Can sustained arousal explain the Chronic Fatigue Syndrome?

Stress-Related Chronic Fatigue Syndrome: A Case Report with a Positive Response to Alpha-Methyl-P-Tyrosine (AMPT) Treatment

Chronic fatigue syndrome (CFS) is a heterogeneous disorder with a genetically associated vulnerability of the catecholamine metabolism (e.g., catechol O-methyltransferase polymorphisms), in which environmental factors have an important impact. Alpha-methyl-p-tyrosine (AMPT; also referred to as metyrosine) is an approved medication for the treatment of pheochromocytoma. As a tyrosine hydroxylase inhibitor, AMPT may be a potential candidate for the treatment of diseases involving catecholamine alterations. However, only small-scale clinical trials have tested AMPT repurposing in a few other illnesses. The current case report compiles genetic and longitudinal biochemical data for over a year of follow-up of a male patient sequentially diagnosed with sustained overstress, neurasthenia, CFS (diagnosed in 2012 as per the Center for Disease Control (CDC/Fukuda)), and postural orthostatic tachycardia syndrome (POTS) over a 10-year period and reports the patient's symptom improvement in response to low-medium doses of AMPT. This case was recognized as a stress-related CFS case. Data are reported from medical records provided by the patient to allow a detailed response to treatment targeting the hyperadrenergic state presented by the patient. We highlight the lack of a positive response to classical approaches to treating CFS, reflecting the limitations of CFS diagnosis and available treatments to alleviate patients' symptoms. The current pathomechanism hypothesis emphasizes monoamine alterations (hyperadrenergic state) in the DA/adrenergic system and a dysfunctional autonomic nervous system resulting from sympathetic overactivity. The response of the patient to AMPT treatment highlights the relevance of pacing with regard to stressful situations and increased activity. Importantly, the results do not indicate causality between AMPT and its action on the monoamine system, and future studies should evaluate the implications of other targets.

Associations between pain intensity, psychosocial factors, and pain-related disability in 4285 patients with chronic pain

Pain, a widespread challenge affecting daily life, is closely linked with psychological and social factors. While pain clearly influences daily function in those affected, the complete extent of its impact is not fully understood. Given the close connection between pain and psychosocial factors, a deeper exploration of these aspects is needed. In this study, we aim to examine the associations between psychosocial factors, pain intensity, and pain-related disability among patients with chronic pain. We used data on 4285 patients from the Oslo University Hospital Pain Registry, and investigated pain-related disability, pain intensity, pain catastrophizing, psychological distress, perceived injustice, insomnia, fatigue, and self-efficacy. We found significant associations between all psychosocial variables and pain-related disability, even after adjusting for demographic factors. In the multiple regression model, sleep problems and pain intensity were identified as primary contributors, alongside psychological distress, and fatigue. Combined, these factors accounted for 26.5% of the variability in pain-related disability, with insomnia and pain intensity exhibiting the strongest associations. While the direction of causation remains unclear, our findings emphasize the potential of interventions aimed at targeting psychosocial factors. Considering the strong link between psychosocial factors and pain-related disability, interventions targeting these factors-particularly insomnia-could reduce disability and enhance quality of life in those who suffer.

Focus on post-exertional malaise when approaching ME/CFS in specialist healthcare improves satisfaction and reduces deterioration

Background

Post-exertional malaise (PEM) is considered a hallmark characteristic of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). This may also apply to subgroups of patients with long COVID-induced ME/CFS. However, it is uncertain to what extent PEM is acknowledged in routine specialist healthcare for ME/CFS patients, and how this affects patient outcomes.

Objective

This study aims to evaluate to what extent ME/CFS patients experienced focus on PEM in specialist healthcare practice and its significance for outcome and care quality.

Methods

Data from two online cross-sectional surveys covering specialist healthcare services for ME/CFS patients at rehabilitation institutes in Norway and two regional hospitals, respectively, were analyzed. Evaluations of 788 rehabilitation stays, 86 hospital consultations, and 89 hospital interventions were included. Logistic regression models and Mann-Whitney U-tests were used to quantify the impact of addressing PEM on health and functioning, care satisfaction, or benefit. Spearman's rank correlation and Cronbach's alpha of focus on PEM with the respondents' perception of healthcare providers' knowledge, symptom acknowledgment, and suitability of intervention were assessed as measures for care quality and their internal consistency, respectively.

Results

PEM was addressed in 48% of the rehabilitation stays, 43% of the consultations, and 65% of the hospital interventions. Failure to address PEM roughly doubled the risk of health deterioration, following rehabilitation (OR = 0.39, 95% CI 0.29-0.52; 40.1% vs. 63.2% P = <0.001) and hospital intervention (OR = 0.34, 95% CI 0.13-0.89; 22.4% vs. 45.2%, p = 0.026). The focus on PEM (PEM-focus) during the clinical contact was associated with significantly higher scores on patients' rated care satisfaction and benefit of both consultation and intervention. Furthermore, addressing PEM was (inter)related to positive views about healthcare providers' level of knowledge of ME/CFS, their acknowledgment of symptoms, obtained knowledge, and the perceived suitability of intervention (Cronbach's alpha ≥0.80).

Discussion

PEM is still frequently not acknowledged in specialist healthcare practice for ME/CFS patients in Norway. Not addressing PEM substantially increased the probability of a decline in health and functioning following the intervention and was strongly associated with reduced perceived care quality, satisfaction, and benefit. These findings may be related to the applied explanatory models for ME/CFS and are most likely of relevance to long COVID.

An investigation on information quality, media richness, and social media fatigue during the disruptions of COVID-19 pandemic

Mobile social platforms have become a valuable information source by which users gain information about the COVID-19 pandemic. However, little is known about whether users have experienced increased daily fatigue as a result of the disruptions caused by pandemic. Drawing on the cognitive activation theory of stress (CATS), this study proposed that two typical characteristics of social media platforms (SMP), information quality and media richness, are associated with event disruptions of the COVID-19 pandemic (EDC), and then induce social media fatigue. To address this, this study used the experience sampling method (ESM), collecting 550 matched cases from 110 users of the WeChat application in mainland China over five consecutive days. Through multilevel structural equation modeling (MSEM), this study discovered three main findings: (1) daily information quality is negatively related to event disruptions of the COVID-19 pandemic, which in turn decreases daily social media fatigue; (2) daily media richness is positively associated with such event disruptions, which ultimately increases daily social media fatigue; (3) these effects were stronger for users who reported higher (vs. lower) levels of health consciousness. The implications of these results for the COVID-19 pandemic and beyond are discussed.

Subjective and objective cognitive function in adolescent with chronic fatigue following Epstein-Barr virus infection

OBJECTIVE

Cognitive difficulties are among the most disruptive and disabling problems reported by chronic fatigue syndrome (CFS) sufferers. Acute Epstein-Barr virus (EBV) infection is a trigger of chronic fatigue (CF) and CFS. The aim of this study was to investigate subjectively reported and objectively measured cognitive functioning in fatigued and non-fatigued adolescents six months after EBV infection.

METHODS

A total of 195 adolescents (12-19 years) with acute EBV infection were followed prospectively for six months, after which they were grouped as chronically fatigued (CF⁺) and non-fatigued (CF^-) cases based on questionnaire score; the CF⁺-group was further subgrouped according to CFS diagnosis. A group of 70 healthy controls was also included. Groups were cross-sectionally compared on objective measures of processing speed, executive functions and memory, and subjective cognitive functioning.

RESULTS

There were no group differences regarding objective cognitive measures, but the CF⁺-group reported significantly (p < 0.001) more cognitive problems (cognitive symptoms sum score = 9.5) compared to the CF^--group (cognitive symptoms sum score = 5.3) and the healthy control group (cognitive symptoms sum score = 6.4). The CFS subgroup rated symptoms scores even higher but did not differ on cognitive performance tests.

