Tag: review

Chronic fatigue syndrome: an update focusing on phenomenology and pathophysiology

Abstract:

PURPOSE OF REVIEW: Chronic fatigue syndrome is a controversial condition especially concerning its clinical definition and aetiopathogenesis. Most recent research progress has been made in phenomenology and pathophysiology and we focused our review on these two areas.

RECENT FINDINGS: The phenomenology research supports the notion of a discrete fatigue syndrome which can be distinguished from depression and anxiety. The current case definition, however, may need an improvement based on empirical data. Recent advances in understanding the pathophysiology of chronic fatigue syndrome continue to demonstrate the involvement of the central nervous system. Hyperserotonergic state and hypoactivity of the hypothalamic-pituitary-adrenal axis constitute other findings, but the question of whether these alterations are a cause or consequence of chronic fatigue syndrome still remains unanswered. Immune system involvement in the pathogenesis seems certain but the findings on the specific mechanisms are still inconsistent. Genetic studies provide some evidence of the syndrome being a partly genetic condition, but environmental effects seem to be still predominant and identification of specific genes is still at a very early stage.

SUMMARY: The recent findings suggest that further research is needed in improving the current case definition; investigating overlaps and boundaries among various functional somatic syndromes; answering the question of whether the pathophysiologic findings are a cause or consequence; and elucidating the involvement of the central nervous system, immune system and genetic factors.

 

Source: Cho HJ, Skowera A, Cleare A, Wessely S. Chronic fatigue syndrome: an update focusing on phenomenology and pathophysiology. Curr Opin Psychiatry. 2006 Jan;19(1):67-73. https://www.ncbi.nlm.nih.gov/pubmed/16612182

 

Aetiology and pathogenesis of chronic fatigue syndrome: a review

Abstract:

Chronic fatigue syndrome (CFS) is a debilitating disease of uncertain aetiology that is characterised by unexplained, severe fatigue associated with a number of typical symptoms. This paper reviews the scientific literature related to current theories about the aetiology and pathogenesis of CFS by focussing on what appear to be the four most significant aspects in the development and perpetuation of this disease: the role of infectious agents as well as immunological, neuroendocrine, and psychiatric factors. A multifactorial model for the aetiology of CFS, which includes and draws together these four aspects, is proposed; and suggestions are offered regarding approaches to the diagnosis and treatment of this disease.

 

Source: Mihrshahi R, Beirman R. Aetiology and pathogenesis of chronic fatigue syndrome: a review. N Z Med J. 2005 Dec 16;118(1227):U1780. http://www.ncbi.nlm.nih.gov/pubmed/16372029

 

A systematic review describing the prognosis of chronic fatigue syndrome

Abstract:

AIM: To perform a systematic review of studies describing the prognosis of chronic fatigue (CF) and chronic fatigue syndrome (CFS) and to identify occupational outcomes from such studies.

METHOD: A literature search was used to identify all studies describing the clinical follow-up of patients following a diagnosis of CF or CFS. The prognosis is described in terms of the proportion of individuals improved during the period of follow-up. Return to work, other medical illnesses and death as outcomes are also considered, as are variables which may influence prognosis.

RESULTS: Twenty-eight articles met the inclusion criteria and, for the 14 studies of subjects meeting operational criteria for CFS, the median full recovery rate was 5% (range 0-31%) and the median proportion of patients who improved during follow-up was 39.5% (range 8-63%). Less fatigue severity at baseline, a sense of control over symptoms and not attributing illness to a physical cause were all associated with a good outcome. Return to work at follow-up ranged from 8 to 30% in the three studies that considered this outcome.

CONCLUSIONS: Full recovery from untreated CFS is rare. The prognosis for an improvement in symptoms is less gloomy. This review looks at the course of CF/CFS without systematic intervention. However, there is increasing evidence for the effectiveness of cognitive behavioural and graded exercise therapies. Medical retirement should be postponed until a trial of such treatment has been given.

 

Source: Cairns R, Hotopf M. A systematic review describing the prognosis of chronic fatigue syndrome. Occup Med (Lond). 2005 Jan;55(1):20-31. http://occmed.oxfordjournals.org/content/55/1/20.long (Full artricle)

 

Epidemiology of chronic fatigue syndrome

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) is a controversial disorder with different case definitions, aetiological models and proposed treatments. An epidemiological approach is likely to bring some clarity to the field.

AIM: The aim of this article is to review the literature on the epidemiology of fatigue, chronic fatigue and CFS.

