Chronic multisymptom illness affecting Air Force veterans of the Gulf War

CONTEXT

Gulf War (GW) veterans report nonspecific symptoms significantly more often than their nondeployed peers. However, no specific disorder has been identified, and the etiologic basis and clinical significance of their symptoms remain unclear.

OBJECTIVES

To organize symptoms reported by US Air Force GW veterans into a case definition, to characterize clinical features, and to evaluate risk factors.

DESIGN

Cross-sectional population survey of individual characteristics and symptoms and clinical evaluation (including a structured interview, the Medical Outcomes Study Short Form 36, psychiatric screening, physical examination, clinical laboratory tests, and serologic assays for antibodies against viruses, rickettsia, parasites, and bacteria) conducted in 1995.

PARTICIPANTS AND SETTING

The cross-sectional questionnaire survey included 3723 currently active volunteers, irrespective of health status or GW participation, from 4 air force populations. The cross-sectional clinical evaluation included 158 GW veterans from one unit, irrespective of health status.

MAIN OUTCOME MEASURES

Symptom-based case definition; case prevalence rate for GW veterans and nondeployed personnel; clinical and laboratory findings among veterans who met the case definition.

RESULTS

We defined a case as having 1 or more chronic symptoms from at least 2 of 3 categories (fatigue, mood-cognition, and musculoskeletal). The prevalence of mild-to-moderate and severe cases was 39% and 6%, respectively, among 1155 GW veterans compared with 14% and 0.7% among 2520 nondeployed personnel. Illness was not associated with time or place of deployment or with duties during the war. Fifty-nine clinically evaluated GW veterans (37%) were noncases, 86 (54%) mild-to-moderate cases, and 13 (8%) severe cases. Although no physical examination, laboratory, or serologic findings identified cases, veterans who met the case definition had significantly diminished functioning and well-being.

CONCLUSIONS

Among currently active members of 4 Air Force populations, a chronic multisymptom condition was significantly associated with deployment to the GW. The condition was not associated with specific GW exposures and also affected nondeployed personnel.

Prevalence and patterns of Gulf War illness in Kansas veterans: association of symptoms with characteristics of person, place, and time of military service

Gulf War veterans have reported health problems that they attribute to their military service, but little is understood about the nature or extent of these conditions. To determine whether Kansas Gulf War veterans are affected by excess health problems, a population-based survey of 1,548 veterans who served in the Persian Gulf War (PGW) and 482 veterans who served elsewhere (non-PGW) was conducted in 1998. Gulf War illness, defined as having chronic symptoms in three of six domains, occurred in 34% of PGW veterans, 12% of non-PGW veterans who reported receiving vaccines during the war, and 4% of non-PGW veterans who did not receive vaccines. The prevalence of Gulf War illness was lowest among PGW veterans who served on board ship (21%) and highest among those who were in Iraq and/or Kuwait (42%). Among PGW veterans who served away from battlefield areas, Gulf War illness was least prevalent among those who departed the region prior to the war (9%) and most prevalent among those who departed in June or July of 1991 (41%). Observed patterns suggest that excess morbidity among Gulf War veterans is associated with characteristics of their wartime service, and that vaccines used during the war may be a contributing factor.

Health of UK servicemen who served in Persian Gulf War

BACKGROUND

Various symptoms in military personnel in the Persian Gulf War 1990-91 have caused international speculation and concern. We investigated UK servicemen.

METHODS

We did a cross-sectional postal survey on a random sample of Gulf War veterans (Gulf War cohort, n=4248) and, stratified for age and rank, servicemen deployed to the Bosnia conflict (Bosnia cohort, n=4250) and those serving during the Gulf War but not deployed there (Era cohort, n=4246). We asked about deployment, exposures, symptoms, and illnesses. We analysed men only. Our outcome measures were physical health, functional capacity (SF-36), the general health questionnaire, the Centers for Disease Control and Prevention (CDC) multisymptom criteria for Gulf War illness, and post-traumatic stress reactions.