CONCLUSION

Subjective experiences of cognitive difficulties characterize adolescents with CF and CFS six months after acute EBV infection, whereas objective measures of cognitive impairment are inconspicuous.

A qualitative reflexive thematic analysis into the experiences of being identified with a BRCA1/2 gene alteration: "So many little, little traumas could have been avoided"

Background

BRCA1/2 alterations increase females’ lifetime breast cancer risk to 40 – 90%, ovarian cancer to 10 – 60%, and males’ lifetime prostate cancer risk to ~ 10 – 25%. Psychosocial issues such as heightened distress can, therefore, occur in this population. This study aimed to explore the subjective experiences and needs of the BRCA1/2 alteration population in navigating cancer risk reduction measures.

Method

This study aimed to explore the experiences and identify the needs of 18 BRCA1/2 alteration carriers, recruited through strategic sampling. A public and patient panel (N = 6) collaborated on study development. Data were analysed using reflexive thematic analysis.

Results

Two themes were identified: (i) Healthcare Services as a Burden to Navigate, and (ii) Burden Experienced Through Interactions with Healthcare Professionals. Results indicated uncertainty regarding care pathways, alongside a lack of relevant information. Participants felt unsupported by healthcare professionals, and as though healthcare professionals often perceive them as a burden.

Conclusions

These findings suggest that the quality of interactions in healthcare systems are of relevance to the BRCA1/2 alteration population, and that uncertainty surrounding access to services and information is prevalent. The establishment of specialist hereditary cancer clinics could reduce such burden.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-022-08372-w.

The Pathobiology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: The Case for Neuroglial Failure

Although myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) has a specific and distinctive profile of clinical features, the disease remains an enigma because causal explanation of the pathobiological matrix is lacking. Several potential disease mechanisms have been identified, including immune abnormalities, inflammatory activation, mitochondrial alterations, endothelial and muscular disturbances, cardiovascular anomalies, and dysfunction of the peripheral and central nervous systems. Yet, it remains unclear whether and how these pathways may be related and orchestrated. Here we explore the hypothesis that a common denominator of the pathobiological processes in ME/CFS may be central nervous system dysfunction due to impaired or pathologically reactive neuroglia (astrocytes, microglia and oligodendrocytes). We will test this hypothesis by reviewing, in reference to the current literature, the two most salient and widely accepted features of ME/CFS, and by investigating how these might be linked to dysfunctional neuroglia. From this review we conclude that the multifaceted pathobiology of ME/CFS may be attributable in a unifying manner to neuroglial dysfunction. Because the two key features - post exertional malaise and decreased cerebral blood flow - are also recognized in a subset of patients with post-acute sequelae COVID, we suggest that our findings may also be pertinent to this entity.

Neurovascular Dysregulation and Acute Exercise Intolerance in ME/CFS: A Randomized, Placebo-Controlled Trial of Pyridostigmine

BACKGROUND

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by intractable fatigue, postexertional malaise, and orthostatic intolerance, but its pathophysiology is poorly understood. Pharmacologic cholinergic stimulation was used to test the hypothesis that neurovascular dysregulation underlies exercise intolerance in ME/CFS.

RESEARCH QUESTION

Does neurovascular dysregulation contribute to exercise intolerance in ME/CFS, and can its treatment improve exercise capacity?

STUDY DESIGN AND METHODS

Forty-five subjects with ME/CFS were enrolled in a single-center, randomized, double-blind, placebo-controlled trial. Subjects were assigned in a 1:1 ratio to receive a 60-mg dose of oral pyridostigmine or placebo after an invasive cardiopulmonary exercise test (iCPET). A second iCPET was performed 50 min later. The primary end point was the difference in peak exercise oxygen uptake (Vo₂). Secondary end points included exercise pulmonary and systemic hemodynamics and gas exchange.

RESULTS

Twenty-three subjects were assigned to receive pyridostigmine and 22 to receive placebo. The peak Vo₂ increased after pyridostigmine but decreased after placebo (13.3 ± 13.4 mL/min vs -40.2 ± 21.3 mL/min; P < .05). The treatment effect of pyridostigmine was 53.6 mL/min (95% CI, -105.2 to -2.0). Peak vs rest Vo₂ (25.9 ± 15.3 mL/min vs -60.8 ± 25.6 mL/min; P < .01), cardiac output (-0.2 ± 0.6 L/min vs -1.9 ± 0.6 L/min; P < .05), and right atrial pressure (1.0 ± 0.5 mm Hg vs -0.6 ± 0.5 mm Hg; P < .05) were greater in the pyridostigmine group compared with placebo.

INTERPRETATION

Pyridostigmine improves peak Vo₂ in ME/CFS by increasing cardiac output and right ventricular filling pressures. Worsening peak exercise Vo₂, cardiac output, and right atrial pressure following placebo may signal the onset of postexertional malaise. We suggest that treatable neurovascular dysregulation underlies acute exercise intolerance in ME/CFS.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT03674541; URL: www.

CLINICALTRIALS

gov.

Does the Lightning Process Training Programme Reduce Chronic Fatigue in Adolescent and Young Adult Cancer Survivors? A Mixed-Methods Pilot Study

Simple Summary

Chronic fatigue is a common late adverse effect following oncological therapies. No effective treatments exist, although cognitive behaviour therapy has been reported to offer some benefits. The Lightning Process^® is a three-day educational training programme with a six-month follow-up comprising elements derived from cognitive behaviour therapy, neurolinguistic programming, and stress theory, which are presented in a condensed form. This pilot intervention study represents the first systematic account of the experience and perceived efficacy of the LP training programme in 13 adolescent and young adult cancer survivors treated for sarcoma or Hodgkin lymphoma. Statistically significant improvements were documented for all the patient-reported outcome measure (PROM) questionnaires comparing the pre- and post-intervention periods. The qualitative findings of the interviews corresponded well with the PROMs findings, as participants emphasised that they now experienced both less fatigue and explicit improvement in their energy level.

Abstract

Background: We report on a pilot intervention study exploring the efficacy of the Lightning Process^® training programme for reducing chronic fatigue and improving health-related quality of life in cancer survivors. Methods: 13 adolescent and young adult cancer survivors previously treated for sarcoma or Hodgkin lymphoma were enrolled. A mixed-methods approach was applied. This involved the use of five validated patient-reported outcome measure (PROM) questionnaires at baseline and the three- and six-month follow-up points to obtain quantitative data. Semi-structured interviews were conducted after the intervention with emphasis on the participants’ experiences and outcomes. A reflexive thematic analysis was applied to the transcripts. Results: A significant reduction (p < 0.001) in the total fatigue score from baseline to the three- and six-month follow-up points was documented. The correlation coefficients between the various PROMs at baseline and the six-month follow-up point indicated considerable overlap between the measures. The qualitative findings of the interviews corresponded well with the PROM findings. Most participants experienced both less fatigue and explicit improvement in their energy level. The aspects of the intervention found to be particularly helpful were the theoretical rationale and the coping techniques mediated. Conclusion: These encouraging results here reported should be of interest to the general oncological community, although they require confirmation through a larger and controlled study.