METHOD: A literature search was conducted using the databases Medline and Pubmed as well as the reference lists of recent reviews to identify the relevant studies. The aim was not to do a systematic review but to review the key studies in the area to highlight the methodological issues.

RESULTS: The review is organized according to the following areas: the prevalence of fatigue and chronic fatigue, the prevalence and incidence of CFS, epidemiological associations such as gender, social class and psychiatric co-morbidity and CFS in special groups such as those recovering from a viral infection, specific occupational groups and Gulf War veterans.

CONCLUSION: While fatigue as a symptom is very common, CFS is relatively rare. Many of the epidemiological associations seen in specialist clinics are not found in community samples. It is unlikely that one specific causal factor can explain CFS. Future studies should go beyond estimating the prevalence to testing more complex aetiological models.

 

Source: Ranjith G. Epidemiology of chronic fatigue syndrome. Occup Med (Lond). 2005 Jan;55(1):13-9. http://occmed.oxfordjournals.org/content/55/1/13.long (Full article)

 

Chronic fatigue syndrome: a review

Abstract:

Chronic fatigue syndrome is a relatively unknown and underdiagnosed entity in Italy where its epidemiology remains uncertain, as well as its etiology, although it causes important disability in those affected. Classification criteria by Fukuda are available to diagnose the syndrome. Its epidemiology indicates that it is probably more frequent in Northern countries and it is described in Gulf War veterans. Etiological hypotheses include infectious diseases, immunology and neurology. Among these hypotheses sickness behavior mimes certain aspects of this syndrome and is characterized by a cytokine imbalance in the central nervous system and in the periphery. There are no valid therapies available at the moment. In the laboratory of Immunogenetics, we are constituting a biological bank of the syndrome to study the immunogenetic aspects of the disease in the hope of elucidating some of the obscure areas of its etiopathogenesis.

 

Source: Carlo-Stella N, Lorusso L, Candura SM, Cuccia M. Chronic fatigue syndrome: a review. Recenti Prog Med. 2004 Nov;95(11):546-52; quiz 560. [Article in Italian] http://www.ncbi.nlm.nih.gov/pubmed/15598093

 

Chronic fatigue syndrome (cfs)

Abstract:

The Chronic Fatigue Syndrome (CFS) is described based on the revision of Fukuda et al. The question “whether CFS can be discussed as a homogenous disorder?” has been reviewed and the answer is “no”. Other overlapping syndromes are mentioned. Disorders with fatigue as a symptom are depression, somatisation, irritable bowel syndrome, effort-syndrome, hyperventilation, conservation-withdrawal.

Among the pathogenetic factors of CFS immune systems disorders, neuroendocrine abnormalities, autonomic activity, neuroimaging, neuropsychological abnormalities, exercise capacity and muscle function and psychological processes (attribution, perception, symptom avoidance and neutralisation of conflicts) are discussed.

Since CFS cannot be comprehended without knowledge of the ontogenetic development of the affect “fatigue”, it is extensively described. Based on this knowledge, fatigue as an affect and the CFS are embedded in a context, which has as its basis the fight-flight reaction and the conservation-withdrawal reaction. Weighing the evidence, it is concluded that CFS in its varieties can best be understood as a manifestation of the activation of the two biological emergency reactions: fight-flight and conservation-withdrawal.

The physician should interview and examine each individual patient according to the Harvey Cushing dictum: The physician should not only study the diseased organ, but the man with his diseased organ, and not only these. He should comprehend the man with his diseased organ in his environment. This leads to study of the biological, psychological and social factors contributing to each patient’s illness. Work-up and therapy have to be based on this integrated approach. The latter encompasses conflict centred psychotherapy, stepwise increasing physical activation and antidepressive drugs.

 

Source: Adler RH. Chronic fatigue syndrome (cfs). Swiss Med Wkly. 2004 May 15;134(19-20):268-76. http://www.smw.ch/for-readers/archive/backlinks/?url=/docs/archive200x/2004/19/smw-10213.html (Full article)

 

Disability and chronic fatigue syndrome: a focus on function

Abstract:

BACKGROUND: Evidence was sought in the published literature on how best to measure, monitor, and treat disability in patients with chronic fatigue syndrome (CFS).

METHODS: A systematic review was performed of English-language literature published between January 1, 1988, and November 15, 2001. Interventional and observational studies of adults with CFS were eligible if they reported measures of disability and employment. A qualitative synthesis of results relating impairment measures to employment was performed.

