2010 – Page 11 – American ME and CFS Society

Abnormalities in pH handling by peripheral muscle and potential regulation by the autonomic nervous system in chronic fatigue syndrome

Abstract:

OBJECTIVES: To examine muscle acid handling following exercise in chronic fatigue syndrome (CFS/ME) and the relationship with autonomic dysfunction.

DESIGN: Observational study.

SETTING: Regional fatigue service. SUBJECTS & INTERVENTIONS: Chronic fatigue syndrome (n = 16) and age and sex matched normal controls (n = 8) underwent phosphorus magnetic resonance spectroscopy (MRS) to evaluate pH handling during exercise. Subjects performed plantar flexion at fixed 35% load maximum voluntary contraction. Heart rate variability was performed during 10 min supine rest using digital photophlethysmography as a measure of autonomic function.

RESULTS: Compared to normal controls, the CFS/ME group had significant suppression of proton efflux both immediately postexercise (CFS: 1.1 +/- 0.5 mmol L(-1) min(-1) vs. normal: 3.6 +/- 1.5 mmol L(-1) min(-1), P < 0.001) and maximally (CFS: 2.7 +/- 3.4 mmol L(-1) min(-1) vs. control: 3.8 +/- 1.6 mmol L(-1) min(-1), P < 0.05). Furthermore, the time taken to reach maximum proton efflux was significantly prolonged in patients (CFS: 25.6 +/- 36.1 s vs. normal: 3.8 +/- 5.2 s, P < 0.05). In controls the rate of maximum proton efflux showed a strong inverse correlation with nadir muscle pH following exercise (r(2) = 0.6; P < 0.01). In CFS patients, in contrast, this significant normal relationship was lost (r(2) = 0.003; P = ns). In normal individuals, the maximum proton efflux following exercise were closely correlated with total heart rate variability (r(2) = 0.7; P = 0.007) this relationship was lost in CFS/ME patients (r(2) < 0.001; P = ns).

CONCLUSION: Patients with CFS/ME have abnormalities in recovery of intramuscular pH following standardised exercise degree of which is related to autonomic dysfunction. This study identifies a novel biological abnormality in patients with CFS/ME which is potentially open to modification.

Source: Jones DE, Hollingsworth KG, Taylor R, Blamire AM, Newton JL. Abnormalities in pH handling by peripheral muscle and potential regulation by the autonomic nervous system in chronic fatigue syndrome. J Intern Med. 2010 Apr;267(4):394-401. doi: 10.1111/j.1365-2796.2009.02160.x. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2796.2009.02160.x/full (Full article)

Nurse led, home based self help treatment for patients in primary care with chronic fatigue syndrome: randomised controlled trial

Abstract:

OBJECTIVE: To evaluate the effectiveness of home delivered pragmatic rehabilitation-a programme of gradually increasing activity designed collaboratively by the patient and the therapist-and supportive listening-an approach based on non-directive counselling-for patients in primary care with chronic fatigue syndrome/myalgic encephalomyelitis or encephalitis (CFS/ME).

DESIGN: Single blind, randomised, controlled trial.

SETTING: 186 general practices across the north west of England between February 2005 and May 2007.

PARTICIPANTS: 296 patients aged 18 or over with CFS/ME (median illness duration seven years) diagnosed using the Oxford criteria.

INTERVENTIONS: Participants were randomly allocated to pragmatic rehabilitation, supportive listening, or general practitioner treatment as usual. Both therapies were delivered at home in 10 sessions over 18 weeks by one of three adult specialty general nurses who had received four months’ training, including supervised practice, in each of the interventions. GP treatment as usual was unconstrained except that patients were not to be referred for systematic psychological therapies during the treatment period. Main outcome measures The primary clinical outcomes were fatigue and physical functioning at the end of treatment (20 weeks) and 70 weeks from recruitment compared with GP treatment as usual. Lower fatigue scores and higher physical functioning scores denote better outcomes.

