Tag: review

Defining and managing chronic fatigue syndrome

Abstract:

Objectives: Objectives of this evidence report are to summarize research evidence regarding the case definitions, prevalence, natural history and therapy of chronic fatigue syndrome (CFS).

Search Strategy: English and non-English citations were identified through July 2000 from four electronic bibliographic databases (MEDLINE, The Cochrane Library, PsycINFO, EMBASE), CFS Internet sites, the Journal of Chronic Fatigue Syndrome, references of pertinent articles, textbooks, and experts. The electronic search was updated through October 2000 using PubMed; experts identified relevant citations up to January 2001.

Selection Criteria: Published and unpublished studies that were conducted after 1980 and that involved adults with CFS were reviewed.

Data Collection and Analysis: Two reviewers (physician, psychometrician, research methodologist, and/or nurse) independently abstracted data from the selected studies. Data were synthesized descriptively, emphasizing the quality and methodologic design of studies. Meta-analyses were not done because of marked heterogeneity of study designs.

Main Results: There are four well-recognized case definitions of CFS, and the Centers for Disease Control and Prevention (CDC) is spearheading the development of a fifth. Definitions, developed primarily by expert knowledge and consensus, have evolved over time. A few comparative research studies support the concept of a condition, characterized by prolonged fatigue and impaired ability to function, which is captured by the case definitions. The superiority of one case definition over another is not well established. The validity of any definition is difficult to establish because there are no clear biologic markers for CFS, and no effective treatments specific only to CFS have been identified.

Findings from surveys show that the prevalence of CFS in community populations is probably less than 1% and in primary care populations less than 3%. The reliability of these estimates is limited, because surveys used different case definitions and varied assessment and reporting methods, and sometimes had poor response rates.

Precise estimates of recovery, improvement, and/or relapse from CFS are not possible because there are few natural history studies and those that are available have involved selected referral populations or have used varying case definitions and followup methods.

 

Source: Mulrow CD, Ramirez G, Cornell JE, Allsup K. Defining and managing chronic fatigue syndrome. Evid Rep Technol Assess (Summ). 2001 Sep;(42):1-4. http://www.ncbi.nlm.nih.gov/books/NBK33797/ (Full article)

 

Neuroendocrine mechanisms in fibromyalgia-chronic fatigue

Abstract:

Fibromyalgia and chronic fatigue syndrome are poorly understood disorders that share similar demographic and clinical characteristics. Because of the clinical similarities between both disorders it was suggested that they share a common pathophysiological mechanism, namely, central nervous system dysfunction.

This chapter presents data demonstrating neurohormonal abnormalities, abnormal pain processing and autonomic nervous system dysfunction in fibromyalgia and chronic fatigue syndrome. The possible contribution of the central nervous system dysfunction to the development and symptomatology of these conditions is discussed. The chapter concludes by reviewing the effect of current treatments and emerging therapeutic modalities in fibromyalgia and chronic fatigue syndrome.

 

Source: Buskila D, Press J. Neuroendocrine mechanisms in fibromyalgia-chronic fatigue. Best Pract Res Clin Rheumatol. 2001 Dec;15(5):747-58. http://www.ncbi.nlm.nih.gov/pubmed/11812019

 

The neuroendocrinology of chronic fatigue syndrome and fibromyalgia

Abstract:

BACKGROUND: Disturbance of the HPA axis may be important in the pathophysiology of chronic fatigue syndrome (CFS) and fibromyalgia. Symptoms may be due to: (1) low circulating cortisol; (2) disturbance of central neurotransmitters; or (3) disturbance of the relationship between cortisol and central neurotransmitter function. Accumulating evidence of the complex relationship between cortisol and 5-HT function, make some form of hypothesis (3) most likely. We review the methodology and results of studies of the HPA and other neuroendocrine axes in CFS.

METHOD: Medline, Embase and Psychlit were searched using the Cochrane Collaboration strategy. A search was also performed on the King’s College CFS database, which includes over 3000 relevant references, and a citation analysis was run on the key paper (Demitrack et al. 1991).

RESULTS: One-third of the studies reporting baseline cortisol found it to be significantly low, usually in one-third of patients. Methodological differences may account for some of the varying results. More consistent is the finding of reduced HPA function, and enhanced 5-HT function on neuroendocrine challenge tests. The opioid system, and arginine vasopressin (AVP) may also be abnormal, though the growth hormone (GH) axis appears to be intact, in CFS.

