Category: Symptoms

Parasympathetic activity is reduced during slow-wave sleep, but not resting wakefulness, in patients with chronic fatigue syndrome

Abstract:

STUDY OBJECTIVES: Physiological dearousal characterized by an increase in parasympathetic nervous system activity is important for good-quality sleep. Previous research shows that nocturnal parasympathetic activity (reflected by heart rate variability [HRV]) is diminished in individuals with chronic fatigue syndrome (CFS), suggesting hypervigilant sleep. This study investigated differences in nocturnal autonomic activity across sleep stages and explored the association of parasympathetic activity with sleep quality and self-reported physical and psychological wellbeing in individuals with CFS.

METHODS: Twenty-four patients with medically diagnosed CFS, and 24 matched healthy control individuals participated. Electroencephalography and HRV were recorded during sleep in participants’ homes using a minimally invasive ambulatory device. Questionnaires were used to measure self-reported wellbeing and sleep quality.

RESULTS: Sleep architecture in patients with CFS differed from that of control participants in slower sleep onset, more awakenings, and a larger proportion of time spent in slow-wave sleep (SWS). Linear mixed-model analyses controlling for age revealed that HRV reflecting parasympathetic activity (normalized high frequency power) was reduced in patients with CFS compared to control participants, particularly during deeper stages of sleep. Poorer self-reported wellbeing and sleep quality was associated with reduced parasympathetic signaling during deeper sleep, but not during wake before sleep, rapid eye movement sleep, or with the proportion of time spent in SWS.

CONCLUSIONS: Autonomic hypervigilance during the deeper, recuperative stages of sleep is associated with poor quality sleep and self-reported wellbeing. Causal links need to be confirmed but provide potential intervention opportunities for the core symptom of unrefreshing sleep in CFS.

© 2020 American Academy of Sleep Medicine.

Source: Fatt SJ, Beilharz JE, Joubert M, Wilson C, Lloyd AR, Vollmer-Conna U, Cvejic E. Parasympathetic activity is reduced during slow-wave sleep, but not resting wakefulness, in patients with chronic fatigue syndrome. J Clin Sleep Med. 2020 Jan 15;16(1):19-28. doi: 10.5664/jcsm.8114. Epub 2019 Nov 27. https://www.ncbi.nlm.nih.gov/pubmed/31957647

Elevated blood lactate in resting conditions correlate with post-exertional malaise severity in patients with Myalgic encephalomyelitis/Chronic fatigue syndrome

Abstract:

Elevated blood lactate after moderate exercise was reported in some of patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). We hypothesised that blood lactate could be also elevated in resting conditions. We aimed investigating the frequency of elevated lactate at rest in ME/CFS patients, and comparing characteristics of ME/CFS patients with and without elevated lactate.

Patients fulfilling international consensus criteria for ME/CFS who attended the internal medicine department of University hospital Angers-France between October 2011 and December 2017 were included retrospectively. All patients were systematically hospitalised for an aetiological workup and overall assessment.

We reviewed their medical records for data related to the assessment: clinical characteristics, comorbidities, fatigue features, post-exertional malaise (PEM) severity, and results of 8 lactate measurements at rest. Patients having ≥1 lactate measurement ≥2 mmol/L defined elevated lactate group. The study included 123 patients. Elevated (n = 55; 44.7%) and normal (n = 68; 55.3%) lactate groups were comparable except for PEM, which was more severe in the elevated lactate group after adjusting for age at disease onset, sex, and comorbidities (OR 2.47, 95% CI: 1.10-5.55). ME/CFS patients with elevated blood lactate at rest may be at higher risk for more severe PEM. This finding may be of interest in ME/CFS management.