The SARS-CoV-2 receptor angiotensin-converting enzyme 2 (ACE2) in myalgic encephalomyelitis/chronic fatigue syndrome: A meta-analysis of public DNA methylation and gene expression data

People with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) often report a high frequency of viral infections and flu-like symptoms during their disease course. Given that this reporting agrees with different immunological abnormalities and altered gene expression profiles observed in the disease, we aimed at answering whether the expression of the human angiotensin-converting enzyme 2 (ACE2), the major cell entry receptor for SARS-CoV-2, is also altered in these patients. In particular, a low expression of ACE2 could be indicative of a high risk of developing COVID-19. We then performed a meta-analysis of public data on CpG DNA methylation and gene expression of this enzyme and its homologous ACE protein in peripheral blood mononuclear cells and related subsets. We found that patients with ME/CFS have decreased methylation levels of four CpG probes in the ACE locus (cg09920557, cg19802564, cg21094739, and cg10468385) and of another probe in the promoter region of the ACE2 gene (cg08559914). We also found a decreased expression of ACE2 but not of ACE in patients when compared to healthy controls. Accordingly, in newly collected data, there was evidence for a significant higher proportion of samples with an ACE2 expression below the limit of detection in patients than healthy controls. Altogether, patients with ME/CFS can be at a higher COVID-19 risk and, if so, they should be considered a priority group for vaccination by public health authorities. To further support this conclusion, similar research is recommended for other human cell entry receptors and cell types, namely, those cells targeted by the virus.

Anticipation of and response to exercise in adolescents with CFS: An experimental study

BACKGROUND

Using a laboratory-based exercise task, this study investigated objective exercise performance as well as expectations, anxiety and perceived task performance ratings in adolescents with CFS compared to healthy controls and illness controls.

METHOD

Trials of a sit-stand exercise task (SST) were undertaken (CFS: n = 61, asthma (AS): n = 31, healthy adolescents (HC): n = 78). Adolescents rated their expectations, pre- and post-task anxiety, and perceived task difficulty. Their parents independently rated their performance expectations of their child.

RESULTS

The CFS group took significantly longer to complete the SST than the AS group (MD 3.71, 95% CI [2.41, 5.01] p < .001) and HC (MD 3.61, 95% CI [2.41, 4.81], p < .001). Adolescents with CFS had lower expectations for their performance on the exercise task than AS participants (MD -11.79, 95% CI [-22.17, -1.42] p = .022) and HC (MD -15.08, 95% CI [-23.01, -7.14] p < .001). They rated their perceived exertion as significantly greater than AS (MD 3.04, 95% CI [1.86, 4.21] p < .001) and HC (MD 2.98, 95% CI [1.99, 3.98], p < .001). The CFS group reported greater anxiety pre-task than AS (MD 14.11, 95% CI [5.57, 22.65] p < .001) and HC (MD 11.19, 95% CI [2.64, 19.75], p. = 007). Parental group differences showed similar patterns to the adolescents''.

CONCLUSIONS

Lower expectations and greater anxiety regarding exercise may reflect learning from previous difficult experiences which could impact future exercise performance. Further examination of pre-exercise expectations and post-exercise appraisals could improve our understanding of the mechanisms by which fatigue is maintained.

Resilience during uncertainty? Greater social connectedness during COVID-19 lockdown is associated with reduced distress and fatigue

BACKGROUND

Social connections are crucial for our health and well-being. This is especially true during times of high uncertainty and distress, such as during the COVID-19 lockdown. This period was characterized by unprecedented physical distancing (often communicated as social distancing) measures resulting in significant changes to people's usual social lives. Given the potential effects of this disruption on people's well-being, it is crucial to identify factors which are associated with negative health outcomes, and conversely, those that promote resilience during times of adversity.

AIMS

We examined the relationship between individuals' levels of social connectedness during lockdown and self-reported stress, worry, and fatigue.

METHOD

Survey data were collected from 981 individuals in a representative sample of Austrian citizens. Data collection occurred during the last week of a six-week nationwide lockdown due to the COVID-19 pandemic. The final sample consisted of 902 participants. Participants were asked to complete validated questionnaires to assess levels of social connectedness as well as measures of perceived stress, worry-both general and COVID-19 specific-and symptoms of fatigue during the previous two weeks.

RESULTS

Our results demonstrate that greater social connectedness during the lockdown period was associated with lower levels of perceived stress, as well as general and COVID-19-specific worries. Furthermore, we found a negative relationship between fatigue and social connectedness, which was mediated by feelings of stress, general worries, and COVID-19-specific worries-respectively, indicating that individuals with smaller network sizes, who were highly distressed during the pandemic, were also likely to report feeling more fatigued.

CONCLUSION

Our findings highlight the important role that social connections play in promoting resilience by buffering against negative physical and mental health outcomes, particularly in times of adversity in times of adversity.

Metacognitive Beliefs as Predictors of Return to Work After Intensive Return-to-Work Rehabilitation in Patients With Chronic Pain, Chronic Fatigue and Common Psychological Disorders: Results From a Prospective Trial

Background

Metacognitions are associated with work status, but no research has examined to what extent metacognitions before treatment and change in metacognitions following treatment predict return to work (RTW) prospectively. The present study aims to address these two gaps in knowledge.

Methods

212 patients on long-term sick leave (>8 weeks) with extensive fatigue, chronic pain conditions and/or mental distress received 3.5 weeks of intensive rehabilitation treatment, aimed at returning them to work. Only part of the population (n = 137) had complete follow-up data on metacognitions. Metacognitions were measured with the Metacognitions Questionnaire 30 (MCQ-30), while RTW was measured using official registry data from the Norwegian Labor and Welfare Service. A registry record of participation in competitive work ≥2.5 days (50% work participation) per week, averaging over 14 weeks, was chosen as an outcome reflecting a successful RTW. The registry data spanned a total of 56 weeks per participant.

Results

Our results indicated that baseline MCQ scores was not associated with RTW. This was analyzed for the total MCQ score as well as for all subscales. We observed substantial changes in metacognitions following treatment, and a 1-point change in the total sum of metacognitive beliefs was associated with 5% greater odds for successful RTW at all time points (p = 0.040), while a 1-point change on the subscale of beliefs about the need to control thoughts gave 20% greater odds for successful RTW (p = 0.016).

Conclusion

Metacognitions concerning the need to control thoughts appear to have a significant influence on patients return to work. Here, we observed that a change in these beliefs following treatment substantially affected RTW over the course of 1 year.

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

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.

Clinical symptoms and markers of disease mechanisms in adolescent chronic fatigue following Epstein-Barr virus infection: An exploratory cross-sectional study

INTRODUCTION

Acute Epstein-Barr virus (EBV) infection is a trigger of chronic fatigue (CF) and Chronic Fatigue Syndrome (CFS). The aim of this cross-sectional study was to explore clinical symptoms as well as markers of disease mechanisms in fatigued and non-fatigued adolescents 6 months after EBV-infection, and in healthy controls.

MATERIALS AND METHODS

A total of 200 adolescents (12-20 years old) with acute EBV infection were assessed 6 months after the initial infectious event and divided into fatigued (EBV CF+) and non-fatigued (EBV CF-) cases based on questionnaire score. The EBV CF+ cases were further sub-divided according to case definitions of CFS. In addition, a group of 70 healthy controls with similar distribution of sex and age was included. Symptoms were mapped with a questionnaire. Laboratory assays included EBV PCR and serology; detailed blood leukocyte phenotyping and serum high-sensitive C-reactive protein; and plasma and urine cortisol and catecholamines. Assessment of autonomic activity was performed with continuous, non-invasive monitoring of cardiovascular variables during supine rest, controlled breathing and upright standing. Differences between EBV CF+ and EBV CF- were assessed by simple and multiple linear regression adjusting for sex as well as symptoms of depression and anxiety. A p-value ≤ 0.05 was considered statistically significant. This study is part of the CEBA-project (Chronic fatigue following acute Epstein-Barr virus infection in adolescents).

