Physical Activity Measures in Patients With Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Correlations Between Peak Oxygen Consumption, the Physical Functioning Scale of the SF-36 Questionnaire, and the Number of Steps From an Activity Meter

Abstract:

Background: Most studies to assess effort intolerance in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) have used questionnaires. Few studies have compared questionnaires with objective measures like an actometer or an exercise test. This study compared three measures of physical activity in ME/CFS patients: the physical functioning scale (PFS) of the SF-36, the number of steps/day (Steps) using an actometer, and the %peak VO2 of a cardiopulmonary stress test.

Methods: Female ME/CFS patients were selected from a clinical database if the three types of measurements were available, and the interval between measurements was ≤ 3 months. Data from the three measures were compared by linear regression.

Results: In 99 female patients the three different measures were linearly, significantly, and positively correlated (PFS vs Steps, PFS vs %peak VO2 and Steps vs %peak VO2: all P < 0.001). Subgroup analysis showed that the relations between the three measures were not different in patients with versus without fibromyalgia and with versus without a maximal exercise effort (RER ≥ 1.1). In 20 patients re-evaluated for symptom worsening, the mean of all three measures was significantly lower (P < 0.0001), strengthening the observation of the relations between them. Despite the close correlation, we observed a large variation between the three measures in individual patients.

Conclusions: Given the large variation in ME/CFS patients, the use of only one type of measurement is inadequate. Integrating the three modalities may be useful for patient care by detecting overt discrepancies in activity and may inform studies that compare methods of improving exercise capacity.

Source: van Campen CMC, Rowe PC, Verheugt FWA, Visser FC. Physical activity measures in patients with myalgic encephalomyelitis/chronic fatigue syndrome: correlations between peak oxygen consumption, the physical functioning scale of the SF-36 questionnaire, and the number of steps from an activity meter. J Transl Med. 2020;18(1):228. Published 2020 Jun 8. doi:10.1186/s12967-020-02397-7 https://pubmed.ncbi.nlm.nih.gov/32513266/

Heart Rate Thresholds to Limit Activity in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Patients (Pacing): Comparison of Heart Rate Formulae and Measurements of the Heart Rate at the Lactic Acidosis Threshold during Cardiopulmonary Exercise Testing

Abstract:

Introduction: Based on the hypothesis that oxidative metabolism is impaired in ME/CFS, a previous study recommended a pacing self-management strategy to prevent post-exertional malaise. This strategy involved a prescription to maintain a heart rate below the anaerobic threshold during physical activities. In the absence of lactate sampling or a cardiopulmonary exercise test (CPET), the pacing self-management formula defines 55% of the age-specific predicted maximal heart rate as the heart rate at the anaerobic threshold. Thus far there has been no empiric evidence to test this self-pacing method of predicting heart rate at anaerobic threshold. The aim of this study was to compare published formula-derived heart rates at the anaerobic threshold with the actual heart rate at the lactic acidosis threshold as determined by CPET.

Methods and Results: Adults with ME/CFS who had undergone a symptom-limited CPET were eligible for this study (30 males, 60 females). We analysed males and females separately because of sex-based differences in peak oxygen consumption. From a review paper, formulae to calculate maximal predicted heart rate were used for healthy subjects. We compared the actual heart rate at the lactic acid threshold during CPET to the predicted heart rates determined by formulae. Using Bland-Altman plots, calculated bias: the mean difference between the actual CPET heart rate at the anaerobic threshold and the formula predicted heart rate across several formulae varied between -28 and 19 bpm in male ME/CFS patients. Even in formulae with a clinically acceptable bias, the limits of agreement (mean bias ± 2SD) were unacceptably high for all formulae. For female ME/CFS patients, bias varied between 6 and 23 bpm, but the limits of agreement were also unacceptably high for all formulae.

Conclusion: Formulae generated in an attempt to help those with ME/CFS exercise below the anaerobic threshold do not reliably predict actual heart rates at the lactic acidosis threshold as measured by a cardiopulmonary exercise test. Formulae based on age-dependent predicted peak heart rate multiplied by 55% have a wide age-specific variability and therefore have a limited application in clinical practice.

Source: van Campen, C. , Rowe, P. and Visser, F. (2020) Heart Rate Thresholds to Limit Activity in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Patients (Pacing): Comparison of Heart Rate Formulae and Measurements of the Heart Rate at the Lactic Acidosis Threshold during Cardiopulmonary Exercise Testing. Advances in Physical Education, 10, 138-154. doi: 10.4236/ape.2020.102013. https://www.scirp.org/journal/paperinformation.aspx?paperid=100333 (Full text)

Cerebral blood flow is reduced in ME/CFS during head-up tilt testing even in the absence of hypotension or tachycardia: a quantitative, controlled study using Doppler echography

Abstract:

Objective: The underlying hypothesis in orthostatic intolerance (OI) syndromes is that symptoms are associated with cerebral blood flow (CBF) reduction. Indirect CBF measurements (transcranial Doppler flow velocities), provide inconsistent support of this hypothesis. The aim of the study was to measure CBF during a 30 min head-up tilt test (HUT), using Doppler flow imaging of carotid and vertebral arteries, in individuals with chronic fatigue syndrome/myalgic encephalomyelitis (ME/CFS), a condition with a high prevalence of OI.

