Warning Signals of Post-Exertional Malaise in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Retrospective Analysis of 197 Patients

Abstract:

Post-exertional malaise (PEM), the key feature of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), is characterized by baseline symptom exacerbation after exposure to a stressor, and some patients can experience new or non-typical symptoms. We hypothesized that new or non-typical symptoms occurring long enough before onset of baseline symptom exacerbation could be warning signals predicting PEM.

Adult ME/CFS patients who attended the internal medicine department of Angers University Hospital (France) between October 2011 and December 2019 were included in a retrospective medical records review. Patients who experienced one or more new or non-typical symptoms before baseline symptom exacerbation were compared with the rest of the study population for PEM features, epidemiological characteristics, fatigue features, and comorbidities. New or non-typical symptoms preceded baseline symptom exacerbation in 27/197 (13.7%) patients, and the most frequent ones were mood disorders (37%). When compared to the rest of the study population, only PEM intensity was significantly lower in these patients (p = 0.004), even after adjustment for sex and age at disease onset (p = 0.007).

New or non-typical symptoms preceding baseline symptom exacerbation in some ME/CFS patients could be warning signals for PEM. Their identification could help preventing PEM occurrences or reducing their intensity leading to improving disease prognosis.

Source: Ghali A, Lacout C, Ghali M, Gury A, Delattre E, Lavigne C, Urbanski G. Warning Signals of Post-Exertional Malaise in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Retrospective Analysis of 197 Patients. J Clin Med. 2021 Jun 7;10(11):2517. doi: 10.3390/jcm10112517. PMID: 34200126. https://pubmed.ncbi.nlm.nih.gov/34200126/

Systematic Review of Sleep Characteristics in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

(1) Background-Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a multifaceted illness characterized by profound and persistent fatigue unrelieved by rest along with a range of other debilitating symptoms. Experiences of unrefreshing and disturbed sleep are frequently described by ME/CFS patients. This is the first systematic review assessing sleep characteristics in ME/CFS. The aim of this review is to determine whether there are clinical characteristics of sleep in ME/CFS patients compared to healthy controls using objective measures such as polysomnography and multiple sleep latency testing.

(2) Methods-the following databases-Pubmed, Embase, Medline (EBSCO host) and Web of Science, were systematically searched for journal articles published between January 1994 to 19 February 2021. Articles that referred to polysomnography or multiple sleep latency testing and ME/CFS patients were selected, and further refined through use of specific inclusion and exclusion criteria. Quality and bias were measured using the Joanna Briggs Institute checklist.

(3) Results-twenty observational studies were included in this review. The studies investigated objective measures of sleep quality in ME/CFS. Subjective measures including perceived sleep quality and other quality of life factors were also described.

(4) Conclusions-Many of the parameters measured including slow- wave sleep, apnea- hypopnea index, spectral activity and multiple sleep latency testing were inconsistent across the studies. The available research on sleep quality in ME/CFS was also limited by recruitment decisions, confounding factors, small sample sizes and non-replicated findings. Future well-designed studies are required to understand sleep quality in ME/CFS patients.

Source: Maksoud R, Eaton-Fitch N, Matula M, Cabanas H, Staines D, Marshall-Gradisnik S. Systematic Review of Sleep Characteristics in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Healthcare (Basel). 2021 May 11;9(5):568. doi: 10.3390/healthcare9050568. PMID: 34065013. https://pubmed.ncbi.nlm.nih.gov/34065013/

Dissecting the nature of post-exertional malaise

Abstract:

Background: Post-exertional malaise (PEM) is a defining characteristic of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) but there is insufficient research dissecting the nature of PEM from the patients’ perspective.

Methods: A PEM questionnaire administered to 150 ME/CFS patients. It included open-ended questions about triggers, experiences, recovery, and prevention. Responses were re-coded into concise, representative topics. Chi-Square tests of independence were then used to test for differences and relationships between duration of ME/CFS illness (<4 years and >10 years), PEM onset and duration, and gender with PEM trigger, experience, recovery, and prevention.

