Chronic unexplained fatigue

Comment on: Chronic unexplained fatigue. [Postgrad Med J. 2002]

 

I found the editorial on chronic fatigue syndrome by White both surprising and disappointing, because he used the title “Chronic unexplained fatigue” and the subtitle “A riddle wrapped in a mystery inside an enigma”, but his editorial, by ignoring very important facts about chronic fatigue syndrome, actually perpetuates that riddle, rather than helping to solve it.

If a puzzling and poorly manageable condition shares more than 40 features, including all of its diagnostic criteria, with a well known and easily treatable disease, this astounding clinical overlap should not be ignored, because reason not only suggests that the mysterious illness may simply be a form of the well known disease, but also hints that it is worthwhile assessing whether the classic therapy for that treatable disease could be effective for the enigmatic condition as well.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1757928/pdf/v078p00763a.pdf

 

Source: Baschetti R. Chronic unexplained fatigue. Postgrad Med J. 2002 Dec;78(926):763; author reply 763. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1757928/pdf/v078p00763a.pdf

 

Role of fatigue in limiting physical activities in humans with neuromuscular diseases

Abstract:

New methods of examining both central and peripheral fatigue are now available. A broader understanding of the mechanisms of fatigue in healthy human subjects has begun to emerge. The mechanisms of fatigue in patients with various neuromuscular diseases are even more complex than in healthy persons. Examples of both central and peripheral fatigue in various neuromuscular diseases and other disorders are presented, including metabolic myopathy, chronic fatigue syndrome, postpolio syndrome, and amyotrophic lateral sclerosis.

 

Source: Miller RG. Role of fatigue in limiting physical activities in humans with neuromuscular diseases. Am J Phys Med Rehabil. 2002 Nov;81(11 Suppl):S99-107. http://www.ncbi.nlm.nih.gov/pubmed/12409815

 

Immunological variables mediate cognitive dysfunction in gulf war veterans but not civilians with chronic fatigue syndrome

Abstract:

We explored the relationship between a set of immunological variables and a set of cognitive and functional status measures and a diagnosis of chronic fatigue syndrome (CFS) in civilians and veterans using various regression and factor analytic methods.

Our approach emphasized the extraction of a few distinct factors in order to limit statistical problems associated with doing large numbers of multiple comparisons. This approach led to our finding cytokine data grouping into type 1 and type 2 clusters. A type 2 cluster plus a T and B cell factor predicted CFS caseness for Gulf War veterans but not for civilians with CFS. When a cognitive variable, reaction time, was added into the model, both immunological factors lost statistical significance; this indicates that the cognitive variable reaction time moderated the effects of the immunological factors in predicting patient status.

We did a similar analysis on the roles of the immunological and cognitive variables in functional status using SF-36 data. Higher levels of these same two immunological factors predicted poorer general health as well as poorer physical and social functioning in Gulf War veterans but not in civilians with CFS. When the reaction time factor was added, only the lymphocyte factor remained significant. This implies that lymphocytes are directly related to functional status in Gulf War veterans with CFS, but the Th2 factor produces its effect on functional status via changes in cognitive abilities.

Copyright 2002 S. Karger AG, Basel

 

Source: Brimacombe M, Zhang Q, Lange G, Natelson B. Immunological variables mediate cognitive dysfunction in gulf war veterans but not civilians with chronic fatigue syndrome. Neuroimmunomodulation. 2002-2003;10(2):93-100. http://www.ncbi.nlm.nih.gov/pubmed/12372983

 

High rates of autoimmune and endocrine disorders, fibromyalgia, chronic fatigue syndrome and atopic diseases among women with endometriosis: a survey analysis

Abstract:

BACKGROUND: Women with endometriosis may also have associated disorders related to autoimmune dysregulation or pain. This study examined whether the prevalence of autoimmune, chronic pain and fatigue and atopic disorders is higher in women with endometriosis than in the general female population.

