyridostigmine bromide (PB) anti-nerve gas pill exposure resulted in slower processing speed on attentional tasks and a trend for executive impairment compared with non-exposed women. Brain imaging outcomes showed lower gray matter volumes and smaller caudate in exposed women. Conclusions: Although subtle and limited findings were present in this group of women veterans, it suggests that continued follow-up of GW women veterans is warranted. Future research should continue to evaluate differences between men and women in GW veteran samples. The BBRAIN women sub-repository is recruiting and these data are available to the research community for studies of women veterans.

A - 88 Parkinson's Disease and Deep Brain Stimulation (DBS) Device Settings: Effects of Amplitude, Pulse Width, and Frequency on Cognitive Performance

OBJECTIVE

Frontal systems decline after DBS for Parkinson's disease has been consistently reported, with high frequency settings (>130 Hz) correlating with decreased executive functioning and verbal fluency. The present study replicates and expands upon these findings.

METHOD

Six DBS recipients underwent standardized pre/post-surgical neuropsychological testing. Two-tailed T-tests assessed changes in cognitive scores. Correlational analyses explored relationships between cognitive scores and UPDRS, H&Y, and stimulator settings (amplitude, pulse width, and frequency).

RESULTS

All participants underwent bilateral STN stimulation. Pre/post averages were: UPDRS (43.0 and 26.2) and H&Y (2.7 and 2.3) with average stimulator settings of amplitude (2.7 V), pulse width (60.8 μs), and frequency (151.7 Hz). Pre/post neuropsychological testing revealed significant decline on the Behavioral Dyscontrol Scale (p = <0.01) with an average raw score decline of 3.17 points. All other cognitive scores showed non-significant improvement (p-value range = 0.22-0.89). H&Y change significantly correlated with semantic fluency (r = 0.96). UPDRS change significantly correlated with motoric processing speed (r = 0.91), semantic fluency (r = -0.93), and confrontation naming (r = -0.86). Stimulator amplitude significantly correlated with auditory attention (r = 0.82); simple planning (r = 0.96); and verbal memory (r = -0.86). Stimulator frequency significantly correlated with auditory attention (r = 0.87), simple planning (r = 0.97), and verbal memory (r = -0.96). Simulator pulse width was not significant.

CONCLUSION

The study examines effects of bilateral STN stimulation on cognitive outcomes in patients with PD. A significant improvement in motor function was accompanied by a significant decline in performance on upper motor bilateral dexterity and inhibition. Correlation analysis shows the relationship between changes in cognition and motor function, as well as the correlation between stimulator settings and specific cognitive functions.

Cognitive decrements in 1991 Gulf War veterans: associations with Gulf War illness and neurotoxicant exposures in the Boston Biorepository, Recruitment, and Integrative Network (BBRAIN) cohorts

BACKGROUND

During deployment, veterans of the 1991 Gulf War (GW) were exposed to multiple war-related toxicants. Roughly a third of these veterans continue to exhibit neurotoxicant induced symptoms of Gulf War Illness (GWI), a multi-faceted condition that includes fatigue, pain and cognitive decrements. When studied empirically, both deployed veterans with exposures and those who meet the criteria for GWI are more likely to show deficits in the area of neuropsychological functioning. Although studies have shown cognitive impairments in small sample sizes, it is necessary to revisit these findings with larger samples and newer cohorts to see if other areas of deficit emerge with more power to detect such differences. A group of researchers and clinicians with expertise in the area of GWI have identified common data elements (CDE) for use in research samples to compare data sets. At the same time, a subgroup of researchers created a new repository to share these cognitive data and biospecimens within the GWI research community.

METHODS

The present study aimed to compare cognitive measures of attention, executive functioning, and verbal memory in a large sample of GWI cases and healthy GW veteran controls using neuropsychological tests recommended in the CDEs. We additionally subdivided samples based on the specific neurotoxicant exposures related to cognitive deficits and compared exposed versus non-exposed veterans regardless of case criteria status. The total sample utilized cognitive testing outcomes from the newly collated Boston, Biorepository, Recruitment, and Integrative Network (BBRAIN) for GWI.

