Category: Overlapping Illnesses

Neurobehavioral deficits associated with chronic fatigue syndrome in veterans with Gulf War unexplained illnesses

Abstract:

Gulf War unexplained illnesses (GWUI) are a heterogeneous collection of symptoms of unknown origin known to be more common among veterans of the Gulf War than among nonveterans. In the present study we focused on one of these unexplained illnesses.

We tested the hypothesis that in a sample of Persian Gulf War veterans chronic fatigue syndrome (CFS) was associated with cognitive deficits on computerized cognitive testing after controlling for the effects of premorbid cognitive differences. We obtained Armed Forces Qualification Test (AFQT) data acquired around the date of induction into the military on 94 veterans of the Gulf War, 32 with CFS and 62 healthy controls. Controls performed better than participants diagnosed with CFS on the AFQT. Cognitive deficits were associated with CFS on 3 of 8 variables after the effect of premorbid AFQT scores was removed with ANCOVA.

 

Source: Binder LM, Storzbach D, Campbell KA, Rohlman DS, Anger WK; Members of the Portland Environmental Hazards Research Center. Neurobehavioral deficits associated with chronic fatigue syndrome in veterans with Gulf War unexplained illnesses. J Int Neuropsychol Soc. 2001 Nov;7(7):835-9. http://www.ncbi.nlm.nih.gov/pubmed/11771626

 

A biochemical analysis of people with chronic fatigue who have Irlen Syndrome: speculation concerning immune system dysfunction

Abstract:

This study investigated the biological basis of visual processing disabilities in adults with Chronic Fatigue Syndrome. The study involved 61 adults with symptoms of Chronic Fatigue Syndrome who were screened for visual processing problems (Irlen Syndrome) and divided into two groups according to the severity of symptoms of Irlen Syndrome.

Significant variations were identified in blood lipids and urine amino and organic acids of the two groups, which may be indicative of activation of the immune system due to some infective agent. It was suggested that metabolic profiling may help the development of more valid diagnostic categories and allow more investigation of immune system dysfunction as a possible causal factor in a range of learning and behaviour disorders.

 

Source: Robinson GL, McGregor NR, Roberts TK, Dunstan RH, Butt H. A biochemical analysis of people with chronic fatigue who have Irlen Syndrome: speculation concerning immune system dysfunction. Percept Mot Skills. 2001 Oct;93(2):486-504. http://www.ncbi.nlm.nih.gov/pubmed/11769907

 

Symptom factor analysis, clinical findings, and functional status in a population-based case control study of Gulf War unexplained illness

Abstract:

Few epidemiological studies have been conducted that have incorporated clinical evaluations of Gulf War veterans with unexplained health symptoms and healthy controls. We conducted a mail survey of 2022 Gulf War veterans residing in the northwest United States and clinical examinations on a subset of 443 responders who seemed to have unexplained health symptoms or were healthy. Few clinical differences were found between cases and controls.

The most frequent unexplained symptoms were cognitive/psychological, but significant overlap existed with musculoskeletal and fatigue symptoms. Over half of the veterans with unexplained musculoskeletal pain met the criteria for fibromyalgia, and a significant portion of the veterans with unexplained fatigue met the criteria for chronic fatigue syndrome. Similarities were found in the clinical interpretation of unexplained illness in this population and statistical factor analysis performed by this study group and others.

 

Source: Bourdette DN, McCauley LA, Barkhuizen A, Johnston W, Wynn M, Joos SK, Storzbach D, Shuell T, Sticker D. Symptom factor analysis, clinical findings, and functional status in a population-based case control study of Gulf War unexplained illness. J Occup Environ Med. 2001 Dec;43(12):1026-40. http://www.ncbi.nlm.nih.gov/pubmed/11765674

 

Familial corticosteroid-binding globulin deficiency due to a novel null mutation: association with fatigue and relative hypotension

Abstract:

Corticosteroid-binding globulin is a 383-amino acid glycoprotein that serves a hormone transport role and may have functions related to the stress response and inflammation. We describe a 39-member Italian-Australian family with a novel complete loss of function (null) mutation of the corticosteroid-binding globulin gene. A second, previously described, mutation (Lyon) segregated independently in the same kindred. The novel exon 2 mutation led to a premature termination codon corresponding to residue -12 of the procorticosteroid-binding globulin molecule (c.121G–>A).

Among 32 family members there were 3 null homozygotes, 19 null heterozygotes, 2 compound heterozygotes, 3 Lyon heterozygotes, and 5 individuals without corticosteroid-binding globulin mutations. Plasma immunoreactive corticosteroid-binding globulin was undetectable in null homozygotes, and mean corticosteroid-binding globulin levels were reduced by approximately 50% at 18.7 +/- 1.3 microg/ml (reference range, 30-52 microg/ml) in null heterozygotes. Morning total plasma cortisol levels were less than 1.8 microg/dl in homozygotes and were positively correlated to the plasma corticosteroid-binding globulin level in heterozygotes. Homozygotes and heterozygote null mutation subjects had a high prevalence of hypotension and fatigue.