RESULTS

The EBV CF+ group had significantly higher scores for all clinical symptoms. All markers of infection and most immune, neuroendocrine and autonomic markers were similar across the EBV CF+ and EBV CF- group. However, the EBV CF+ group had slightly higher serum C-reactive protein (0.48 vs 0.43 mg/L, p = 0.031, high-sensitive assay), total T cell (CD3+) count (median 1573 vs 1481 × 10⁶ cells/L, p = 0.012), plasma norepinephrine (1420 vs 1113 pmol/L, p = 0.01) and plasma epinephrine (363 vs 237 nmol/L, p = 0.032); lower low-frequency:high frequency (LF/HF) ratio of heart rate variability at supine rest (0.63 vs 0.76, p = 0.008); and an attenuated decline in LF/HF ratio during controlled breathing (-0.11 vs -0.25, p = 0.002). Subgrouping according to different CFS diagnostic criteria did not significantly alter the results. Within the EBV CF+ group, there were no strong correlations between clinical symptoms and markers of disease mechanisms. In a multiple regression analysis, serum CRP levels were independently associated with serum cortisol (B = 4.5 × 10^-4, p < 0.001), urine norepinephrine (B = 9.6 × 10^-2, p = 0.044) and high-frequency power of heart rate variability (B = -3.7 × 10^-2, p = 0.024).

CONCLUSIONS

In adolescents, CF and CFS 6 months after acute EBV infection are associated with high symptom burden, but no signs of increased viral load and only subtle alterations of immune, autonomic, and neuroendocrine markers of which no one is strongly correlated with symptom scores. A slight sympathetic over parasympathetic predominance is evident in CF and might explain slightly increased CRP levels.

Fatigue in Epstein-Barr virus infected adolescents and healthy controls: A prospective multifactorial association study

OBJECTIVE

Acute Epstein-Barr virus (EBV) infection is a known trigger of both acute and chronic fatigue. The aim of this study was to investigate associations to fatigue in adolescents with EBV infection during the initial stage and six months after, as well as in healthy controls.

METHODS

200 adolescents (12-20 years old) with EBV infection were assessed as soon as possible after the onset of symptoms (EBV_baseline) and six months later (EBV_{six months}, 5 drop-outs). Also, 70 healthy controls (HC) were included. Associations between current fatigue and 148 different variables (including symptoms, functional abilities and biomarkers) were investigated separately for EBV_baseline, EBV_{six months} and HC using linear regression modelling.

RESULTS

Fatigue was associated with symptoms of sleeping difficulties, negative emotions, and quality of life under all circumstances. Fatigue was independently associated with markers of immune response at EBV_{six months} and in HC, not at EBV_baseline. An association between fatigue and markers of autonomic cardiovascular control was only present at EBV_{six months}. Cognitive functioning shifted from a positive association to fatigue at EBV_baseline to a negative trend at EBV_{six months.} Markers of infection were not associated with fatigue at EBV_baseline, EBV_{six months} nor in HC.

CONCLUSION

Irrespective of the cause, fatigue is important for quality of life and is highly associated with negative emotions. Markers of infection and immune response had respectively none and barely any association to fatigue. Autonomic alterations and cognitive dysfunction were exclusively associated with fatigue long after infection, corroborating findings from studies of the Chronic Fatigue Syndrome.

Associations between clinical symptoms, plasma norepinephrine and deregulated immune gene networks in subgroups of adolescent with Chronic Fatigue Syndrome

BACKGROUND

Chronic Fatigue Syndrome (CFS) is one of the most important causes of disability among adolescents while limited knowledge exists on genetic determinants underlying disease pathophysiology.

METHODS

We analyzed deregulated immune-gene modules using Pathifier software on whole blood gene expression data (29 CFS patients, 18 controls). Deconvolution of immune cell subtypes based on gene expression profile was performed using CIBERSORT. Supervised consensus clustering on pathway deregulation score (PDS) was used to define CFS subgroups. Associations between PDS and immune, neuroendocrine/autonomic and clinical markers were examined. The impact of plasma norepinephrine level on clinical markers over time was assessed in a larger cohort (91 patients).

RESULTS

A group of 29 immune-gene sets was shown to differ patients from controls and detect subgroups within CFS. Group 1P (high PDS, low norepinephrine, low naïve CD4+ composition) had strong association with levels of serum C-reactive protein and Transforming Growth Factor-beta. Group 2P (low PDS, high norepinephrine, high naïve CD4+ composition) had strong associations with neuroendocrine/autonomic markers. The corresponding plasma norepinephrine level delineated 91 patients into two subgroups with significant differences in fatigue score.

CONCLUSION

We identified 29 immune-gene sets linked to plasma norepinephrine level that could delineate CFS subgroups. Plasma norepinephrine stratification revealed that lower levels of norepinephrine were associated with higher fatigue. Our data suggests potential involvement of neuro-immune dysregulation and genetic stratification in CFS.

"It´s incredible how much I´ve had to fight." Negotiating medical uncertainty in clinical encounters

Purpose: Clinical encounters related to medically unexplained physical symptoms (MUPS) are associated with high levels of conflict between patients and doctors. Collaborative difficulties are fused by the medical uncertainty that dominates these consultations. The main aim of this study is to explore the interactional dynamics of clinical encounters riddled by medical uncertainty, as experienced by people living with long-term medically unexplained fatigue in Norway. Method: A qualitative thematic analysis of written texts from 256 study participants. Results: We found that patients experience being met with disbelief, inappropriate psychological explanations, marginalisation of experiences, disrespectful treatment, lack of physical examination and damaging health advice. The main source of their discontent is not the lack of biomedical knowledge, but doctors who fail to communicate acknowledgement of patients’ experiences, knowledge and autonomy. War metaphors are emblematic of how participants describe their medical encounters. The overarching storyline depicts experiences of being caught in a power struggle with doctors and health systems, fused by a lack of common conceptual ground. Conclusion: When physical symptoms cannot be detected, explained and managed by biomedical knowledge and technology, good doctor-patient partnerships are crucial. Without clearly acknowledging patients’ perspectives and capabilities in clinical practice, such partnerships cannot be achieved.

Transforming growth factor beta (TGF-β) in adolescent chronic fatigue syndrome

BACKGROUND

Chronic fatigue syndrome (CFS) is a prevalent and disabling condition among adolescent. The disease mechanisms are unknown. Previous studies have suggested elevated plasma levels of several cytokines, but a recent meta-analysis of 38 articles found that of 77 different cytokines measured in plasma, transforming growth factor beta (TGF-β) was the only one that was elevated in patients compared to controls in a sufficient number of articles. In the present study we therefore compared the plasma levels of the three TGF-β isoforms in adolescent CFS patients and healthy controls. In addition, the study explored associations between TGF-β levels, neuroendocrine markers, clinical markers and differentially expressed genes within the CFS group.

METHODS

CFS patients aged 12-18 years (n = 120) were recruited nation-wide to a single referral center as part of the NorCAPITAL project (ClinicalTrials ID: NCT01040429). A broad case definition of CFS was applied, requiring 3 months of unexplained, disabling chronic/relapsing fatigue of new onset, whereas no accompanying symptoms were necessary. Healthy controls (n = 68) were recruited from local schools. The three isoforms of TGF-β (TGF-β1, TGF-β2, TGF-β3) were assayed using multiplex technology. Neuroendocrine markers encompassed plasma and urine levels of catecholamines and cortisol, as well as heart rate variability indices. Clinical markers consisted of questionnaire scores for symptoms of post-exertional malaise, inflammation, fatigue, depression and trait anxiety, as well as activity recordings. Whole blood gene expression was assessed by RNA sequencing in a subgroup of patients (n = 29) and controls (n = 18).

RESULTS

Plasma levels of all three isoforms of TGF-β were equal in the CFS patients and the healthy controls. Subgrouping according to the Fukuda and Canada 2003 criteria of CFS did not reveal differential results. Within the CFS group, all isoforms of TGF-β were associated with plasma cortisol, urine norepinephrine and urine epinephrine, and this association pattern was related to fatigue score. Also, TGF-β3 was related to expression of the B cell annotated genes TNFRSF13C and CXCR5.