FINDINGS

There were 8195 (65.1%) valid responses. The Gulf War cohort reported symptoms and disorders significantly more frequently than those in the Bosnia and Era cohorts, which were similar. Perception of physical health and ability were significantly worse in the Gulf War cohort than in the other cohorts, even after adjustment for confounders. Gulf War veterans were more likely than the Bosnia cohort to have substantial fatigue (odds ratio 2.2 [95% CI 1.9-2.6]), symptoms of post-traumatic stress (2.6 [1.9-3.4]), and psychological distress (1.6 [1.4-1.8]), and were nearly twice as likely to reach the CDC case definition (2.5 [2.2-2.8]). In the Gulf War, Bosnia, and Era cohorts, respectively, 61.9%, 36.8%, and 36.4% met the CDC criteria, which fell to 25.3%, 11.8%, and 12.2% for severe symptoms. Potentially harmful exposures were reported most frequently by the Gulf War cohort. All exposures showed associations with all of the outcome measures in the three cohorts. Exposures specific to the Gulf were associated with all outcomes. Vaccination against biological warfare and multiple routine vaccinations were associated with the CDC multisymptom syndrome in the Gulf War cohort.

INTERPRETATION

Service in the Gulf War was associated with various health problems over and above those associated with deployment to an unfamiliar hostile environment. Since associations of ill health with adverse events and exposures were found in all cohorts, however, they may not be unique and causally implicated in Gulf-War-related illness. A specific mechanism may link vaccination against biological warfare agents and later ill health, but the risks of illness must be considered against the protection of servicemen.

Multiple chemical sensitivity: a 1999 consensus

Consensus criteria for the definition of multiple chemical sensitivity (MCS) were first identified in a 1989 multidisciplinary survey of 89 clinicians and researchers with extensive experience in, but widely differing views of, MCS. A decade later, their top 5 consensus criteria (i.e., defining MCS as [1] a chronic condition [2] with symptoms that recur reproducibly [3] in response to low levels of exposure [4] to multiple unrelated chemicals and [5] improve or resolve when incitants are removed) are still unrefuted in published literature. Along with a 6th criterion that we now propose adding (i.e., requiring that symptoms occur in multiple organ systems), these criteria are all commonly encompassed by research definitions of MCS. Nonetheless, their standardized use in clinical settings is still lacking, long overdue, and greatly needed--especially in light of government studies in the United States, United Kingdom, and Canada that revealed 2-4 times as many cases of chemical sensitivity among Gulf War veterans than undeployed controls. In addition, state health department surveys of civilians in New Mexico and California showed that 2-6%, respectively, already had been diagnosed with MCS and that 16% of the civilians reported an "unusual sensitivity" to common everyday chemicals. Given this high prevalence, as well as the 1994 consensus of the American Lung Association, American Medical Association, U.S. Environmental Protection Agency, and the U.S. Consumer Product Safety Commission that "complaints [of MCS] should not be dismissed as psychogenic, and a thorough workup is essential," we recommend that MCS be formally diagnosed--in addition to any other disorders that may be present--in all cases in which the 6 aforementioned consensus criteria are met and no single other organic disorder (e.g., mastocytosis) can account for all the signs and symptoms associated with chemical exposure. The millions of civilians and tens of thousands of Gulf War veterans who suffer from chemical sensitivity should not be kept waiting any longer for a standardized diagnosis while medical research continues to investigate the etiology of their signs and symptoms.

Posttraumatic stress disorder and self-reported physical health status among U.S. Military personnel serving during the Gulf War period: a population-based study

The objective of this study was to investigate the relation between posttraumatic stress disorder (PTSD) and perceived physical health. Participants included 3,682 Gulf War veterans and control subjects of the same era who completed a telephone survey about their health status. PTSD was assessed using the PTSD Checklist-Military Version. Veterans screening positive for PTSD reported significantly more physical health symptoms and medical conditions than did veterans without PTSD. They were also more likely to rate their health status as fair or poor and to report lower levels of health-related quality of life. The results of this study are consistent with studies of other combat veterans and provide further support for an association between PTSD and adverse physical health outcomes. Stressful or traumatic life events, such as those encountered during a rapid military deployment and conflict, are associated with a variety of adverse health effects. These health effects may manifest themselves in both psychological and physical outcomes. Health care providers must be attentive to recognize and evaluate both of these dimensions.

An investigation of the impact of posttraumatic stress disorder on physical health

In a large sample of Gulf War veterans (N = 2301) we examined the relations between PTSD symptoms assessed immediately upon returning from the Gulf War and self-reported health problems assessed 18-24 months later. PTSD symptomatology was predictive of self-reported health problems over time for both men and women veterans, even after the effects of combat exposure were removed from the analysis. Female veterans reported significantly more health problems than male veterans, however, there was no interactive effect of gender and PTSD on health problems. These findings provide further support for the theory that psychological response to stressors impacts health outcome.