Methods: 429 ME/CFS patients were studied: 247 had a normal heart rate (HR) and blood pressure (BP) response to HUT, 62 had delayed orthostatic hypotension (dOH), and 120 had postural orthostatic tachycardia syndrome (POTS). We also studied 44 healthy controls (HC). CBF measurements were made at mid-tilt and end-tilt. Before mid-tilt, we administered a verbal questionnaire to ascertain for 15 OI symptoms.

Results: End-tilt CBF reduction was 7% in HC versus 26% in the overall ME/CFS group, 24% in patients with a normal HR/BP response, 28% in those with dOH, and 29% in POTS patients (all P<.0005). Using a lower limit of normal of 2SD of CBF reduction in HC (13% reduction), 82% of patients with normal HR/BP response, 98% with dOH and 100% with POTS showed an abnormal CBF reduction. There was a linear correlation of summed OI symptoms with the degree of CBF reduction at mid-tilt (P<.0005).

Conclusions: During HUT, extracranial Doppler measurements demonstrate that CBF is reduced in ME/CFS patients with POTS, dOH, and even in those without HR/BP abnormalities.

Significance: This study shows that orthostatic intolerance symptoms are related to CBF reduction, and that the majority of ME/CFS patients (90%) show an abnormal cerebral flow reduction during orthostatic stress testing. This may have implications for the diagnosis and treatment of ME/CFS patients.

Source: C. (Linda) M.C.van Campen, Freek W.A. Verheugt, Peter C. Rowe, Frans C.Visser. Cerebral blood flow is reduced in ME/CFS during head-up tilt testing even in the absence of hypotension or tachycardia: a quantitative, controlled study using Doppler echography. Clinical Neurophysiology Practice. Available online 8 February 2020. https://doi.org/10.1016/j.cnp.2020.01.003 https://www.sciencedirect.com/science/article/pii/S2467981X20300044 (Full text)

Long Term Follow up of Young People With Chronic Fatigue Syndrome Attending a Pediatric Outpatient Service

Abstract:

Aim: To determine the reported duration of illness, the functional and educational long-term outcomes, predictive factors for recovery and seek feedback regarding management in pediatric/adolescent myalgic encepahalomyelitis/chronic fatigue syndrome (ME/CFS).

Methods: A cohort observational study of 784 young people, mean age 14.6 (6-18) years, with ME/CFS diagnosed at a specialist pediatric hospital and receiving regular care, was conducted with follow-up for a mean 8 (range 1-21) years after onset. Baseline symptoms, history, depression and anxiety questionnaires were available from 418. The remaining 366, did not have similar standardized baseline information. Questionnaires requested functional rating, persistent symptoms, duration of illness if “recovered,” social engagement and school/work attendance. Feedback was sought regarding management, support services, useful information, helpful interventions or personnel and use of alternative therapies. Reported recovery and function were compared with baseline information and between the two groups.

Results: Follow-up data were returned from 81.8%. There was no significant difference in functional score (if reported recovery) or illness duration related to provision of baseline data. The mean duration of illness was 5 (range 1-15) years in the 50% who reported recovery. By 5 years 38% and by 10 years 68% reported recovery. At 10 years the mean functional score was 8/10 (range 2-10) with 5% scoring <6. Depression, anxiety or severity of illness at diagnosis was not predictive of non-recovery. Designing and monitoring their own management plan that included educational, social, physical and enjoyable activities, as well as having symptom management and understanding professionals were highly valued. However, remaining engaged in an education system that flexibly accommodated their illness and aspirations was consistently reported as crucial for long term functioning.

Conclusions: ME/CFS in young people has a mean duration of 5 years (1-15) with 68% reporting recovery by 10 years. All improved functionally with 5% remaining very unwell and a further 20% significantly unwell. There were no obvious baseline predictors for recovery. However, depression, anxiety, orthostatic intolerance and to a lesser extent pain at follow up were identified as hampering recovery or function. Supportive professionals, remaining engaged in education and management strategies were identified as helpful.