METHODS AND RESULTS: A cross-sectional survey was conducted in 1998 by the Endometriosis Association of 3680 USA members with surgically diagnosed endometriosis. Almost all responders had pain (99%), and many reported infertility (41%). Compared with published rates in the general USA female population, women with endometriosis had higher rates of hypothyroidism (9.6 versus 1.5%, P < 0.0001), fibromyalgia (5.9 versus 3.4%, P < 0.0001), chronic fatigue syndrome (4.6 versus 0.03%, P < 0.0001), rheumatoid arthritis (1.8 versus 1.2%, P = 0.001), systemic lupus erythematosus (0.8 versus 0.04%, P < 0.0001), Sjögren’s syndrome (0.6 versus 0.03%, P < 0.0001) and multiple sclerosis (0.5 versus 0.07%, P < 0.0001), but not hyperthyroidism or diabetes. Allergies and asthma were more common among women with endometriosis alone (61%, P < 0.001 and 12%, P < 0.001 respectively) and highest in those with fibromyalgia or chronic fatigue syndrome (88%, P < 0.001 and 25%, P < 0.001 respectively) than in the USA female population (18%, P < 0.001 and 5%, P < 0.001 respectively).

CONCLUSIONS: Hypothyroidism, fibromyalgia, chronic fatigue syndrome, autoimmune diseases, allergies and asthma are all significantly more common in women with endometriosis than in women in the general USA population.

 

Source: Sinaii N, Cleary SD, Ballweg ML, Nieman LK, Stratton P. High rates of autoimmune and endocrine disorders, fibromyalgia, chronic fatigue syndrome and atopic diseases among women with endometriosis: a survey analysis. Hum Reprod. 2002 Oct;17(10):2715-24. http://humrep.oxfordjournals.org/content/17/10/2715.long (Full article)

 

The role of environmental factors in medically unexplained symptoms and related syndromes: conference summary and recommendations

Abstract:

This monograph of peer-reviewed articles is based on presentations at the conference “Environmental Factors in Medically Unexplained Physical Symptoms and Related Syndromes” held 10-12 January 2001 in Piscataway, New Jersey, USA. The purpose of the conference was to determine research priorities for elucidating the role of environmental factors in medically unexplained symptoms and symptom syndromes. These include conditions such as chronic fatigue syndrome, multiple chemical sensitivities, sick building syndrome, Gulf War illness, and the like. Approximately 1 1/2 days were devoted to plenary talks and 1 day was devoted to break-out sessions to discuss epidemiologic, psychosocial, and experimental research. Recommendations were made for a series of epidemiologic, psychosocial, and experimental research approaches, with acknowledgment that nosology issues are clearly fundamental to advancing understanding of these conditions.

 

Source: Kipen HM, Fiedler N. The role of environmental factors in medically unexplained symptoms and related syndromes: conference summary and recommendations. Environ Health Perspect. 2002 Aug;110 Suppl 4:591-5. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1241210/ (Full article)

 

A computational analysis of Canale-Smith syndrome: chronic lymphadenopathy simulating malignant lymphoma

Abstract:

OBJECTIVE: The objective of this study was to simulate changes in the human T cell system representing Canale-Smith syndrome using a dynamic computer model of T cell development and comparing with available human data.

STUDY DESIGN: Physiological stepwise maturation and function of T lymphocytes in the computer model is altered by introducing functional disturbances following lymphotropic virus infection. In the present model, acute and chronic persistent infection with the human herpesvirus-6 (HHV-6) was simulated, and ensuing changes in T cell populations were compared with those measured in human patients.

RESULTS: Using our computer model we previously found that simulated acute HHV-6 infection produced T cell computer data, which resembled an infectious mononucleosis-like disease in patients. Simulated chronic persistent infection, instead, resulted in variable cell changes comparing well to patients with chronic fatigue syndrome. In one setting, however, persistent immature lymphocytosis was observed similar to what initial has been described in this journal as Canale-Smith syndrome.

CONCLUSION: Using a computer model developed by us we were able to produce simulations that resemble the immune system features of Canale-Smith syndrome. Further understanding of these simulation results may possibly guide future investigations into this disorder.

