Toward a new definition of chronic fatigue syndrome

To the editor,

I agree with Lane when he writes that the operative criteria for diagnosing chronic fatigue syndrome (CFS) are unsatisfactory. Some patients who have been assigned this label may be better described as having depression or somatization, and this mislabeling prejudices the understanding of CFS in cross-sectional studies.1 Lane is presumably referring to the definition of the Centers for Disease Control and Prevention, with its concentration on physical symptoms.2 This definition also is not all that helpful in assigning a label to individuals for the purposes of estimating prognosis or deciding on treatment because the physical symptoms cited are nonspecific.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1071345/

 

Source: Robertson-Ritchie H. Toward a new definition of chronic fatigue syndrome. West J Med. 2001 Apr;174(4):241. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1071345/ (Full article)

 

Increased sensitivity to glucocorticoids in peripheral blood mononuclear cells of chronic fatigue syndrome patients, without evidence for altered density or affinity of glucocorticoid receptors

Abstract:

BACKGROUND: In this study we tested the hypothesis that the increased sensitivity to glucocorticoids in chronic fatigue syndrome (CFS)-patients can be attributed to an altered functioning of their glucocorticoid receptors (GR).

METHODS: For this purpose, affinity and distribution of the GR were studied in purified, peripheral blood mononuclear cells (PBMC) of 10 CFS patients and 14 controls along with the responsiveness of these cells to glucocorticoids in vitro.

RESULTS: Affinity (Kd) and number of GR was not different in PBMC of CFS patients when compared with the controls (Kd, 12.9 +/- 8.9 nmol vs 18.8 +/- 16.2 nmol and GR number, 4,839 +/- 2,824/ cell vs 4,906 +/- 1,646/cell). Moreover, RT-PCR revealed no differences in GR messenger RNA expression. Nevertheless, PBMC from CFS patients showed an increased sensitivity to glucocorticoids in vitro. In CFS patients 0.01 micromol dexamethasone suppressed PBMC proliferation by 37%, whereas the controls were only suppressed by 17% (P < 0.01). Addition of phorbol 12-myristate 13-acetate to the cultures rendered the cells resistant to dexamethasone with regard to proliferation and IL-10 and IFN-gamma production, but not to IL-2 and TNF-alpha production in both patients and controls. No difference between patients and controls was observed in this respect

CONCLUSIONS: In conclusion, PBMC of CFS patients display an increased sensitivity to glucocorticoids, which cannot be explained by number or affinity of the GR but should rather be attributed to molecular processes beyond the actual binding of the ligand to the GR.

 

Source: Visser J, Lentjes E, Haspels I, Graffelman W, Blauw B, de Kloet R, Nagelkerken L. Increased sensitivity to glucocorticoids in peripheral blood mononuclear cells of chronic fatigue syndrome patients, without evidence for altered density or affinity of glucocorticoid receptors. J Investig Med. 2001 Mar;49(2):195-204. http://www.ncbi.nlm.nih.gov/pubmed/11288761

 

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

 

Chronic fatigue syndrome: an update

Abstract:

The chronic fatigue syndrome is characterised by a fatigue that is disproportionate to the intensity of effort that is undertaken, has persisted for 6 months or longer, and has no obvious cause. Unless there has been a long period of patient- or physician-imposed inactivity, objective data may show little reduction in muscle strength or peak aerobic power, but the affected individual avoids heavy activity.

The study of aetiology and treatment has been hampered by the low disease prevalence (probably <0.1% of the general population), and (until recently) by a lack of clear and standardised diagnostic criteria. It is unclear how far the aetiology is similar for athletes and nonathletes. It appears that in top competitors, overtraining and/or a negative energy balance can be precipitating factors. A wide variety of other possible causes and/or precipitating factors have been cited in the general population, including psychological stress, disorders of personality and affect, dysfunction of the hypothalamic-pituitary-adrenal axis, hormonal imbalance, nutritional deficits, immune suppression or activation and chronic infection. However, none of these factors have been observed consistently. The prognosis is poor; often disability and impairment of athletic performance are prolonged.