CONCLUSIONS: The significance of these changes, remains unclear. We have little understanding of how neuroendocrine changes relate to the experience of symptoms, and it is unclear whether these changes are primary, or secondary to behavioural changes in sleep or exercise. Longitudinal studies of populations at risk for CFS will help to resolve these issues.

 

Source: Parker AJ, Wessely S, Cleare AJ. The neuroendocrinology of chronic fatigue syndrome and fibromyalgia. Psychol Med. 2001 Nov;31(8):1331-45. http://www.ncbi.nlm.nih.gov/pubmed/11722149

 

Interventions for the treatment and management of chronic fatigue syndrome: a systematic review

Erratum in: JAMA 2002 Mar 20;287(11):1401.

Abstract:

CONTEXT: A variety of interventions have been used in the treatment and management of chronic fatigue syndrome (CFS). Currently, debate exists among health care professionals and patients about appropriate strategies for management.

OBJECTIVE: To assess the effectiveness of all interventions that have been evaluated for use in the treatment or management of CFS in adults or children.

DATA SOURCES: Nineteen specialist databases were searched from inception to either January or July 2000 for published or unpublished studies in any language. The search was updated through October 2000 using PubMed. Other sources included scanning citations, Internet searching, contacting experts, and online requests for articles.

STUDY SELECTION: Controlled trials (randomized or nonrandomized) that evaluated interventions in patients diagnosed as having CFS according to any criteria were included. Study inclusion was assessed independently by 2 reviewers. Of 350 studies initially identified, 44 met inclusion criteria, including 36 randomized controlled trials and 8 controlled trials.

DATA EXTRACTION: Data extraction was conducted by 1 reviewer and checked by a second. Validity assessment was carried out by 2 reviewers with disagreements resolved by consensus. A qualitative synthesis was carried out and studies were grouped according to type of intervention and outcomes assessed.

DATA SYNTHESIS: The number of participants included in each trial ranged from 12 to 326, with a total of 2801 participants included in the 44 trials combined. Across the studies, 38 different outcomes were evaluated using about 130 different scales or types of measurement. Studies were grouped into 6 different categories. In the behavioral category, graded exercise therapy and cognitive behavioral therapy showed positive results and also scored highly on the validity assessment. In the immunological category, both immunoglobulin and hydrocortisone showed some limited effects but, overall, the evidence was inconclusive. There was insufficient evidence about effectiveness in the other 4 categories (pharmacological, supplements, complementary/alternative, and other interventions).

CONCLUSIONS: Overall, the interventions demonstrated mixed results in terms of effectiveness. All conclusions about effectiveness should be considered together with the methodological inadequacies of the studies. Interventions which have shown promising results include cognitive behavioral therapy and graded exercise therapy. Further research into these and other treatments is required using standardized outcome measures.

Comment in:

Measuring the quality of trials of treatments for chronic fatigue syndrome. [JAMA. 2001]

Chronic fatigue syndrome–trials and tribulations. [JAMA. 2001]

Review: behavioural interventions show the most promise for chronic fatigue syndrome. [Evid Based Nurs. 2002]

Review: behavioral interventions show the most promise for the chronic fatigue syndrome. [ACP J Club. 2002]

Review: cognitive behavioural therapy and graded exercise show the most promise for chronic fatigue syndrome. [Evid Based Ment Health. 2002]

 

Source: Whiting P, Bagnall AM, Sowden AJ, Cornell JE, Mulrow CD, Ramírez G. Interventions for the treatment and management of chronic fatigue syndrome: a systematic review. JAMA. 2001 Sep 19;286(11):1360-8. http://www.ncbi.nlm.nih.gov/pubmed/11560542

 

Chronic fatigue syndrome: neurological findings may be related to blood–brain barrier permeability

Abstract:

Despite volumes of international research, the etiology of chronic fatigue syndrome (CFS) remains elusive. There is, however, considerable evidence that CFS is a disorder involving the central nervous system (CNS).

It is our hypothesis that altered permeability of the blood-brain barrier (BBB) may contribute to ongoing signs and symptoms found in CFS. To support this hypothesis we have examined agents that can increase the blood-brain barrier permeability (BBBP) and those that may be involved in CFS.

The factors which can compromise the normal BBBP in CFS include viruses, cytokines, 5-hydroxytryptamine, peroxynitrite, nitric oxide, stress, glutathione depletion, essential fatty acid deficiency, and N-methyl-D-aspartate overactivity. It is possible that breakdown of normal BBBP leads to CNS cellular dysfunction and disruptions of neuronal transmission in CFS. Abnormal changes in BBBP have been linked to a number of disorders involving the CNS; based on review of the literature we conclude that the BBB integrity in CFS warrants investigation.