Results: Physical exertion was the most common trigger of PEM. The onset of PEM occurred within minutes after physical exertion compared to within hours after cognitive exertion (<0.05). ME/CFS patients sick for <4 years reported stress as a trigger significantly more often than those sick for >10 years (<0.001). ME/CFS patients sick for <4 years experienced more orthostatic symptoms during PEM than those sick for >10 years. ME/CFS patients sick for >10 years reported using medications to recover from PEM significantly more that those sick for <4 years (<0.01). Pacing and avoiding specific triggers were common approaches to prevent PEM.

Conclusions: There are differences in PEM triggers, experiences and recovery based on duration of illness. Asking about PEM is important for diagnosis and to understand how to manage PEM. Given that PEM occurs more quickly after physical versus cognitive exertion, these results should instigate research on the relationship of upright posture, hypoperfusion and PEM.

Source: Megan Hartle, Lucinda Bateman & Suzanne D. Vernon (2021) Dissecting the nature of post-exertional malaise, Fatigue: Biomedicine, Health & Behavior, DOI: 10.1080/21641846.2021.1905415 https://www.tandfonline.com/doi/full/10.1080/21641846.2021.1905415 (Full text)

Exploratory study into the relationship between the symptoms of chronic fatigue syndrome (CFS)/myalgic encephalomyelitis (ME) and fibromyalgia (FM) using a quasiexperimental design

Abstract:

Objective: To explore the relationship between symptoms of chronic fatigue syndrome (CFS)/myalgic encephalomyelitis (ME) and fibromyalgia (FM). The hypothesis predicated that there would be no significant differences between the group’s symptom experience.

Design: A quasiexperimental design. Structural equation modelling (SEM) and invariance testing.

Participants: Males (M) and females (F) >16 with a confirmed diagnosis of CFS/ME or FM by a general practitioner or specialist. CFS/ME (n=101, F: n=86, M: n=15, mean (M) age M=45.5 years). FM (n=107, F: n=95, M: n=12, M=47.2 years).

Outcome measures: Diagnostic criteria: the American Centers for Disease Control and Prevention (CDC) for CFS/ME and the American College of Rheumatology (ACR) criteria for FM. Additional symptom questionnaires measuring: pain, sleep quality, fatigue, quality of life, anxiety and depression, locus of control and self-esteem.

Results: Invariance was confirmed with the exception of the American CDC Symptom Inventory, Fibromyalgia Impact Questionnaire and Hospital Anxiety and Depression Scale (p<0.05) based on five questions. Consequently, it was erroneous to conclude differences. Therefore, the Syndrome Model was created. SEM could not have tested the ACR previously, as it comprised a single data point. Thus, it was combined with these three questionnaires, increasing the data points, to create this new measurable model. Results confirmed no significant differences between groups (p=0.07 (p<0.05)).

Conclusion: Participants responded in a similar manner to the questionnaire, confirming the same symptom experience. It is important to consider this in context with differing criteria and management guidelines, as this may influence diagnosis and the trajectory of patient’s management. With the biomedical cause currently unclear, it is the symptom experience and the impact on quality of life that is important. These findings are meaningful for patients, clinicians and policy development and support the requirement for future research.

Source: Mckay PG, Walker H, Martin CR, Fleming M. Exploratory study into the relationship between the symptoms of chronic fatigue syndrome (CFS)/myalgic encephalomyelitis (ME) and fibromyalgia (FM) using a quasiexperimental design. BMJ Open. 2021 Feb 1;11(2):e041947. doi: 10.1136/bmjopen-2020-041947. PMID: 33526500. https://bmjopen.bmj.com/content/11/2/e041947.long (Full text)

Numeric Rating Scales Show Prolonged Post-exertional Symptoms After Orthostatic Testing of Adults With Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Introduction: Muscle pain, fatigue, and concentration problems are common among individuals with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). These symptoms are commonly increased as part of the phenomenon of postexertional malaise (PEM). An increase in the severity of these symptoms is described following physical or mental exercise in ME/CFS patients. Another important symptom of ME/CFS is orthostatic intolerance, which can be detected by head-up tilt testing (HUT). The effect of HUT on PEM has not been studied extensively. For this purpose, we assessed numeric rating scales (NRS) for pain, fatigue, and concentration pre- and post-HUT. As pain is a core symptom in fibromyalgia (FM), we subgrouped ME/CFS patients by the presence or absence of FM.

