What is in a name? Comparing diagnostic criteria for chronic fatigue syndrome with or without fibromyalgia

Cognitive Dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome-Aetiology and Potential Treatments

Systemic infection and inflammation impair mental function through a combination of altered attention and cognition. Here, we comprehensively review the relevant literature and report personal clinical observations to discuss the relationship between infection, peripheral inflammation, and cerebral and cognitive dysfunction in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Cognitive dysfunction in ME/CFS could result from low-grade persistent inflammation associated with raised pro-inflammatory cytokines. This may be caused by both infectious and non-infectious stimuli and lead to altered regional cerebral blood flow accompanied by disturbed neuronal function. Immune dysregulation that manifests as a subtle immunodeficiency or the autoimmunity targeting of one or more neuronal receptors may also be a contributing factor. Efforts to reduce low-grade systemic inflammation and viral reactivation and to improve mitochondrial energy generation in ME/CFS have the potential to improve cognitive dysfunction in this highly disabling condition.

Long COVID for the Rheumatologist: Current Understanding and Approach to Management

There are estimated tens of millions of individuals throughout the world suffering from a variety of postinfectious sequela following infection with severe acute respiratory syndrome coronavirus 2 also commonly referred to as long coronavirus disease (COVID). Long COVID is providing an opportunity for the field of rheumatology to explore the relationship between similar syndromes including fibromyalgia seen in patients with underlying inflammatory and noninflammatory rheumatic diseases, as well as other postacute infectious sequela and bring our field's traditional skill sets to bear on improving our understanding of these disorders and the care of such patients.

Myalgic encephalomyelitis/chronic fatigue syndrome from current evidence to new diagnostic perspectives through skeletal muscle and metabolic disturbances

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a demanding medical condition for patients and society. It has raised much more public awareness after the COVID-19 pandemic since ME/CFS and long-COVID patients share many clinical symptoms such as debilitating chronic fatigue. However, unlike long COVID, the etiopathology of ME/CFS remains a mystery despite several decades' research. This review moves from pathophysiology of ME/CFS through the compelling evidence and most interesting hypotheses. It focuses on the pathophysiology of skeletal muscle by proposing the hypothesis that skeletal muscle tissue offers novel opportunities for diagnosis and treatment of this syndrome and that new evidence can help resolve the long-standing debate on terminology.

The Adaptive Force as a Potential Biomechanical Parameter in the Recovery Process of Patients with Long COVID

Long COVID patients show symptoms, such as fatigue, muscle weakness and pain. Adequate diagnostics are still lacking. Investigating muscle function might be a beneficial approach. The holding capacity (maximal isometric Adaptive Force; AFisomax) was previously suggested to be especially sensitive for impairments. This longitudinal, non-clinical study aimed to investigate the AF in long COVID patients and their recovery process. AF parameters of elbow and hip flexors were assessed in 17 patients at three time points (pre: long COVID state, post: immediately after first treatment, end: recovery) by an objectified manual muscle test. The tester applied an increasing force on the limb of the patient, who had to resist isometrically for as long as possible. The intensity of 13 common symptoms were queried. At pre, patients started to lengthen their muscles at ~50% of the maximal AF (AFmax), which was then reached during eccentric motion, indicating unstable adaptation. At post and end, AFisomax increased significantly to ~99% and 100% of AFmax, respectively, reflecting stable adaptation. AFmax was statistically similar for all three time points. Symptom intensity decreased significantly from pre to end. The findings revealed a substantially impaired maximal holding capacity in long COVID patients, which returned to normal function with substantial health improvement. AFisomax might be a suitable sensitive functional parameter to assess long COVID patients and to support therapy process.