Copyright 2001 Harcourt Publishers Ltd.

 

Source: Bested AC, Saunders PR, Logan AC. Chronic fatigue syndrome: neurological findings may be related to blood–brain barrier permeability. Med Hypotheses. 2001 Aug;57(2):231-7. http://www.ncbi.nlm.nih.gov/pubmed/11461179

 

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

 

Chronic fatigue: symptom and syndrome

Abstract:

Chronic fatigue is common, is difficult to measure, can be associated with considerable morbidity, and is rarely a subject of controversy. The chronic fatigue syndrome also presents problems in definition and measurement, is associated with even more morbidity than chronic fatigue itself, and is often controversial. Particularly unclear is the way in which chronic fatigue and the chronic fatigue syndrome relate to each other: Is one the severe form of the other, or are they qualitatively and quantitatively different? We know that many things can cause chronic fatigue, and this is probably true for the chronic fatigue syndrome, too. We can anticipate that discrete causes of the chronic fatigue syndrome will be found in the future, even if these causes are unlikely to fall neatly along the physical-psychological divide that some expect. The causes of chronic fatigue are undoubtedly many, both in a population and in any individual person, even when a discrete cause, such as depression or cancer, is identified. Social, behavioral, and psychological variables are important in both chronic fatigue and the chronic fatigue syndrome. Interventions that address these general variables can be successful, and currently they are often more successful than interventions directed at specific causes.

 

Source: Wessely S. Chronic fatigue: symptom and syndrome. Ann Intern Med. 2001 May 1;134(9 Pt 2):838-43. http://www.ncbi.nlm.nih.gov/pubmed/11346319

 

Anti-nuclear envelope antibodies: Clinical associations

Abstract:

OBJECTIVES: Characterization of the clinical associations and clinical implications of antibodies reacting with antigens of the nuclear envelope.

METHODS: Description of an illustrative case and a MEDLINE search-assisted literature review of relevant cases.

RESULTS: With indirect immunofluorescence, autoantibodies directed against various antigens of the nuclear envelope stain the nucleus in a ring-like (rim) pattern. Autoantibodies against 5 antigenic components of the nuclear envelope have been described: anti-gp210, p62, lamina, lamina-associated polypeptides, and lamin B receptor. Antibodies to antigens of the nuclear pore complex, such as gp210 and p62, are highly specific (> 95%) for primary biliary cirrhosis and may aid in the serologic diagnosis of this condition, especially in cases in which antimitochondrial antibodies are not detectable. In contrast, antilamin antibodies are not disease-specific but seem to be associated with lupus anticoagulant or anticardiolipin antibodies, antiphospholipid syndrome, thrombocytopenia, autoimmune liver diseases, and arthralgia. High-titered antilamin antibodies help to define a subset of lupus patients with antiphospholipid antibodies who are at a lower risk of developing thrombotic events. In addition, preliminary data suggest that the presence of antilamin antibodies may be helpful in the diagnosis of chronic fatigue syndrome.

CONCLUSIONS: Each of the antibodies reacting with nuclear membrane antigens has its own spectrum of disease associations.

RELEVANCE: Determination of anti-nuclear envelope antibody pattern by indirect immunofluorescence, with subsequent determination of the specific antibody, carries important diagnostic and prognostic implications in various autoimmune conditions.

 

Source: Nesher G, Margalit R, Ashkenazi YJ. Anti-nuclear envelope antibodies: Clinical associations. Semin Arthritis Rheum. 2001 Apr;30(5):313-20. http://www.ncbi.nlm.nih.gov/pubmed/11303304

 

Coping and illness cognitions: chronic fatigue syndrome

Abstract:

The chronic fatigue syndrome (CFS) is described, and research on coping with this illness reviewed and analysed. CFS is a severely disabling illness of unknown etiology, which has occurred in epidemic forms all over the world. However, the number of sufferers has dramatically increased over previous years. The heterogeneous symptomatology of CFS was reviewed, and diagnostic criteria were discussed. The difficulty in establishing causality was emphasized. An interaction of factors appears most likely to be associated with illness onset and maintenance. As the mediating factor could be sufferers’ coping behavior, the existing coping literature was reviewed. There might be an association between coping and physical and psychological well-being. Finally, recommendations are made for longitudinal research on coping and coping effectiveness, and for the development of therapeutic interventions.

 

Source: Ax S, Gregg VH, Jones D. Coping and illness cognitions: chronic fatigue syndrome. Clin Psychol Rev. 2001 Mar;21(2):161-82. http://www.ncbi.nlm.nih.gov/pubmed/11293364

 

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