Interpretation of symptoms in chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is an illness characterised by fatigue and other symptoms. Both psychological and biological aetiological factors have been proposed, but the disorder is of uncertain origin. The aetiology of the symptoms is therefore ambiguous. It has been suggested (a) that patients with CFS tend to interpret their symptoms as indicating physical illness and (b) they tend not to interpret these symptoms in terms of negative emotion.

In order to test these hypotheses we developed a self-report questionnaire to assess the interpretation of symptoms in patients with CFS. It was administered to patients with CFS, patients with depression, patients with multiple sclerosis (MS), and normal controls. Preliminary results suggest that the measure has acceptable psychometric properties.

Patients with CFS were more likely than either depressed patients or normal controls to interpret symptoms (characteristic of CFS) in terms of physical illness, but did not differ in this from the MS patients. When compared with all three other groups (including the MS patients), the patients with CFS were least likely to interpret symptoms in terms of negative emotional states. The theoretical and clinical implications of the findings are discussed.

 

Source: Dendy C, Cooper M, Sharpe M. Interpretation of symptoms in chronic fatigue syndrome. Behav Res Ther. 2001 Nov;39(11):1369-80. http://www.ncbi.nlm.nih.gov/pubmed/11686271

 

A twin study of the etiology of prolonged fatigue and immune activation

Abstract:

Risk factors to prolonged fatigue syndromes (PFS) are controversial. Pre-morbid and/or current psychiatric disturbance, and/or disturbed cell-mediated immunity (CMI), have been proposed as etiologic factors.

Self-report measures of fatigue and psychologic distress and three in vitro measures of CMI were collected from 124 twin pairs. Crosstwin-crosstrait correlations were estimated for the complete monozygotic (MZ; 79 pairs) and dizygotic (DZ; 45 pairs) twin groups. Multivariate genetic and environmental models were fitted to explore the patterns of covariation between etiologic factors. For fatigue, the MZ correlation was more than double the DZ correlation (0.49 versus 0.16) indicating strong genetic control of familial aggregation.

By contrast, for in vitro immune activation measures MZ and DZ correlations were similar (0.49-0.69 versus 0.42-0.53) indicating the etiologic role of shared environments. As small univariate associations were noted between prolonged fatigue and the in vitro immune measures (r = -0.07 to -0.12), multivariate models were fitted. Relevant etiologic factors included: a common genetic factor accounting for 48% of the variance in fatigue which also accounted for 4%, 6% and 8% reductions in immune activation; specific genetic factors for each of the in vitro immune measures; a shared environment factor influencing the three immune activation measures; and, most interestingly, unique environmental influences which increased fatigue but also increased markers of immune activation.

PFS that are associated with in vitro measures of immune activation are most likely to be the consequence of current environmental rather than genetic factors. Such environmental factors could include physical agents such as infection and/or psychologic stress.

 

Source: Hickie IB, Bansal AS, Kirk KM, Lloyd AR, Martin NG. A twin study of the etiology of prolonged fatigue and immune activation. Twin Res. 2001 Apr;4(2):94-102. http://www.ncbi.nlm.nih.gov/pubmed/11665341

 

Cognitive behavioral therapy for chronic fatigue syndrome in a general hospital–feasible and effective

Abstract:

Cognitive behavior therapy (CBT) has been shown to be effective in recent randomized controlled trials for chronic fatigue syndrome (CFS). We examined the effectiveness of CBT in a general hospital setting in a retrospective questionnaire follow-up study of 94 patients offered CBT by liaison psychiatry services. The questionnaire response rate was 61%.

Eighteen percent had returned to normal functioning at follow-up. For the group as a whole, there was a significant improvement in the functional and social impairment and the number of frequently experienced symptoms. Those in work or study at follow-up was 53% (29% pretreatment), and 65% of patients mentioned occupational stress as a contributory factor in their illness. There was a significant reduction in the frequency of attendance at primary care in the year after the end of CBT.