Source: Ghali A, Lacout C, Ghali M, Gury A, Beucher AB, Lozac’h P, Lavigne C, Urbanski G. Elevated blood lactate in resting conditions correlate with post-exertional malaise severity in patients with Myalgic encephalomyelitis/Chronic fatigue syndrome. Sci Rep. 2019 Dec 11;9(1):18817. doi: 10.1038/s41598-019-55473-4. ncbi.nlm.nih.gov/pubmed/31827223

Parasympathetic activity is reduced during slow-wave sleep, but not resting wakefulness, in patients with chronic fatigue syndrome

Abstract:

STUDY OBJECTIVES: Physiological dearousal characterized by an increase in parasympathetic nervous system activity is important for good-quality sleep. Previous research shows that nocturnal parasympathetic activity (reflected by heart rate variability [HRV]) is diminished in individuals with chronic fatigue syndrome (CFS), suggesting hypervigilant sleep. This study investigated differences in nocturnal autonomic activity across sleep stages and explored the association of parasympathetic activity with sleep quality and self-reported physical and psychological wellbeing in individuals with CFS.

METHODS: Twenty-four patients with medically diagnosed CFS, and 24 matched healthy control individuals participated. Electroencephalography and HRV were recorded during sleep in participants’ homes using a minimally invasive ambulatory device. Questionnaires were used to measure self-reported wellbeing and sleep quality.

RESULTS: Sleep architecture in patients with CFS differed from that of control participants in slower sleep onset, more awakenings, and a larger proportion of time spent in slow-wave sleep (SWS). Linear mixed-model analyses controlling for age revealed that HRV reflecting parasympathetic activity (normalized high frequency power) was reduced in patients with CFS compared to control participants, particularly during deeper stages of sleep. Poorer self-reported wellbeing and sleep quality was associated with reduced parasympathetic signaling during deeper sleep, but not during wake before sleep, rapid eye movement sleep, or with the proportion of time spent in SWS.

CONCLUSIONS: Autonomic hypervigilance during the deeper, recuperative stages of sleep is associated with poor quality sleep and self-reported wellbeing. Causal links need to be confirmed but provide potential intervention opportunities for the core symptom of unrefreshing sleep in CFS.

© 2019 American Academy of Sleep Medicine.

Source: Fatt SJ, Beilharz JE, Joubert M, Wilson C, Lloyd AR, Vollmer-Conna U, Cvejic E. Parasympathetic activity is reduced during slow-wave sleep, but not resting wakefulness, in patients with chronic fatigue syndrome. J Clin Sleep Med. 2019 Nov 27. pii: jc-19-00271. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/31771749

Psychometric properties of the PROMIS® Fatigue Short Form 7a among adults with myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

PURPOSE: To evaluate the psychometric properties of the Patient-Reported Outcome Measurement Information System® Fatigue Short Form 7a (PROMIS F-SF) among people with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

METHODS: Analyses were conducted using data from the Multi-Site Clinical Assessment of ME/CFS study, which recruited participants from seven ME/CFS specialty clinics across the US. Baseline and follow-up data from ME/CFS participants and healthy controls were used. Ceiling/Floor effects, internal consistency reliability, differential item functioning (DIF), known-groups validity, and responsiveness were examined.

RESULTS: The final sample comprised 549 ME/CFS participants at baseline, 386 of whom also had follow-up. At baseline, the sample mean of PROMIS F-SF T-score was 68.6 (US general population mean T-score of 50 and standard deviation of 10). The PROMIS F-SF demonstrated good internal consistency reliability (Cronbach’s α = 0.84) and minimal floor/ceiling effects. No DIF was detected by age or sex for any item. This instrument also showed good known-groups validity with medium-to-large effect sizes (η2 = 0.08-0.69), with a monotonic increase of the fatigue T-score across ME/CFS participant groups with low, medium, and high functional impairment as measured by three different variables (p < 0.01), and with significantly higher fatigue T-scores among ME/CFS participants than healthy controls (p < 0.0001). Acceptable responsiveness was found with small-to-medium effect sizes (Guyatt’s Responsiveness Statistic = 0.28-0.54).

CONCLUSIONS: Study findings support the reliability and validity of PROMIS F-SF as a measure of fatigue for ME/CFS and lend support to the drug development tool submission for qualifying this measure to evaluate therapeutic effect in ME/CFS clinical trials.