Case report: Individualized pulsed electromagnetic field therapy in a Long COVID patient using the Adaptive Force as biomarker

The increasing prevalence of Long COVID is an imminent public health disaster, and established approaches have not provided adequate diagnostics or treatments. Recently, anesthetic blockade of the stellate ganglion was reported to improve Long COVID symptoms in a small case series, purportedly by "rebooting" the autonomic nervous system. Here, we present a novel diagnostic approach based on the Adaptive Force (AF), and report sustained positive outcome for one severely affected Long COVID patient using individualized pulsed electromagnetic field (PEMF) at the area C7/T1. AF reflects the capacity of the neuromuscular system to adapt adequately to external forces in an isometric holding manner. In case, maximal isometric AF (AFisomax) is exceeded, the muscle merges into eccentric muscle action. Thereby, the force usually increases further until maximal AF (AFmax) is reached. In case adaptation is optimal, AFisomax is ~99-100% of AFmax. This holding capacity (AFisomax) was found to be vulnerable to disruption by unpleasant stimulus and, hence, was regarded as functional parameter. AF was assessed by an objectified manual muscle test using a handheld device. Prior to treatment, AFisomax was considerably lower than AFmax for hip flexors (62 N = ~28% AFmax) and elbow flexors (71 N = ~44% AFmax); i.e., maximal holding capacity was significantly reduced, indicating dysfunctional motor control. We tested PEMF at C7/T1, identified a frequency that improved neuromuscular function, and applied it for ~15 min. Immediately post-treatment, AFisomax increased to ~210 N (~100% AFmax) at hip and 184 N (~100% AFmax) at elbow. Subjective Long COVID symptoms resolved the following day. At 4 weeks post-treatment, maximal holding capacity was still on a similarly high level as for immediately post-treatment (~100% AFmax) and patient was symptom-free. At 6 months the patient's Long COVID symptoms have not returned. This case report suggests (1) AF could be a promising diagnostic for post-infectious illness, (2) AF can be used to test effective treatments for post-infectious illness, and (3) individualized PEMF may resolve post-infectious symptoms.

Relationship between Kinesiophobia and Mobility, Impact of the Disease, and Fear of Falling in Women with and without Fibromyalgia: A Cross-Sectional Study

Background: Kinesiophobia is defined as fear of movement due to the painful experience of it. The main symptom of fibromyalgia is persistent and widespread pain associated with other symptoms. This study analyzes the kinesiophobia between women with fibromyalgia and apparently healthy women and investigates the relationship between kinesiophobia and physical fitness tests, fear of falling, and the impact of the fibromyalgia. Methods: Fifty-one women participated in this study were divided into two groups: (1) women with fibromyalgia and (2) apparently healthy women. Participants completed questionnaires to assess kinesiophobia, fear of falling, and the impact of fibromyalgia. Subsequently, participants completed the physical tests Timed Up and Go, 10-step stair ascent, and handgrip strength. Results: Women with fibromyalgia had significant differences in kinesiophobia and fear of falling compared to apparently healthy women. Similarly, performance in the physical tests was lower, except for the handgrip strength, which maintained similar values to the apparently healthy women. Significant relationships were found only in the fibromyalgia group between kinesiophobia, the impact of the disease, fear of falling, and the Timed Up and Go and 10-step stair ascent tests. Conclusions: Women with fibromyalgia showed higher kinesiophobia scores, worse performance in mobility tests, and higher fear of falling than apparently healthy women. Kinesiophobia score is related to Timed Up and Go performance, the 10-step stair ascent, the fear of falling, and the impact of the disease in women with fibromyalgia.

Systematic review and meta-analysis of cognitive impairment in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is commonly associated with cognitive complaints. To bring out the neuropsychological symptomatology inherent to ME/CFS, we conducted a systematic review according to PRISMA and MOOSE guidelines of the literature through the analysis of 764 studies published between 1988 and 2019 by using PubMed Central website and Clarivate analytics platform. We performed a meta-analysis to delineate an idea of the neuropsychological profile inherent in ME/CFS. The clinical picture typically affects visuo-spatial immediate memory (g = - 0.55, p = 0.007), reading speed (g = - 0.82, p = 0.0001) and graphics gesture (g = - 0.59, p = 0.0001). Analysis also revealed difficulties in several processes inherent in episodic verbal memory (storage, retrieval, recognition) and visual memory (recovery) and a low efficiency in attentional abilities. Executive functions seemed to be little or not affected and instrumental functions appeared constantly preserved. With regard to the complexity and heterogeneity of the cognitive phenotype, it turns out that determining a sound clinical picture of ME/CFS cognitive profile must go through a neuropsychological examination allowing a complete evaluation integrating the notion of agreement between the choice and the number of tests and the complexity intrinsic to the pathology.