CONCLUSIONS

Plasma levels of all TGF-β isoforms were not altered in adolescent CFS. However, the TGF-β isoforms were associated with neuroendocrine markers, an association related to fatigue score. Furthermore, TGF-β3 might partly mediate an association between plasma cortisol and B cell gene expression. Trial registration Clinical Trials NCT01040429.

Grey and white matter differences in Chronic Fatigue Syndrome - A voxel-based morphometry study

OBJECTIVE

Investigate global and regional grey and white matter volumes in patients with Chronic Fatigue Syndrome (CFS) using magnetic resonance imaging (MRI) and recent voxel-based morphometry (VBM) methods.

METHODS

Forty-two patients with CFS and thirty healthy volunteers were scanned on a 3-Tesla MRI scanner. Anatomical MRI scans were segmented, normalized and submitted to a VBM analysis using randomisation methods. Group differences were identified in overall segment volumes and voxel-wise in spatially normalized grey matter (GM) and white matter (WM) segments.

RESULTS

Accounting for total intracranial volume, patients had larger GM volume and lower WM volume. The voxel-wise analysis showed increased GM volume in several structures including the amygdala and insula in the patient group. Reductions in WM volume in the patient group were seen primarily in the midbrain, pons and right temporal lobe.

CONCLUSION

Elevated GM volume in CFS is seen in areas related to processing of interoceptive signals and stress. Reduced WM volume in the patient group partially supports earlier findings of WM abnormalities in regions of the midbrain and brainstem.

Altered right anterior insular connectivity and loss of associated functions in adolescent chronic fatigue syndrome

Impairments in cognition, pain intolerance, and physical inactivity characterize adolescent chronic fatigue syndrome (CFS), yet little is known about its neurobiology. The right dorsal anterior insular (dAI) connectivity of the salience network provides a motivational context to stimuli. In this study, we examined regional functional connectivity (FC) patterns of the right dAI in adolescent CFS patients and healthy participants. Eighteen adolescent patients with CFS and 18 aged-matched healthy adolescent control participants underwent resting-state functional magnetic resonance imaging. The right dAI region of interest was examined in a seed-to-voxel resting-state FC analysis using SPM and CONN toolbox. Relative to healthy adolescents, CFS patients demonstrated reduced FC of the right dAI to the right posterior parietal cortex (PPC) node of the central executive network. The decreased FC of the right dAI–PPC might indicate impaired cognitive control development in adolescent CFS. Immature FC of the right dAI–PPC in patients also lacked associations with three known functional domains: cognition, pain and physical activity, which were observed in the healthy group. These results suggest a distinct biological signature of adolescent CFS and might represent a fundamental role of the dAI in motivated behavior.

Stress vulnerability in adolescents with chronic fatigue syndrome: experimental study investigating heart rate variability and skin conductance responses

BACKGROUND

Stress vulnerability has been implicated in adolescent chronic fatigue syndrome (CFS), but has rarely been investigated directly. This study compared psychological and physiological responses to a laboratory social performance task in adolescents with CFS with chronic illness (asthma) and healthy control groups.

METHODS

Adolescents with CFS (n = 60), adolescents with asthma (n = 31) and healthy adolescents (n = 78) completed questionnaires before and after a social performance task. Skin conductance responses (SCR; mean SCR and Max-Min) and heart rate variability (low frequency/high frequency; LF/HF and root mean square difference of successive RR intervals; RMSSD) was measured before, during and after the task.

RESULTS

Baseline heart rate variability (HRV) (RMSSD) was significantly lower in the CFS and Asthma groups than the HC. During the speech, the CFS and Asthma groups had higher HRV (LF/HF) than the HC, adjusting for baseline LF/HF. Although the asthma group showed a subsequent reduction in HRV during recovery, the CFS group did not. Similarly, during recovery after the task, the CFS group showed a continued increase in skin conductance (Min-Max), unlike the Asthma and HC groups. Compared to control groups, adolescents with CFS expected to find the task more difficult, were more anxious beforehand and afterwards, rated it as more difficult, evaluated their performance more negatively and had lower observer ratings of performance. Parents of adolescents with CFS expected that their child would perform less well in the task than parents of control participants.

CONCLUSIONS

Adolescents with CFS showed autonomic nervous system responses that are consistent with chronic stress vulnerability, difficulty coping with acute stress and slower recovery after acute stress. Self-report measures also indicated greater trait, pre- and posttask anxiety in the CFS group.

Whole blood gene expression in adolescent chronic fatigue syndrome: an exploratory cross-sectional study suggesting altered B cell differentiation and survival

BACKGROUND

Chronic fatigue syndrome (CFS) is a prevalent and disabling condition affecting adolescents. The pathophysiology is poorly understood, but immune alterations might be an important component. This study compared whole blood gene expression in adolescent CFS patients and healthy controls, and explored associations between gene expression and neuroendocrine markers, immune markers and clinical markers within the CFS group.

METHODS

CFS patients (12-18 years old) were recruited nation-wide to a single referral center as part of the NorCAPITAL project. A broad case definition of CFS was applied, requiring 3 months of unexplained, disabling chronic/relapsing fatigue of new onset, whereas no accompanying symptoms were necessary. Healthy controls having comparable distribution of gender and age were recruited from local schools. Whole blood samples were subjected to RNA sequencing. Immune markers were blood leukocyte counts, plasma cytokines, serum C-reactive protein and immunoglobulins. Neuroendocrine markers encompassed plasma and urine levels of catecholamines and cortisol, as well as heart rate variability indices. Clinical markers consisted of questionnaire scores for symptoms of post-exertional malaise, inflammation, fatigue, depression and trait anxiety, as well as activity recordings.

RESULTS

A total of 29 CFS patients and 18 healthy controls were included. We identified 176 genes as differentially expressed in patients compared to controls, adjusting for age and gender factors. Gene set enrichment analyses suggested impairment of B cell differentiation and survival, as well as enhancement of innate antiviral responses and inflammation in the CFS group. A pattern of co-expression could be identified, and this pattern, as well as single gene transcripts, was significantly associated with indices of autonomic nervous activity, plasma cortisol, and blood monocyte and eosinophil counts. Also, an association with symptoms of post-exertional malaise was demonstrated.

CONCLUSION

Adolescent CFS is characterized by differential gene expression pattern in whole blood suggestive of impaired B cell differentiation and survival, and enhanced innate antiviral responses and inflammation. This expression pattern is associated with neuroendocrine markers of altered HPA axis and autonomic nervous activity, and with symptoms of post-exertional malaise. Trial registration Clinical Trials NCT01040429.

Perspectives on Technology-Assisted Relaxation Approaches to Support Mind-Body Skills Practice in Children and Teens: Clinical Experience and Commentary

It has been well-established that a variety of mind-body (MB) techniques, including yoga, mental imagery, hypnosis, biofeedback, and meditation, are effective at addressing symptoms such as pain, anxiety, nausea, and insomnia, as well as helping with a wide variety of medical, emotional, and behavioral issues in pediatric populations. In addition, MB skills can also be health-promoting in the long-term, and with regular practice, could potentially contribute to longer attention spans, social skills, emotional regulation, and enhanced immune system functioning. Importantly, the benefits accrued from MB skills are largely dose-dependent, meaning that individuals who practice with some consistency tend to benefit the most, both in the short- and long-term. However, clinical experience suggests that for busy patients, the regular practice of MB skills can be challenging and treatment adherence commonly becomes an issue. This commentary reviews the concept of technology-assisted relaxation as an engaging and effective option to enhance treatment adherence (i.e., daily practice) for pediatric patients, for whom MB skills have been recommended to address physical and mental health challenges.