Relationship of physical symptoms to posttraumatic stress disorder among veterans seeking care for gulf war-related health concerns

OBJECTIVES

Studies of the relationship of posttraumatic stress disorder (PTSD) to physical symptoms in war veterans consistently show a positive relationship. However, traumatic experiences causing PTSD may correlate with other war exposures and medical illnesses potentially accounting for those symptoms.

METHODS

We analyzed data obtained from 21,244 Gulf War veterans seeking care for war-related health concerns to assess the relationship of PTSD to physical symptoms independent of environmental exposure reports and medical illness. At assessment, veterans provided demographic information and checklists of 15 common physical symptoms and 20 wartime environmental exposures. Up to seven ICD-9 provider diagnoses were ranked in order of estimated clinical significance. The relationship of provider-diagnosed PTSD to various physical symptoms and to the total symptom count was then determined in bivariate and multivariate analyses.

RESULTS

Veterans diagnosed with PTSD endorsed an average of 6.7 (SD = 3.9) physical symptoms, those with a non-PTSD psychological condition endorsed 5.3 (3.5), those with medical illness endorsed 4.3 (3.4), and a group diagnosed as "healthy" endorsed 1.2 (2.2). For every symptom, the proportion of veterans reporting the symptom was highest in those with PTSD, second highest in those with any psychological condition, third highest in those with any medical illness, and lowest in those labeled as healthy. The PTSD-symptom count relationship was independent of demographic characteristics, veteran-reported environmental exposures, and comorbid medical conditions, even when symptoms overlapping with those of PTSD were excluded.

CONCLUSIONS

PTSD diminishes the general health perceptions of care-seeking Gulf War veterans. Clinicians should carefully consider PTSD when evaluating Gulf War veterans with vague, multiple, or medically unexplained physical symptoms.

Is there a Gulf War syndrome?

BACKGROUND

UK veterans of the Gulf War report more ill health than servicemen who were not deployed to the Gulf War. We investigated whether the pattern of symptom reporting by veterans of the Gulf War differed from that in active servicemen who had not fought in the Gulf War or who had fought in other conflicts.

METHODS

We used a population-based cross-sectional design. We sent a standardised survey that asked about 50 physical symptoms to three UK military cohorts; men who had served in the Gulf War, those who had served in the Bosnia conflict, and men who had been in active service but not deployed to the Gulf War (Era cohort). We used exploratory factor analysis to identify underlying factors and describe the factor structure of the symptoms reported in the Gulf War cohort. Confirmatory factor analysis was used to test the fit of this factor structure in the Bosnia and Era cohorts.

FINDINGS

Three factors in the Gulf War cohort together accounted for about 20% of the common variance. We labelled the factors mood, respiratory system, and peripheral nervous system, according to the symptoms that loaded on to them. In the confirmatory factor analysis, the factor structure identified in the Gulf War cohort fitted reasonably well in the Bosnia and Era cohorts.

INTERPRETATION

Although results from complex modelling procedures need to be interpreted with caution, our findings do not support a unique Gulf War syndrome. The mechanisms behind increased self-reporting of symptoms need further investigation.

Risk factors for multisymptom illness in US Army veterans of the Gulf War

This research study examined the prevalence of symptoms and identified risk factors for reported symptoms among a group of Army Gulf War (GW) veterans. A survey was mailed to all members of the Ft. Devens cohort in 1997, representing the third assessment of a group that consisted of 2949 US Army soldiers deployed to the Gulf, and was studied initially in 1991. A total of 1290 subjects responded to the mailed survey; aggressive follow-up methods to address non-response bias were employed. Subjects were classified as having multisymptom illness if they reported symptoms from at least two of three symptom categories (fatigue, mood-cognition, musculoskeletal). Sixty percent of the respondents met criteria for multisymptom illness. Female gender, lower levels of education, psychological symptoms, self-reported use of a medical clinic in the Gulf, ingestion of anti-nerve gas pills (pyridostigmine bromide), anthrax vaccination, tent heaters, exposure to oil fire smoke, and chemical odors were significantly related to multisymptom illness in logistic regression analyses. Analyses in which subjects were stratified by level of psychological symptoms revealed different sets of GW-service environmental exposures and suggest that subgroups of GW veterans may have different sets of risk factors.