Theory: Treatments for Prolonged ICU Patients May Provide New Therapeutic Avenues for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

We here provide an overview of treatment trials for prolonged intensive care unit (ICU) patients and theorize about their relevance for potential treatment of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Specifically, these treatment trials generally target: (a) the correction of suppressed endocrine axes, notably through a "reactivation" of the pituitary gland's pulsatile secretion of tropic hormones, or (b) the interruption of the "vicious circle" between inflammation, oxidative and nitrosative stress (O&NS), and low thyroid hormone function. There are significant parallels in the treatment trials for prolonged critical illness and ME/CFS; this is consistent with the hypothesis of an overlap in the mechanisms that prevent recovery in both conditions. Early successes in the simultaneous reactivation of pulsatile pituitary secretions in ICU patients-and the resulting positive metabolic effects-could indicate an avenue for treating ME/CFS. The therapeutic effects of thyroid hormones-including in mitigating O&NS and inflammation and in stimulating the adreno-cortical axis-also merit further studies. Collaborative research projects should further investigate the lessons from treatment trials for prolonged critical illness for solving ME/CFS.

Hand grip strength and fatigability: correlation with clinical parameters and diagnostic suitability in ME/CFS

BACKGROUND

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex and debilitating disease accompanied by muscular fatigue and pain. A functional measure to assess muscle fatigability of ME/CFS patients is, however, not established in clinical routine. The aim of this study is to evaluate by assessing repeat maximum handgrip strength (HGS), muscle fatigability as a diagnostic tool and its correlation with clinical parameters.

METHODS

We assessed the HGS of 105 patients with ME/CFS, 18 patients with Cancer related fatigue (CRF) and 66 healthy controls (HC) using an electric dynamometer assessing maximal (Fmax) and mean force (Fmean) of ten repetitive measurements. Results were correlated with clinical parameters, creatinine kinase (CK) and lactate dehydrogenase (LDH). Further, maximum isometric quadriceps strength measurement was conducted in eight ME/CFS patients and eight HC.

RESULTS

ME/CFS patients have a significantly lower Fmax and Fmean HGS compared to HC (p < 0.0001). Further, Fatigue Ratio assessing decline in strength during repeat maximal HGS measurement (Fmax/Fmean) was higher (p ≤ 0.0012). The Recovery Ratio after an identical second testing 60 min later was significantly lower in ME/CFS compared to HC (Fmean2/Fmean1; p ≤ 0.0020). Lower HGS parameters correlated with severity of disease, post-exertional malaise and muscle pain and with higher CK and LDH levels after exertion.

CONCLUSION

Repeat HGS assessment is a sensitive diagnostic test to assess muscular fatigue and fatigability and an objective measure to assess disease severity in ME/CFS.

Hypothesis: Mechanisms That Prevent Recovery in Prolonged ICU Patients Also Underlie Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Here the hypothesis is advanced that maladaptive mechanisms that prevent recovery in some intensive care unit (ICU) patients may also underlie Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Specifically, these mechanisms are: (a) suppression of the pituitary gland's pulsatile secretion of tropic hormones, and (b) a "vicious circle" between inflammation, oxidative and nitrosative stress (O&NS), and low thyroid hormone function. This hypothesis should be investigated through collaborative research projects.

Predicting GP visits: A multinomial logistic regression investigating GP visits amongst a cohort of UK patients living with Myalgic encephalomyelitis

Background

Myalgic Encephalomyelitis (ME) is a chronic condition whose status within medicine is the subject of on-going debate. Some medical professionals regard it as a contentious illness. Others report a lack of confidence with diagnosis and management of the condition. The genesis of this paper was a complaint, made by an ME patient, about their treatment by a general practitioner. In response to the complaint, Healthwatch Trafford ran a patient experience-gathering project.