RESULTS: A total of 257 (87%) of the 296 patients who entered the trial were assessed at 70 weeks, the primary outcome point. Analysis was on an intention to treat basis, with robust treatment effects estimated after adjustment for missing data using probability weights. Immediately after treatment (at 20 weeks), patients allocated to pragmatic rehabilitation (n=95) had significantly improved fatigue (effect estimate -1.18, 95% confidence interval -2.18 to -0.18; P=0.021) but not physical functioning (-0.18, 95% CI -5.88 to +5.52; P=0.950) compared with patients allocated to treatment as usual (n=100). At one year after finishing treatment (70 weeks), there were no statistically significant differences in fatigue or physical functioning between patients allocated to pragmatic rehabilitation and those on treatment as usual (-1.00, 95% CI -2.10 to +0.11; P=0.076 and +2.57, 95% CI 3.90 to +9.03; P=0.435). At 20 weeks, patients allocated to supportive listening (n=101) had poorer physical functioning than those allocated to treatment as usual (-7.54, 95% CI -12.76 to -2.33; P=0.005) and no difference in fatigue. At 70 weeks, patients allocated to supportive listening did not differ significantly from those allocated to treatment as usual on either primary outcome.

CONCLUSIONS: For patients with CFS/ME in primary care, pragmatic rehabilitation delivered by trained nurse therapists improves fatigue in the short term compared with unconstrained GP treatment as usual, but the effect is small and not statistically significant at one year follow-up. Supportive listening delivered by trained nurse therapists is not an effective treatment for CFS/ME.

Trial registration International Standard Randomised Controlled Trial Number IRCTN74156610.

Comment in:

Pragmatic rehabilitation for chronic fatigue syndrome. [BMJ. 2010]

Nurse-delivered, home-based pragmatic rehabilitation has a short-term effect on improving fatigue in people with chronic fatigue syndrome compared with usual GP care, but effects were not sustained at 1 year. [Evid Based Nurs. 2010]

Source: Wearden AJ, Dowrick C, Chew-Graham C, Bentall RP, Morriss RK, Peters S, Riste L, Richardson G, Lovell K, Dunn G; Fatigue Intervention by Nurses Evaluation (FINE) trial writing group and the FINE trial group and 23 Collaborators. Nurse led, home based self help treatment for patients in primary care with chronic fatigue syndrome: randomised controlled trial. BMJ. 2010 Apr 23;340:c1777. doi: 10.1136/bmj.c1777. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2859122/ (Full article)

Fibromyalgia and related conditions: electromyogram profile during isometric muscle contraction

Abstract:

OBJECTIVES: To evaluate electromyogram (EMG) profiles in patients with three related conditions: fibromyalgia, chronic fatigue syndrome, and depression.

METHODS: We studied 44 healthy volunteers, 22 patients with fibromyalgia, 11 patients with chronic fatigue syndrome, and 10 patients admitted for depression. The trapezius electromyogram was recorded during maximally sustained, bilateral, 90 degrees abduction of the shoulders. EMG signal frequency and amplitude were measured throughout the test.

RESULTS: In the fibromyalgia group, isometric contraction duration was significantly shorter than in the other two patient groups (P<0.001) and the EMG frequency and amplitude pattern indicated premature discontinuation of the muscle contraction. Findings in the chronic fatigue patients were similar to those in the healthy controls. The patients with depression had a distinctive EMG profile characterized by excessive initial motor-unit recruitment with a shift in the frequency spectrum.

CONCLUSIONS: Fibromyalgia was associated with a specific EMG pattern indicating premature discontinuation of the muscle contraction. Therefore, maximal voluntary muscle contraction tests may be of limited value for assessing function in fibromyalgia patients. Chronic fatigue syndrome patients had similar EMG findings to those in the healthy controls. The EMG alterations in the patients with depression were consistent with manifestations of psychomotor retardation.

Source: Maquet D, Croisier JL, Dupont C, Moutschen M, Ansseau M, Zeevaert B, Crielaard JM. Fibromyalgia and related conditions: electromyogram profile during isometric muscle contraction. Joint Bone Spine. 2010 May;77(3):264-7. doi: 10.1016/j.jbspin.2010.02.003. Epub 2010 Apr 22. https://www.ncbi.nlm.nih.gov/pubmed/20417143

Pain inhibition and postexertional malaise in myalgic encephalomyelitis/chronic fatigue syndrome: an experimental study

Abstract:

OBJECTIVES: To examine the efficacy of the pain inhibitory systems in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) during two different types of exercise and to examine whether the (mal)functioning of pain inhibitory systems is associated with symptom increases following exercise.

DESIGN: A controlled experimental study.

SETTING AND SUBJECTS: Twenty-two women with ME/CFS and 22 healthy sedentary controls were studied at the Department of Human Physiology, Vrije Universiteit Brussel.