We conclude that cognitive behavioral therapy is an acceptable treatment for most patients and can be used in a general hospital outpatient setting by a variety of trained therapists. However, a proportion of patients do not benefit and remain significantly disabled by the condition.

 

Source: Akagi H, Klimes I, Bass C. Cognitive behavioral therapy for chronic fatigue syndrome in a general hospital–feasible and effective. Gen Hosp Psychiatry. 2001 Sep-Oct;23(5):254-60. http://www.ncbi.nlm.nih.gov/pubmed/11600166

 

Defensive coping styles in chronic fatigue syndrome

Abstract:

OBJECTIVE: The cognitive-behavioral model of chronic fatigue syndrome (CFS) proposes that rigidly held beliefs act to defend individuals against low self-esteem. This study is the first to investigate the prevalence of a potential mechanism, the Defensive High Anxious coping style, among individuals with CFS.

METHODS: The study comprised 68 participants (24 CFS; 24 healthy volunteers; 20 chronic illness volunteers). Participants completed the Bendig short form of the Taylor Manifest Anxiety Scale (B-MAS) and the Marlowe-Crowne Social Desirability Scale (MC) in order to ascertain the distribution of participants in each group within the four coping styles defined by Weinberger et al. [J. Abnorm. Psychol. 88 (1979) 369].

RESULTS: A greater number of participants in the CFS group (46%) were classified as Defensive High Anxious compared to the two comparison groups [chi(2)(2)=8.84, P=.012].

CONCLUSION: This study provides support for the existence of defensive coping mechanisms as described by the cognitive-behavioral model of CFS. Furthermore, it has been suggested that this particular coping style may impinge directly on physical well being through similar mechanisms as identified in CFS, and further research linking these areas of research is warranted.

 

Source: Creswell C, Chalder T. Defensive coping styles in chronic fatigue syndrome. J Psychosom Res. 2001 Oct;51(4):607-10. http://www.ncbi.nlm.nih.gov/pubmed/11595249

 

Premorbid “overactive” lifestyle in chronic fatigue syndrome and fibromyalgia. An etiological factor or proof of good citizenship?

Abstract:

OBJECTIVE: In a former study, we have shown that patients suffering from chronic fatigue syndrome (CFS) or chronic pain, when questioned about their premorbid lifestyle, reported a high level of “action-proneness” as compared to control groups. The aim of the present study was to control for the patients’ possible idealisation of their previous attitude towards action.

METHODS: A validated Dutch self-report questionnaire measuring “action-proneness” (the HAB) was completed by 62 randomly selected tertiary care CFS and fibromyalgia (FM) patients, as well as by their significant others (SOs).

RESULTS: HAB scores of the patients and those of the SOs were very similar and significantly higher than the norm values. Whether or not the SO showed sympathy for the patient’s illness did not influence the results to a great extent. SOs with a negative attitude towards the illness even characterized the patients as more “action-prone.”

CONCLUSIONS: These results provide further support for the hypothesis that a high level of “action-proneness” may play a predisposing, initiating and/or perpetuating role in CFS and FM.

 

Source: Van Houdenhove B, Neerinckx E, Onghena P, Lysens R, Vertommen H. Premorbid “overactive” lifestyle in chronic fatigue syndrome and fibromyalgia. An etiological factor or proof of good citizenship? J Psychosom Res. 2001 Oct;51(4):571-6. http://www.ncbi.nlm.nih.gov/pubmed/11595245

 

Chronic fatigue syndrome

Comment in: Chronic fatigue syndrome. [Br J Gen Pract. 2001]

Comment on: Frequency of attendance in general practice and symptoms before development of chronic fatigue syndrome: a case-control study. [Br J Gen Pract. 2001]

 

The study of Hamilton et al in the July issue of the BJGP, 1 claims that a higher consultation rate in people with chronic fatigue syndrome (CFS) before they develop the diagnosis supports the hypothesis that behavioural factors have a role in its aetiology. A similar case-control study of mothers and fathers of Down’s syndrome children showed that both mothers and fathers had significantly more recorded illnesses before the birth of the child and that the mothers had significantly more psychosis, neurosis or self-poisoning.2