Source: Rowe KS. Long Term Follow up of Young People With Chronic Fatigue Syndrome Attending a Pediatric Outpatient Service. Front Pediatr. 2019 Feb 21;7:21. doi: 10.3389/fped.2019.00021. eCollection 2019. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6393360/ (Full article)

Impaired Health-Related Quality of Life in Adolescent Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: The Impact of Core Symptoms

Abstract:

Objective: The objectives of this study were to compare the health-related quality of life (HRQOL) of a North American population of adolescents and young adults with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) to (1) healthy controls (HC), (2) adolescents with ME/CFS in other countries, and (3) other forms of pediatric chronic illness, and (4) to examine the influence of the core illness symptoms in the Institute of Medicine (IOM) case definition on impaired HRQOL.

Study design: Cross-sectional study comparing individuals with ME/CFS referred to a tertiary care Chronic Fatigue clinic and HC. Eligible participants were age 10-30 years and met the Fukuda criteria for CFS. HC were eligible if they were age 10-30 years, with self-reported good, very good, or excellent general health. Pediatric HRQOL was measured using the PedsQL (Pediatric Quality of Life Inventory) and other validated instruments.

Results: We enrolled 55 consecutive ME/CFS patients (46 F) aged 10-23 years. From a pool of 69 potential HC we selected 55 with similar age and gender distribution for comparison. The total and subscale scores on the PedsQL and on all other measures of HRQOL indicated significantly worse function among those with ME/CFS (all P < 0.001). The self-reported frequency of post-exertional malaise (PEM) was significantly associated with the severity of impaired HRQOL (P < 0.001). Cognitive impairment had a weaker association with the PedsQL score (P = 0.02). Orthostatic intolerance was present in 96% of the ME/CFS population. Of the 55 who satisfied the Fukuda criteria, 47 (85%) also satisfied the IOM criteria for the diagnosis. Those meeting the IOM criteria had worse PedsQL total scores than those meeting just the Fukuda criteria (P < 0.001).

Conclusions: HRQOL was substantially lower in an ambulatory population of adolescents and young adults with ME/CFS than for healthy controls in North America, consistent with reports from other continents. HRQOL was also lower in ME/CFS than has been described in children with asthma, diabetes mellitus, epilepsy, eosinophilic gastroenteritis, and cystic fibrosis. The findings of this study lend further support to the inclusion of PEM, cognitive impairment, and orthostatic intolerance as core symptoms of pediatric ME/CFS.

Source: Roma M, Marden CL, Flaherty MAK, Jasion SE, Cranston EM, Rowe PC. Impaired Health-Related Quality of Life in Adolescent Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: The Impact of Core Symptoms. Front Pediatr. 2019 Feb 15;7:26. doi: 10.3389/fped.2019.00026. eCollection 2019. https://www.ncbi.nlm.nih.gov/pubmed/30828572

Blood Volume Status in ME/CFS Correlates With the Presence or Absence of Orthostatic Symptoms: Preliminary Results

Abstract:

Introduction: Conflicting data have been published on the reduction of circulating blood volume in adults with Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). The aim of the present study was to compare blood volumes based on the presence or absence of orthostatic symptoms.

Methods and results: Twenty consecutive adults with ME/CFS participated in the study. All underwent dual isotope blood volume measurement and were evaluated for a clinical suspicion of orthostatic intolerance (OI). The mean age was 34 (10) years, and median duration of disease was 7.5 (6-10) years. The mean (SD) absolute blood volume was 59 (8) ml/kg, a value -11 (7) ml/kg below the reference blood volume. Of the 12 patients, 4 had no OI and 8 had a clinical suspicion of OI. In 8 patients with OI, absolute blood volumes were significantly lower than for the 4 without OI (56 [2] vs. 66 [5]; p < 0.05) as were the differences between the measured and the reference blood volume (-14 [2]; vs. -4 [3]; p < 0.02).

Conclusions: Adults with ME/CFS had a significantly lower blood volume if they had a clinical suspicion of OI compared to those without a clinical suspicion of OI, as well as a significantly lower blood volume compared to the expected value. The data suggest that accounting for symptoms of OI could enhance the detection of the subset with reduced blood volume.

Source: van Campen CLMC1, Rowe PC2, Visser FC1. Blood Volume Status in ME/CFS Correlates With the Presence or Absence of Orthostatic Symptoms: Preliminary Results. Front Pediatr. 2018 Nov 15;6:352. doi: 10.3389/fped.2018.00352. eCollection 2018. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6262290/ (Full article)

Low Sensitivity of Abbreviated Tilt Table Testing for Diagnosing Postural Tachycardia Syndrome in Adults With ME/CFS

Abstract:

Introduction: Orthostatic intolerance is common among individuals with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). In some ME/CFS case definitions, orthostatic intolerance is considered a core feature of the disorder. Some studies have employed tilt table tests lasting 2-5 min to diagnose one common form of orthostatic intolerance, postural tachycardia syndrome (POTS). We examined the diagnostic yield of abbreviated durations of tilt testing in adults meeting criteria for ME/CFS, and identified the proportion with POTS misdiagnosed using testing of <10 min.

