Tag: review

Chronic fatigue syndrome and occupational health

Abstract:

Chronic fatigue syndrome (CFS) is a controversial condition that many occupational physicians find difficult to advise on. In this article we review the nature and definition of CFS, the principal aetiologic hypotheses and the evidence concerning prognosis. We also outline a practical approach to patient assessment, diagnosis and management. The conclusions of this review are then applied to the disability discrimination field. The implications of the new UK occupational health legislation are also examined. Despite continuing controversy about the status, aetiology and optimum management of CFS, we argue that much can be done to improve the outcome for patients with this condition. The most urgent needs are for improved education and rehabilitation, especially in regard to employment. Occupational physicians are well placed to play an important and unique role in meeting these needs.

 

Source: Mounstephen A, Sharpe M. Chronic fatigue syndrome and occupational health. Occup Med (Lond). 1997 May;47(4):217-27. http://occmed.oxfordjournals.org/content/47/4/217.long (Full article)

 

Chronic fatigue syndrome–aetiological aspects

Abstract:

The chronic fatigue syndrome (CFS) has been intensively studied over the last 40 years, but no conclusions have yet been agreed as to its cause. Most cases nowadays are sporadic. In the established chronic condition there are no consistently abnormal physical signs or abnormalities on laboratory investigation.

Many physicians remain convinced that the symptoms are psychological rather than physical in origin. This view is reinforced by the emotional way in which many patients present themselves. The overlap of symptoms between CFS and depression remains a source of confusion and difficulty. But even if all CFS patients were rediagnosed as depressives, this would not negate the possibility of an underlying organic cause for the condition, in view of the growing evidence that depression itself has a physical cause and responds best to physical treatments.

There is some evidence both for active viral infection and for an immunological disorder in the CFS. Many observations suggest that the syndrome could derive from residual damage to the reticular activating system (RAS) of the upper brain stem and/or to its cortical projections. Such damage could be produced by a previous viral infection, leaving functional defects unaccompanied by any gross histological changes.

In animal experiments activation of the RAS can change sleep state and activate or stimulate cortical functions. RAS lesions can produce somnolence and apathy. Studies by modern imaging techniques have not been entirely consistent, but many magnetic resonance imaging (MRI) studies already suggest that small discrete patchy brain stem and subcortical lesions can often be seen in CFS.

Regional blood flow studies by single photon-emission computerized tomography (SPECT) have been more consistent. They have revealed blood flow reductions in many regions, especially in the hind brain. Similar lesions have been reported after poliomyelitis and in multiple sclerosis–in both of which conditions chronic fatigue is characteristically present. In the well-known post-polio fatigue syndrome, lesions predominate in the RAS of the brain stem. If similar underlying lesions in the RAS can eventually be identified in CFS, the therapeutic target for CFS would be better defined than it is at present. A number of logical approaches to treatment can already be envisaged.

Comment in:

Chronic fatigue syndrome. [Eur J Clin Invest. 1997]

Similarity of symptoms in chronic fatigue syndrome and Addison’s disease. [Eur J Clin Invest. 1997]

 

Source: Dickinson CJ. Chronic fatigue syndrome–aetiological aspects. Eur J Clin Invest. 1997 Apr;27(4):257-67. http://www.ncbi.nlm.nih.gov/pubmed/9134372

 

Fibromyalgia, chronic fatigue syndrome, and myofascial pain syndrome

Abstract:

The diagnosis of fibromyalgia continues to generate heated debate. The presence of multiple lifetime psychiatric diagnoses was not intrinsically related to fibromyalgia but rather to the decision of patients to seek specialty medical care. Better outcome measures in fibromyalgia were tested. Neurally mediated hypotension may be associated with chronic fatigue syndrome (CFS). Treatment of patients with fibromyalgia and CFS continues to be of limited success, although the role of multidisciplinary group intervention appears promising. Two position papers focused on the adverse aspects of the medicolegal issues in fibromyalgia and CFS.