INTERVENTIONS: All subjects performed a submaximal exercise test and a self-paced, physiologically limited exercise test on a cycle ergometer. The exercise tests were undertaken with continuous cardiorespiratory monitoring. Before and after the exercise bouts, subjects filled out questionnaires to assess health status, and underwent pressure pain threshold measurements. Throughout the study, subjects’ activity levels were assessed using accelerometry.

RESULTS: In patients with ME/CFS, pain thresholds decreased following both types of exercise, whereas they increased in healthy subjects. This was accompanied by a worsening of the ME/CFS symptom complex post-exercise. Decreased pressure thresholds during submaximal exercise were associated with postexertional fatigue in the ME/CFS group (r = 0.454; P = 0.034).

CONCLUSIONS:These observations indicate the presence of abnormal central pain processing during exercise in patients with ME/CFS and demonstrate that both submaximal exercise and self-paced, physiologically limited exercise trigger postexertional malaise in these patients. Further study is required to identify specific modes and intensity of exercise that can be performed in people with ME/CFS without exacerbating symptoms.

Comment in: Chronic fatigue syndrome reflects loss of adaptability. [J Intern Med. 2010]

Source: Van Oosterwijck J, Nijs J, Meeus M, Lefever I, Huybrechts L, Lambrecht L, Paul L. Pain inhibition and postexertional malaise in myalgic encephalomyelitis/chronic fatigue syndrome: an experimental study. J Intern Med. 2010 Sep;268(3):265-78. doi: 10.1111/j.1365-2796.2010.02228.x. Epub 2010 Mar 3. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2796.2010.02228.x/full (Full article)

Effects of exercise on behavior and peripheral blood lymphocyte apoptosis in a rat model of chronic fatigue syndrome

Abstract:

This study examined the effects of exercise on behavior and peripheral blood leukocyte apoptosis in a rat model of chronic fatigue syndrome (CFS).

Thirty-six healthy male Sprague-Dawley rats were equally randomized into 3 groups: the control group, CFS model group and the exercise group in terms of body weight. A total of 25 rats entered the final statistical analysis due to 11 deaths during the study. CFS model was established by subjecting the rats in CFS model group and exercise group to electric shock, chronic restraint stress and cold water swim. Besides, rats in the exercise group took running wheel exercise.

After a week of conditioning feeding, model construction and running wheel exercise were performed simultaneously, and lasted for 23 consecutive days. The behavior experiments, including running wheel exercise, open-field test, tail suspension test and Morris water maze test, were conducted, either before or after the model establishment. Rats were sacrificed and peripheral blood was obtained for the assessment of lymphocyte apoptosis index by flow cytometry (FCM).

It was found that as compared with those in the control group, the weight of the rats was decreased obviously (P<0.01), the mobility time in the open-field and the tail suspension tests was shortened significantly (P<0.01), the time to locate the platform was enhanced (P<0.01) and the cell apoptosis index was increased substantially (P<0.01) in the CSF model group.

Meanwhile, in comparison to the model group, the behavior in the open-field and the tail suspension tests was improved significantly (P<0.05), and the apoptosis index decreased remarkably (P<0.01) in the exercise group. It is concluded that sport intervention can prevent lymphocyte apoptosis and improve animal behavior rather than the memory.

Source: Zou J, Yuan J, Lv S, Tu J. Effects of exercise on behavior and peripheral blood lymphocyte apoptosis in a rat model of chronic fatigue syndrome. J Huazhong Univ Sci Technolog Med Sci. 2010 Apr;30(2):258-64. doi: 10.1007/s11596-010-0225-y. Epub 2010 Apr 21. https://www.ncbi.nlm.nih.gov/pubmed/20407885

U.S. healthcare providers’ knowledge, attitudes, beliefs, and perceptions concerning Chronic Fatigue Syndrome

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) is a debilitating illness with particular difficulties for healthcare providers because there are no diagnostic signs or laboratory tests and because management aims to merely improve symptoms. Further complicating management, healthcare providers’ awareness concerning CFS has not been rigorously assessed. The present study aimed to ascertain United States (U.S.) healthcare providers’ awareness of CFS and to assess their knowledge, attitudes, and beliefs (KAB) related to diagnosis and management of the illness. This information forms the foundation for developing CFS educational strategies.

