Slow wave sleep in the chronically fatigued: Power spectra distribution patterns in chronic fatigue syndrome and primary insomnia

Abstract:

OBJECTIVES: To investigate slow wave sleep (SWS) spectral power proportions in distinct clinical conditions sharing non-restorative sleep and fatigue complaints without excessive daytime sleepiness (EDS), namely the chronic fatigue syndrome (CFS) and primary insomnia (PI). Impaired sleep homeostasis has been suspected in both CFS and PI.

METHODS: We compared perceived sleep quality, fatigue and sleepiness symptom-intensities, polysomnography (PSG) and SWS spectral power distributions of drug-free CFS and PI patients without comorbid sleep or mental disorders, with a good sleeper control group.

RESULTS: Higher fatigue without EDS and impaired perceived sleep quality were confirmed in both patient groups. PSG mainly differed in sleep fragmentation and SWS durations. Spectral analysis revealed a similar decrease in central ultra slow power (0.3-0.79Hz) proportion during SWS for both CFS and PI and an increase in frontal power proportions of faster frequencies during SWS in PI only. The latter was correlated to affective symptoms whereas lower central ultra slow power proportions were related to fatigue severity and sleep quality impairment.

CONCLUSIONS: In combination with normal (PI) or even increased SWS durations (CFS), we found consistent evidence for lower proportions of slow oscillations during SWS in PI and CFS.

SIGNIFICANCE: Observing normal or increased SWS durations but lower proportions of ultra slow power, our findings suggest a possible quantitative compensation of altered homeostatic regulation.

Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

 

Source: Neu D, Mairesse O, Verbanck P, Le Bon O. Slow wave sleep in the chronically fatigued: Power spectra distribution patterns in chronic fatigue syndrome and primary insomnia. Clin Neurophysiol. 2015 Oct;126(10):1926-33. doi: 10.1016/j.clinph.2014.12.016. Epub 2015 Jan 10. https://www.ncbi.nlm.nih.gov/pubmed/25620040

 

Are stamina and fatigue polar opposites? A case study

Abstract:

Most individuals with Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS) (Carruthers et al., 2003 ), Myalgic Encephalomyelitis (ME) (Carruthers et al., 2011 ), and chronic fatigue syndrome (CFS) (Fukuda et al., 1994 ) indicate that they experience fatigue and sharp decreases in energy levels, which hinder the ability to engage in physical activities (Friedberg & Jason, 1998 ). However, there are some individuals who reduce activity engagement in order to avoid a worsening of symptoms; thus these individuals may endorse lower levels of fatigue.

Accordingly, those with low levels of fatigue but low endurance/stamina might be inadvertently excluded from some criteria based on the fatigue requirement. The current study serves as an exploration of the relationship between fatigue and stamina and the effects of these constructs on illness symptomology and their implications for assessment and diagnosis.

 

Source: So S, Evans M, Jason LA, Brown A. Are stamina and fatigue polar opposites? A case study. J Prev Interv Community. 2015;43(1):32-41. doi: 10.1080/10852352.2014.973235. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4295717/ (Full article)

 

Problems in defining post-exertional malaise

Abstract:

Post-exertional malaise (PEM) is a cardinal symptom of the illnesses referred to as Myalgic Encephalomyelitis (ME), Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS), and chronic fatigue syndrome (CFS). PEM is reported to occur in many of these patients, and with several criteria (e.g., ME and ME/CFS), this symptom is mandatory (Carruthers et al., 2003 , 2011 ).

In the present study, 32 participants diagnosed with CFS (Fukuda et al., 1994 ) were examined on their responses to self-report items that were developed to capture the characteristics and patterns of PEM. As shown in the results, the slight differences in wording for various items may affect whether one is determined to have PEM according to currently used self-report criteria to assess CFS. Better understanding of how this symptom is assessed might help improve the diagnostic reliability and validity of ME, ME/CFS, and CFS.

 

Source: Jason LA, Evans M, So S, Scott J, Brown A. Problems in defining post-exertional malaise. J Prev Interv Community. 2015;43(1):20-31. doi: 10.1080/10852352.2014.973239. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4295644/ (Full article)

 

The association between daytime napping and cognitive functioning in chronic fatigue syndrome

Abstract:

OBJECTIVES: The precise relationship between sleep and physical and mental functioning in chronic fatigue syndrome (CFS) has not been examined directly, nor has the impact of daytime napping. This study aimed to examine self-reported sleep in patients with CFS and explore whether sleep quality and daytime napping, specific patient characteristics (gender, illness length) and levels of anxiety and depression, predicted daytime fatigue severity, levels of daytime sleepiness and cognitive functioning, all key dimensions of the illness experience.