Source: Yang M, Keller S, Lin JS. Psychometric properties of the PROMIS® Fatigue Short Form 7a among adults with myalgic encephalomyelitis/chronic fatigue syndrome. Qual Life Res. 2019 Sep 10. doi: 10.1007/s11136-019-02289-4. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/31506915

Unexplained exertional intolerance associated with impaired systemic oxygen extraction

Abstract:

PURPOSE: The clinical investigation of exertional intolerance generally focuses on cardiopulmonary diseases, while peripheral factors are often overlooked. We hypothesize that a subset of patients exists whose predominant exercise limitation is due to abnormal systemic oxygen extraction (SOE).

METHODS: We reviewed invasive cardiopulmonary exercise test (iCPET) results of 313 consecutive patients presenting with unexplained exertional intolerance. An exercise limit due to poor SOE was defined as peak exercise (Ca-vO2)/[Hb] ≤ 0.8 and VO2max < 80% predicted in the absence of a cardiac or pulmonary mechanical limit. Those with peak (Ca-vO2)/[Hb] > 0.8, VO2max ≥ 80%, and no cardiac or pulmonary limit were considered otherwise normal. The otherwise normal group was divided into hyperventilators (HV) and normals (NL). Hyperventilation was defined as peak PaCO2 < [1.5 × HCO3 + 6].

RESULTS: Prevalence of impaired SOE as the sole cause of exertional intolerance was 12.5% (32/257). At peak exercise, poor SOE and HV had less acidemic arterial blood compared to NL (pHa = 7.39 ± 0.05 vs. 7.38 ± 0.05 vs. 7.32 ± 0.02, p < 0.001), which was explained by relative hypocapnia (PaCO2 = 29.9 ± 5.4 mmHg vs. 31.6 ± 5.4 vs. 37.5 ± 3.4, p < 0.001). For a subset of poor SOE, this relative alkalemia, also seen in mixed venous blood, was associated with a normal PvO2 nadir (28 ± 2 mmHg vs. 26 ± 4, p = 0.627) but increased SvO2 at peak exercise (44.1 ± 5.2% vs. 31.4 ± 7.0, p < 0.001).

CONCLUSIONS: We identified a cohort of patients whose exercise limitation is due only to systemic oxygen extraction, due to either an intrinsic abnormality of skeletal muscle mitochondrion, limb muscle microcirculatory dysregulation, or hyperventilation and left shift the oxyhemoglobin dissociation curve.

Source: Melamed KH, Santos M, Oliveira RKF, Urbina MF, Felsenstein D, Opotowsky AR, Waxman AB, Systrom DM. Unexplained exertional intolerance associated with impaired systemic oxygen extraction. Eur J Appl Physiol. 2019 Sep 6. doi: 10.1007/s00421-019-04222-6. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/31493035

MicroRNAs as biomarkers of pain intensity in patients with chronic fatigue syndrome

Abstract:

BACKGROUND: Numerous experimental models have shown that microRNAs play an important role in regulating pain-processing in clinical pain disorders. In this study, we evaluated a set of micro-RNAs as diagnostic biomarkers of pain intensity in adolescents with chronic fatigue syndrome (CFS). We then correlated the expression of these microRNAs with the levels of inflammatory markers and pain-related comorbidities in adolescents with CSF and healthy controls (HCs).

METHODS: A total of 150 adolescents, aged 12-18 years, participated in this study between April 2016 and April 2017. The participants were classified into two groups: adolescents with CFS (n=100) and HCs (n=50). RT-PCR was used to evaluate the expression of miR-558, miR-146a, miR-150, miR-124, and miR-143. Immunoassay analysis was used to assess the levels of immune inflammatory markers IL-6, TNF-α, and COX-2.

RESULTS: Adolescents with CFS showed significantly higher pain thresholds than comparable non-fatigued HCs. Also, enjoy of life and relation to others as the life domains, showed lower pain interference in CFS patients. Differential expression of miR-558, miR-146a, miR-150, miR-124, and miR-143 was significantly down regulated and notably interfered with pain intensity and frequency in patients with CFS. Also, the expression of these miRNAs was significantly correlated with that of IL-6, TNF-α, and COX-2, which have been shown to mediate pain intensity in patients with CFS.