Symptoms in 18,495 Persian Gulf War veterans. Latency of onset and lack of association with self-reported exposures

Toxic or environmental exposures have been suggested as a possible cause of symptoms reported by Gulf War veterans. To further explore this hypothesis, we analyzed findings in 18,495 military personnel evaluated in the Department of Defense Comprehensive Clinical Evaluation Program. The program was established in 1994 to evaluate Persian Gulf veterans eligible for Department of Defense medical care who had health concerns after service in the Persian Gulf during Operation Desert Shield/Desert Storm. The evaluation included a structured clinical assessment, a physician-administered symptom checklist, and a patient questionnaire addressing self-reported exposures, combat experiences, and work loss. Among 18,495 patients examined, the most common symptoms were joint pain, fatigue, headache, memory or concentration difficulties, sleep disturbances, and rash. Symptom onset was often delayed, with two-thirds of symptoms not developing until after individuals returned from the Gulf War and 40% of symptoms having a latency period exceeding one year. There was no association between individual symptoms and patient demographics, specific self-reported exposures, or types of combat experience. Increased symptom counts were associated with work loss, the number of self-reported exposures, the number of types of combat experience, and certain ICD-9 diagnostic categories, particularly psychological disorders. Prolonged latency of symptom onset and the lack of association with any self-reported exposures makes illness related to toxic exposure less likely.

Brain abnormalities in Gulf War syndrome: evaluation with 1H MR spectroscopy

PURPOSE

To test for neuronal brain damage in the basal ganglia and brainstem in Gulf War veterans by using magnetic resonance (MR) spectroscopy.

MATERIALS AND METHODS

Twenty-two Gulf War veterans with one of three factor analysis-derived syndromes (case patients); 18 well veterans matched for age, sex, and education level (control subjects); and six Gulf War veterans with syndrome 2 from a different population (replication sample) underwent long echo time (272 msec) proton (hydrogen 1) MR spectroscopy on a 4 x 2 x 2-cm voxel in the basal ganglia bilaterally and a 2 x 2 x 2-cm voxel in the pons. Syndromes 1-3 are described as "impaired cognition," "confusion-ataxia," and "central pain," respectively.

RESULTS

The N-acetylaspartate-to-creatine (NAA/Cr) ratio, which reflects functional neuronal mass, was significantly lower in the basal ganglia and brainstem of Gulf War veterans with the three syndromes than in those structures of the control subjects (P =.007). The finding was corroborated in the replication sample (P =.002). Veterans with syndrome 2 (the most severe clinically) had evidence of decreased NAA/Cr in both the basal ganglia and the brainstem; those with syndrome 1, in the basal ganglia only; and those with syndrome 3, in the brainstem only.

CONCLUSION

Veterans with different Gulf War syndromes have biochemical evidence of neuronal damage in different distributions in the basal ganglia and brainstem.

Mitochondrial dysfunction in Gulf War illness revealed by 31Phosphorus Magnetic Resonance Spectroscopy: a case-control study

BACKGROUND

Approximately 1/3 of 1990-1 Gulf War veterans developed chronic multisymptom health problems. Implicated exposures bear mechanisms that adversely affect mitochondria. Symptoms emphasize fatigue, cognition and muscle (brain and muscle are aerobically demanding); with protean additional domains affected, compatible with mitochondrial impairment. Recent evidence supports treatments targeting cell bioenergetics (coenzyme10) to benefit Gulf War illness symptoms. However, no evidence has directly documented mitochondrial or bioenergetic impairment in Gulf War illness.

OBJECTIVE

We sought to objectively assess for mitochondrial dysfunction, examining post-exercise phosphocreatine-recovery time constant (PCr-R) using (31)Phosphorus Magnetic Resonance Spectroscopy ((31)P-MRS), in Gulf War veterans with Gulf War illness compared to matched healthy controls. PCr-R has been described as a "robust and practical" index of mitochondrial status.

DESIGN AND PARTICIPANTS

Case-control study from 2012-2013. Fourteen community-dwelling Gulf War veterans and matched controls from the San Diego area comprised 7 men meeting CDC and Kansas criteria for Gulf War illness, and 7 non-deployed healthy controls matched 1:1 to cases on age, sex, and ethnicity.

OUTCOME MEASURE

Calf muscle phosphocreatine was evaluated by (31)P-MRS at rest, through 5 minutes of foot pedal depression exercise, and in recovery, to assess PCr-R. Paired t-tests compared cases to matched controls.