RESULTS: Of 3840 studies identified, 37 reported employment status and some measure of mental or physical impairment associated with disability. Most patients with CFS in these studies were unemployed. In 22 studies, the employment status of control subjects was also available. Only depression seemed to be associated with unemployment in patients with CFS. No other measurable impairment seemed to be consistently associated with disability or work outcomes. Only cognitive behavior therapy, rehabilitation, and exercise therapy interventions were associated with restoring the ability to work. No specific patient characteristics were identified as best predictors of positive employment outcomes. No quantitative syntheses of results were performed.

CONCLUSIONS: For questions of disability and employment in CFS, the limitations inherent in the current literature are extensive. Methodologically rigorous, longitudinal, and interventional studies are needed to determine baseline characteristics that are associated with the inability to work and interventions that are effective in restoring the ability to work in the CFS population. Simple and consistent evaluations of functional capacity in patients with CFS are needed.

 

Source: Ross SD, Estok RP, Frame D, Stone LR, Ludensky V, Levine CB. Disability and chronic fatigue syndrome: a focus on function. Arch Intern Med. 2004 May 24;164(10):1098-107. http://www.ncbi.nlm.nih.gov/pubmed/15159267

 

Chronic fatigue syndrome: traditional and community-based approaches to rehabilitation

Abstract:

Chronic fatigue syndrome (CFS) is a controversial condition defined by 6 months or more of unexplained fatigue, and at least four out of eight cognitive and physical symptoms. Over the past 2 decades, CFS has been the subject of significant debate regarding its definition, cause and recommended treatment. Because a cure for the syndrome has not yet been located, efforts to improve functioning and overall quality of life through rehabilitation represent the most practised form of treatment to date.

However, controversy remains as to which approach to rehabilitation is most effective for individuals with CFS. Interventions which take place within real-world environments and utilise community-based organizations such as centres for independent living offer a newly explored means of support and rehabilitation.

The present paper reviews a variety of approaches to rehabilitation for individuals with CFS, describing their applications with different types of patients, and providing critical commentary on the research methodologies used to evaluate them. Innovative community-based rehabilitation programmes and their outcomes are described as an alternative with some promise that may compliment more traditional approaches.

 

Source: Taylor RR. Chronic fatigue syndrome: traditional and community-based approaches to rehabilitation. Health Soc Care Community. 2004 May;12(3):171-85. http://www.ncbi.nlm.nih.gov/pubmed/19777707

 

Unloading the trunk: neurasthenia, CFS and race

Abstract:

The aetiologies of both chronic fatigue syndrome (CFS) and its predecessor neurasthenia, have been linked to technological advances in ‘developed’ countries. This paper discusses how this has led to a form of race thinking within discussions about fatigue which has persisted for more than a century. We review the historical development of this race thinking from neurasthenia to CFS and describe how it is manifested in both the lay- and medical literature. We also review the epidemiological literature on CFS and ethnicity to better understand the relatively low percentage of non-white patients seen in tertiary referral clinics for CFS. The aim of this paper is to act as a starting point for a debate on race and CFS.

 

Source: Luthra A, Wessely S. Unloading the trunk: neurasthenia, CFS and race. Soc Sci Med. 2004 Jun;58(11):2363-9. http://www.ncbi.nlm.nih.gov/pubmed/15047091

 

Acetylcholine mediated vasodilatation in the microcirculation of patients with chronic fatigue syndrome

Abstract:

The aetiology of chronic fatigue syndrome (CFS) remains controversial and a number of hypotheses have been put forward to explain it. Research into the condition is hindered by the considerable heterogeneity seen across patients but several reports have highlighted disturbances to cholinergic mechanisms in terms of central nervous system activity, neuromuscular function and autoantibodies to muscarinic cholinergic receptors. This paper examines an altogether separate function for acetylcholine and that is its role as an important and generalized vasodilator.

Most diseases are accompanied by a blunted response to acetylcholine but the opposite is true for CFS. Such sensitivity is normally associated with physical training so the finding in CFS is anomalous and may well be relevant to vascular symptoms that characterise many patients. There are several mechanisms that might lead to ACh endothelial sensitivity in CFS patients and various experiments have been designed to unravel the enigma. These are reported here.

 

Source: Spence VA, Khan F, Kennedy G, Abbot NC, Belch JJ. Acetylcholine mediated vasodilatation in the microcirculation of patients with chronic fatigue syndrome. Prostaglandins Leukot Essent Fatty Acids. 2004 Apr;70(4):403-7. http://www.ncbi.nlm.nih.gov/pubmed/15041034