RESULTS

Participants included 411 GW veterans, 312 GWI (cases) and 99 healthy veterans (controls). Veterans with GWI showed significantly poorer attention, executive functioning, learning, and short-and-long term verbal memory than those without GWI. Further, GW veterans with exposures to acetylcholinesterase inhibiting pesticides and nerve gas agents, had worse performance on executive function tasks. Veterans with exposure to oil well fires had worse performance on verbal memory and those with pyridostigmine bromide anti-nerve gas pill exposures had better verbal memory and worse performance on an attention task compared to unexposed veterans.

CONCLUSIONS

This study replicates prior results regarding the utility of the currently recommended CDEs in determining impairments in cognitive functioning in veterans with GWI in a new widely-available repository cohort and provides further evidence of cognitive decrements in GW veterans related to war-related neurotoxicant exposures.

Genetic association between the APOE ε4 allele, toxicant exposures and Gulf war illness diagnosis

INTRODUCTION

Exposure to nerve agents, pyridostigmine bromide (PB), pesticides, and oil-well fires during the 1991 Gulf War (GW) are major contributors to the etiology of Gulf War Illness (GWI). Since the apolipoprotein E (APOE) ε4 allele is associated with the risk of cognitive decline with age, particularly in the presence of environmental exposures, and cognitive impairment is one of the most common symptoms experienced by veterans with GWI, we examined whether the ε4 allele was associated with GWI.

METHODS

Using a case-control design, we obtained data on APOE genotypes, demographics, and self-reported GW exposures and symptoms that were deposited in the Boston Biorepository and Integrative Network (BBRAIN) for veterans diagnosed with GWI (n = 220) and healthy GW control veterans (n = 131). Diagnosis of GWI was performed using the Kansas and/or Center for Disease Control (CDC) criteria.

RESULTS

Age- and sex-adjusted analyses showed a significantly higher odds ratio for meeting the GWI case criteria in the presence of the ε4 allele (Odds ratio [OR] = 1.84, 95% confidence interval [CI = 1.07-3.15], p ≤ 0.05) and with two copies of the ε4 allele (OR = 1.99, 95% CI [1.23-3.21], p ≤ 0.01). Combined exposure to pesticides and PB pills (OR = 4.10 [2.12-7.91], p ≤ 0.05) as well as chemical alarms and PB pills (OR = 3.30 [1.56-6.97] p ≤ 0.05) during the war were also associated with a higher odds ratio for meeting GWI case criteria. There was also an interaction between the ε4 allele and exposure to oil well fires (OR = 2.46, 95% CI [1.07-5.62], p ≤ 0.05) among those who met the GWI case criteria.

CONCLUSION

These findings suggest that the presence of the ε4 allele was associated with meeting the GWI case criteria. Gulf War veterans who reported exposure to oil well fires and have an ε4 allele were more likely to meet GWI case criteria. Long-term surveillance of veterans with GWI, particularly those with oil well fire exposure, is required to better assess the future risk of cognitive decline among this vulnerable population.

Boston biorepository, recruitment and integrative network (BBRAIN): A resource for the Gulf War Illness scientific community

AIMS

Gulf War Illness (GWI), a chronic debilitating disorder characterized by fatigue, joint pain, cognitive, gastrointestinal, respiratory, and skin problems, is currently diagnosed by self-reported symptoms. The Boston Biorepository, Recruitment, and Integrative Network (BBRAIN) is the collaborative effort of expert Gulf War Illness (GWI) researchers who are creating objective diagnostic and pathobiological markers and recommend common data elements for GWI research.

MAIN METHODS

BBRAIN is recruiting 300 GWI cases and 200 GW veteran controls for the prospective study. Key data and biological samples from prior GWI studies are being merged and combined into retrospective datasets. They will be made available for data mining by the BBRAIN network and the GWI research community. Prospective questionnaire data include general health and chronic symptoms, demographics, measures of pain, fatigue, medical conditions, deployment and exposure histories. Available repository biospecimens include blood, plasma, serum, saliva, stool, urine, human induced pluripotent stem cells and cerebrospinal fluid.

KEY FINDINGS

To date, multiple datasets have been merged and combined from 15 participating study sites. These data and samples have been collated and an online request form for repository requests as well as recommended common data elements have been created. Data and biospecimen sample requests are reviewed by the BBRAIN steering committee members for approval as they are received.