RESULTS

PCr-R was significantly prolonged in Gulf War illness cases vs their matched controls: control values, mean ± SD, 29.0 ± 8.7 seconds; case values 46.1 ± 18.0 seconds; difference 17.1 ± 14.9 seconds; p = 0.023. PCr-R was longer for cases relative to their matched controls for all but one pair; moreover while values clustered under 31 seconds for all but one control, they exceeded 35 seconds (with a spread up to 70 seconds) for all but one case.

DISCUSSION

These data provide the first direct evidence supporting mitochondrial dysfunction in Gulf War illness. Findings merit replication in a larger study and/or corroboration with additional mitochondrial assessment tools.

Patient activism and the struggle for diagnosis: Gulf War illnesses and other medically unexplained physical symptoms in the US

We examine Gulf War illnesses--which include the fatigue, joint pain, dermatitis, headaches, memory loss, blurred vision, diarrhea, and other symptoms reported by Gulf War veterans--in relation to other medically unexplained physical symptoms such as multiple chemical sensitivity, chronic fatigue syndrome, and fibromyalgia. Our intent is to examine the diagnosis negotiations involved in these mysterious diseases, by showing the different forms of legitimacy involved in such interactions. Factors involved in diagnostic legitimacy are: diagnostic legitimacy in the medical community, lay acceptance of the diagnosis, uncertainty in looking for causes, and social mobilization. We conclude by noting that research may not be able to find any cause for these diseases/conditions; hence, it may be necessary to embrace medical uncertainty, and also to accept patient experience in order to facilitate diagnosis, treatment, and recovery process. Such a change can alter patients' expectations and taken-for-granted assumptions about medicine, and perhaps in turn reduce the frequency with which dissatisfied individuals form illness groups that mobilize to challenge what they see as an unresponsive medical system.

Evaluation and management of medically unexplained physical symptoms

BACKGROUND

Medically unexplained physical symptoms (MUPS) and related syndromes are common in medical care and the general population, are associated with extensive morbidity, and have a large impact on functioning. Much of medical practice emphasizes specific pharmacological and surgical intervention for discrete disease states. Medical science, with its emphasis on identifying etiologically meaningful diseases comprised of homogeneous groups of patients, has split MUPS into a number of diagnostic entities or syndromes, each with its own hypothesized pathogenesis. However, research suggests these syndromes may be more similar than different, sharing extensive phenomenological overlap and similar risk factors, treatments, associated morbidities, and prognoses. Examples of syndromes consisting of MUPS include chronic fatigue syndrome, fibromyalgia, multiple chemical sensitivities, somatoform disorders, and 'Gulf War Syndrome.'

REVIEW SUMMARY

This paper is a narrative review of the increasing body of evidence suggesting that MUPS and related syndromes are common, disabling, and costly. It emphasizes that MUPS occur along a continuum of symptom count, severity, and duration and may be divided into acute, subacute (or recurrent), and chronic types. Predisposing, precipitating, and perpetuating factors influence the natural history of MUPS.

CONCLUSIONS

Effective symptom management involves collaborative doctor-patient approaches for identification of problems based on a combination of medical importance and patient readiness to initiate behavioral change, negotiated treatment goals and outcomes, gradual physical activation and exercise prescription. Additionally, efforts should be made to teach and support active rather than passive coping with the symptoms.

Clinical findings for the first 1000 Gulf war veterans in the Ministry of Defence's medical assessment programme

OBJECTIVE

To review the clinical findings in the first 1000 veterans seen in the Ministry of Defence's Gulf war medical assessment programme to examine whether there was a particular illness related to service in the Gulf.

DESIGN

Case series of 1000 veterans who presented to the programme between 11 October 1993 and 24 February 1997.

SUBJECTS

Gulf war veterans.

MAIN OUTCOME MEASURES

Diagnosis of veterans' conditions according to ICD-10 (international classification of diseases, 10th revision). Cases referred for psychiatric assessment were reviewed for available diagnostic information from consultant psychiatrists.

RESULTS

588 (59%) veterans had more than one diagnosed condition, 387 (39%) had at least one condition for which no firm somatic or psychological diagnosis could be given, and in 90 (9%) veterans no other main diagnosis was made. Conditions characterised by fatigue were found in 239 (24%) of patients. At least 190 (19%) patients had a psychiatric condition, which in over half was due to post-traumatic stress disorder. Musculoskeletal disorders and respiratory conditions were also found to be relatively common (in 182 (18%) and 155 (16%) patients respectively).