Method

Data was collected from 476 participants (411 women and 65 men), living with ME from across the UK. Multinomial logistic regression investigated the predictive utility of length of time with ME; geographic location (i.e. Manchester vs. rest of UK); trust in GP; whether the patient had received a formal diagnosis; time taken to diagnosis; and gender. The outcome variable was number of GP visits per year.

Results

All variables, with the exception of whether the patient had received a formal diagnosis, were significant predictors.

Conclusions

Relationships between ME patients and their GPs are discussed and argued to be key to the effective delivery of care to this patient cohort. Identifying potential barriers to doctor patient interactions in the context of ME is crucial.

Tumorbedingte Fatigue - Prozessevaluation eines Seminars der Universitätsmedizin Greifswald

Cancer-related fatigue - Process evaluation of a seminar of the University Medicine Greifswald Abstract. Background: Fatigue is the most common and stressful symptom in cancer patients and their relatives. The patient information center (PIZ) of the University Medicine Greifswald enables patients to learn how to deal with fatigue and to understand their disease. The fatigue seminar is well accepted by seminar participants, but it is rarely taken up by patients. Aim: The primary objective of this observational study was to find out how well-known this seminar is, whether it is recommended to patients and what the reasons for missing referrals are.

METHODS

Medical and nursing staff of all 13 wards of the Oncology Centre was surveyed by means of a self-developed questionnaire. The questions were analyzed on a single item level. Descriptive statistics and measures of correlation were determined.

RESULTS

The fatigue seminar of the PIZ is hardly known to the n = 115 respondents and / or is not always recommended to those affected. Where the PIZ has been present in the past, the knowledge about fatigue is higher and the seminar is better known. Screening instruments are hardly used for diagnostics.

CONCLUSIONS

The fatigue seminar needs to be promoted in a better way. In order to increase its popularity, it should be presented both to the psychological staff and on the wards. The systematic inclusion of screening instruments in the treatment path of cancer patients and the inclusion of the fatigue seminar in the range of treatment for patients with distressing fatigue symptoms should be discussed.

DNA Methylation and Brain-Derived Neurotrophic Factor Expression Account for Symptoms and Widespread Hyperalgesia in Patients With Chronic Fatigue Syndrome and Comorbid Fibromyalgia

OBJECTIVE

The epigenetics of neurotrophic factors holds the potential to unravel the mechanisms underlying the pathophysiology of complex conditions such as chronic fatigue syndrome (CFS). This study was undertaken to explore the role of brain-derived neurotrophic factor (BDNF) genetics, epigenetics, and protein expression in patients with both CFS and comorbid fibromyalgia (CFS/FM).

METHODS

A repeated-measures study was conducted in 54 participants (28 patients with CFS/FM and 26 matched healthy controls). Participants underwent a comprehensive assessment, including questionnaires, sensory testing, and blood withdrawal. Serum BDNF (sBDNF) protein levels were measured using enzyme-linked immunosorbent assay, while polymorphism and DNA methylation were measured in blood using pyrosequencing technology. To assess the temporal stability of the measures, participants underwent the same assessment twice within 4 days.

RESULTS

Repeated-measures mixed linear models were used for between-group analysis, with mean differences and 95% confidence intervals (95% CIs) shown. Compared to controls, serum BNDF was higher in patients with CFS/FM (F = 15.703; mean difference 3.31 ng/ml [95% CI 1.65, 4.96]; P = 0.001), whereas BDNF DNA methylation in exon 9 was lower (F = 7.543; mean difference -2.16% [95% CI -3.93, -0.83]; P = 0.007). BDNF DNA methylation was mediated by the Val66Met (rs6265) polymorphism. Lower methylation in the same region predicted higher sBDNF levels (F = 7.137, β = -0.408 [95% CI -0.711, -0.105]; P = 0.009), which in turn predicted participants' symptoms (F = 14.410, β = 3.747 [95% CI 1.79, 5.71]; P = 0.001) and widespread hyperalgesia (F = 4.147, β = 0.04 [95% CI 0.01, 0.08]; P = 0.044).