Prevention of overtraining by careful monitoring seems the most effective approach in athletes. In those where the condition is established, treatment should aim at breaking the vicious cycle of effort avoidance, deterioration in physical condition and an increase in fatigue through a combination of encouragement and a progressive exercise programme.

 

Source: Shephard RJ. Chronic fatigue syndrome: an update. Sports Med. 2001;31(3):167-94. http://www.ncbi.nlm.nih.gov/pubmed/11286355

 

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

 

Urinary free cortisol in chronic fatigue syndrome

Abstract:

OBJECTIVE: The authors measured 24-hour urinary free cortisol in a group of well-characterized patients with chronic fatigue syndrome.

METHOD: They obtained 24-hour urine collections from 121 consecutive clinic patients with chronic fatigue syndrome and 64 comparison subjects without the syndrome.

RESULTS: Urinary free cortisol was significantly lower in the subjects with chronic fatigue syndrome regardless of the presence or absence of current or past comorbid psychiatric illness. Lower levels of urinary free cortisol were not related to medication use, sleep disturbance, or disability levels.

CONCLUSIONS: There is mild hypocortisolism in chronic fatigue syndrome. Whether a primary feature or secondary to other factors, hypocortisolism may be one factor contributing to the symptoms of chronic fatigue syndrome.

 

Source: Cleare AJ, Blair D, Chambers S, Wessely S. Urinary free cortisol in chronic fatigue syndrome. Am J Psychiatry. 2001 Apr;158(4):641-3. http://www.ncbi.nlm.nih.gov/pubmed/11282703

 

Illness perceptions and mood in chronic fatigue syndrome

Abstract:

BACKGROUND: Individual beliefs and cognitions may affect adjustment to chronic fatigue syndrome (CFS) and illness perceptions, in particular, have been reported to correlate with both disability and psychological adjustment to CFS in self-diagnosed cases.

OBJECTIVES: The aim of the present study was to examine these relationships in a clinic sample of CFS patients assessed by both a physician and psychiatrist.

METHOD: A sample of 173 patients referred to a multidisciplinary CFS clinic and fulfilling current operational criteria for CFS [Ann Intern Med 121 (1994) 953; J R Soc Med 84 (1991) 118.] were randomly selected from the clinic database and surveyed with the Hospital Anxiety and Depression scale, Fatigue Questionnaire and Illness Perceptions Questionnaire [J Psychosom Res 37 (1993) 147; Psychol Health 11 (1996) 431; Acta Psychiatr Scand 67 (1983) 361.].

RESULTS: A total of 126 patients responded (73% response rate). The illness perception components studied were consequences (of illness), illness identity, causes (of illness), the ability to control/cure the illness and (expected) timeline of the illness. These components accounted for 15%, 28% and 30% of the variance in levels of fatigue, depression and anxiety, respectively. Two of the illness perception components (consequences and illness identity) were stronger predictors of fatigue score than mood scores.

CONCLUSIONS: These findings confirmed in a clinical sample that illness perceptions are associated with variation in both disability and psychological adjustment in CFS. Illness perceptions may have an important and long-lasting effect on adaptation to CFS, and it is necessary to have a greater understanding of their role in order to tailor effective interventions for the condition.

 

Source: Edwards R, Suresh R, Lynch S, Clarkson P, Stanley P. Illness perceptions and mood in chronic fatigue syndrome. J Psychosom Res. 2001 Feb;50(2):65-8. http://www.ncbi.nlm.nih.gov/pubmed/11274662

 

Chronic fatigue in general practice: is counselling as good as cognitive behaviour therapy? A UK randomised trial

Abstract:

BACKGROUND: Fatigue is a common symptom for which patients consult their doctors in primary care. With usual medical management the majority of patients report that their symptoms persist and become chronic. There is little evidence for the effectiveness of any fatigue management in primary care.