METHODS: We combined convenience and probability samples to measure CFS KAB among healthcare providers. In the convenience sample, 1,255 healthcare providers (81% response rate) from 13 professional conferences completed a 12-item form. Descriptive statistics were reported for 9 KAB item responses and chi-square tests were performed for examining their association with giving a diagnosis of CFS. We used principal component analysis to construct multidimensional subscales and perform a general linear model to examine factors associated with subscales. The probability sample involved data on 15 CFS-specific questions from 2006 and 2007 DocStyles web-based panel surveys collected from 2,750 physicians (average response rate 55%). We calculated descriptive and chi-square statistics. The significance was set at two-tailed with the alpha level of 0.05.

RESULTS: Healthcare providers in both samples were aware of CFS and exhibited a high level of knowledge. Overall, 96% of respondents in the DocStyles (probability) sample had heard about CFS. Healthcare providers in the conference (convenience) sample demonstrated good KAB scores; physicians’ scores were highest on KAB scales and lowest in perception. Nurses’ scores were lowest in knowledge. More than 40% of physicians reported ever giving a CFS diagnosis and in the DocStyles (probability) sample more than 80% of physicians correctly identified CFS symptoms. Physicians reported professional journals, the Internet, and continuing education programs as the top 3 sources from which they obtain CFS information.

CONCLUSIONS: Findings from these combined samples fill a gap in the evidence-base of U.S. healthcare providers’ and knowledge, attitudes, and beliefs concerning CFS. Importantly, respondents in both samples expressed similar knowledge, attitudes, beliefs and perceptions. Awareness was high and negative attitudes were low. The primary areas for future education should address diagnosis and management of CFS and should be delivered through those venues providers indicated they primarily use. Data from this study provide a benchmark for evaluation the success of these future efforts.

Source: Brimmer DJ, Fridinger F, Lin JM, Reeves WC. U.S. healthcare providers’ knowledge, attitudes, beliefs, and perceptions concerning Chronic Fatigue Syndrome. BMC Fam Pract. 2010 Apr 21;11:28. doi: 10.1186/1471-2296-11-28. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2875206/ (Full article)

The central role of cognitive processes in the perpetuation of chronic fatigue syndrome

Abstract:

OBJECTIVE: Chronic fatigue syndrome (CFS) is considered to be one of the functional somatic syndromes (FSS). Cognitions and behavior are thought to perpetuate the symptoms of CFS. Behavioral interventions based on the existing models of perpetuating factors are quite successful in reducing fatigue and disabilities. The evidence is reviewed that cognitive processes, particularly those that determine the perception of fatigue and its effect on behavior, play a central role in the maintenance of symptoms.

METHOD: Narrative review.

RESULTS: Findings from treatment studies suggest that cognitive factors mediate the positive effect of behavioral interventions on fatigue. Increased fitness or increased physical activity does not seem to mediate the treatment response. Additional evidence for the role of cognitive processes is found in studies comparing the subjective beliefs patients have of their functioning with their actual performance and in neurobiological research.

CONCLUSION: Three different cognitive processes may play a role in the perpetuation of CFS symptoms. The first is a general cognitive representation in which fatigue is perceived as something negative and aversive and CFS is seen as an illness that is difficult to influence. The second process involved is the focusing on fatigue. The third element is formed by specific dysfunctional beliefs about activity and fatigue.

Source: Knoop H, Prins JB, Moss-Morris R, Bleijenberg G. The central role of cognitive processes in the perpetuation of chronic fatigue syndrome. J Psychosom Res. 2010 May;68(5):489-94. doi: 10.1016/j.jpsychores.2010.01.022. Epub 2010 Mar 16. https://www.ncbi.nlm.nih.gov/pubmed/20403509

Chronic fatigue syndrome: Is it one discrete syndrome or many? Implications for the “one vs. many” functional somatic syndromes debate

Abstract:

There is a current debate as to whether “functional somatic syndromes” (FSSs) are more similar to or different from each other. While at the same time, there is evidence of heterogeneity within single syndromes. So, it could be that these syndromes are all part of one big process/illness, are discrete in their own right, or that they are heterogeneous collections of different illnesses lumped together by common symptoms but separated by uncommon pathophysiologies. The example of chronic fatigue syndrome (CFS) is instructive. There is evidence to support all three models of understanding. Three recent large studies have suggested that FSSs are both similar and dissimilar at the same time. The solution to the debate is that we need to both “lump” and “split.” We need to study both the similarities between syndromes and their dissimilarities to better understand what we currently call the FSSs.