Among 19 adults with the null mutation, the systolic blood pressure z-score was 12.1 +/- 3.5; 11 of 19 subjects (54%) had a systolic blood pressure below the third percentile. The mean diastolic blood pressure z-score was 18.1 +/- 3.4; 8 of 19 subjects (42%) had a diastolic blood pressure z-score below 10.

Idiopathic chronic fatigue was present in 12 of 14 adult null heterozygote subjects (86%) and in 2 of 3 null homozygotes. Five cases met the Centers for Disease Control criteria for chronic fatigue syndrome. Fatigue questionnaires revealed scores of 25.1 +/- 2.5 in 18 adults with the mutation vs. 4.2 +/- 1.5 in 23 healthy controls (P < 0.0001).

Compound heterozygosity for both mutations resulted in plasma cortisol levels comparable to those in null homozygotes. Abnormal corticosteroid-binding globulin concentrations or binding affinity may lead to the misdiagnosis of isolated ACTH deficiency. The mechanism of the association between fatigue and relative hypotension is not established by these studies. As idiopathic fatigue disorders are associated with relatively low plasma cortisol, abnormalities of corticosteroid-binding globulin may be pathogenic.

 

Source: Torpy DJ, Bachmann AW, Grice JE, Fitzgerald SP, Phillips PJ, Whitworth JA, Jackson RV. Familial corticosteroid-binding globulin deficiency due to a novel null mutation: association with fatigue and relative hypotension. J Clin Endocrinol Metab. 2001 Aug;86(8):3692-700. http://www.ncbi.nlm.nih.gov/pubmed/11502797

 

A review of the evidence for overlap among unexplained clinical conditions

Abstract:

PURPOSE: Unexplained clinical conditions share features, including symptoms (fatigue, pain), disability out of proportion to physical examination findings, inconsistent demonstration of laboratory abnormalities, and an association with “stress” and psychosocial factors. This literature review examines the nature and extent of the overlap among these unexplained clinical conditions and the limitations of previous research.

DATA SOURCES: English-language articles were identified by a search of the MEDLINE database from 1966 to January 2001 by using individual syndromes and their hallmark symptoms as search terms.

STUDY SELECTION: Studies that assessed patients with at least one unexplained clinical condition and that included information on symptoms, overlap with other unexplained clinical conditions, or physiologic markers. Conditions examined were the chronic fatigue syndrome, fibromyalgia, the irritable bowel syndrome, multiple chemical sensitivity, temporomandibular disorder, tension headache, interstitial cystitis, and the postconcussion syndrome.

DATA EXTRACTION: Information on authorship, patient and control groups, eligibility criteria, case definitions, study methods, and major findings.

DATA SYNTHESIS: Many similarities were apparent in case definition and symptoms, and the proportion of patients with one unexplained clinical condition meeting criteria for a second unexplained condition was striking. Tender points on physical examination and decreased pain threshold and tolerance were the most frequent and consistent objective findings. A major shortcoming of all proposed explanatory models is their inability to account for the occurrence of unexplained clinical conditions in many affected patients.

CONCLUSIONS: Overlap between unexplained clinical conditions is substantial. Most studies are limited by methodologic problems, such as case definition and the selection and recruitment of case-patients and controls.

 

Source: Aaron LA, Buchwald D. A review of the evidence for overlap among unexplained clinical conditions. Ann Intern Med. 2001 May 1;134(9 Pt 2):868-81. http://www.ncbi.nlm.nih.gov/pubmed/11346323

 

High prevalence of serum markers of coeliac disease in patients with chronic fatigue syndrome

There has been recent interest in the possibility that undiagnosed coeliac disease (CD) might be the cause of diverse clinical symptoms, most particularly “tired all the time”.1 A recent study reported a prevalence of three in 100 cases in a primary care environment in which samples were taken from patients with a range of symptoms and signs.2 The second most frequent symptom reported by the endomysial antibody (EMA) positive patients was “being tired all the time”. We decided to examine the prevalence of EMA in patients attending our tertiary referral centre with the diagnosis of chronic fatigue syndrome (CFS).