Methods and Results: In eligible ME/CFS patients who underwent HUT, NRS of pain, fatigue, and concentration were obtained pre-HUT, immediately after HUT, at 24 and 48 h, and at 7 days posttest. We studied 174 ME/CFS patients with FM, 104 without FM, and 30 healthy controls (HC). Values for all symptoms were unchanged for HC pre- and post-HUT. Compared with pre-HUT, the three NRS post-HUT were significantly elevated in both ME/CFS patient groups even after 7 days. NRS pain was significantly higher at all time points measured in the ME/CFS patients with FM compared with those without FM. In ME/CFS patients, the maximum fatigue and concentration scores occurred directly post-HUT, whereas pain perception reached the maximum 24 h post-HUT.

Conclusion: NRS scores of pain, fatigue, and concentration were significantly increased even at 7 days post-HUT compared with pre-HUT in ME/CFS patients with and without FM, suggesting that orthostatic stress is an important determinant of PEM.

Source: C (Linda) M. C. van Campen, Peter C. Rowe, Freek W. A. Verheugt and Frans C. Visser. Numeric Rating Scales Show Prolonged Post-exertional Symptoms After Orthostatic Testing of Adults With Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Front. Med., 27 January 2021 | https://doi.org/10.3389/fmed.2020.602894 https://www.frontiersin.org/articles/10.3389/fmed.2020.602894/full  (Full text)

Paradigm shift to disequilibrium in the genesis of orthostatic intolerance in patients with myalgic encephalomyelitis and chronic fatigue syndrome

Abstract:

Background: Orthostatic intolerance (OI) markedly impairs activities of daily living in patients with myalgic encephalomyelitis (ME) or chronic fatigue syndrome. OI is surmised to be a cardiovascular symptom correlated with cerebral hypo-perfusion and exaggerated sympathetic activation. Postural instability or disequilibrium may be part of the etiology of OI.

Methods: The study comprised 72 patients with ME (18 men, 54 women; mean age, 37 ± 10 years) who underwent neurological examinations and the 10 min standing test. We quantified disequilibrium (instability upon standing with feet together and eyes shut), ability to complete the 10 min standing test, and postural orthostatic tachycardia (POT) during the test.

Results: Disequilibrium was detected in 23/72 (32%) patients and POT in 16 (22%). Nineteen (26%) patients failed to complete the 10 min standing test; disequilibrium was significantly more common in the 19- patient subgroup than in the 53-patient test-completing subgroup (89% vs. 11%, p < 0.01). However, the rate of POT was not different between the groups (21% vs. 23%, p = 1.00). Compared with the 49 (68%) patients without disequilibrium, the 23 (32%) patients with disequilibrium were significantly more likely to have failed to complete the test (74% vs. 4%, p < 0.01). The rate of POT was comparable between the groups (23% vs. 22%, p = 1.00). Among patients with disequilibrium who failed to complete the 10 min standing test and had a previous record, 6/8 had completed the test 6-24 months earlier when all six had reported no disequilibrium.

Conclusion: Disequilibrium should be recognized as an important cause of OI in patients with ME.

Source: Miwa K, Inoue Y. Paradigm shift to disequilibrium in the genesis of orthostatic intolerance in patients with myalgic encephalomyelitis and chronic fatigue syndrome. Int J Cardiol Hypertens. 2020 May 20;5:100032. doi: 10.1016/j.ijchy.2020.100032. PMID: 33447761; PMCID: PMC7803012. https://pubmed.ncbi.nlm.nih.gov/33447761/

The Prospects of the Two-Day Cardiopulmonary Exercise Test (CPET) in ME/CFS Patients: A Meta-Analysis

Abstract:

Background: The diagnosis of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is problematic due to the lack of established objective measurements. Postexertional malaise (PEM) is a hallmark of ME/CFS, and the two-day cardiopulmonary exercise test (CPET) has been tested as a tool to assess functional impairment in ME/CFS patients. This study aimed to estimate the potential of the CPET.