Girls with CSF showed significantly decreased expression levels of these miRNAs compared with the levels of boys with CSF. Girls with CSF also showed increased expression of inflammatory pain-related markers IL-6, TNF-α, and COX-2, compared with the levels of boys with CSF

CONCLUSIONS: The intensity and consequences of pain were influenced by differential expression of miR-558, miR-146a, miR-150, miR-124, and miR-143, which was directly, associated with higher expression of immune inflammatory related genes TNFα, IL-6, and COX-2 in adolescences with CFS. Further studies of larger patient cohorts will help clarify the role of miRNAs in the pathogenesis of CFS.

This article is protected by copyright. All rights reserved.

Source: Al-Rawaf HA, Alghadir AH, Gabr SA. MicroRNAs as biomarkers of pain intensity in patients with chronic fatigue syndrome. Pain Pract. 2019 Jul 8. doi: 10.1111/papr.12817. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/31282597

Post-Exertional Malaise Is Associated with Hypermetabolism, Hypoacetylation and Purine Metabolism Deregulation in ME/CFS Cases

Abstract:

Post-exertional malaise (PEM) is a cardinal predictive symptom in the definition of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). If the cases overexert themselves they have what is termed “payback” resulting in a worsening of symptoms or relapse which can last for days, weeks or even months. The aim was to assess the changes in biochemistry associated with the cases self-reported PEM scores over a 7-day period and the frequency of reporting over a 12-month period.

Forty-seven ME/CFS cases and age/sex-matched controls had a clinical examination, completed questionnaires; were subjected to standard serum biochemistry; had their serum and urine metabolomes analyzed in an observational study. Thirty-five of the 46 ME/CFS cases reported PEM in the last 7-days and these were allocated to the PEM group.

The principal biochemical change related to the 7-day severity of PEM was the fall in the purine metabolite, hypoxanthine. This decrease correlated with alterations in the glucose:lactate ratio highly suggestive of a glycolytic anomaly. Increased excretion of urine metabolites within the 7-day response period indicated a hypermetabolic event was occurring. Increases in urine excretion of methylhistidine (muscle protein degradation), mannitol (intestinal barrier deregulation) and acetate were noted with the hypermetabolic event.

These data indicate hypoacetylation was occurring, which may also be related to deregulation of multiple cytoplasmic enzymes and DNA histone regulation. These findings suggest the primary events associated with PEM were due to hypoacetylation and metabolite loss during the acute PEM response.

Source: Neil R. McGregor, Christopher W. Armstrong , Donald P. Lewis and Paul R. Gooley. Post-Exertional Malaise Is Associated with Hypermetabolism, Hypoacetylation and Purine Metabolism Deregulation in ME/CFS Cases. Diagnostics 2019, 9(3), 70; https://doi.org/10.3390/diagnostics9030070 https://www.mdpi.com/2075-4418/9/3/70/htm (Full article)

Chronic Fatigue Syndrome and chronic pain conditions – vitally protective systems gone wrong

Abstract:

Chronic Fatigue Syndrome (CFS) and chronic pain syndromes represent major health problems in society. These conditions are disabling and strongly associated with low quality of life. Even though CFS and chronic pain are separate conditions, they have strikingly much in common. Both pain and fatigue are important sensations with protective value in an acute situation. It can be life-threatening not to be aware of them.

However, as these symptoms become chronic, their protective roles decrease and instead they become health problems. Our understanding of the perception of pain and fatigue has shifted through the years, from a dualistic biomedical point of view to a holistic biopsychosocial understanding. This combined with the increasing evidence of how our brain works in a predictive/anticipatory manner, gives a deeper understanding of why treatments like cognitive behavior therapies and stress relief therapies can help these patients recover to better health.

Source: Pedersen M. Chronic Fatigue Syndrome and chronic pain conditions – vitally protective systems gone wrong. Scand J Pain. 2019 Jun 29. pii: /j/sjpain.ahead-of-print/sjpain-2019-0072/sjpain-2019-0072.xml. doi: 10.1515/sjpain-2019-0072. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/31256069

Orthostatic intolerance in chronic fatigue syndrome

Abstract:

BACKGROUND: Orthostatic intolerance (OI) is a significant problem for those with chronic fatigue syndrome (CFS). We aimed to characterize orthostatic intolerance in CFS and to study the effects of exercise on OI.