 

Source: Goldenberg DL. Fibromyalgia, chronic fatigue syndrome, and myofascial pain syndrome. Curr Opin Rheumatol. 1997 Mar;9(2):135-43. http://www.ncbi.nlm.nih.gov/pubmed/9135918

 

The prognosis of chronic fatigue and chronic fatigue syndrome: a systematic review

Abstract:

The prognosis of chronic fatigue syndrome and chronic fatigue has been studied in numerous small case series. We performed a systematic review of all studies to determine the proportion of individuals with the conditions who recovered at follow-up, the risk of developing alternative physical diagnoses, and the risk factors for poor prognosis.

A literature search of all published studies which included a follow-up of patients with chronic fatigue syndrome or chronic fatigue were performed. Of 26 studies identified, four studied fatigue in children, and found that 54-94% of children recovered over the periods of follow-up. Another five studies operationally defined chronic fatigue syndrome in adults and found that < 10% of subjects return to pre-morbid levels of functioning, and the majority remain significantly impaired. The remaining studies used less stringent criteria to define their cohorts. Among patients in primary care with fatigue lasting < 6 months, at least 40% of patients improved.

As the definition becomes more stringent the prognosis appears to worsen. Consistently reported risk factors for poor prognosis are older age, more chronic illness, having a comorbid psychiatric disorder and holding a belief that the illness is due to physical causes.

Comment in:

Chronic fatigue syndrome. [QJM. 1997]

Chronic fatigue syndrome. [QJM. 1997]

 

Source: Joyce J, Hotopf M, Wessely S. The prognosis of chronic fatigue and chronic fatigue syndrome: a systematic review. QJM. 1997 Mar;90(3):223-33. http://qjmed.oxfordjournals.org/content/90/3/223.long (Full article)

 

Chronic fatigue syndrome: a 20th century illness?

Abstract:

The chronic fatigue syndrome has become the fin de siècle illness, now getting similar attention to that of neurasthenia, which dominated medical thinking at the turn of the century.

Myalgic encephalomyelitis was an early term introduced in the United Kingdom in 1957 for this state, but it had little or no public or professional prominence. Until then “chronic fatigue had become invisible”, with “no name, no known etiology, no case illustrations or clinical accounts in the medical textbook, no ongoing research activity–nothing to relate it to current medical knowledge”.

The reconstruction of chronic fatigue began in the mid-1980s, with the emergence of “chronic Epstein-Barr virus syndrome”, which was later converted to chronic fatigue syndrome. The former term, which first emerged in the mid-1980s, is now regarded as a misnomer and should be abandoned.

In the popular American literature the term “chronic fatigue and immune deficiency syndrome” is preferred by the most active of the patient lobbies, while myalgic encephalomyelitis continues to be the usual label in the United Kingdom.

The relevant research linking chronic fatigue syndrome with somatization is reviewed in this article. Understanding the nature of somatization can still shed some light on the meaning of chronic fatigue at the end of the 20th century.

 

Source: Wessely S. Chronic fatigue syndrome: a 20th century illness? Scand J Work Environ Health. 1997;23 Suppl 3:17-34. http://www.sjweh.fi/show_abstract.php?abstract_id=239 (Full article)

 

Neuroendocrine correlates of chronic fatigue syndrome: a brief review

Abstract:

Chronic fatigue syndrome remains one of the more perplexing syndromes in contemporary clinical medicine. One approach to understanding this condition has been to acknowledge its similarities to other disorders of clearer pathophysiology.

In this review, a rationale for the study of neuroendocrine correlates of chronic fatigue syndrome is presented, based in part on the clinical observation that asthenic or fatigue states share many of the somatic symptom characteristics seen in recognized endocrine disorders. Of additional interest is the observation that psychological symptoms, particularly disturbances in mood and anxiety, are equally prominent in this condition.

At this time, several reports have provided replicated evidence of disruptions in the integrity of the hypothalamic-pituitary-adrenal axis in patients with chronic fatigue syndrome. It is notable that the pattern of the alteration in the stress response apparatus is not reminiscent of the well-understood hypercortisolism of melancholic depression but, rather, suggests a sustained inactivation of central nervous system components of this system.