SIGNIFICANCE

The BBRAIN repository network serves as a much needed resource for GWI researchers to utilize for identification and validation of objective diagnostic and pathobiological markers of the illness.

Brain-Immune Interactions as the Basis of Gulf War Illness: Clinical Assessment and Deployment Profile of 1990-1991 Gulf War Veterans in the Gulf War Illness Consortium (GWIC) Multisite Case-Control Study

The Boston University-based Gulf War Illness Consortium (GWIC) is a multidisciplinary initiative developed to provide detailed understanding of brain and immune alterations that underlie Gulf War illness (GWI), the persistent multisymptom disorder associated with military service in the 1990–1991 Gulf War. The core GWIC case-control clinical study conducted in-depth brain and immune evaluation of 269 Gulf War veterans (223 GWI cases, 46 controls) at three U.S. sites that included clinical assessments, brain imaging, neuropsychological testing, and analyses of a broad range of immune and immunogenetic parameters. GWI cases were similar to controls on most demographic, military, and deployment characteristics although on average were two years younger, with a higher proportion of enlisted personnel vs. officers. Results of physical evaluation and routine clinical lab tests were largely normal, with few differences between GWI cases and healthy controls. However, veterans with GWI scored significantly worse than controls on standardized assessments of general health, pain, fatigue, and sleep quality and had higher rates of diagnosed conditions that included hypertension, respiratory and sinus conditions, gastrointestinal conditions, and current or lifetime depression and post-traumatic stress disorder. Among multiple deployment experiences/exposures reported by veterans, multivariable logistic regression identified just two significant GWI risk factors: extended use of skin pesticides in theater (adjusted OR = 3.25, p = 0.005) and experiencing mild traumatic brain injury during deployment (OR = 7.39, p = 0.009). Gulf War experiences associated with intense stress or trauma (e.g., participation in ground combat) were not associated with GWI. Data and samples from the GWIC project are now stored in a repository for use by GWI researchers. Future reports will present detailed findings on brain structure and function, immune function, and association of neuroimmune measures with characteristics of GWI and Gulf War service.

A common language for Gulf War Illness (GWI) research studies: GWI common data elements

AIMS

The Gulf War Illness programs (GWI) of the United States Department of Veteran Affairs and the Department of Defense Congressionally Directed Medical Research Program collaborated with experts to develop Common Data Elements (CDEs) to standardize and systematically collect, analyze, and share data across the (GWI) research community.

MAIN METHODS

A collective working group of GWI advocates, Veterans, clinicians, and researchers convened to provide consensus on instruments, case report forms, and guidelines for GWI research. A similar initiative, supported by the National Institute of Neurologic Disorders and Stroke (NINDS) was completed for a comparative illness, Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), and provided the foundation for this undertaking. The GWI working group divided into two sub-groups (symptoms and systems assessment). Both groups reviewed the applicability of instruments and forms recommended by the NINDS ME/CFS CDE to GWI research within specific domains and selected assessments of deployment exposures. The GWI CDE recommendations were finalized in March 2018 after soliciting public comments.

KEY FINDINGS

GWI CDE recommendations are organized in 12 domains that include instruments, case report forms, and guidelines. Recommendations were categorized as core (essential), supplemental-highly recommended (essential for specified conditions, study types, or designs), supplemental (commonly collected, but not required), and exploratory (reasonable to use, but require further validation). Recommendations will continually be updated as GWI research progresses.

SIGNIFICANCE

The GWI CDEs reflect the consensus recommendations of GWI research community stakeholders and will allow studies to standardize data collection, enhance data quality, and facilitate data sharing.

Gulf War Illness Clinical Trials and Interventions Consortium (GWICTIC): A collaborative research infrastructure for intervention and implementation

AIMS

There is an inadequate portfolio of treatments for Gulf War Illness (GWI), a complex disease involving multiple organ systems, and early-phase clinical trials are hampered by many logistical problems. To address these challenges, the Gulf War Illness Clinical Trials and Interventions Consortium (GWICTIC) was formed with the aims of (i) creating a collaborative consortium of clinical and scientific researchers that will rapidly implement rigorous and innovative phase I and II clinical trials for GWI, (ii) perform at least four phase I or II clinical trials, (iii) provide a foundation of scalable infrastructure and management in support of the efficient and successful operation of the GWICTIC, and (iv) partner with the Boston Biorepository, Recruitment & Integrated Network for GWI and other GWI investigators to develop a common data element platform for core assessments and outcomes.

