Impaired sleep in chronic fatigue syndrome: how is it best measured?

Abstract:

The goal was to examine comparative efficacy of polysomnography, actigraphy, and self-report in evaluating the sleep/wake experience of individuals with chronic fatigue syndrome (CFS). Sleep parameters were evaluated by the three measurement modalities for the same night in 49 participants with CFS. Psychological and daytime functioning were measured by self-report. Results indicate that: (a) objectively measured nocturnal sleep time effectively approximated subjective experience although nocturnal wakefulness did not; (b) total sleep time and sleep efficiency differentiated individuals with and without insomnia complaints; (c) daytime sleepiness, fatigue, and non-refreshing sleep were not reflected by the objective sleep-related measures (polysomnography and actigraphy).

 

Source: Creti L, Libman E, Baltzan M, Rizzo D, Bailes S, Fichten CS. Impaired sleep in chronic fatigue syndrome: how is it best measured? J Health Psychol. 2010 May;15(4):596-607. Doi: 10.1177/1359105309355336. https://www.ncbi.nlm.nih.gov/pubmed/20460416

 

A retrospective review of the sleep characteristics in patients with chronic fatigue syndrome and fibromyalgia

Abstract:

This study characterizes findings on sleep testing and Human Leukocyte Antigen (HLA) markers in a group of patients with fibromyalgia (FM) and chronic fatigue syndrome (CFS). One hundred eighteen patients seen in a general neurology practice over 5 years meeting standard clinical criteria for FM or CFS were analyzed retrospectively. Cases of untreated sleep apnea or restless legs syndrome were excluded prior to inclusion in this study.

Ninety-two patients had multiple sleep latency testing (MSLT). Seventy-three (80%) were abnormal by standard criteria. Of 57 females having positive MSLTs, 22 (39%) had one or more periods of sleep onset rapid eye movement (SOREM), and 5 of 16 (31%) males with positive MSLTs had one or more SOREM. Highly fragmented sleep, as previously described in FM, was seen but not analyzed quantitatively. HLA DQB1*0602 was obtained in 74 patients, and positive in 32 (43%), P < 0.0001 compared with published values in 228 populations.

In our patients, who presented with neuromuscular fatigue or generalized pain, we found a sleep disorder characterized by objective hypersomnia. Some patients had characteristics of narcolepsy. Objective assessment by sleep studies can assist the diagnostic process, aid future research, and provide rationale for treatment.

 

Source: Spitzer AR, Broadman M. A retrospective review of the sleep characteristics in patients with chronic fatigue syndrome and fibromyalgia. Pain Pract. 2010 Jul-Aug;10(4):294-300. doi: 10.1111/j.1533-2500.2009.00352.x. Epub 2010 Mar 2. https://www.ncbi.nlm.nih.gov/pubmed/20230458

 

Classification of myalgic encephalomyelitis/chronic fatigue syndrome by types of fatigue

Abstract:

Persons with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) often complain of fatigue states (eg, postexertional malaise, brain fog) that are qualitatively different than normal, daily fatigue. Given the heterogeneous nature of ME/CFS, it is likely that individuals with this illness experience these fatigue types differently in terms of severity and frequency. It is also possible that meaningful subgroups of patients exist that exhibit different patterns of the fatigue experience. The purpose of this study was to investigate whether individuals with ME/CFS can be classified in a meaningful way according to the different types of fatigue they experience.

One hundred individuals with ME/CFS participated in the study. Individuals that met inclusion criteria were administered the Multiple Fatigue Types Questionnaire (MFTQ), a 5-factor instrument that distinguishes between different types of fatigue. A cluster analysis was used to classify patients into various clusters based on factor subscale scores. Using a 3-factor solution, individuals were classified according to illness severity (low, moderate, severe) across the different fatigue factors.

However, a 5-cluster solution enabled participants with moderate to severe fatigue levels to fall into more differentiated clusters and demonstrate distinct fatigue state patterns. These results suggest that fatigue patterns of individuals with ME/CFS are heterogeneous, and that patients may be classified into meaningful subgroups.

 

Source: Jason LA, Boulton A, Porter NS, Jessen T, Njoku MG, Friedberg F. Classification of myalgic encephalomyelitis/chronic fatigue syndrome by types of fatigue. Behav Med. 2010 Jan-Mar;36(1):24-31. Doi: 10.1080/08964280903521370. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4852700/ (Full article)

 

Women with chronic fatigue syndrome and sexual dysfunction: past, present, and future

Abstract:

Sexual dysfunction is a problem experienced by patients with chronic fatigue syndrome (CFS). Some studies indicate that CFS has a direct influence on sexual dysfunction, particularly hypoactive sexual desire. At this time, data on this subject are scarce, but the concept is emerging that CFS interferes with several aspects of the patients’ life, particularly sexuality. Further randomized controlled studies are needed to improve our knowledge of sexual dysfunction in CFS, to define the true impact of this condition on the patient’s sex life, and to improve the therapeutic management of this aspect of the disease.