METHODS: CFS (n = 39) and control (n = 25) subjects had recumbent and standing symptoms assessed using the 20-point, anchored, ordinal Gracely Box Scale before and after submaximal exercise. The change in heart rate (ΔHR ≥ 30 bpm) identified Postural Orthostatic Tachycardia Syndrome (POTS) before and after exercise, and the transient, exercise-induced postural tachycardia Stress Test Activated Reversible Tachycardia (START) phenotype only after exercise.

RESULTS: Dizziness and lightheadedness were found in 41% of recumbent CFS subjects and in 72% of standing CFS subjects. Orthostatic tachycardia did not account for OI symptoms in CFS. ROC analysis with a threshold ≥ 2/20 on the Gracely Box Scale stratified CFS subjects into three groups: No OI (symptoms < 2), Postural OI (only standing symptoms ≥ 2), and Persistent OI (recumbent and standing symptoms ≥ 2).

CONCLUSIONS: Dizziness and Lightheadedness symptoms while recumbent are an underreported finding in CFS and should be measured when doing a clinical evaluation to diagnose orthostatic intolerance. POTS was found in 6 and START was found in 10 CFS subjects. Persistent OI had symptoms while recumbent and standing, highest symptom severity, and lability in symptoms after exercise.

Trial registration: The trial was registered at the following: https://clinicaltrials.gov/ct2/show/NCT03567811.

Source: Garner R, Baraniuk JN. Orthostatic intolerance in chronic fatigue syndrome. J Transl Med. 2019 Jun 3;17(1):185. doi: 10.1186/s12967-019-1935-y.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6547462/ (Full article)

Hyperactivation of proprioceptors induces microglia-mediated long-lasting pain in a rat model of chronic fatigue syndrome

Abstract:

BACKGROUND: Patients diagnosed with chronic fatigue syndrome (CFS) or fibromyalgia experience chronic pain. Concomitantly, the rat model of CFS exhibits microglial activation in the lumbar spinal cord and pain behavior without peripheral tissue damage and/or inflammation. The present study addressed the mechanism underlying the association between pain and chronic stress using this rat model.

METHODS: Chronic or continuous stress-loading (CS) model rats, housed in a cage with a thin level of water (1.5 cm in depth), were used. The von Frey test and pressure pain test were employed to measure pain behavior. The neuronal and microglial activations were immunohistochemically demonstrated with antibodies against ATF3 and Iba1. Electromyography was used to evaluate muscle activity.

RESULTS: The expression of ATF3, a marker of neuronal hyperactivity or injury, was first observed in the lumbar dorsal root ganglion (DRG) neurons 2 days after CS initiation. More than 50% of ATF3-positive neurons simultaneously expressed the proprioceptor markers TrkC or VGluT1, whereas the co-expression rates for TrkA, TrkB, IB4, and CGRP were lower than 20%. Retrograde labeling using fluorogold showed that ATF3-positive proprioceptive DRG neurons mainly projected to the soleus. Substantial microglial accumulation was observed in the medial part of the dorsal horn on the fifth CS day. Microglial accumulation was observed around a subset of motor neurons in the dorsal part of the ventral horn on the sixth CS day. The motor neurons surrounded by microglia were ATF3-positive and mainly projected to the soleus. Electromyographic activity in the soleus was two to three times higher in the CS group than in the control group. These results suggest that chronic proprioceptor activation induces the sequential activation of neurons along the spinal reflex arc, and the neuronal activation further activates microglia along the arc. Proprioceptor suppression by ankle joint immobilization significantly suppressed the accumulation of microglia in the spinal cord, as well as the pain behavior.

CONCLUSION: Our results indicate that proprioceptor-induced microglial activation may be a key player in the initiation and maintenance of abnormal pain in patients with CFS.

Source: Yasui M, Menjyo Y, Tokizane K, Shiozawa A, Tsuda M, Inoue K, Kiyama H. Hyperactivation of proprioceptors induces microglia-mediated long-lasting pain in a rat model of chronic fatigue syndrome. J Neuroinflammation. 2019 Mar 30;16(1):67. doi: 10.1186/s12974-019-1456-x. https://jneuroinflammation.biomedcentral.com/articles/10.1186/s12974-019-1456-x (Full article)