CONCLUSION

Many Gulf war veterans had a wide variety of symptoms. This initial review shows no evidence of a single illness, psychological or physical, to explain the pattern of symptoms seen in veterans in the assessment programme. As the veterans assessed by the programme were all self selected, the prevalence of illness in Gulf war veterans cannot be determined from this study. Furthermore, it is not known whether the veterans in this study were representative of sick veterans as a group.

Deployment stressors and a chronic multisymptom illness among Gulf War veterans

Unusual health problems have been reported by Gulf War (GW) veterans, but no single etiology has been linked to these illnesses. This study was conducted to determine the association between self-reported GW deployment stressors and an illness defined by a combination of fatigue, mood-cognition, and musculoskeletal symptoms. A total of 1002 GW veterans from this cross-sectional survey of four Air Force units completed a self-administered questionnaire that asked about symptoms, demographic and military characteristics, and stressors during deployment. Severe and mild-moderate illness was positively associated with self-reports of pyridostigmine bromide use, insect repellent use and belief in a threat from biological or chemical weapons. Injuries requiring medical attention were only associated with severe illness. These results suggest a link between self-reported chemical, emotional, and physical exposures, and GW veterans' illness. Further research is needed to determine physiological and psychological mechanisms through which such stressors could have contributed to this symptom complex.

Neuropsychological characteristics of Gulf War illness: A meta-analysis

OBJECTIVE

Gulf War illness (GWI) is a disorder related to military service in the 1991 GW. Prominent symptoms include fatigue, pain and cognitive problems. These symptoms were reported by GW Veterans (GWV) immediately after the war and were eventually incorporated into case definitions of GWI. Neuropsychological function in GW veterans has been studied both among deployed GWV and in GWV diagnosed with GWI. Results have been inconsistent between and across GW populations. The purpose of the present investigation was to better characterize neuropsychological function in this veteran population.

METHODS

Meta-analysis techniques were applied to published studies on neuropsychological performance in GWV to identify domains of dysfunction in deployed vs. non-deployed GW-era veterans and symptomatic vs. non-symptomatic GWVs.

RESULTS

Significantly decreased performance was found in three functional domains: attention and executive function, visuospatial skills and learning/memory.

CONCLUSIONS

These findings document the cognitive decrements associated with GW service, validate current GWI case definitions using cognitive criteria, and identify test measures for use in GWI research assessing GWI treatment trial efficacy.

Blunted circadian variation in autonomic regulation of sinus node function in veterans with Gulf War syndrome

PURPOSE

To test the hypothesis that subtle abnormalities of the autonomic nervous system underlie the chronic symptoms reported by many Gulf War veterans, such as chronic diarrhea, dizziness, fatigue, and sexual dysfunction.

METHODS

Twenty-two ill Gulf War veterans and 19 age-, sex-, and education-matched control veterans underwent measurement of circadian rhythm of heart rate variability by 24-hour electrocardiography, ambulatory blood pressure recording, Valsalva ratio testing, sympathetic skin response evaluation, sweat imprint testing, and polysomnography. Investigators were blinded to case- or control-group status.

RESULTS

High-frequency spectral power of heart rate variability increased normally 2.2-fold during sleep in controls but only 1.2-fold in ill veterans (P <0.0001). In ill veterans as compared with controls, it was lower at night (P = 0.0006), higher during the morning (P = 0.007), but no different during the rest of the day (P = 0.8). The mean heart rate of ill veterans also declined less at night (P = 0.0002), and their corrected QT intervals tended to be longer over the full 24 hours (P = 0.07), particularly at night (P = 0.03). Blunting of the nocturnal heart rate dip in ill veterans was confirmed by 24-hour automatic ambulatory blood pressure monitoring (P = 0.05) and polysomnography (P = 0.03). These differences remained significant after adjusting for potential confounders. Cases and controls were similar on measures of sympathetic adrenergic and sudomotor function, sleep architecture, respiratory function, and circadian variation in blood pressure and body temperature.

CONCLUSION

Some symptoms of Gulf War syndrome may be due to subtle autonomic nervous system dysfunction.

Unexplained Symptoms After Terrorism and War: An Expert Consensus Statement

Twelve years of concern regarding a possible "Gulf War syndrome" has now given way to societal concerns of a "World Trade Center syndrome" and efforts to prevent unexplained symptoms following the most recent war in Iraq. These events serve to remind us that unexplained symptoms frequently occur after war and are likely after terrorist attacks. An important social priority is to recognize, define, prevent, and care for individuals with unexplained symptoms after war and related events (eg, terrorism, natural or industrial disasters). An international, multidisciplinary, and multiinstitutional consensus project was completed to summarize current knowledge on unexplained symptoms after terrorism and war.