Source: White PD. Chronic fatigue syndrome: Is it one discrete syndrome or many? Implications for the “one vs. many” functional somatic syndromes debate. J Psychosom Res. 2010 May;68(5):455-9. doi: 10.1016/j.jpsychores.2010.01.008. Epub 2010 Mar 17. https://www.ncbi.nlm.nih.gov/pubmed/20403504

One single diagnosis, bodily distress syndrome, succeeded to capture 10 diagnostic categories of functional somatic syndromes and somatoform disorders

Abstract:

BACKGROUND: In order to clarify the classification of physical complaints not attributable to verifiable, conventionally defined diseases, a new diagnosis of bodily distress syndrome was introduced. The aim of this study was to test if patients diagnosed with one of six different functional somatic syndromes or a DSM-IV somatoform disorder characterized by physical symptoms were captured by the new diagnosis.

METHOD: A stratified sample of 978 consecutive patients from neurological (n=120) and medical (n=157) departments and from primary care (n=701) was examined applying post-hoc diagnoses based on the Schedules for Clinical Assessment in Neuropsychiatry diagnostic instrument. Diagnoses were assigned only to clinically relevant cases, i.e., patients with impairing illness.

RESULTS: Bodily distress syndrome included all patients with fibromyalgia (n=58); chronic fatigue syndrome (n=54) and hyperventilation syndrome (n=49); 98% of those with irritable bowel syndrome (n=43); and at least 90% of patients with noncardiac chest pain (n=129), pain syndrome (n=130), or any somatoform disorder (n=178). The overall agreement of bodily distress syndrome with any of these diagnostic categories was 95% (95% CI 93.1-96.0; kappa 0.86, P<.0001). Symptom profiles of bodily distress syndrome organ subtypes were similar to those of the corresponding functional somatic syndromes with diagnostic agreement ranging from 90% to 95%.

CONCLUSION: Bodily distress syndrome seem to cover most of the relevant “somatoform” or “functional” syndromes presenting with physical symptoms, not explained by well-recognized medical illness, thereby offering a common ground for the understanding of functional somatic symptoms. This may help unifying research efforts across medical disciplines and facilitate delivery of evidence-based care.

Source: Fink P, Schröder A. One single diagnosis, bodily distress syndrome, succeeded to capture 10 diagnostic categories of functional somatic syndromes and somatoform disorders. J Psychosom Res. 2010 May;68(5):415-26. doi: 10.1016/j.jpsychores.2010.02.004. https://www.ncbi.nlm.nih.gov/pubmed/20403500

Sex differences in plasma prolactin response to tryptophan in chronic fatigue syndromepatients with and without comorbid fibromyalgia

Abstract:

BACKGROUND: Some think chronic fatigue syndrome (CFS) and fibromyalgia (FM) are variants of the same illness process. This would imply that CFS patients with and without comorbid FM have similar biological underpinnings. To test this, we compared serotonergic-based responses, plasma prolactin (PRL), and self-reported measures of fatigue to intravenous infusion of tryptophan among patients with CFS alone, CFS + FM, and healthy controls.

METHODS: Men and women with CFS alone or CFS + FM and healthy subjects, none with current major depressive disorder (MDD), were given 120 mg of L-tryptophan per kg lean body mass intravenously (i.v.). Before and after tryptophan infusion, blood samples were collected, and plasma PRL, tryptophan, and kynurenine concentrations were determined.

RESULTS: Women with CFS alone, but not CFS + FM, showed upregulated plasma PRL responses compared with controls. There were no differences among groups of men. Plasma tryptophan and kynurenine concentrations did not differ among groups.

CONCLUSIONS: These results indicate that women with CFS alone have upregulated serotonergic tone that is not seen in those with comorbid FM. The lack of effect in men suggests a mechanism that might explain, in part, the increased prevalence of CFS in women. The data support the interpretation that CFS in women is a different illness from FM.

Source: Weaver SA, Janal MN, Aktan N, Ottenweller JE, Natelson BH. Sex differences in plasma prolactin response to tryptophan in chronic fatigue syndrome patients with and without comorbid fibromyalgia. J Womens Health (Larchmt). 2010 May;19(5):951-8. doi: 10.1089/jwh.2009.1697. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2875960/ (Full article)