CONCLUSION

Our findings indicate that sBDNF levels are elevated in patients with CFS/FM and that BDNF methylation in exon 9 accounts for the regulation of protein expression. Altered BDNF levels might represent a key mechanism explaining CFS/FM pathophysiology.

Medically Unexplained Symptoms (MUS): Faults and Implications

The classification of medically unexplained symptoms (MUS) could have negative consequences for patients with functional somatic syndromes (FSS). By grouping related but distinct syndromes into one label, the MUS classification fails to inform clinicians about their patients' health condition. In research settings, the MUS classification makes patient samples more heterogeneous, obstructing research into the underlying pathology of FSS. Long-term studies have shown that MUS are often appraised as medically explained symptoms at follow-up and vice versa, raising doubts about the reliability of this distinction.

Myalgic encephalomyelitis or chronic fatigue syndrome: how could the illness develop?

A model of the development and progression of chronic fatigue syndrome (myalgic encephalomyelitis), the aetiology of which is currently unknown, is put forward, starting with a consideration of the post-infection role of damage-associated molecular patterns and the development of chronic inflammatory, oxidative and nitrosative stress in genetically predisposed individuals. The consequences are detailed, including the role of increased intestinal permeability and the translocation of commensal antigens into the circulation, and the development of dysautonomia, neuroinflammation, and neurocognitive and neuroimaging abnormalities. Increasing levels of such stress and the switch to immune and metabolic downregulation are detailed next in relation to the advent of hypernitrosylation, impaired mitochondrial performance, immune suppression, cellular hibernation, endotoxin tolerance and sirtuin 1 activation. The role of chronic stress and the development of endotoxin tolerance via indoleamine 2,3-dioxygenase upregulation and the characteristics of neutrophils, monocytes, macrophages and T cells, including regulatory T cells, in endotoxin tolerance are detailed next. Finally, it is shown how the immune and metabolic abnormalities of chronic fatigue syndrome can be explained by endotoxin tolerance, thus completing the model.

Assessing chronic fatigue syndrome: Self-reported physical functioning and correlations with physical testing

The pathophysiology of chronic fatigue syndrome (CFS) remains unclear; no biomarkers have thus far been identified or physical tests designed to underpin its diagnosis. Assessment mainly uses Fukuda's criteria and is based on the exclusion of symptoms related to other diseases/syndromes, subjective self-reporting, and outcomes of self-report questionnaires. In order to improve the baseline assessment and progress evaluation of individuals suspected of CFS and using an association-oriented research strategy and a cross-correlational design, this study investigates possible associations between the performance on two physical tests, i.e. 'Timed Loaded Standing' (TLS), assessing trunk-arm endurance, and the 'Stops Walking with Eyes Closed while performing a secondary Cognitive Task' (SWECCT), measuring impaired automaticity of gait, and the results of two self-report questionnaires, the Checklist Individual Strength (CIS, total score and fatigue subscale score) and the physical functioning and vitality subscales of the Short Form Health Survey (SF-36) to gauge the participants' subjective feelings of fatigue and beliefs regarding their abilities to perform daily-life activities. Comparisons of the outcomes obtained in 27 female patients with a confirmed diagnosis of CFS revealed that trunk-arm endurance as measured with the TLS correlated with the SF-36 physical functioning subscale only (raw p value: 0.004). None of the other correlations were statistically significant. It is concluded that the TLS may have potential as an objective assessment tool to support the diagnosis and monitoring of treatment effects in CFS.