Effect of basal ganglia injury on central dopamine activity in Gulf War syndrome: correlation of proton magnetic resonance spectroscopy and plasma homovanillic acid levels

BACKGROUND

Many complaints of Gulf War veterans are compatible with a neurologic illness involving the basal ganglia.

METHODS

In 12 veterans with Haley Gulf War syndrome 2 and in 15 healthy control veterans of similar age, sex, and educational level, we assessed functioning neuronal mass in both basal ganglia by measuring the ratio of N-acetyl-aspartate to creatine with proton magnetic resonance spectroscopy. Central dopamine activity was assessed by measuring the ratio of plasma homovanillic acid (HVA) and 3-methoxy-4-hydroxyphenlyglycol (MHPG).

RESULTS

The logarithm of the age-standardized HVA/MHPG ratio was inversely associated with functioning neuronal mass in the left basal ganglia (R(2) = 0.56; F(1,27) = 33.82; P<.001) but not with that in the right (R(2) = 0. 04; F(1,26) = 1.09; P =.30). Controlling for age, renal clearances of creatinine and weak organic anions, handedness, and smoking did not substantially alter the associations.

CONCLUSIONS

The reduction in functioning neuronal mass in the left basal ganglia of these veterans with Gulf War syndrome seems to have altered central dopamine production in a lateralized pattern. This finding supports the theory that Gulf War syndrome is a neurologic illness, in part related to injury to dopaminergic neurons in the basal ganglia.

Evaluation of neuromuscular symptoms in veterans of the Persian Gulf War

OBJECTIVE

To comprehensively evaluate complaints of muscle fatigue, weakness, and myalgias in Persian Gulf veterans (PGV).

BACKGROUND

Approximately 700,000 American troops were deployed to the Persian Gulf during Desert Shield and Desert Storm. Upon return from the Gulf, some PGV developed unexplained illnesses, and special referral centers were established for the evaluation of these patients. Among the most common symptoms of these PGV are fatigue, weakness, and myalgias. An Institute of Medicine committee recommended further exploration into the possible etiologies of these complaints.

METHODS

Twenty PGV with severe muscle fatigue, weakness, or myalgias that interfered with their daily activities were referred for an extensive prospective neuromuscular evaluation. Routine laboratory studies included serum creatine kinase (CK), erythrocyte sedimentation rate, thyroid function tests, and exercise forearm tests. All patients received nerve conduction studies (NCS), repetitive nerve stimulation, quantitative and single-fiber electromyography (EMG), and muscle biopsies.

RESULTS

Manual muscle strength examinations were normal in all patients. Six patients had mildly elevated CKs (range 223 to 768 IU/l); otherwise, laboratory tests were unremarkable. NCS were normal except in 2 patients with carpal tunnel syndrome. Quantitative EMGs were normal. One patient had mildly increased jitter on single-fiber EMG. Muscle biopsies demonstrated minor nonspecific abnormalities in 5 patients (i.e., increased central nuclei, rare necrotic fibers, tubular aggregates).

CONCLUSIONS

Despite severe subjective symptoms, most of our patients had no objective evidence of neuromuscular disease. Mildly increased CKs or nonspecific histologic abnormalities on muscle biopsy were evident in 8 patients but were not believed to be clinically significant in most. We found no evidence of a specific neuromuscular disorder in any patient. Exposures to toxins during the Persian Gulf War were not likely responsible for our patients' symptoms.

The search for reliable biomarkers of disease in multiple chemical sensitivity and other environmental intolerances

Whilst facing a worldwide fast increase of food and environmental allergies, the medical community is also confronted with another inhomogeneous group of environment-associated disabling conditions, including multiple chemical sensitivity (MCS), fibromyalgia, chronic fatigue syndrome, electric hypersensitivity, amalgam disease and others. These share the features of poly-symptomatic multi-organ cutaneous and systemic manifestations, with postulated inherited/acquired impaired metabolism of chemical/physical/nutritional xenobiotics, triggering adverse reactions at exposure levels far below toxicologically-relevant values, often in the absence of clear-cut allergologic and/or immunologic involvement. Due to the lack of proven pathogenic mechanisms generating measurable disease biomarkers, these environmental hypersensitivities are generally ignored by sanitary and social systems, as psychogenic or "medically unexplained symptoms". The uncontrolled application of diagnostic and treatment protocols not corresponding to acceptable levels of validation, safety, and clinical efficacy, to a steadily increasing number of patients demanding assistance, occurs in many countries in the absence of evidence-based guidelines. Here we revise available information supporting the organic nature of these clinical conditions. Following intense research on gene polymorphisms of phase I/II detoxification enzyme genes, so far statistically inconclusive, epigenetic and metabolic factors are under investigation, in particular free radical/antioxidant homeostasis disturbances. The finding of relevant alterations of catalase, glutathione-transferase and peroxidase detoxifying activities significantly correlating with clinical manifestations of MCS, has recently registered some progress towards the identification of reliable biomarkers of disease onset, progression, and treatment outcomes.