METHODS: 118 adults meeting the 1994 CDC case criteria for CFS completed a standardised sleep diary over 14 days. Momentary functional assessments of fatigue, sleepiness, cognition and mood were completed by patients as part of usual care. Levels of daytime functioning and disability were quantified using symptom assessment tools, measuring fatigue (Chalder Fatigue Scale), sleepiness (Epworth Sleepiness Scale), cognitive functioning (Trail Making Test, Cognitive Failures Questionnaire), and mood (Hospital Anxiety and Depression Scale).

RESULTS: Hierarchical Regressions demonstrated that a shorter time since diagnosis, higher depression and longer wake time after sleep onset predicted 23.4% of the variance in fatigue severity (p <.001). Being male, higher depression and more afternoon naps predicted 25.6% of the variance in objective cognitive dysfunction (p <.001). Higher anxiety and depression and morning napping predicted 32.2% of the variance in subjective cognitive dysfunction (p <.001). When patients were classified into groups of mild and moderate sleepiness, those with longer daytime naps, those who mainly napped in the afternoon, and those with higher levels of anxiety, were more likely to be in the moderately sleepy group.

CONCLUSIONS: Napping, particularly in the afternoon is associated with poorer cognitive functioning and more daytime sleepiness in CFS. These findings have clinical implications for symptom management strategies.

 

Source: Gotts ZM, Ellis JG, Deary V, Barclay N, Newton JL. The association between daytime napping and cognitive functioning in chronic fatigue syndrome. PLoS One. 2015 Jan 9;10(1):e0117136. doi: 10.1371/journal.pone.0117136. ECollection 2015. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4289075/ (Full article)

 

The impact of symptom stability on time frame and recall reliability in CFS

Abstract:

OBJECTIVE: This study is an investigation of the potential impact of perceived symptom stability on the recall reliability of symptom severity and frequency as reported by individuals with chronic fatigue syndrome (CFS). Symptoms were recalled using three different recall timeframes (the past week, the past month, and the past six months) and at two assessment points (with one week in between each assessment).

METHODS: Participants were 51 adults (45 women and 6 men), between the ages of 29 and 66 with a current diagnosis of CFS. Multilevel Model (MLM) Analyses were used to determine the optimal recall timeframe (in terms of test-retest reliability) for reporting symptoms perceived as variable and as stable over time.

RESULTS: Headaches were recalled more reliably when they were reported as stable over time. Furthermore, the optimal timeframe in terms of test-retest reliability for stable symptoms was highly uniform, such that all Fukuda CFS symptoms were more reliably recalled at the six month timeframe. Furthermore, the optimal timeframe for CFS symptoms perceived as variable, differed across symptoms.

DISCUSSION: Symptom stability and recall timeframe are important to consider in order to improve the accuracy and reliability of the current methods for diagnosing this illness.

 

Source: Evans M, Jason LA. The impact of symptom stability on time frame and recall reliability in CFS. Cogent Psychol. 2015;2(1). pii: 1079945. Epub 2015 Aug 28. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4831646/ (Full article)

 

Evidence for the existence of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) with and without abdominal discomfort (irritable bowel) syndrome

Abstract:

BACKGROUND: There is evidence that Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is accompanied by gastro-intestinal symptoms; and IgA and IgM responses directed against lipopolysaccharides (LPS) of commensal bacteria, indicating bacterial translocation.

METHODS: This study was carried out to examine gastro-intestinal symptoms in subjects with ME/CFS versus those with chronic fatigue (CF). The two groups were dissected by dichotomizing those fulfilling and not fulfilling Fukuda’s critera. In these groups, we examined the association between gastro-intestinal symptoms and the IgA and IgM responses directed against commensal bacteria.

RESULTS: Using cluster analysis performed on gastro-intestinal symptoms we delineated that the cluster analysis-generated diagnosis of abdominal discomfort syndrome (ADS) was significantly higher in subjects with ME/CFS (59.6%) than in those with CF (17.7%). The diagnosis of ADS was strongly associated with the diagnosis of irritable bowel syndrome (IBS). There is evidence that ME/CFS consists of two subgroups, i.e. ME/CFS with and without ADS. Factor analysis showed four factors, i.e. 1) inflammation-hyperalgesia; 2) fatigue-malaise; 3) gastro-intestinal symptoms/ADS; and 4) neurocognitive symptoms. The IgA and IgM responses to LPS of commensal bacteria were significantly higher in ME/CFS patients with ADS than in those without ADS.