MAIN METHODS

The GWICTIC brings together a multidisciplinary team of researchers at several institutions to provide scientific innovation, statistical and computational rigor, and logistical efficiency in the development and implementation of early-phase low-risk clinical trials for GWI. The GWICTIC core trials adhere to a Veteran-centered philosophy and focus on interventions with multiple mechanistic targets to maximize the likelihood of efficacy. To support rapid and efficient study startup and implementation across the GWI research community, the GWICTIC will share infrastructure with investigator-initiated research studies funded under separate mechanisms.

SIGNIFICANCE

The GWICTIC will leverage the efficiencies of centralized research support and innovative trial designs to address several longstanding needs in the GWI interventions research community.

Neurotoxicant exposures and rates of Chronic Multisymptom Illness and Kansas Gulf War Illness criteria in Gulf War deployed women veterans

AIMS

This study analyzed deployment-related exposures and risk of Persian Gulf War Illness (GWI) in women veterans from the Veterans Affairs (VA) Cooperative Studies Program 585 Gulf War Era Cohort and Biorepository (GWECB CSP#585).

MAIN METHODS

We examined the associations between GW deployment-related exposures and case definitions for GWI in deployed GW women. Multivariate regression analyses controlling for demographic outcomes were performed.

KEY FINDINGS

Surveys were obtained from 202 GW deployed women veterans. Self-reported exposure to smoke from oil well fires as well as chemical and biological warfare were the only exposures significantly associated with the Center for Disease Control and Prevention (CDC) GWI criteria. Seventy-nine women were excluded from the rest of the analyses as they met Kansas GW illness exclusion criteria. Eligible women who self-reported deployment-related exposure to smoke from oil wells, pyridostigmine bromide (PB) pills, pesticide cream, pesticide treated uniforms, and insect baits were significantly more likely to meet the Kansas GWI criteria (n = 123) than those unexposed and exposures were related to Kansas symptom subdomain endorsements.

SIGNIFICANCE

These results suggest that women GW veterans reporting deployment related exposures of pesticide, oil well fire and PB pills are significantly more likely to meet the Kansas GWI criteria in this national cohort of GW women suggesting its utility in future studies. In addition, based on these results it appears that women exposed to particular toxicants during the war may benefit from more targeted treatment strategies dependent upon the mechanism of exposure of their toxicant induced outcomes.

Neuroimaging Markers for Studying Gulf-War Illness: Single-Subject Level Analytical Method Based on Machine Learning

Gulf War illness (GWI) refers to the multitude of chronic health symptoms, spanning from fatigue, musculoskeletal pain, and neurological complaints to respiratory, gastrointestinal, and dermatologic symptoms experienced by about 250,000 GW veterans who served in the 1991 Gulf War (GW). Longitudinal studies showed that the severity of these symptoms often remain unchanged even years after the GW, and these veterans with GWI continue to have poorer general health and increased chronic medical conditions than their non-deployed counterparts. For better management and treatment of this condition, there is an urgent need for developing objective biomarkers that can help with simple and accurate diagnosis of GWI. In this study, we applied multiple neuroimaging techniques, including T1-weighted magnetic resonance imaging (T1W-MRI), diffusion tensor imaging (DTI), and novel neurite density imaging (NDI) to perform both a group-level statistical comparison and a single-subject level machine learning (ML) analysis to identify diagnostic imaging features of GWI. Our results supported NDI as the most sensitive in defining GWI characteristics. In particular, our classifier trained with white matter NDI features achieved an accuracy of 90% and F-score of 0.941 for classifying GWI cases from controls after the cross-validation. These results are consistent with our previous study which suggests that NDI measures are sensitive to the microstructural and macrostructural changes in the brain of veterans with GWI, which can be valuable for designing better diagnosis method and treatment efficacy studies.