 

Source: Krueger GR, Brandt ME, Wang G, Berthold F, Buja LM. A computational analysis of Canale-Smith syndrome: chronic lymphadenopathy simulating malignant lymphoma. Anticancer Res. 2002 Jul-Aug;22(4):2365-71. http://www.ncbi.nlm.nih.gov/pubmed/12174928

 

Long-term follow-up of patients from the 1989 Q fever outbreak: no evidence of excess cardiac disease in those with fatigue

Abstract:

BACKGROUND: In 1989, an outbreak of Q fever (C. burnetii infection) with 147 confirmed cases occurred in Solihull, West Midlands. Three patients developed cardiomyopathy in the subsequent 10 years. The cohort has been followed up with respect to the development of fatigue and, in this instance, cardiac effects after the original infection.

AIM: To determine whether persisting fatigue after Q fever represented sub-clinical cardiomyopathy.

DESIGN: Prospective follow-up study.

METHODS: All traceable subjects from the original outbreak, and community age-, sex- and smoking-matched controls, were studied. Questionnaires for idiopathic fatigue, 12-lead ECG, echocardiography, spirometry and shuttle walk distance were undertaken, and a subset with CDC-defined chronic fatigue syndrome had gated cardiac scans.

RESULTS: Of the original cohort, 19 had died, three had emigrated and 10 were untraceable. Of the remaining 115, 108 responded to a mailed questionnaire and 87 were investigated further, of whom 85 provided complete data. Two developed aortic valve vegetations, one of whom died. Chronic fatigue syndrome was found in 20% of cases and 5.3% of controls (including those with co-morbidities), falling to 8.2% and 0 when excluding those with co-morbidities. There were no significant differences in ECG and echocardiographic investigations or shuttle-walk distance between those with fatigue and those without. Six of the seven patients with CFS had gated cardiac scans: all were within normal limits.

CONCLUSIONS: These findings do not support the existence of a sub-clinical cardiomyopathy in the patients in this cohort who suffer from fatigue after acute Q fever, although endocarditis can occur after acute infection.

Comment in: Q fever: still a mysterious disease. [QJM. 2002]

 

Source: Ayres JG, Wildman M, Groves J, Ment J, Smith EG, Beattie JM. Long-term follow-up of patients from the 1989 Q fever outbreak: no evidence of excess cardiac disease in those with fatigue. QJM. 2002 Aug;95(8):539-46. http://qjmed.oxfordjournals.org/content/95/8/539.long (Full article)

 

Chronic fatigue following infection by Coxiella burnetii (Q fever): ten-year follow-up of the 1989 UK outbreak cohort

Abstract:

BACKGROUND: Some patients exposed to Q fever (Coxiella burnetii infection) may develop chronic fatigue.

AIM: To determine whether subjects involved in the West Midlands Q fever outbreak of 1989 had increased fatigue, compared to non-exposed controls, 10 years after exposure.

DESIGN: Matched cohort study comparing cases to age-, sex- and smoking-history-matched controls not exposed to Q fever.

METHODS: A postal questionnaire was sent to subjects at home, followed by further assessment in hospital, including a physical examination and blood tests.

RESULTS: Of 108 Q-exposed subjects, 70 (64.8%) had fatigue, 37 idiopathic chronic fatigue (ICF) (34.3%), vs. 29/80 (36.3%) and 12 (15.0%), respectively, in controls. In 77 matched pairs, fatigue was commoner in Q-exposed subjects than in controls: 50 (64.9%) vs. 27 (35.1%), p<0.0001. ICF was found in 25 (32.5%) of Q-exposed patients and 11(14.3%) of controls (p=0.01). There were 36 (46.8%) GHQ cases in Q-exposed subjects, vs. 18 (23.4%) controls (p=0.004). A matched analysis of those more intensively studied showed fatigue in 48 (66.7%) Q-exposed patients and 25 (34.7%) controls, (p<0.0001), ICF in 25 (34.7%) Q-exposed and 10 (13.9%) controls (p=0.004), and chronic fatigue syndrome (CFS) in 14 (19.4%) Q-exposed patients and three (4.2%) controls (p=0.003). Thirty-four (47.2%) Q-exposed patients were GHQ cases compared to 17 (23.6%) controls (p=0.004).