The problem with such findings is deciding what they mean. No-one would suggest that Down’s syndrome is caused by ‘behavioural factors,’ so why should anyone believe that of CFS? There is no more evidence that increased frequency of attendance before diagnosis points to behavioural factors in CFS than that it points to non-dysjunction in the germ cells of mothers of Down’s syndrome children.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1314117/pdf/11593850.pdf

 

Source: Murdoch JC. Chronic fatigue syndrome. Br J Gen Pract. 2001 Sep;51(470):758. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1314117/pdf/11593850.pdf (Full comment)

 

LPS-induced IL-10 production in whole blood cultures from chronic fatigue syndrome patients is increased but supersensitive to inhibition by dexamethasone

Abstract:

Several causes have been held responsible for the chronic fatigue syndrome (CFS), including an altered hypothalamus-pituitary-adrenal gland (HPA)-axis activity, viral infections and a reduced Th1 activity. Therefore, it was investigated whether the regulation of IL-10 is different in CFS.

LPS-induced cytokine secretion in whole blood cultures showed a significant increase in IL-10 and a trend towards a decrease in IL-12 as compared with healthy controls. In patients and controls, IL-12 secretion was equally sensitive to suppression by dexamethasone, whereas IL-10 secretion appeared more sensitive in CFS-patients. In controls, IL-10 and IL-12 secretion were inversely correlated with free serum cortisol (r=-0.492, p<0.02 and r=-0.434, p<0.05, respectively). In CFS, such an inverse correlation was found for IL-12 (r=-0.611, p<0.02) but not for IL-10 (r=-0.341, ns).

These data are suggestive for a disturbed glucocorticoid regulation of IL-10 in CFS.

 

Source: Visser J, Graffelman W, Blauw B, Haspels I, Lentjes E, de Kloet ER, Nagelkerken L. LPS-induced IL-10 production in whole blood cultures from chronic fatigue syndrome patients is increased but supersensitive to inhibition by dexamethasone. J Neuroimmunol. 2001 Oct 1;119(2):343-9. http://www.ncbi.nlm.nih.gov/pubmed/11585638

 

Cardiovascular responses of women with chronic fatigue syndrome to stressful cognitive testing before and after strenuous exercise

Abstract:

OBJECTIVE: The purpose of this study was to compare the cardiovascular responses of patients with chronic fatigue syndrome (CFS) to healthy control subjects when performing stressful cognitive tasks before and after strenuous exercise.

METHOD: Beat-by-beat blood pressure and electrocardiogram were recorded on 19 women with CFS and 20 healthy nonexercising (ie, sedentary) women while they performed cognitive tests before, immediately after, and 24 hours after incremental exercise to exhaustion.

RESULTS: Diminished heart rate (p <.01) and systolic (p <.01) and diastolic (p <.01) blood pressure responses to stressful cognitive testing were seen in patients with CFS when compared with healthy, sedentary controls. This diminished stress response was seen consistently in patients with CFS across three separate cognitive testing sessions. Also, significant negative correlations between self-ratings of CFS symptom severity and cardiovascular responses were seen (r = -0.62, p <.01).

CONCLUSIONS: Women with CFS have a diminished cardiovascular response to cognitive stress; however, exercise did not magnify this effect. Also, the data showed that the patients with the lowest cardiovascular reactivity had the highest ratings of CFS symptom severity, which suggests that the individual response of the patient with CFS to stress plays a role in the common complaint of symptoms worsening after stress.

 

Source: LaManca JJ, Peckerman A, Sisto SA, DeLuca J, Cook S, Natelson BH. Cardiovascular responses of women with chronic fatigue syndrome to stressful cognitive testing before and after strenuous exercise. Psychosom Med. 2001 Sep-Oct;63(5):756-64. http://www.ncbi.nlm.nih.gov/pubmed/11573024

 

Corticospinal inhibition appears normal in patients with chronic fatigue syndrome

Abstract:

The pathogenesis of chronic fatigue syndrome (CFS) remains unknown. Thresholds and latencies of motor evoked potentials (MEPs) in response to transcranial magnetic stimulation (TMS) are normal but intracortical inhibition has not been investigated.