Changes in Health Status in the Ft. Devens Gulf War Veterans Cohort: 1997-2017

Gulf War veterans (GWVs) were exposed to numerous neurotoxicants during deployment. Upon returning home, many reported a multitude of symptoms including fatigue, pain, gastrointestinal and respiratory issues, and neurological, cognitive, and mood complaints, collectively termed "Gulf War Illness (GWI)." Now, nearly 30 years post-war, many GWVs continue to suffer from these symptoms, in addition to health concerns associated with normal aging. While most research on GWVs has been cross-sectional, it is important to evaluate the progression and onset of new GWI symptoms longitudinally. The current study investigated the health of GWVs 25+ years after the war by resurveying the Ft. Devens Cohort and comparing their current health to their health reported 15 to 20 years earlier. The sample consists of 317 GWVs (~54 years old at the latest survey, 38 women) who responded to both surveys (1997-1998 and 2013-2017). Multivariable regression analyses were used to assess changes in GWI symptomatology and prevalence of medical conditions. The rates of 12 of 25 health symptoms increased significantly from the prior 1997-1998 survey. Anxiety, numbness in extremities, depressed mood, and joint pain had the greatest increase in endorsement. The rates of 7 of 16 medical conditions increased significantly from the prior 1997-1998 survey. High blood pressure, diabetes, and cancer had the greatest increase in prevalence. In summary, this study demonstrates that both symptoms and physician-diagnosed medical conditions associated with GW deployment/exposure increased in prevalence. For GWVs, focus by providers on the treatment of cognitive and mental health issues as well as cardiovascular and cerebrovascular risk factors is warranted. Targeting symptom alleviation would help improve the quality of life in these veterans until treatments addressing the entire illness become available.

Neuropsychological Findings in Gulf War Illness: A Review

This review paper summarizes the accumulation of research investigating neuropsychological outcomes in veterans with Gulf War illness (GWI). Earlier research focused on Gulf War veterans (GW) who were deployed versus non-deployed, as well as those who were symptomatic versus asymptomatic, or compared neuropsychological test results to published norms. Further research became more sophisticated, investigating specific GWI criteria, as well as the result of neurotoxicant exposure and the relationship to possible neurocognitive outcomes. As the early research supported both psychological and physiological effects on GWI; current research as summarized in this literature review supports the presence of neuropsychological deficits, particularly in the domains of attention, executive functioning, memory, and motor functioning related to chemical exposures that can be exacerbated by comorbid mood-related conditions. The same test battery has not been used consistently making it difficult to compare results among studies. Therefore, researchers created a resource to provide recommendations for the recently listed Neuropsychological Tests for Common Data Elements (CDEs) for use in all future GWI studies. Future research is necessary to further understand patterns of neuropsychological test data and how these decrements may relate to immunological or other biological markers, and the impact of trauma from physical and psychological stressors. In conclusion, there is consistent evidence that GWI is characterized by neuropsychological decrements - with future research these findings may aid in the diagnosis and assessment of treatment trial efficacy of GW veterans.

Influence of different surface treatments of poly(n-butyl acrylate) networks on fibroblasts adhesion, morphology and viability

BACKGROUND

Physical and chemical characteristics of implant materials determine the fate of long-term cardiovascular devices. However, there is still a lack of fundamental understanding of the molecular mechanisms occurring in the material-tissue interphase. In a previous study, soft covalently crosslinked poly(n-butyl acrylate) networks (cPnBA) were introduced as sterilizable, non-toxic and immuno-compatible biomaterials with mechanical properties adjustable to blood vessels. Here we study the influence of different surface treatments in particular oxygen plasma modification and fibrinogen deposition as well as a combinatorial approach on the adhesion and viability of fibroblasts.

MATERIAL AND METHODS

Two types of cPnBA networks with Young's moduli of 0.19±0.01 MPa (cPnBA04) and 1.02±0.01 MPa (cPnBA73) were synthesized and post-modified using oxygen plasma treatment (OPT) or fibrinogen coating (FIB) or a combination of both (OPT+FIB). The water contact angles of the differently post-treated cPnBAs were studied to monitor changes in the wettability of the polymer surfaces. Because of the key role of vascular fibroblasts in regeneration processes around implant materials, here we selected L929 fibroblasts as model cell type to explore morphology, viability, metabolic activity, cell membrane integrity as well as characteristics of the focal adhesions and cell cytoskeleton on the cPnBA surfaces.