 

Source: Blazquez A, Alegre J, Ruiz E. Women with chronic fatigue syndrome and sexual dysfunction: past, present, and future. J Sex Marital Ther. 2009;35(5):347-59. doi: 10.1080/00926230903065179. https://www.ncbi.nlm.nih.gov/pubmed/20183003

 

Cytokines across the night in chronic fatigue syndrome with and without fibromyalgia

Abstract:

The symptoms of chronic fatigue syndrome (CFS) are consistent with cytokine dysregulation. This has led to the hypothesis of immune dysregulation as the cause of this illness. To further test this hypothesis, we did repeated blood sampling for cytokines while patients and matched healthy controls slept in the sleep lab.

Because no one method for assaying cytokines is acknowledged to be better than another, we assayed for protein in serum, message in peripheral blood lymphocytes (PBLs), and function in resting and stimulated PBLs.

We found no evidence of proinflammatory cytokine upregulation. Instead, in line with some of our earlier studies, we did find some evidence to support a role for an increase in interleukin-10, an anti-inflammatory cytokine. Although the changes were small, they may contribute to the common complaint in CFS patients of disrupted sleep.

 

Source: Nakamura T, Schwander SK, Donnelly R, Ortega F, Togo F, Broderick G, Yamamoto Y, Cherniack NS, Rapoport D, Natelson BH. Cytokines across the night in chronic fatigue syndrome with and without fibromyalgia. Clin Vaccine Immunol. 2010 Apr;17(4):582-7. doi: 10.1128/CVI.00379-09. Epub 2010 Feb 24. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2849324/ (Full article)

 

Evidence for generalized hyperalgesia in chronic fatigue syndrome: a case control study

Abstract:

Several studies provided evidence for generalized hyperalgesia in fibromyalgia or whiplash-associated disorders. In chronic fatigue syndrome, however, pain is a frequently reported complaint, but up to now, evidence for generalized hyperalgesia is lacking.

The aim of this study is to examine whether the pressure pain thresholds (PPTs) at both symptomatic and asymptomatic sites differ in chronic fatigue syndrome (CFS) patients with chronic pain, compared to healthy controls.

Therefore, 30 CFS patients with chronic pain and 30 age- and gender-matched healthy controls indicated on a Margolis Pain Diagram where they felt pain lasting longer than 24 h in the past 4 weeks. After completing a test battery of questionnaires evaluating pain cognitions, functional status and symptomatology, a blinded researcher assessed PPTs bilaterally at seven nonspecific sites on both trunk and extremities. PPTs were compared for the two complete groups.

In addition, PPTs of patients and controls who did not report pain in a respective zone were compared. PPTs of the patients were significantly lower (p<0.001) compared to those of the control group, also when pain-free samples per zone were compared (p<0.001). The mean PPT was 3.30 kg/cm2 in all CFS patients and 8.09 kg/cm2 in the controls. No confounding factors responsible for the observed differences, as, e.g., catastrophizing and depression, could be revealed.

These findings provide evidence for the existence of hyperalgesia even in asymptomatic areas (generalized secondary hyperalgesia). The generalized hyperalgesia may represent the involvement of a sensitized central nervous system.

 

Source: Meeus M, Nijs J, Huybrechts S, Truijen S. Evidence for generalized hyperalgesia in chronic fatigue syndrome: a case control study. Clin Rheumatol. 2010 Apr;29(4):393-8. doi: 10.1007/s10067-009-1339-0. https://www.ncbi.nlm.nih.gov/pubmed/20077123

 

Sleep is not disrupted by exercise in patients with chronic fatigue syndromes

Abstract:

PURPOSE: Patients with chronic fatigue syndrome (CFS) report that exertion produces dramatic symptom worsening. We hypothesized this might be due to the exacerbation of an underlying sleep disorder, which we have previously demonstrated to exist.

METHODS: Female patients with CFS and matched healthy controls with no evidence of major depressive disorder were studied with overnight polysomnography on a baseline night and on a night after their performance of a maximal exercise test.

RESULTS: CFS patients as a group had evidence for disturbed sleep compared with controls. Although exercise improved sleep for healthy subjects, it did not do this for the group as a whole. When we stratified the sample on the basis of self-reported sleepiness after a night’s sleep, the patient group with reduced morning sleepiness showed improvement in sleep structure, whereas those with increased morning sleepiness continued to show evidence for sleep disruption.

CONCLUSIONS: Sleep is disturbed in CFS patients as a group, but exercise does not exacerbate this sleep disturbance. Approximately half the patients studied actually sleep better after exercise. Therefore, activity-related symptom worsening is not caused by worsened sleep.