Methods: We reviewed studies of the two-day CPET and meta-analyzed the differences between ME/CFS patients and controls regarding four parameters: volume of oxygen consumption and level of workload at peak (VO2peak, Workloadpeak) and at ventilatory threshold (VO2@VT, Workload@VT).

Results: The overall mean values of all parameters were lower on the 2nd day of the CPET than the 1st in ME/CFS patients, while it increased in the controls. From the meta-analysis, the difference between patients and controls was highly significant at Workload@VT (overall mean: -10.8 at Test 1 vs. -33.0 at Test 2, p < 0.05), which may reflect present the functional impairment associated with PEM.

Conclusions: Our results show the potential of the two-day CPET to serve as an objective assessment of PEM in ME/CFS patients. Further clinical trials are required to validate this tool compared to other fatigue-inducing disorders, including depression, using well-designed large-scale studies.

Source: Lim EJ, Kang EB, Jang ES, Son CG. The Prospects of the Two-Day Cardiopulmonary Exercise Test (CPET) in ME/CFS Patients: A Meta-Analysis. J Clin Med. 2020 Dec 14;9(12):E4040. doi: 10.3390/jcm9124040. PMID: 33327624. https://pubmed.ncbi.nlm.nih.gov/33327624/

Profile of circulating microRNAs in myalgic encephalomyelitis and their relation to symptom severity, and disease pathophysiology

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex chronic disease, rooted in multi-system dysfunctions characterized by unexplained debilitating fatigue. Post-exertional malaise (PEM), defined as the exacerbation of the patient’s symptoms following minimal physical or mental stress, is a hallmark of ME/CFS. While multiple case definitions exist, there is currently no well-established biomarkers or laboratory tests to diagnose ME/CFS. Our study aimed to investigate circulating microRNA expression in severely ill ME/CFS patients before and after an innovative stress challenge that stimulates PEM. Our findings highlight the differential expression of eleven microRNAs associated with a physiological response to PEM. The present study uncovers specific microRNA expression signatures associated with ME/CFS in response to PEM induction and reports microRNA expression patterns associated to specific symptom severities. The identification of distinctive microRNA expression signatures for ME/CFS through a provocation challenge is essential for the elucidation of the ME/CFS pathophysiology, and lead to accurate diagnoses, prevention measures, and effective treatment options.

Source: Nepotchatykh, E., Elremaly, W., Caraus, I. et al. Profile of circulating microRNAs in myalgic encephalomyelitis and their relation to symptom severity, and disease pathophysiology. Sci Rep 10, 19620 (2020). https://doi.org/10.1038/s41598-020-76438-y  https://www.nature.com/articles/s41598-020-76438-y (Full text)

Characterization of Post-exertional Malaise in Patients With Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome is characterized by persistent and disabling fatigue, exercise intolerance, cognitive difficulty, and musculoskeletal/joint pain. Post-exertional malaise is a worsening of these symptoms after a physical or mental exertion and is considered a central feature of the illness. Scant observations in the available literature provide qualitative assessments of post-exertional malaise in patients with myalgic encephalomyelitis/chronic fatigue syndrome. To enhance our understanding, a series of outpatient focus groups were convened.

Methods: Nine focus groups totaling 43 patients who reported being diagnosed with myalgic encephalomyelitis/chronic fatigue syndrome were held between November 2016 and August 2019. Focus groups queried post-exertional malaise in daily life and participants’ retrospective memory of post-exertional malaise that followed an exercise provocation with a cardiopulmonary exercise test. Data analysis followed the grounded theory method to systematically code and categorize the data to find meaningful patterns. A qualitative software package was used to move text into categories during data coding.