CONCLUSIONS: The findings show that ADS is a characteristic of a subset of patients with ME/CFS and that increased bacterial translocation (leaky gut) is associated with ADS symptoms. This study has defined a pathway phenotype, i.e bacterial translocation, that is related to ME/CFS and ADS/IBS and that may drive systemic inflammatory processes.

 

Source: Maes M, Leunis JC, Geffard M, Berk M. Evidence for the existence of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) with and without abdominal discomfort (irritable bowel) syndrome. Neuro Endocrinol Lett. 2014;35(6):445-53. https://www.ncbi.nlm.nih.gov/pubmed/25433843

 

Non-REM sleep EEG power distribution in fatigue and sleepiness

Abstract:

OBJECTIVES: The aim of this study is to contribute to the sleep-related differentiation between daytime fatigue and sleepiness.

METHODS: 135 subjects presenting with sleep apnea-hypopnea syndrome (SAHS, n=58) or chronic fatigue syndrome (CFS, n=52) with respective sleepiness or fatigue complaints and a control group (n=25) underwent polysomnography and psychometric assessments for fatigue, sleepiness, affective symptoms and perceived sleep quality. Sleep EEG spectral analysis for ultra slow, delta, theta, alpha, sigma and beta power bands was performed on frontal, central and occipital derivations.

RESULTS: Patient groups presented with impaired subjective sleep quality and higher affective symptom intensity. CFS patients presented with highest fatigue and SAHS patients with highest sleepiness levels. All groups showed similar total sleep time. Subject groups mainly differed in sleep efficiency, wake after sleep onset, duration of light sleep (N1, N2) and slow wave sleep, as well as in sleep fragmentation and respiratory disturbance. Relative non-REM sleep power spectra distributions suggest a pattern of power exchange in higher frequency bands at the expense of central ultra slow power in CFS patients during all non-REM stages. In SAHS patients, however, we found an opposite pattern at occipital sites during N1 and N2.

CONCLUSIONS: Slow wave activity presents as a crossroad of fatigue and sleepiness with, however, different spectral power band distributions during non-REM sleep. The homeostatic function of sleep might be compromised in CFS patients and could explain why, in contrast to sleepiness, fatigue does not resolve with sleep in these patients. The present findings thus contribute to the differentiation of both phenomena.

Copyright © 2014 Elsevier Inc. All rights reserved.

 

Source: Neu D, Mairesse O, Verbanck P, Linkowski P, Le Bon O. Non-REM sleep EEG power distribution in fatigue and sleepiness. J Psychosom Res. 2014 Apr;76(4):286-91. doi: 10.1016/j.jpsychores.2014.02.002. Epub 2014 Feb 17. https://www.ncbi.nlm.nih.gov/pubmed/24630178

 

Endogenous pain modulation in response to exercise in patients with rheumatoid arthritis, patients with chronic fatigue syndrome and comorbid fibromyalgia, and healthy controls: a double-blind randomized controlled trial

Abstract:

OBJECTIVE: Temporal summation (TS) of pain, conditioned pain modulation (CPM), and exercise-induced analgesia (EIA) are often investigated in chronic pain populations as an indicator for enhanced pain facilitation and impaired endogenous pain inhibition, respectively, but interactions are not yet clear both in healthy controls and in chronic pain patients. Therefore, the present double-blind randomized placebo-controlled study evaluates pains cores, TS, and CPM in response to exercise in healthy controls, patients with chronic fatigue syndrome and comorbid fibromyalgia (CFS/FM), and patients with rheumatoid arthritis (RA), both under placebo and paracetamol condition.

METHODS: Fifty-three female volunteers – of which 19 patients with CFS/FM, 16 patients with RA, and 18 healthy controls – underwent a submaximal exercise test on a bicycle ergometer on 2 different occasions (paracetamol vs. placebo), with an interval of 7 days. Before and after exercise, participants rated pain intensity during TS and CPM.

RESULTS: Patients with rheumatoid arthritis showed decreased TS after exercise, both after paracetamol and placebo (P < 0.05). In patients with CFS/FM, results were less univocal. A nonsignificant decrease in TS was only observed after taking paracetamol. CPM responses to exercise are inconclusive, but seem to worsen after exercise. No adverse effects were seen.