Eleven patients with CFS were compared with 11 control subjects. Each patient completed a questionnaire using visual analogue indices of pain, fatigue, anxiety and depression. Subjects released a button to initiate simple (SRTs) and choice reaction time (CRTs) tasks; for each task, movement times were measured between release of the initiation button and depression of a second button 15 cm away. Subjects held a 10 % maximum voluntary contraction in the thenar muscles of their dominant hand while TMS was applied to the motor cortex; the duration and extent of inhibition of surface electromyographic (EMG) activity were assessed at stimulus strengths above and below the threshold for MEPs.

Patients had significantly (P < 0.05) higher mean indices of fatigue than of pain, anxiety or depression. Mean (+/- S.E.M.) SRTs (but not CRTs) were longer in patients (309 +/- 45 ms) than in controls (218 +/- 9 ms). Movement times were longer in patients for both SRTs and CRTs. TMS thresholds, expressed as a percentage of the maximum stimulator output, were not significantly (P > 0.05) different in both groups for both MEPs (patients, 34 +/- 3%; controls, 36 +/- 3%) and inhibition of voluntary contraction (patients, 29 +/- 2%; controls, 34 +/- 4%). The duration and extent of inhibition did not differ significantly between groups at any stimulus strength. The pattern of change in duration and extent of inhibition with increasing stimulus intensity was no different in the two groups. The duration and extent of corticospinal inhibition in patients with CFS did not differ from controls, adding further evidence to the notion that the feeling of fatigue and the slowness of movement seen in CFS is not manifest in corticospinal output pathways.

 

Source: Zaman R, Puri BK, Main J, Nowicky AV, Davey NJ. Corticospinal inhibition appears normal in patients with chronic fatigue syndrome. Exp Physiol. 2001 Sep;86(5):547-50. http://www.ncbi.nlm.nih.gov/pubmed/11571481

 

IgE levels are the same in chronic fatigue syndrome (CFS) and control subjects when stratified by allergy skin test results and rhinitis types

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) has an uncertain pathogenesis. Allergies have been suggested as one cause.

OBJECTIVE: The aim of this study was to compare serum immunoglobulin (Ig)E in CFS and control subjects to determine whether IgE levels were elevated in CFS. This would be suggestive of increased atopy in CFS.

METHODS: IgE was measured by quantitative ELISA (sandwich) immunoassay in 95 CFS and 109 non-CFS control subjects. Subjects were classified by positive or negative allergy skin tests (AST) and rhinitis questionnaires (rhinitis score, RhSc) into four rhinitis types: nonallergic rhinitis (NAR with positive RhSc and negative AST); allergic rhinitis (AR with positive AST and RhSc); atopic/no rhinitis (AST positive/RhSc negative); and nonatopic/no rhinitis (both AST and RhSc negative) subjects.

RESULTS: IgE was not significantly different between control (128 +/- 18 IU/mL, mean +/- SEM) and CFS (133 +/- 43 IU/mL) groups, or between control and CFS groups classified into the four rhinitis types. IgE was significantly higher in subjects with positive AST whether or not they had positive RhSc or CFS symptoms.

CONCLUSIONS: Elevated IgE and positive AST indicate allergen sensitization, but are not necessarily indicators of symptomatic allergic diseases. There was no association between IgE levels and CFS, indicating that atopy was probably not more prevalent in CFS. Therefore, TH2-lymphocyte and IgE-mast cell mechanisms are unlikely causes of CFS.

 

Source: Repka-Ramirez MS, Naranch K, Park YJ, Velarde A, Clauw D, Baraniuk JN. IgE levels are the same in chronic fatigue syndrome (CFS) and control subjects when stratified by allergy skin test results and rhinitis types. Ann Allergy Asthma Immunol. 2001 Sep;87(3):218-21. http://www.ncbi.nlm.nih.gov/pubmed/11570618