Recent work also implicates alterations in central serotonergic tone in the overall pathophysiology of this finding. The implications of these observations are far from clear, but they highlight the fact that, though chronic fatigue syndrome overlaps with the well-described illness category of major depression, these are not identical clinical conditions.

 

Source: Demitrack MA. Neuroendocrine correlates of chronic fatigue syndrome: a brief review. J Psychiatr Res. 1997 Jan-Feb;31(1):69-82. http://www.ncbi.nlm.nih.gov/pubmed/9201649

 

Chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) has emerged as a public health concern over the past decade. A working case definition was created in 1988 and revised in 1994, and this has been used to establish prevalence estimates using physician-based surveillance and an a random digit dial telephone survey. Although CFS has some characteristics of an infectious disease, so far no infectious agent has been associated with the illness. Studies of immune function in CFS patients failed to detect differences between cases and healthy controls. However, when cases were subgrouped according to whether they had a sudden or gradual onset, differences in immunologic markers were detected between cases and their matched controls.

 

Source: Mawle AC. Chronic fatigue syndrome. Immunol Invest. 1997 Jan-Feb;26(1-2):269-73. http://www.ncbi.nlm.nih.gov/pubmed/9037629

 

Chronic fatigue syndrome

Abstract:

Fatigue is one of the most common medical complaints. Sometimes, fatigue is chronic, unexplained and induces significant distress or impairment in social, occupational or other important areas of functioning. This condition was described as neurasthenia by Beard at the end of the 19th Century; more recently the United States Centers for Disease Control and Prevention (CDC) suggested to call it “Chronic Fatigue Syndrome” (SFC). Both are considered as physical diseases and share certain therapeutic measures. Pathophysiology is still unknown and may involve viral agents, immunological processes or psychiatric disorders. Similarly most of the treatments which have been properly evaluated seem to be more or less inefficacious.

 

Source: Rouillon F, Delhommeau L, Vinceneux P. Chronic fatigue syndrome. Presse Med. 1996 Dec 21;25(40):2031-6. [Article in French] http://www.ncbi.nlm.nih.gov/pubmed/9082378

 

Fatigue in the chronic fatigue syndrome: a cognitive phenomenon?

Abstract:

What is the source of the perception of excessive fatigue in the chronic fatigue syndrome (CFS)? Studies of physiological response to aerobic activity, of muscle pathology and muscle function in CFS, are reviewed, and suggest that the subjective report of fatigue is not due to any peripheral impairment. In addition, current technological methods such as electroencephalography have failed to uncover the nature of any abnormality in the central motor unit. A physiological model which proposes that patients with CFS possess a reduced threshold for sensory fatigue signals is rejected, because it fails to account for recent findings. Instead, it is suggested that the perception of fatigue in CFS is enhanced by idiosyncrasies in cognitive processing. The implications of this view to our understanding of the perpetuation of CFS as a whole are explored.

 

Source: Fry AM, Martin M. Fatigue in the chronic fatigue syndrome: a cognitive phenomenon? J Psychosom Res. 1996 Nov;41(5):415-26. http://www.ncbi.nlm.nih.gov/pubmed/9032706

 

Chronic fatigue syndrome. Summary of a report of a joint committee of the Royal Colleges of Physicians, Psychiatrists and General Practitioners

Abstract:

Chronic Fatigue Syndrome (CFS) is not a single diagnostic entity. It is a symptom complex which can be reached by many different routes. The conceptual model of CFS needs to be changed from one determined by a single cause/agent to one in which dysfunction is the end stage of a multifactorial process. Although it is important to recognise the role of factors that precipitate the condition, greater understanding is required of factors that predispose individuals to develop the illness, and those that perpetuate disability.

 

Source: Wessely S. Chronic fatigue syndrome. Summary of a report of a joint committee of the Royal Colleges of Physicians, Psychiatrists and General Practitioners. J R Coll Physicians Lond. 1996 Nov-Dec;30(6):497-504. http://www.ncbi.nlm.nih.gov/pubmed/8961200