RESULTS

Compared to non-treated cPnBAs the advancing water-contact angles were found to be reduced after all surface modifications (p < 0.05, each), while lowest values were observed after the combined surface treatment (OPT+FIB). The latter differed significantly from the single OPT and FIB. The number of adherent fibroblasts and their adherence behavior differed on both pristine cPnBA networks. The fibroblast density on cPnBA04 was 743±434 cells·mm-2, was about 6.5 times higher than on cPnBA73 with 115±73 cells·mm-2. On cPnBA04 about 20% of the cells were visible as very small, round and buckled cells while all other cells were in a migrating status. On cPnBA73, nearly 50% of fibroblasts were visible as very small, round and buckled cells. The surface functionalization either using oxygen plasma treatment or fibrinogen coating led to a significant increase of adherent fibroblasts, particularly the combination of both techniques, for both cPnBA networks. It is noteworthy to mention that the fibrinogen coating overruled the characteristics of the pristine surfaces; here, the fibroblast densities after seeding were identical for both cPnBA networks. Thus, the binding rather depended on the fibrinogen coating than on the substrate characteristics anymore. While the integrity of the fibroblasts membrane was comparable for both polymers, the MTS tests showed a decreased metabolic activity of the fibroblasts on cPnBA.

CONCLUSION

The applied surface treatments of cPnBA successfully improved the adhesion of viable fibroblasts. Under resting conditions as well as after shearing the highest fibroblast densities were found on surfaces with combined post-treatment.

A Review of Epidemiologic Studies of the Health of Gulf War Women Veterans

INTRODUCTION

In the 25 years since the 1990-1991 Gulf War (GW), studies have evaluated Gulf War Illness (GWI), sometimes referred to as medically unexplained multi symptom illness, and other medical and neurological conditions in women GW veterans.

MATERIALS AND METHODS

In this article, we review epidemiologic studies of the health of women who served in the 1990-1991 GW based upon bibliographic searches in PubMed and CINAHL with relevant search terms through September 2015.

RESULTS

A total of 56 articles were identified in the bibliographic searches. By screening abstracts or full-text articles, a total of 21 relevant studies were identified. Results from some studies, but not all, suggest that GWI is more common in women GW veterans than their male counterparts. Few studies of GW veterans focused on women's health. A small number of studies suggested excess rates of woman's health problems, e.g., breast cysts, abnormal Papanicolaou (Pap) smears, yeast infections, and bladder infections. Several studies have identified significantly elevated rates of birth defects and adverse reproductive outcomes among GW veterans. However, findings have varied with different study designs and sample sizes, with some studies showing elevated risks of stillbirths, miscarriages, and/or birth defects and others have not. In some studies, participants reported increased risks of ectopic pregnancies and spontaneous abortions.

CONCLUSION

Further research is needed to provide a comprehensive picture of the health of women GW veterans and to examine a broad range of women's health issues including adverse reproductive outcomes. Some deployment-related health problems only become apparent decades later and other conditions may worsen or improve over time. Assessments are needed of current health status, changes in health symptoms and conditions over time, and possible differences in health outcomes associated with specific experiences and exposures during the war. Future studies would be strengthened by assessing GWI symptom patterns that may be specific to women veterans, examine diagnosed medical conditions among women veterans, and evaluate changes in women's health over time, including changes potentially associated with menopause and age.

Psychiatric diagnoses and neurobehavioral symptom severity among OEF/OIF VA patients with deployment-related traumatic brain injury: a gender comparison

BACKGROUND

Traumatic brain injury (TBI) has substantial negative implications for the post-deployment adjustment of veterans who served in Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF); however, most research on veterans has focused on males. This study investigated gender differences in psychiatric diagnoses and neurobehavioral symptom severity among OEF/OIF veterans with deployment-related TBI.

METHODS

This population-based study examined psychiatric diagnoses and self-reported neurobehavioral symptom severity from administrative records for 12,605 United States OEF/OIF veterans evaluated as having deployment-related TBI. Men (n = 11,951) and women (n = 654) who were evaluated to have deployment-related TBI during a standardized comprehensive TBI evaluation in Department of Veterans Affairs facilities were compared on the presence of psychiatric diagnoses and severity of neurobehavioral symptoms.