You can read the rest of this article here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1731400/pdf/v054p00335a.pdf

 

Source: Skowera A, Peakman M, Cleare A, Davies E, Deale A, Wessely S. High prevalence of serum markers of coeliac disease in patients with chronic fatigue syndrome. J Clin Pathol. 2001 Apr;54(4):335-6. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1731400/ (Full article)

 

The role of gender in fibromyalgia syndrome

Abstract:

Fibromyalgia syndrome (FMS), characterized by widespread pain and tenderness on palpation (tender points), is much more common in women than in men in a proportion of 9:1. Two recent studies have shown important gender differences in various clinical characteristics of FMS. In a community and a clinic sample, women experienced significantly more common fatigue, morning fatigue, hurt all over, total number of symptoms, and irritable bowel syndrome. Women had significantly more tender points. Pain severity, global severity and physical functioning were not significantly different between the sexes, nor were psychologic factors, eg, anxiety, stress, and depression. Gender differences have also been observed in other related syndromes, eg, chronic fatigue syndrome, irritable bowel syndrome, and headaches. The mechanisms of gender differences in these illnesses are not fully understood, but are likely to involve an interaction between biology, psychology, and sociocultural factors.

 

Source: Yunus MB. The role of gender in fibromyalgia syndrome. Curr Rheumatol Rep. 2001 Apr;3(2):128-34. http://www.ncbi.nlm.nih.gov/pubmed/11286669

 

Fibromyalgia and other unexplained clinical conditions

Abstract:

Several unexplained clinical conditions frequently coexist with fibromyalgia; these include chronic fatigue syndrome, irritable bowel syndrome, temporomandibular disorder, tension and migraine headaches, and others. However, only recently have studies directly compared the physiological parameters of these conditions (eg, fibromyalgia vs irritable bowel syndrome) to elucidate underlying pathogenic mechanisms. This review summarizes data from comparative studies and discusses their implications for future research.

 

Source: Aaron LA, Buchwald D. Fibromyalgia and other unexplained clinical conditions. Curr Rheumatol Rep. 2001 Apr;3(2):116-22. http://www.ncbi.nlm.nih.gov/pubmed/11286667

 

Chemical sensitivity and chronic fatigue in Gulf War veterans: a brief report

Abstract:

The foci of this brief report are to (1) describe the prevalence of chemical sensitivity (CS) and chronic fatigue (CF) symptomatology and of presumptive multiple CS and CF syndrome diagnoses, and (2) explore the potential overlap between one purported case definition (i.e., chronic multi-symptom illness) and these unexplained symptom syndromes in a well-characterized group of Gulf War veterans. The number of subjects with CS and CF symptomatology and presumptive multiple CS and CF syndrome diagnoses was higher in the Gulf War-deployed group compared with a group deployed to Germany during the Gulf War. However, the percent differences were not significant when comparing the presumptive diagnoses of multiple CS and CF syndrome. The characteristic differences between the groups and the overlap with chronic multi-symptom illness are also discussed.

 

Source: Proctor SP, Heaton KJ, White RF, Wolfe J. Chemical sensitivity and chronic fatigue in Gulf War veterans: a brief report. J Occup Environ Med. 2001 Mar;43(3):259-64. http://www.ncbi.nlm.nih.gov/pubmed/11285874

 

Multiple chemical sensitivity and chronic fatigue syndrome in British Gulf War veterans

Abstract:

The objective of this study was to measure the prevalence of multiple chemical sensitivity (MCS) and chronic fatigue syndrome (CFS) in British Gulf War veterans and to investigate their association with reported exposures and psychologic morbidity. In 1997–1998, the authors undertook a cross-sectional survey of three cohorts of British military personnel comprising Gulf veterans (n = 3,531), those who had served in Bosnia (n = 2,050), and those serving during the Gulf War but not deployed there (Era cohort, n = 2,614). MCS and CFS were defined according to operational criteria.

The prevalence of MCS in the Gulf, Bosnia, and Era cohorts was 1.3%, 0.3%, and 0.2%, respectively. For CFS, the prevalence was 2.1% (Gulf cohort), 0.7% (Bosnia cohort), and 1.8% (Era cohort). In Gulf veterans, MCS was strongly associated with exposure to pesticides (adjusted odds ratio = 12.3, 95% confidence interval: 5.1, 30.0). Both syndromes were associated with high levels of psychologic morbidity.

These findings suggest that CFS and MCS account for some of the medically unexplained illnesses reported by veterans after deployment to the Gulf. MCS was particularly associated with Gulf deployment and self-reported exposure to pesticides, findings that merit further exploration given the controversial status of this diagnosis and the potential for recall bias in a questionnaire survey.

 

Source: Reid S, Hotopf M, Hull L, Ismail K, Unwin C, Wessely S. Multiple chemical sensitivity and chronic fatigue syndrome in British Gulf War veterans. Am J Epidemiol. 2001 Mar 15;153(6):604-9. http://aje.oxfordjournals.org/content/153/6/604.long (Full article)