The "Gulf War syndrome". Is there evidence of dysfunction in the nervous system?

In a pilot study, 14 Gulf War veterans were randomly selected from a large list of those with unexplained illness, to compare the functional integrity of the peripheral and central nervous system with a group of 13 healthy civilian control subjects using predetermined outcome measures. The controls were matched closely for age, sex, handedness, and physical activity. Outcome measures included scoring of symptoms and clinical neurological signs, quantitative sensory testing of heat, cold and vibration sensibilities, motor and sensory nerve conduction studies on upper and lower limbs, needle EMG of distal and proximal muscles and multimodality evoked potential (visual, brainstem, and somatosensory) studies. Three measurements, all related to peripheral nerve function (cold threshold (P = 0.0002), sural nerve latency (P = 0.034), and median nerve sensory action potential (P = 0.030) were abnormal in the veterans compared with the controls. There may be a dysfunction in the veterans but more studies are required to investigate the findings further and to characterise the dysfunction if confirmed.

Hippocampal dysfunction in Gulf War Syndrome. A proton MR spectroscopy study

The pathogenesis of Gulf War Syndrome (GWS) is not clearly understood. Data exist to suggest that GWS may originate from a combination of chronic fatigue and sensitivity to the exposure of exogenous agents. Since the head region of hippocampus is highly vascularized and thus vulnerable to toxic substances in circulation, we postulated that hippocampal impairment occurs in GWS. To test this, single volume localized in vivo proton MR spectroscopy (MRS) studies of the left and right hippocampi of consenting Gulf War veterans (N=15; 10 with GWS, and 5 without GWS) and control Vietnam veterans (N=6) were conducted in accordance with approved human study protocols. The N-acetyl aspartate (NAA) to creatine and choline to creatine ratios were computed from the spectra. The NAA/creatine ratio of the GWS group (N=10) was found to be significantly lower than that of the entire control group (N=11) or the unaffected GW control group (N=5). No laterality differences were observed among any of the three groups. The choline/creatine ratio of the GWS group was not different from that for either control group. To check the existence of any relationship between age and the NAA/creatine ratios, the entire study population was grouped into those below or above the median age (44.3 years). It was found that the NAA/Cre ratio of the younger group (only Gulf War veterans) was significantly lower than that of the older group. The lower NAA/creatine ratio for the GWS group points to the existence of hippocampal dysfunction.

Cognitive functioning and disturbances of mood in UK veterans of the Persian Gulf War: a comparative study

BACKGROUND

Complaints of poor memory and concentration are common in veterans of the 1991 Persian Gulf War as are other symptoms. Despite a large research effort, such symptoms remain largely unexplained.

METHOD

A comprehensive battery of neuropsychological tests and rating scales was administered to 341 UK servicemen who were returnees from the Gulf War and peace keeping duties in Bosnia, plus non-deployed military controls. All were drawn from a large randomized survey. Most were selected on the basis of impaired physical functioning defined operationally.

RESULTS

Group comparisons revealed an association between physical functioning and symptoms of depression, post-traumatic stress reactions, increased anger and subjective cognitive failures. Poorer performance on some general cognitive measures, sequencing and attention was also seen in association with being 'ill' but virtually all differences disappeared after adjusting for depressed mood or multiple comparisons. Deployment was also associated with symptoms of post-traumatic stress and subjective cognitive failures, independently of health status, as well as minor general cognitive and constructional impairment. The latter remained significantly poorer in the Gulf group even after adjusting for depressed mood.

CONCLUSIONS

Disturbances of mood are more prominent than quantifiable cognitive deficits in Gulf War veterans and probably lead to subjective underestimation of ability. Task performance deficits can themselves be explained by depressed mood although the direction of causality cannot be inferred confidently. Reduced constructional ability cannot be explained in this way and could be an effect of Gulf-specific exposures.