FINDINGS

Posttraumatic stress disorder (PTSD) was the most common psychiatric condition for both genders, although women were less likely than men to have a PTSD diagnosis. In contrast, relative to men, women were 2 times more likely to have a depression diagnosis, 1.3 times more likely to have a non-PTSD anxiety disorder, and 1.5 times more likely to have PTSD with comorbid depression. Multivariate analyses indicated that blast exposure during deployment may account for some of these differences. Additionally, women reported significantly more severe symptoms across a range of neurobehavioral domains.

CONCLUSION

Although PTSD was the most common condition for both men and women, it is also critical for providers to identify and treat other conditions, especially depression and neurobehavioral symptoms, among women veterans with deployment-related TBI.

Neuropsychological screening for cognitive impairment using computer-assisted tasks

The aim of this study was to validate a computer-assisted screening battery for classifying patients into two groups, those with and without cognitive impairment. Participants were all patients referred to the neuropsychology clinics at four VA medical centers during a 1-year period. Patients meeting the study inclusionary criteria (N = 252) were administered the Neurobehavioral Evaluation System-3 (NES3) computer-assisted battery. A detailed neuropsychological examination was carried out by an experienced neuropsychologist, who diagnosed the patient as cognitively impaired or not impaired. The neuropsychologist's diagnosis was the gold standard. Recursive partitioning analyses yielded several classification procedures using the NES3 data to predict the gold standard These procedures produced a set of six NES3 tasks that provide good sensitivity and specificity in predicting di- agnosis. Sensitivity and specificity for the least random classification procedure were 0.87 and 0.67, respectively. The results suggest that computer-assisted screening methods are a promising means of triaging patients.

Interrater reliability of neuropsychological diagnoses: a Department of Veterans Affairs cooperative study

This study examined the interrater reliability of neuropsychological diagnoses produced by clinical neuropsychologists across 4 medical centers. These diagnoses were based on evaluations using a comprehensive battery of commonly used neuropsychological test instruments, interview, history and medical chart review. The diagnoses of individual neuropsychologists were compared to those made by members of an external review panel for each patient evaluated. Patients were first diagnosed as showing cognitive impairment versus no cognitive impairment. If a patient was diagnosed as impaired, a specific neuropsychological diagnosis was assigned. The diagnostic classification for cognitive impairment was moderately reliable [kappa = .48 +/- s.e.(kappa) = .062]. The interrater reliability for specific diagnoses was in the fair to good range [kappa = .44 +/- s.e.(kappa) = .029]. These levels of reliability are comparable to those found for other psychiatric and neurologic specialties and for medical diagnoses made by other health care disciplines.

Neuropsychological function in Gulf War veterans: relationships to self-reported toxicant exposures

BACKGROUND

The present study was aimed at (1) exploring evidence of central nervous system (CNS) dysfunction among Gulf War (GW) veterans on neuropsychological tests and (2) examining whether performance on neuropsychological tests was related to specific neurotoxicant exposures experienced in the Gulf.

METHODS

The GW-deployed groups were selected using stratified random sampling methods from two distinct cohorts of GW veterans. A comparison group that had been called up for GW service but deployed to Germany rather than the Gulf also was examined. Neuropsychological function was assessed using a pre-determined battery chosen to include tests known to be highly sensitive to the behavioral effects of the neurotoxicants thought to have been present in the Gulf.

RESULTS

Self-reported exposures were related to neuropsychological test performance controlling for post-traumatic stress disorder, major depression, and other known covariates of neuropsychological test performance. Results showed that GW-deployed veterans performed more poorly than the Germany-deployed veterans on several specific neuropsychological tests, but after adjustment for multiple comparisons, only the differences in mood complaints remained significant. Within the GW-deployed group, self-reported exposure to chemical warfare agents was associated with poorer performance on cognitive tests involving specific functional domains.

CONCLUSIONS

Results provide evidence that there are subtle differences in CNS function among GW-deployed veterans who report chemical warfare agent exposure while in the GW theater.

Are there cognitive subtypes in adult attention deficit/hyperactivity disorder?