CONCLUSION: This study evaluates pain scores, TS, and CPM in response to submaximal exercise in 2 different chronic pain populations and healthy controls. In patients with RA, exercise had positive effects on TS, suggesting normal EIA. In patients with CFS/FM, these positive effects were only observed after paracetamol and results were inconsistent.

TRIAL REGISTRATION: ClinicalTrials.gov NCT01154647.

 

Source: Meeus M, Hermans L, Ickmans K, Struyf F, Van Cauwenbergh D, Bronckaerts L, De Clerck LS, Moorken G, Hans G, Grosemans S, Nijs J. Endogenous pain modulation in response to exercise in patients with rheumatoid arthritis, patients with chronic fatigue syndrome and comorbid fibromyalgia, and healthy controls: a double-blind randomized controlled trial. Pain Pract. 2015 Feb;15(2):98-106. doi: 10.1111/papr.12181. Epub 2014 Feb 17. https://www.ncbi.nlm.nih.gov/pubmed/24528544

 

The effects of exercise on dynamic sleep morphology in healthy controls and patients with chronic fatigue syndrome

Abstract:

Effects of exercise on dynamic aspects of sleep have not been studied. We hypothesized exercise altered dynamic sleep morphology differently for healthy controls relative to chronic fatigue syndrome (CFS) patients. Sixteen controls (38 ± 9 years) and 17 CFS patients (41 ± 8 years) underwent polysomnography on baseline nights and nights after maximal exercise testing. We calculated transition probabilities and rates (as a measure of relative and temporal transition frequency, respectively) between sleep stages and cumulative duration distributions (as a measure of continuity) of each sleep stage and sleep as a whole.

After exercise, controls showed a significantly greater probability of transition from N1 to N2 and a lower rate of transition from N1 to wake than at baseline; CFS showed a significantly greater probability of transition from N2 to N3 and a lower rate of transition from N2 to N1. These findings suggest improved quality of sleep after exercise. After exercise, controls had improved sleep continuity, whereas CFS had less continuous N1 and more continuous rapid eye movement (REM) sleep. However, CFS had a significantly greater probability and rate of transition from REM to wake than controls. Probability of transition from REM to wake correlated significantly with increases in subjective fatigue, pain, and sleepiness overnight in CFS – suggesting these transitions may relate to patient complaints of unrefreshing sleep.

Thus, exercise promoted transitions to deeper sleep stages and inhibited transitions to lighter sleep stages for controls and CFS, but CFS also reported increased fatigue and continued to have REM sleep disruption. This dissociation suggests possible mechanistic pathways for the underlying pathology of CFS.

 

Source: Kishi A, Togo F, Cook DB, Klapholz M, Yamamoto Y, Rapoport DM, Natelson BH. The effects of exercise on dynamic sleep morphology in healthy controls and patients with chronic fatigue syndrome. Physiol Rep. 2013 Nov;1(6):e00152. doi: 10.1002/phy2.152. Epub 2013 Nov 13. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3871467/ (Full article)

 

Validating a measure of myalgic encephalomyelitis/chronic fatigue syndrome symptomatology

Abstract:

OBJECTIVES: The present study sought to validate a comprehensive self-report measure of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) symptomatology to aid in clinical and research assessment.

METHOD: Exploratory factor analysis (EFA) was used to establish the underlying factor structure of the DePaul Symptom Questionnaire (DSQ) (Jason, Evans, et al., 2010) using a well-characterized sample of individuals (92.6% met the Fukuda et al. criteria (1994) and/or the Clinical Canadian Criteria (Carruthers et al., 2003)), and this structure was then tested on a less stringently recruited sample of individuals utilizing a confirmatory factor analysis (CFA). Convergent and discriminant validity of the DSQ were also examined utilizing alternative measures of symptomatology and functioning.

RESULTS: A 3-factor solution was found using EFA (Neuroendocrine, Autonomic & Immune Dysfunction; Neurological/Cognitive Dysfunction; Post-Exertional Malaise) and the fit of this factor structure was adequate for the second sample.

DISCUSSION: The DSQ is a valid measure of ME/CFS symptomatology. The emergent factors were consistent with previous literature on symptom clusters, and convergent and discriminant validity were established.

 

Source: Brown AA, Jason LA. Validating a measure of myalgic encephalomyelitis/chronic fatigue syndrome symptomatology. Fatigue. 2014;2(3):132-152. Epub 2014 Jul 23. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4871625/ (Full article)