Hand Grip Strength as a Clinical Biomarker for ME/CFS and Disease Severity

Background: The diagnosis of myalgic encephalomyelitis (ME/CFS) in research and clinical practice has largely relied on clinical history, which can be subjective in nature. Clinical signs are often subtle, overlap with other conditions, and are not formally included as part of diagnostic workup. The characterization of clinical signs and biomarkers is needed for better diagnosis and classification of patients and to monitor treatment response. Hand grip strength (HGS) has been used as an objective measure of muscle strength and fatigue, which is a primary symptom of ME/CFS. We assessed the potential usefulness of HGS as a diagnostic marker in ME/CFS. Methods: We compared HGS measurements from participants in the UK ME/CFS Biobank, with groups consisting of people with ME/CFS of differing severity (n = 272), healthy (n = 136), multiple sclerosis (n = 76) controls, and others with chronic fatigue not meeting the diagnosis of ME/CFS (n = 37). We correlated the maximum and minimum of, and differences between, 3 repeated HGS measurements with parameters of disease severity, including fatigue and pain analog scales, and physical and mental component summaries from the SF-36v2TM questionnaire across recruitment groups. Results: HGS indicators were associated with having ME/CFS, with magnitudes of association stronger in severely affected than in mild/moderately affected patients. Compared with healthy controls, being severely affected was associated with a reduction in minimum HGS of 15.3 kg (95%CI 19.3-11.3; p < 0.001), while being mild/moderately affected was associated with a 10.5 kg (95%CI 13.2-7.8; p < 0.001) reduction. The association persisted after adjusting for age, sex and body mass index. ME/CFS cases also showed lower values of maximum HGS and significant drops in values from the first to second and third trials, compared to other study groups. There were significant correlations between HGS indicators and clinical parameters of disease severity, including fatigue analog scale (Spearman's Rho = -0.40, p < 0.001), pain analog scale (Rho = -0.38, p < 0.001), and physical component summary (Rho = 0.42, p < 0.001). Discussion: HGS is markedly reduced in ME/CFS, particularly in patients with more severe disease, and may indicate muscle and fatigue related symptoms. HGS is a potential diagnostic tool in ME/CFS, and could also be used to enhance patient phenotyping and as an outcome measure following interventions.

Dry eye syndrome and the subsequent risk of chronic fatigue syndrome-a prospective population-based study in Taiwan

Background and Aim

The clinical association between dry eye syndrome (DES) and chronic fatigue syndrome (CFS) remain unclear with less evidences. We aimed to investigate the relationship between CFS and DES using a national insurance and prospective cohort study.

Methods

Data from the Longitudinal Health Insurance Database 2000 was applied to estimate the incidence of CFS among patients with DES, and their age- and sex-matched controls without DES over a long-term follow-up period. All participants were CFS free at baseline, before the interval (2005-2007), but were later diagnosed with CFS. DES patients and its relative matched controls were excluded prevalent CFS before the same interval.

Results

We identified 884 patients with DES and 3,536 matched controls in baseline and estimated the hazard ratios for incident CFS in the follow-up period. Patients with DES had a 2.08-fold considerably increasing risk of developing CFS, compared to non-DES group. An elevated risk of developing CFS remained (1.61-fold risk) even after adjusting for age, sex, and comorbidities. There was a presence of increasing risk in DES-related CFS when CFS-related comorbidities existing (adjusted hazard ratio, 1.98, 95% confidence interval, 1.19-3.29; p < 0.01). The subsequent risk for CFS between DES and non-DES patients was significant increased with three or more annual medical visits, the adjusted risk for CFS was 4.88-fold risk (95% CI, 2.26-10.58, p < 0.001).

Conclusion

We recommended that physicians should be aware of the increased risk of CFS among DES patients and adequately assess the health impacts among these patients.

Lower regulatory frequency for postural control in patients with fibromyalgia and chronic fatigue syndrome

As many similar symptoms are reported in fibromyalgia (FM) and chronic fatigue syndrome (CFS), underlying defcits may potentially also be similar. Postural disequilibrium reported in both conditions may thus be explained by similar deviations in postural control strategies. 75 females (25/group FM, CFS and control, age 19-49 years) performed 60 s of quiet standing on a force platform in each of three conditions: 1) firm surface with vision, 2) firm surface without vision and, 3) compliant surface with vision. Migration of center of pressure was decomposed into a slow and a fast component denoting postural sway and lateral forces controlling postural sway, analyzed in the time and frequency domains. Main effects of group for the antero-posterior (AP) and medio-lateral (ML) directions showed that patients displayed larger amplitudes (AP, p = 0.002; ML, p = 0.021) and lower frequencies (AP, p < 0.001; ML, p < 0.001) for the slow component, as well as for the fast component (amplitudes: AP, p = 0.010; ML, p = 0.001 and frequencies: AP, p = 0.001; ML, p = 0.029) compared to controls. Post hoc analyses showed no significant differences between patient groups. In conclusion, both the CFS- and the FM-group differed from the control group. Larger postural sway and insufficient control was found in patients compared to controls, with no significant differences between the two patient groups.