There has been increasing knowledge of the treatment, diagnosis, and demographics of adults with residual attention deficit/hyperactivity disorder (ADHD). However, less is known about the neuropsychological functioning in adults with residual ADHD. In comparing the clinical neuropsychological test performance of a group of adult clinic patients with residual ADHD (N = 30) with that of normal controls (N = 10), we found the patients performed worse on the Trail Making Test, a visual continuous performance test, and the "Brown-Peterson" Auditory Consonant Trigrams Test, but not on any other neuropsychological measures. This pattern indicated a deficit in the area of executive control type functioning, a functional deficit that could be linked to dysregulation of frontal lobe brain systems. Of equal interest was that patients diagnosed with ADHD/hyperactive impulsive type (ADHD+) and patients diagnosed with ADHD/inattentive type (ADHD-) had different types of executive system deficits. ADHD+ was associated with relative deficiency on the Wisconsin Card Sorting Test. ADHD- was associated with relative deficiency on the "Brown-Peterson" Auditory Consonant Trigrams Test, a measure of working memory, as well as less olfactory identification on a smell identification test. The data are discussed in terms of recent localization theories of frontal lobe function. The preliminary data suggest that the different cognitive weaknesses of ADD subtypes may be linked to dysregulation of separate frontal brain regions and/or neurotransmitter systems.

Validation of the NES2 in patients with neurologic disorders

Performance on the Neurobehavioral Evaluation System (NES) has been demonstrated to be affected by exposure to a variety of neurotoxicants. However, the relation of NES subtests to CNS function has not yet been documented in patients diagnosed with neurologic disorders known to implicate specific brain substrates. A validation study of the NES2 was carried out in patients with multiple sclerosis (MS) and Parkinson's disease (PD), disorders exhibiting neuropathology at loci (white matter in MS, basal ganglia in PD) believed to be the sites of action of several known neurotoxicants. The results indicated that performance on certain NES2 subtests was affected in expected ways in both types of patients. However, performance on many more subtests was impaired, relative to controls, in MS than in PD. The relative insensitivity to PD suggests that expansion and refinement of the battery are required if it is to serve well in detecting the effects of toxicants in subjects without frank physical symptoms. These are the goals of a new version of the instrument currently under development (NES3).

A comparison of NES2 and traditional neuropsychological tests in a neurologic patient sample

The Neurobehavioral Evaluation System (NES), a computer-assisted battery of behavioral tests, has been widely used to detect central nervous system dysfunction in occupational and environmental settings and has recently been adapted for testing of neurological patients. The purpose of the present study was to assess the relationship between NES tasks and the traditional neuropsychological tests from which many of the NES tests were developed. For this purpose, comparisons were made between scores on NES tests and traditional neuropsychological tests designed to measure functioning in the same cognitive domains in a sample of patients with idiopathic Parkinson's disease (PD). As has been found in prior studies with normal subjects, correlations between traditional and NES2 tests varied from low to moderate. Correlations tended to be low when the modality of stimulus presentation or responses was different in the NES tests from the traditional tasks (e.g., verbal rather than visual) or when divergent and highly specific cognitive functions were being measured by the tests.

Evoked potential augmenting and reducing: The methodological and theoretical significance of new electrophysiological observations

Buchsbaum's (1976) evoked potential (EP) procedure reveals differences in the slope of P100-N140 amplitude changes with variation of stimulus luminance. Subjects are classed 'augmenters' or 'reducers', respectively, if their slopes are positive or negative. Psychological correlates of this slope index have been reported and it has distinguished psychiatric patient populations from healthy subjects. Data are presented which indicate that the augmenting-reducing slope differences are due to an early slow-wave. For augmenters, the major slow-wave deflection is of positive polarity. At the highest luminance, with a correspondingly shorter latency, the slow-wave increases the positive-going P100 deflection. At the lowest luminance, with a longer latency, it reduces the negative-going N140 deflection. This results in positive slopes. For reducers, the major slow-wave deflection is of negative polarity. This influences the measured P100 and N140 amplitudes in a manner opposite to that described for augmenters and results in negative slopes. Since these findings provide new insights concerning the nature of the Buchsbaum augmenting-reducing phenomenon, they have methodological and theoretical implications. It is concluded that the Buchsbaum procedure is an effective measure of slow-wave differences but that the reducing effect is difficult to explain in terms of Pavlov's concept of protective inhibition. An alternative 'opponent-process' explanation is offered.