Results: A wide range of symptoms were attributed to exertion both in daily lives and following cardiopulmonary exercise testing. While three core symptoms emerged (exhaustion, cognitive difficulties, and neuromuscular complaints), participants’ descriptions were notable for their unique individual variations. Of 18 participants who responded to questions centered around symptoms following a cardiopulmonary exercise test, 17 reported that symptoms started within 24 h and peaked in severity within 72 h following the cardiopulmonary exercise test. Patients described post-exertional malaise as interfering with their ability to lead a “normal” life.

Conclusion: The experience of post-exertional malaise in myalgic encephalomyelitis/chronic fatigue syndrome varies greatly between individuals and leads to a diminished quality of life. myalgic encephalomyelitis/chronic fatigue syndrome patients describe post-exertional malaise as all-encompassing with symptoms affecting every part of the body, difficult to predict or manage, and requiring complete bedrest to fully or partially recover. Given the extensive variability in patients, further research identifying subtypes of post-exertional malaise could lead to better targeted therapeutic options.

Source: Stussman B, Williams A, Snow J, Gavin A, Scott R, Nath A, Walitt B. Characterization of Post-exertional Malaise in Patients With Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Front Neurol. 2020 Sep 18;11:1025. doi: 10.3389/fneur.2020.01025. PMID: 33071931; PMCID: PMC7530890. https://www.frontiersin.org/articles/10.3389/fneur.2020.01025/full  (Full text)

Reductions in Cerebral Blood Flow Can Be Provoked by Sitting in Severe Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Patients

Abstract:

Introduction: In a large study with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) patients, we showed that 86% had symptoms of orthostatic intolerance in daily life and that 90% had an abnormal reduction in cerebral blood flow (CBF) during a standard tilt test. A standard head-up tilt test might not be tolerated by the most severely affected bed-ridden ME/CFS patients. Sitting upright is a milder orthostatic stress. The present study examined whether a sitting test, measuring cerebral blood flow by extracranial Doppler, would be sufficient to provoke abnormal reductions in cerebral blood flow in severe ME/CFS patients.

Methods and results: 100 severe ME/CFS patients were studied, (88 females) and were compared with 15 healthy controls (HC) (13 females). CBF was measured first while seated for at least one hour, followed by a CBF measurement in the supine position. Fibromyalgia was present in 37 patients. Demographic data as well as supine heart rate and blood pressures were not different between ME/CFS patients and HC. Heart rate and blood pressure did not change significantly between supine and sitting both in patients and HC. Supine CBF was not different between patients and HC. In contrast, absolute CBF during sitting was lower in patients compared to HC: 474 (96) mL/min in patients and 627 (89) mL/min in HC; p < 0.0001. As a result, percent CBF reduction while seated was −24.5 (9.4)% in severe ME/CFS patients and −0.4 (1.2)% in HC (p < 0.0001). In the ten patients who had no orthostatic intolerance complaints in daily life, the CBF reduction was −2.7 (2.1)%, which was not significantly different from HC (p = 0.58). The remaining 90 patients with orthostatic intolerance complaints had a −26.9 (6.2)% CBF reduction. No difference in CBF parameters was found in patients with and without fibromyalgia. Patients with a previous diagnosis of postural orthostatic tachycardia syndrome (POTS) had a significantly larger CBF reduction compared with those without POTS: 28.8 (7.2)% vs. 22.3 (9.7)% (p = 0.0008).

Conclusions: A sitting test in severe ME/CFS patients was sufficient to provoke a clinically and statistically significant mean CBF decline of 24.5%. Patients with a previous diagnosis of POTS had a larger CBF reduction while seated, compared to patients without POTS. The magnitude of these CBF reductions is similar to the results in less severely affected ME/CFS patients during head-up tilt, suggesting that a sitting test is adequate for the diagnosis of orthostatic intolerance in severely affected patients.

Source: C (Linda) MC van Campen, Peter C. Rowe, and Frans C Visser. Reductions in Cerebral Blood Flow Can Be Provoked by Sitting in Severe Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Patients. Healthcare 2020, 8(4), 394; https://doi.org/10.3390/healthcare8040394 https://www.mdpi.com/2227-9032/8/4/394/htm (Full text)