DISCUSSION: Subjects who were exposed to Coxiella in 1989 had more fatigue than did controls, and some fulfilled the criteria for CFS. Whether this is due to ongoing antigen persistence or to the psychological effects of prolonged medical follow-up is uncertain.

Comment in: Q fever: still a mysterious disease. [QJM. 2002]

 

Source: Wildman MJ, Smith EG, Groves J, Beattie JM, Caul EO, Ayres JG. Chronic fatigue following infection by Coxiella burnetii (Q fever): ten-year follow-up of the 1989 UK outbreak cohort. QJM. 2002 Aug;95(8):527-38. http://qjmed.oxfordjournals.org/content/95/8/527.long (Full article)

 

Elevated nitric oxide/peroxynitrite mechanism for the common etiology of multiple chemical sensitivity,chronic fatigue syndrome, and posttraumatic stress disorder

Abstract:

Various types of evidence implicate nitric oxide and an oxidant, possibly peroxynitrite, in MCS and chemical intolerance (CI). The positive feedback loops proposed earlier for CFS may explain the chronic nature of MCS (CI) as well as several of its other reported properties. These observations raise the possibility that this proposed elevated nitric oxide/peroxynitrite mechanism may be the mechanism of a new disease paradigm, answering the question raised by Miller earlier: “Are we on the threshold of a new theory of disease?”

 

Source: Pall ML, Satterlee JD. Elevated nitric oxide/peroxynitrite mechanism for the common etiology of multiple chemical sensitivity,chronic fatigue syndrome, and posttraumatic stress disorder.  Ann N Y Acad Sci. 2001 Mar;933:323-9. http://www.ncbi.nlm.nih.gov/pubmed/12000033

 

Controlled exposures to volatile organic compounds in sensitive groups

Abstract:

Sensitivities to chemicals are characterized by symptoms in multiple organ systems in response to low-level chemical exposures. This paper reviews studies of controlled exposures to odorants and to mixtures of volatile organic compounds. Sensitive subgroups include subjects who met Cullen’s 1987 criteria for multiple chemical sensitivity (MCS), Gulf War veterans with chronic fatigue syndrome and chemical sensitivity (CFS/CS), and subjects with specific self-reported sensitivities to methyl terbutyl ether (MTBE) in gasoline (MTBE-sensitive). All studies include comparison of age- and sex-matched healthy controls.

Studies of olfaction did not support unusual sensitivity, defined as lower odor thresholds, among MCS subjects; however, a dose-response pattern of symptoms was observed in response to suprathreshold concentrations of phenyl ethyl alcohol. In blinded, controlled exposures to clean air, gasoline, gasoline/11% MTBE, and gasoline/15% MTBE, a threshold effect was observed with MTBE-sensitive subjects reporting significantly increased symptoms to gasoline/15% MTBE exposure. Autonomic arousal (heart and respiration rate; end-tidal CO2) in response to odor of chemical mixtures may mediate symptoms for subjects with generalized chemical sensitivities, but not for those whose sensitivities are confined to specific chemicals.

For example, Gulf War veterans with CFS/CS experienced reduced end-tidal CO2 when exposed to diesel fumes, while exposure to MTBE did not produce any psychophysiologic changes in MTBE-sensitive subjects. Controlled olfactory and exposure studies reveal that significant responses can be observed in chemically sensitive subjects even when de-adaptation has not occurred. However, these studies suggest that symptoms are not necessarily accompanied by changes in physiologic arousal. Subject characteristics play a critical role in outcomes.

 

Source: Fiedler N, Kipen HM. Controlled exposures to volatile organic compounds in sensitive groups. Ann N Y Acad Sci. 2001 Mar;933:24-37. http://www.ncbi.nlm.nih.gov/pubmed/12000025