On chronic fatigue syndrome and nosological categories

Chronic fatigue syndrome (CFS) is a heterogeneous disease which presents with pronounced disabling fatigue, sleep disturbances, and cognitive impairment that negatively affects patients' functional capability. CFS remains a poorly defined entity and its etiology is still in question. CFS is neither a novel diagnosis nor a new medical condition. From as early as the eighteenth century, a constellation of perplexing symptoms was observed that resembled symptoms of CFS. Commencing with "febricula" and ending with CFS, many names for the disease were proposed including neurocirculatory asthenia, atypical poliomyelitis, Royal Free disease, effort syndrome, Akureyri disease, Tapanui disease, chronic Epstein-Barr virus syndrome, and myalgic encephalitis. To date, it remains unclear whether CFS has an autoimmune component or is a condition that precedes a full-blown autoimmune disease. Research suggests that CFS may overlap with other diseases including postural orthostatic tachycardia syndrome (POTS), autoimmune syndrome induced by adjuvants (ASIA), and Sjögren's syndrome. Additionally, it has been postulated that the earliest manifestations of some autoimmune diseases can present with vague non-specific symptoms similar to CFS. Sometimes only when exposed to a secondary stimulus (e.g., antigen) which could accelerate the natural course of the disease would an individual develop the classic autoimmune disease. Due to the similarity of symptoms, it has been postulated that CFS could simply be an early manifestation of an autoimmune disease. This paper will provide a historical background review of this disease and a discussion of CFS as an entity overlapping with multiple other conditions.

Longitudinal outcomes associated with significant other responses to chronic fatigue and pain

This study investigated significant others' behavior associated with fatigue, pain, and mental health outcomes among 68 individuals with chronic fatigue (43% also had fibromyalgia) over 18 months. More negative significant others' responses were associated with more pain, poorer physical and mental health, and more fatigue-related symptoms over time. More fibromyalgia tender points covaried with more solicitous significant others' responses over time. Better mental health covaried with more distracting significant others' responses over time. The results are discussed in terms of theoretical models of the role of perceived significant others' responses on patient outcomes and recommendations for future research.

Static postural sway of women with and without fibromyalgia syndrome: A cross-sectional study

BACKGROUND

There is a frequent complaint about balance problems among fibromyalgia syndrome patients; however, there are not enough studies that have shown static postural sway of women with fibromyalgia syndrome. This study aimed to compare static postural sway of women with and without fibromyalgia syndrome.

METHODS

This is a cross-sectional study in which twenty-nine women with fibromyalgia syndrome and 20 without took part. A posturography evaluation was performed in six different situations (bipedal, right tandem and left tandem, with eyes opened and closed), and questionnaires for clinical depression symptoms, clinical anxiety symptoms, sleep quality, and Visual Analogue Scales for Pain and Fatigue were applied. Mann-Whitney U test was used to check differences among groups; Wilcoxon matched-pair test was used to check differences intragroup; Cohen d coefficient was used to measure effect sizes and Pearson Correlation Coefficient was used for correlations among variables. Level of significance adopted was 5%.

FINDINGS

Women with fibromyalgia syndrome have presented worse postural sway than women without fibromyalgia syndrome in all situations (P<0.05), and worse scores in all questionnaires (P<0.05). In the eyes closed situations, women with fibromyalgia syndrome presented worse postural sway than women without in the same conditions.

INTERPRETATION

Women with fibromyalgia syndrome have worse performance in the static posture test, more prominent in reduced support bases with eyes closed. Pain, fatigue, depression and anxiety may have directly influenced postural sway in fibromyalgia syndrome patients.