Heart rate variability biofeedback therapy and graded exercise training in management of chronic fatigue syndrome: An exploratory pilot study

OBJECTIVE

Chronic fatigue syndrome (CFS) is characterised by persistent fatigue, exhaustion, and several physical complaints. Research has shown cognitive behavioural therapy (CBT) and graded exercise training (GET) to be the most effective treatments. In a first step we aimed to assess the efficacy of heart rate variability biofeedback therapy (HRV-BF) as a treatment method comprising cognitive and behavioural strategies and GET in the pilot trial. In a second step we aimed to compare both interventions with regard to specific parameters.

METHODS

The study was conducted in an outpatient treatment setting. A total of 28 women with CFS (50.3±9.3years) were randomly assigned to receive either eight sessions of HRV-BF or GET. The primary outcome was fatigue severity. Secondary outcomes were mental and physical quality of life and depression. Data were collected before and after the intervention as well as at a 5-month follow-up.

RESULTS

General fatigue improved significantly after both HRV-BF and GET. Specific cognitive components of fatigue, mental quality of life, and depression improved significantly after HRV-BF only. Physical quality of life improved significantly after GET. There were significant differences between groups regarding mental quality of life and depression favouring HRV-BF.

CONCLUSION

Both interventions reduce fatigue. HRV-BF seems to have additional effects on components of mental health, including depression, whereas GET seems to emphasise components of physical health. These data offer implications for further research on combining HRV-BF and GET in patients with CFS.

TRIAL REGISTRATION

The described trial has been registered at the International Clinical Trials Registry Platform following the number DRKS00005445.

Chronic Fatigue Syndrome: Cognitive, Behavioural and Emotional Processing Vulnerability Factors

BACKGROUND

Cognitive-behavioural models of chronic fatigue syndrome (CFS) suggest that personality factors such as perfectionism and high moral standards may contribute to the development of CFS.

AIMS

To investigate cognitive, behavioural and emotional processing risk factors for CFS.

METHOD

CFS patients (n = 67) at a UK specialist clinic completed questionnaires about psychological characteristics both currently and retrospectively (6 months pre-CFS onset). Responses were compared with those of healthy individuals (n = 73) who rated their current characteristics. Forty-four relatives retrospectively rated the pre-morbid psychological characteristics of the CFS participants.

RESULTS

CFS patients showed similar levels of current perfectionism to controls, though higher pre-morbid perfectionism. CFS patients showed greater self-sacrificial beliefs and more unhelpful beliefs about experiencing and expressing negative emotions, both currently but more markedly prior to onset. In the 6 months pre-illness onset, CFS patients showed more disruption to their primary goal and greater general stress than controls. Ratings of pre-morbid psychological characteristics by relatives were consistent with patients' self-reports. The extent of overinvestment in one goal was significantly associated with fatigue.

CONCLUSIONS

Perfectionism, self-sacrificial tendencies, unhelpful beliefs about emotions, and perceived stress may be present to a greater extent pre-morbidly in CFS patients compared with healthy individuals.

Are persons with fibromyalgia or other musculoskeletal pain more likely to report hearing loss? A HUNT study

BACKGROUND

Leading theories about the pathogenesis of fibromyalgia focus on central nervous dysregulation or sensitization, which can cause altered perception. There is growing evidence that fibromyalgia involves altered perception not only of pain, but also other sensory stimuli. On this basis, we investigated whether individuals with fibromyalgia are more likely to report subjective loss of hearing, adjusted for audiometrically measured loss of hearing, compared to persons without any musculoskeletal pain disorders. In addition, we studied persons with other musculoskeletal pain than fibromyalgia and persons who did not have any musculoskeletal pain.

METHODS

The study includes 44 494 persons from the second health survey in Nord-Trøndelag (HUNT2) who had undergone audiometry and answered a comprehensive questionnaire that mapped fibromyalgia, musculoskeletal pain at various sites and subjective hearing loss. Respondents with other musculoskeletal pain problems than fibromyalgia were divided into two groups with respectively localized and widespread musculoskeletal pain. Data were analyzed with logistic regression models adjusting for age, education, anxiety, depression and hearing thresholds.

RESULTS

In adjusted analysis, individuals with fibromyalgia had increased likelihood to report subjective hearing loss, compared to persons without fibromyalgia or other musculoskeletal pain (OR 4.578, 95% CI 3.622-5.787 and OR 4.523, 95% CI 3.077-6.647 in women and men). Furthermore, people with local and widespread musculoskeletal pain not diagnosed with fibromyalgia, also had increased likelihood to report subjective hearing loss, compared to people with no musculoskeletal pain. This relationship was greater for widespread pain than for localized pain (OR 1.915, 95% CI 1.627-2.255, and 1.796, 95% CI 1.590-2.029, in women and men with local musculoskeletal pain and OR 3.073, 95% CI 2.668-3.539, OR 3.618, 95% CI 3.225-4.058, in women and men with widespread pain, respectively).

CONCLUSIONS

Our findings are consistent with the hypothesis that fibromyalgia is related to a general dysregulation of the central nervous system. The same might also be the case for other local and, in particular, other widespread, musculoskeletal pain.

Genetic variation in catechol-O-methyltransferase modifies effects of clonidine treatment in chronic fatigue syndrome

Clonidine, an α2-adrenergic receptor agonist, decreases circulating norepinephrine and epinephrine, attenuating sympathetic activity. Although catechol-O-methyltransferase (COMT) metabolizes catecholamines, main effectors of sympathetic function, COMT genetic variation effects on clonidine treatment are unknown. Chronic fatigue syndrome (CFS) is hypothesized to result in part from dysregulated sympathetic function. A candidate gene analysis of COMT rs4680 effects on clinical outcomes in the Norwegian Study of Chronic Fatigue Syndrome in Adolescents: Pathophysiology and Intervention Trial (NorCAPITAL), a randomized double-blinded clonidine versus placebo trial, was conducted (N=104). Patients homozygous for rs4680 high-activity allele randomized to clonidine took 2500 fewer steps compared with placebo (Pinteraction=0.04). There were no differences between clonidine and placebo among patients with COMT low-activity alleles. Similar gene-drug interactions were observed for sleep (Pinteraction=0.003) and quality of life (Pinteraction=0.018). Detrimental effects of clonidine in the subset of CFS patients homozygous for COMT high-activity allele warrant investigation of potential clonidine-COMT interaction effects in other conditions.

Emotional conflict processing in adolescent chronic fatigue syndrome: A pilot study using functional magnetic resonance imaging

INTRODUCTION

Studies of neurocognition suggest that abnormalities in cognitive control contribute to the pathophysiology of chronic fatigue syndrome (CFS) in adolescents, yet these abnormalities remain poorly understood at the neurobiological level. Reports indicate that adolescents with CFS are significantly impaired in conflict processing, a primary element of cognitive control.

METHOD

In this study, we examine whether emotional conflict processing is altered on behavioral and neural levels in adolescents with CFS and a healthy comparison group. Fifteen adolescent patients with CFS and 24 healthy adolescent participants underwent functional magnetic resonance imaging (fMRI) while performing an emotional conflict task that involved categorizing facial affect while ignoring overlaid affect labeled words.

RESULTS

Adolescent CFS patients were less able to engage the left amygdala and left midposterior insula (mpINS) in response to conflict than the healthy comparison group. An association between accuracy interference and conflict-related reactivity in the amygdala was observed in CFS patients. A relationship between response time interference and conflict-related reactivity in the mpINS was also reported. Neural responses in the amygdala and mpINS were specific to fatigue severity.

CONCLUSIONS

These data demonstrate that adolescent CFS patients displayed deficits in emotional conflict processing. Our results suggest abnormalities in affective and cognitive functioning of the salience network, which might underlie the pathophysiology of adolescent CFS.

Cow's milk protein intolerance in adolescents and young adults with chronic fatigue syndrome

AIM

To examine the prevalence, clinical features and influence on illness severity of cow's milk protein intolerance in young people with chronic fatigue syndrome.