 

Source: Togo F, Natelson BH, Cherniack NS, Klapholz M, Rapoport DM, Cook DB. Sleep is not disrupted by exercise in patients with chronic fatigue syndromes. Med Sci Sports Exerc. 2010 Jan;42(1):16-22. doi: 10.1249/MSS.0b013e3181b11bc7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2796587/ (Full article)

 

Sleep apnea and psychological functioning in chronic fatigue syndrome

Abstract:

Objectives were to explore: (1) whether sleep apnea/hypopnea syndrome (SAHS) should be considered a chronic fatigue syndrome (CFS) comorbidity, rather than a diagnostic exclusion criterion; and (2) to compare sleep/wake/ psychopathology in individuals with CFS, controls and another illness.

Participants (CFS, SAHS, controls) completed questionnaires and were evaluated for SAHS; 68 percent were subsequently diagnosed with SAHS. CFS participants with and without SAHS did not differ. Both clinical groups were less well adjusted than controls. We conclude that SAHS should not be an exclusion criterion for CFS and that psychological problems in CFS seem a consequence of coping with illness.

 

Source: Libman E, Creti L, Baltzan M, Rizzo D, Fichten CS, Bailes S. Sleep apnea and psychological functioning in chronic fatigue syndrome. J Health Psychol. 2009 Nov;14(8):1251-67. Doi: 10.1177/1359105309344895. https://www.ncbi.nlm.nih.gov/pubmed/19858344

 

Transcription profile analysis of vastus lateralis muscle from patients with chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a disabling condition characterized by unexplained chronic fatigue that impairs normal activities. Many body systems are affected and etiology has not yet been identified. In addition to immunological and psychological aspects, skeletal muscle symptoms are prominent in CFS patients.

In an effort to establish which pathways might be involved in the onset and development of muscle symptoms, we used global transcriptome analysis to identify genes that were differentially expressed in the vastus lateralis muscle of female and male CFS patients.

We found that the expression of genes that play key roles in mitochondrial function and oxidative balance, including superoxide dismutase 2, were altered, as were genes involved in energy production, muscular trophism and fiber phenotype determination. Importantly, the expression of a gene encoding a component of the nicotinic cholinergic receptor binding site was reduced, suggesting impaired neuromuscular transmission. We argue that these major biological processes could be involved in and/or responsible for the muscle symptoms of CFS.

Source: Pietrangelo T, Mancinelli R, Toniolo L, Montanari G, Vecchiet J, Fanò G, Fulle S. Transcription profile analysis of vastus lateralis muscle from patients with chronic fatigue syndrome. Int J Immunopathol Pharmacol. 2009 Jul-Sep;22(3):795-807. https://www.ncbi.nlm.nih.gov/pubmed/19822097

 

Electroencephalographic correlates of Chronic Fatigue Syndrome

Abstract:

BACKGROUND: Unremitting fatigue and unrefreshing sleep, hallmark traits of Chronic Fatigue Syndrome (CFS), are also pathognomonic of sleep disorders. Yet, no reproducible perturbations of sleep architecture, multiple sleep latency times or Epworth Sleepiness Scores are found to be associated consistently with CFS. This led us to hypothesize that sleep homeostasis, rather than sleep architecture, may be perturbed in CFS. To probe this hypothesis, we measured and compared EEG frequencies associated with restorative sleep between persons with CFS and matched controls, both derived from a population-based sample.

METHODS: We evaluated overnight polysomnography (PSG) in 35 CFS and 40 control subjects. PSG records were manually scored and epochs containing artifact removed. Fast Fourier Transformation was utilized to deconstruct individual EEG signals into primary frequency bands of alpha, delta, theta, sigma, and beta frequency domains. The spectral power of each frequency domain for each sleep state was compared between persons with CFS and matched controls.

RESULTS: In persons with CFS, delta power was diminished during slow wave sleep, but elevated during both stage 1 and REM. Alpha power was reduced during stage 2, slow wave, and REM sleep. Those with CFS also had significantly lower theta, sigma, and beta spectral power during stage 2, Slow Wave Sleep, and REM.

DISCUSSION: Employing quantitative EEG analysis we demonstrate reduced spectral power of cortical delta activity during SWS. We also establish reduced spectral power of cortical alpha activity, with the greatest reduction occurring during REM sleep. Reductions in theta, beta, and sigma spectral power were also apparent.

CONCLUSION: Unremitting fatigue and unrefreshing sleep, the waking manifestations of CFS, may be the consequence of impaired sleep homeostasis rather than a primary sleep disorder.

 

Source: Decker MJ, Tabassum H, Lin JM, Reeves WC. Electroencephalographic correlates of Chronic Fatigue Syndrome. Behav Brain Funct. 2009 Oct 6;5:43. doi: 10.1186/1744-9081-5-43. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2765956/ (Full article)