AIM: To compare the effectiveness of cognitive behaviour therapy (CBT) with counselling for patients with chronic fatigue and to describe satisfaction with care.

DESIGN OF STUDY: Randomised trial with parallel group design.

SETTING: Ten general practices located in London and the South Thames region of the United Kingdom recruited patients to the trial between 1996 and 1998. Patients came from a wide range of socioeconomic backgrounds and lived in urban, suburban, and rural areas.

METHOD: Data were collected before randomisation, after treatment, and six months later. Patients were offered six sessions of up to one hour each of either CBT or counselling. Outcomes include: self-report of fatigue symptoms six months later, anxiety and depression, symptom attributions, social adjustment and patients’ satisfaction with care.

RESULTS: One hundred and sixty patients with chronic fatigue entered the trial, 45 (28%) met research criteria for chronic fatigue syndrome; 129 completed follow-up. All patients met Chalder et al’s standard criteria for fatigue. Mean fatigue scores were 23 on entry (at baseline) and 15 at six months’ follow-up. Sixty-one (47%) patients no longer met standard criteria for fatigue after six months. There was no significant difference in effect between the two therapies on fatigue (1.04 [95% CI = -1.7 to 3.7]), anxiety and depression or social adjustment outcomes for all patients and for the subgroup with chronic fatigue syndrome. Use of antidepressants and consultations with the doctor decreased after therapy but there were no differences between groups.

CONCLUSION: Counselling and CBT were equivalent in effect for patients with chronic fatigue in primary care. The choice between therapies can therefore depend on other considerations, such as cost and accessibility.

Comment in:

Chronic fatigue in general practice. [Br J Gen Pract. 2001]

Cognitive behaviour therapy and chronic fatigue syndrome. [Br J Gen Pract. 2001]

 

Source: Ridsdale L, Godfrey E, Chalder T, Seed P, King M, Wallace P, Wessely S; Fatigue Trialists’ Group. Chronic fatigue in general practice: is counselling as good as cognitive behaviour therapy? A UK randomised trial. Br J Gen Pract. 2001 Jan;51(462):19-24. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1313894/ (Full article)

 

Role of impaired lower-limb venous innervation in the pathogenesis of the chronic fatigue syndrome

Abstract:

BACKGROUND: In patients with acute orthostatic hypotension, there is excessive pooling of blood in the legs, which may result from the strikingly subnormal compliance that is demonstrable in the pedal veins during norepinephrine infusion. The common occurrence of delayed orthostatic hypotension and/or tachycardia in the chronic fatigue syndrome (CFS) led to the present studies of foot vein compliance in CFS patients with a linear variable differential transformer.

METHODS: Seven patients with CFS were compared with 7 age- and gender matched healthy control subjects in their blood pressure, heart-rate, and plasma norepinephrine responses to prolonged standing and in measurements of their foot vein contractile responses to intravenous norepinephrine infusions with the linear variable differential transformer.

RESULTS: Excessive, delayed (usually after 10 min) orthostatic reductions in systolic and diastolic blood pressure (P < 0.01) and inconsistently excessive increases in heart rate were found in the CFS patients, in whom venous compliance in response to infused norepinephrine was significantly reduced (P < 0.05).

CONCLUSIONS: In these patients with CFS, delayed orthostatic hypotension was clearly demonstrable, and, as in previously reported patients with orthostatic hypotension of acute onset, this was associated with reduced pedal vein compliance during norepinephrine infusion, implying impaired sympathetic innervation of foot veins. The rapid symptomatic improvement demonstrated in previous studies of CFS patients during correction of orthostatic venous pooling by inflation of military antishock trousers (MAST) to 35 mm Hg may suggest that excessive lower body venous pooling, perhaps by reducing cerebral perfusion, is involved in the orthostatic component of fatigue in these patients.

 

Source: Streeten DH. Role of impaired lower-limb venous innervation in the pathogenesis of the chronic fatigue syndrome. Am J Med Sci. 2001 Mar;321(3):163-7. http://www.ncbi.nlm.nih.gov/pubmed/11269790