METHODS

In a two-year prospective study of 55 adolescents and young adults with chronic fatigue syndrome, we defined intolerance to milk protein if subjects reported (i) no evidence of immediate or anaphylactic reactions to milk, (ii) at least 2 of the following 3 chronic symptoms: gastroesophageal reflux, early satiety and epigastric/abdominal pain, (iii) improvement in upper gastrointestinal symptoms on a milk protein elimination diet and (iv) at least 2 recurrences of upper gastrointestinal symptoms >two hours following open re-exposure to milk protein. Subjects completed three quality of life surveys at baseline and at six months.

RESULTS

The mean (SD) age of the 55 participants was 16.5 (2.1) years. Seventeen (31%; 95% CI, 19-43%) met study criteria for cow's milk protein intolerance. Compared to milk-tolerant subjects, milk-sensitive participants had significantly worse health-related quality of life at baseline but not at six months (after institution of the milk-free diet).

CONCLUSION

Cow's milk protein intolerance is a common problem in young people with chronic fatigue syndrome and is a treatable contributor to their symptoms.

Aberrant Resting-State Functional Connectivity in the Salience Network of Adolescent Chronic Fatigue Syndrome

Neural network investigations are currently absent in adolescent chronic fatigue syndrome (CFS). In this study, we examine whether the core intrinsic connectivity networks (ICNs) are altered in adolescent CFS patients. Eighteen adolescent patients with CFS and 18 aged matched healthy adolescent control subjects underwent resting-state functional magnetic resonance imaging (rfMRI). Data was analyzed using dual-regression independent components analysis, which is a data-driven approach for the identification of independent brain networks. Intrinsic connectivity was evaluated in the default mode network (DMN), salience network (SN), and central executive network (CEN). Associations between network characteristics and symptoms of CFS were also explored. Adolescent CFS patients displayed a significant decrease in SN functional connectivity to the right posterior insula compared to healthy comparison participants, which was related to fatigue symptoms. Additionally, there was an association between pain intensity and SN functional connectivity to the left middle insula and caudate that differed between adolescent patients and healthy comparison participants. Our findings of insula dysfunction and its association with fatigue severity and pain intensity in adolescent CFS demonstrate an aberration of the salience network which might play a role in CFS pathophysiology.

Altered neuroendocrine control and association to clinical symptoms in adolescent chronic fatigue syndrome: a cross-sectional study

BACKGROUND

Chronic fatigue syndrome (CFS) is a common and disabling disorder, and a major threat against adolescent health. The pathophysiology is unknown, but alteration of neuroendocrine control systems might be a central element, resulting in attenuation of the hypothalamus-pituitary-adrenalin (HPA) axis and enhancement of the sympathetic/adrenal medulla (SAM) system. This study explored differences in neuroendocrine control mechanisms between adolescent CFS patients and healthy controls, and whether characteristics of the control mechanisms are associated with important clinical variables within the CFS group.

METHODS

CFS patients 12-18 years of age were recruited nation-wide to a single referral center as part of the NorCAPITAL project. A broad case definition of CFS was applied. A comparable group of healthy controls were recruited from local schools. A total of nine hormones were assayed and subjected to network analyses using the ARACNE algorithm. Symptoms were charted by a questionnaire, and daily physical activity was recorded by an accelerometer.

RESULTS

A total of 120 CFS patients and 68 healthy controls were included. CFS patients had significantly higher levels of plasma norepinephrine, plasma epinephrine and plasma FT4, and significantly lower levels of urine cortisol/creatinine ratio. Subgrouping according to other case definitions as well as adjusting for confounding factors did not alter the results. Multivariate linear regression models as well as network analyses revealed different interrelations between hormones of the HPA axis, the SAM system, and the thyroid system in CFS patients and healthy controls. Also, single hormone degree centrality was associated with clinical markers within the CFS group.

CONCLUSION

This study reveals different interrelation between hormones of the HPA axis, the SAM system, and the thyroid system in CFS patients and healthy controls, and an association between hormone control characteristics and important clinical variables in the CFS group. These results add to the growing insight of CFS disease mechanisms. Trial registration Clinical Trials NCT01040429.

Myalgic Encephalomyelitis: Symptoms and Biomarkers

Myalgic Encephalomyelitis (ME) continues to cause significant morbidity worldwide with an estimated one million cases in the United States. Hurdles to establishing consensus to achieve accurate evaluation of patients with ME continue, fueled by poor agreement about case definitions, slow progress in development of standardized diagnostic approaches, and issues surrounding research priorities. Because there are other medical problems, such as early MS and Parkinson's Disease, which have some similar clinical presentations, it is critical to accurately diagnose ME to make a differential diagnosis. In this article, we explore and summarize advances in the physiological and neurological approaches to understanding, diagnosing, and treating ME. We identify key areas and approaches to elucidate the core and secondary symptom clusters in ME so as to provide some practical suggestions in evaluation of ME for clinicians and researchers. This review, therefore, represents a synthesis of key discussions in the literature, and has important implications for a better understanding of ME, its biological markers, and diagnostic criteria. There is a clear need for more longitudinal studies in this area with larger data sets, which correct for multiple testing.

Pain and pressure pain thresholds in adolescents with chronic fatigue syndrome and healthy controls: a cross-sectional study

OBJECTIVES

Although pain is a significant symptom in chronic fatigue syndrome (CFS), pain is poorly understood in adolescents with CFS. The aim of this study was to explore pain distribution and prevalence, pain intensity and its functional interference in everyday life, as well as pressure pain thresholds (PPT) in adolescents with CFS and compare this with a control group of healthy adolescents (HC).

METHODS

This is a case-control, cross-sectional study on pain including 120 adolescents with CFS and 39 HCs, aged 12-18 years. We measured pain frequency, pain severity and pain interference using self-reporting questionnaires. PPT was measured using pressure algometry. Data were collected from March 2010 until October 2012 as part of the Norwegian Study of Chronic Fatigue Syndrome in Adolescents: Pathophysiology and Intervention Trial.

RESULTS

Adolescents with CFS had significantly lower PPTs compared with HCs (p<0.001). The Pain Severity Score and the Pain Interference Score were significantly higher in adolescents with CFS compared with HCs (p<0.001). Almost all adolescents with CFS experienced headache, abdominal pain and/or pain in muscles and joints. Moreover, in all sites, the pain intensity levels were significantly higher than in HCs (p<0.001).

CONCLUSIONS

We found a higher prevalence of severe pain among adolescents with CFS and lowered pain thresholds compared with HCs. The mechanisms, however, are still obscure. Large longitudinal population surveys are warranted measuring pain thresholds prior to the onset of CFS.

TRIAL REGISTRATION NUMBER

Clinical Trials, NCT01040429; The Norwegian Study of Chronic Fatigue Syndrome in Adolescents: Pathophysiology and Intervention Trial (NorCAPITAL) http://www.clinicaltrials.gov.

Orthostatic responses in adolescent chronic fatigue syndrome: contributions from expectancies as well as gravity

BACKGROUND

Orthostatic intolerance is common in chronic fatigue syndrome (CFS), and several studies have documented an abnormal sympathetic predominance in the autonomic cardiovascular response to gravitational stimuli. The aim of this study was to explore whether the expectancies towards standing are contributors to autonomic responses in addition to the gravitational stimulus itself.

METHODS

A total of 30 CFS patients (12-18 years of age) and 39 healthy controls underwent 20° head-up tilt test and a motor imagery protocol of standing upright. Beat-to-beat cardiovascular variables were recorded.

RESULTS

At supine rest, CFS patients had significantly higher heart rate, diastolic blood pressure, and mean arterial blood pressure, and lower stroke index and heart rate variability (HRV) indices. The response to 20° head-up tilt was identical in the two groups. The response to imaginary upright position was characterized by a stronger increase of HRV indices of sympathetic predominance (power in the low-frequency range as well as the ratio low-frequency: high-frequency power) among CFS patients.