Gross and fine motor function in fibromyalgia and chronic fatigue syndrome

Purpose

This paper aimed to investigate motor proficiency in fine and gross motor function, with a focus on reaction time (RT) and movement skill, in patients with fibromyalgia (FM) and chronic fatigue syndrome (CFS) compared to healthy controls (HC).

Methods

A total of 60 individuals (20 CFS, 20 FM, and 20 HC), age 19–49 years, participated in this study. Gross motor function in the lower extremity was assessed using a RT task during gait initiation in response to an auditory trigger. Fine motor function in the upper extremity was measured during a precision task (the Purdue Pegboard test) where the number of pins inserted within 30 s was counted.

Results

No significant differences were found between FM and CFS in any parameters. FM and CFS groups had significantly longer RT than HC in the gait initiation (p=0.001, and p=0.004 respectively). In the Purdue Pegboard test, 20% in the FM group, 15% in the CFS groups, and 0% of HC group, scored below the threshold of the accepted performance. However, there were no significant differences between FM, CFS, and HC in this task (p=0.12).

Conclusion

Compared to controls, both CFS and FM groups displayed significantly longer RT in the gait initiation task. Generally, FM patients showed the worst results in both tests, although no group differences were found in fine motor control, according to the Purdue Pegboard test.

TauG-guidance of dynamic balance control during gait initiation in patients with chronic fatigue syndrome and fibromyalgia

BACKGROUND

Impaired postural control has been reported in static conditions in chronic fatigue syndrome and fibromyalgia, but postural control in dynamic tasks have not yet been investigated. Thus, we investigated measurements from a force plate to evaluate dynamic balance control during gait initiation in patients with chronic fatigue syndrome and fibromyalgia compared to matched healthy controls.

METHODS

Thirty female participants (10 per group) performed five trials of gait initiation. Center of pressure (CoP) trajectory of the initial weight shift onto the supporting foot in the mediolateral direction (CoPX) was analyzed using General Tau Theory. We investigated the hypothesis that tau of the CoPX motion-gap (τCoPx) is coupled onto an intrinsic tauG-guide (τG) by keeping the relation τCoPx=KτG, where K is a scaling factor that determines the relevant kinematics of a movement.

FINDINGS

Mean K values were 0.57, 0.55, and 0.50 in fibromyalgia, chronic fatigue syndrome, and healthy controls, respectively. Both patient groups showed K values significantly higher than 0.50 (P<0.05), indicating that patients showed poorer dynamic balance control, CoPX colliding with the boundaries of the base of support (K>0.5).

INTERPRETATION

The findings revealed a lower level of dynamic postural control in both fibromyalgia and chronic fatigue syndrome compared to controls.

Accurate diagnosis of myalgic encephalomyelitis and chronic fatigue syndrome based upon objective test methods for characteristic symptoms

Although myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS) are considered to be synonymous, the definitional criteria for ME and CFS define two distinct, partially overlapping, clinical entities. ME, whether defined by the original criteria or by the recently proposed criteria, is not equivalent to CFS, let alone a severe variant of incapacitating chronic fatigue. Distinctive features of ME are: muscle weakness and easy muscle fatigability, cognitive impairment, circulatory deficits, a marked variability of the symptoms in presence and severity, but above all, post-exertional “malaise”: a (delayed) prolonged aggravation of symptoms after a minor exertion. In contrast, CFS is primarily defined by (unexplained) chronic fatigue, which should be accompanied by four out of a list of 8 symptoms, e.g., headaches. Due to the subjective nature of several symptoms of ME and CFS, researchers and clinicians have questioned the physiological origin of these symptoms and qualified ME and CFS as functional somatic syndromes. However, various characteristic symptoms, e.g., post-exertional “malaise” and muscle weakness, can be assessed objectively using well-accepted methods, e.g., cardiopulmonary exercise tests and cognitive tests. The objective measures acquired by these methods should be used to accurately diagnose patients, to evaluate the severity and impact of the illness objectively and to assess the positive and negative effects of proposed therapies impartially.