CONCLUSIONS

These results suggest that in CFS patients expectancies towards orthostatic challenge might be additional determinants of autonomic cardiovascular modulation along with the gravitational stimulus per se.

Impaired range of motion of limbs and spine in chronic fatigue syndrome

OBJECTIVE

To determine whether adolescents and young adults with chronic fatigue syndrome (CFS) have a greater prevalence of impaired range of motion (ROM) of the limbs and spine than healthy control patients.

STUDY DESIGN

Case-control study comparing rates of abnormal ROM in 48 consecutive adolescents and young adults with CFS and 48 healthy control patients matched by sex and joint hypermobility. We examined range of ankle dorsiflexion, passive straight-leg raise, seated slump, upper-limb neurodynamic test, prone knee bend, and prone press-up. Abnormal ROM was defined before the study began. The number of abnormal responses ranged from 0 (normal ROM throughout) to 11 (impaired ROM in all areas tested).

RESULTS

The median number of areas with impaired ROM was greater in patients with CFS at the onset of stretch in the involved limb (5 vs 2, P<.001) and at end-range (2 vs 0, P<.001). Patients with CFS were more likely to have greater than 3 areas of impaired ROM (OR 6.0, 95% CI 2.1-17.3; P<.001) and were more likely to develop abnormal symptomatic responses to the individual tests and to the overall assessment (40% vs 4%; P<.001).

CONCLUSIONS

Impaired ROM is more common in subjects with CFS than in healthy adolescents and young adults matched by sex and joint hypermobility. Adding a longitudinal strain to the nerves and soft tissues provoked symptoms in some subjects with CFS. The causes, functional impact, and optimal treatment of these abnormalities warrant further study.

Brain sensitization to external and internal stimuli

Sensitization is defined as a non-associative learning process occurring when repeated administrations of a stimulus result in a progressive amplification of a response (Shettleworth, 2010). The purpose of this review paper is to discuss whether brain sensitization is helpful in common health problems in man. The paper reviews data on brain sensitization covering increased behavioral, physiological, cognitive, and emotional responses in man and animals. The paper concludes that brain sensitization may be a helpful concept to understand subjective and "unexplained" health complaints (nonspecific muscle pain, mood changes, fatigue, and gastrointestinal complaints), and, therefore, relevant for evidence based treatment and prevention of these common health problems.

Medically unexplained conditions considered by patients in general practice

BACKGROUND

Patients frequently present with multiple and 'unexplained' symptoms, often resulting in complex consultations. To better understand these patients is a challenge to health care professionals, in general, and GPs, in particular.

OBJECTIVES

In our research on symptom reporting, we wanted to explore whether patients consider that they may suffer from conditions commonly regarded as unexplained, and we explored associations between these concerns and symptom load, life stressors and socio-demographic factors.

METHODS

Consecutive, unselected patients in general practice completed questionnaires addressing eight conditions commonly regarded as unexplained (amalgam poisoning, Candida syndrome, fibromyalgia, food intolerance, electromagnetic hypersensitivity, burnout syndrome, chronic fatigue syndrome and irritable bowel syndrome). With logistic regression, we analysed associations with symptom load, burden of life stressors with negative impact on present health and socio-demographic variables.

RESULTS

Out of the 909 respondents (response rate = 88.8%), 863 had complete data. In total, 39.6% of patients had considered that they may suffer from one or more unexplained conditions (UCs). These concerns were strongly and positively associated with recent symptom load and number of life stressors. If we excluded burnout and food intolerance, corresponding associations were found.

CONCLUSION

Patients frequently considered that they may suffer from UCs. The likelihood of such concerns strongly increased with an increasing symptom load and with the number of life stressors with negative impact on present health. Hence, the number of symptoms may be a strong indicator of whether patients consider their symptoms part of such often controversial multisymptom conditions.

'Sometimes it feels as if the world goes on without me': adolescents' experiences of living with chronic fatigue syndrome

AIMS AND OBJECTIVES

To explore the experience of being an adolescent with chronic fatigue syndrome.

BACKGROUND

Despite ample research, chronic fatigue syndrome is still poorly understood, and there are still controversies related to the illness. Adolescents with chronic fatigue syndrome are often unable to attend school and lose social relations with friends. The challenges they face will affect their quality of life.

DESIGN

A qualitative, phenomenological hermeneutical design.

METHOD

Six boys and twelve girls, aged 12-18, were interviewed, emphasising their own experiences living with chronic fatigue syndrome. Analyses were performed using a phenomenological hermeneutical method.

RESULTS

The core theme, 'Sometimes it feels as if the world goes on without me', encompasses the feelings an adolescent living with chronic fatigue syndrome might have about life. The core theme was supported by four subthemes: 'On the side of life--locked in and shut out'; 'the body, the illness and me'; 'if the illness is not visible to others, does it exist?'; and 'handling life while hoping for a better future'. The subthemes reflect the experience of social isolation, their own and others' understanding of the illness and hope for the future.

CONCLUSIONS

Not being able to be with friends, or attend school, made the adolescents feel different and forgotten. They felt alienated in their own bodies and were struggling to be visible to themselves and to their surroundings. Spending less time with friends and more time with their parents constituted a threat to independence and development. Yet they managed to envision a better future despite all the difficulties.

RELEVANCE FOR CLINICAL PRACTICE

To provide effective support and constructive relations to adolescents with chronic fatigue syndrome, all health professions involved need insight from the persons who are themselves ill. Health centres could function as resource centres for patients and healthcare professionals.

C-reactive protein predicts fatigue independently of depression in breast cancer patients prior to chemotherapy

Heightened inflammatory activity has been proposed as a mechanism for the development of cancer-related fatigue (CRF), a common and distressing condition that can negatively affect quality of life. Inflammation is also implicated in the pathogenesis of depression, and depression is a strong predictor of CRF. Thus, the role of the pro-inflammatory cytokine network in CRF may be mediated by depression or both conditions may share similar underlying physiological processes. The current study investigated associations between fatigue, depression and inflammatory cytokine (IFN-γ, IL-6, TNF-α) and CRP concentrations, as well as kynurenine pathway (KP) activation, in 61 breast cancer patients prior to chemotherapy. Changes in inflammatory markers and KP activation over time were also explored, and associations with changes in fatigue and depression were examined. Higher levels of CRP were significantly correlated with fatigue and depression before chemotherapy; nevertheless, CRP predicted fatigue independently of depression. Although greater kynurenine concentrations were associated with increased immune activation, there was no evidence that the KP played a role in fatigue or depression. Furthermore, no relationships emerged between either fatigue or depression and IFN-γ, IL-6, or TNF-α before chemotherapy. Nevertheless, kynurenine levels pre- and post-treatment significantly predicted changes in depression, suggesting that heightened KP activation may contribute to depressive symptoms in patients treated for cancer. In addition, IL-6 significantly covaried with fatigue. These preliminary findings provide some support for the idea that low-grade inflammation contributes to the development of CRF, independently of depression; however, there was no evidence that this is mediated by KP activity.

Allostatic overload in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating condition characterised by diverse symptoms such as fatigue, pain, sleep disturbance and autonomic dysfunction. There remains to be a singular biomarker identified for this illness, hence numerous theories about its development and perpetuation have been posited in the literature. This brief report presents the model of 'allostasis' as a framework for understanding ME/CFS, specifically the notion that the physiological mechanisms employed in the body to deal with stress termed here as 'allostatic states' (e.g. elevation of inflammatory cytokines), may in and of themselves contribute to the perpetuation of the disorder. This theoretical assertion has important consequences for the understanding of ME/CFS and treatment; rather than searching for a singular pathogen responsible for this condition, ME/CFS can be conceptualised as a maladaptive stress disorder and interventions aimed at addressing the allostatic states may be incorporated into current symptom management programmes.