Methods: Eligible participants were consecutive individuals satisfying study criteria for ME/CFS and POTS evaluated at the Stichting CardioZorg (SCZ, Hoofddorp, NL) between November 2012 and August 2018. Individuals being treated with medications commonly used to manage orthostatic intolerance were excluded. Head-up tilt table testing involved 15 min of supine posture then 20 min at 70 degrees upright. Only the data from the first 10-min upright were used. POTS was defined as an increase in HR during a maximum of 10 min of upright tilt of at least 30 beats per minute (bpm), in the absence of either classical or delayed orthostatic hypotension. We measured the time until HR criteria for POTS were reached using survival curves, and compared survival curves between subgroups divided by age, sex, disease duration, and degree of hypocapnia during the test.

Results: Of 627 individuals with ME/CFS evaluated during the study period, 155 met criteria for POTS. The median time to reaching HR criteria for POTS was 3 min. A two-minute tilt table test would miss 55% (95% CI, 48-63%) of those meeting POTS criteria over the course of 10 min upright. The median time to reaching HR criteria for POTS did not differ by sex, age, duration of ME/CFS, or hypocapnia during tilt.

Conclusions: Abbreviated tilt table testing misses a substantial proportion of those ultimately diagnosed with POTS during a 10-min tilt table test, and should be abandoned for the clinical diagnosis and in epidemiologic studies designed to estimate the prevalence of POTS among those with ME/CFS.

Source: van Campen CLMC, Rowe PC, Visser FC. Low Sensitivity of Abbreviated Tilt Table Testing for Diagnosing Postural Tachycardia Syndrome in Adults With ME/CFS. Front Pediatr. 2018 Nov 16;6:349. doi: 10.3389/fped.2018.00349. eCollection 2018. https://www.ncbi.nlm.nih.gov/pubmed/30505831

Two-Year Follow-Up of Impaired Range of Motion in Chronic Fatigue Syndrome

Abstract:

OBJECTIVE: To measure changes in range of motion (ROM) over time in a cohort of 55 adolescents and young adults with chronic fatigue syndrome and to determine whether changes in ROM correlated with changes in health-related quality of life.

STUDY DESIGN: Participants underwent a standardized examination of 11 areas of limb and spine ROM at baseline and at 3- to 6-month intervals for 2 years, resulting in a ROM score that ranged from 0 (normal throughout) to 11 (abnormal ROM in all areas tested). We measured the time until the ROM score was ≤2 (the score in healthy age-matched controls). Change in ROM was measured by subtracting the 24-month from the baseline ROM score and by summing the degrees of change in the 10 tests with continuous outcomes. Health-related quality of life was measured using the Pediatric Quality of Life Inventory 4.0 (PedsQL).

RESULTS: The mean age at enrollment was 16.5 years (range 10-23). Two-year follow-up was available for 53 (96%). The proportion with a ROM score of >2 fell gradually over 2 years, from 78% at entry to 20% at 24 months (P < .001). ROM scores improved from a median of 5 at entry to 2 at 24 months (P < .001). The change in the summed degrees of improvement in ROM correlated positively with improvement in the PedsQL physical function subscale (r = 0.30; P < .03).

CONCLUSIONS: In association with multimodal therapy, young people with chronic fatigue syndrome experienced progressively less impairment in ROM over 2 years, correlating with improvements in the physical function subscale of the PedsQL.

Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Source: Rowe PC, Marden CL, Flaherty MAK, Jasion SE, Cranston EM, Fontaine KR, Violand RL. Two-Year Follow-Up of Impaired Range of Motion in Chronic Fatigue Syndrome. J Pediatr. 2018 Jun 1. pii: S0022-3476(18)30659-0. doi: 10.1016/j.jpeds.2018.05.012. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/29866593

Improvement of severe myalgic encephalomyelitis/chronic fatigue syndrome symptoms following surgical treatment of cervical spinal stenosis

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a potentially disabling disorder. Little is known about the contributors to severe forms of the illness. We describe three consecutive patients with severe ME/CFS whose symptoms improved after recognition and surgical management of their cervical spinal stenosis.

Methods: All patients satisfied clinical criteria for ME/CFS and orthostatic intolerance, and were later found to have cervical spinal stenosis. Overall function was assessed before and after surgery using the Karnofsky score and the SF-36 physical function subscale score.

Results: Neurological findings included > 3+ deep tendon reflexes in 2 of 3, a positive Hoffman sign in 2 of 3, tremor in 2 of 3, and absent gag reflex in 1 of 3. The cervical spine canal diameter in the three patients ranged from 6 to 8.5 mm. One had congenital cervical stenosis with superimposed spondylosis, and two had single- or two-level spondylosis. Anterior cervical disc replacement surgery in two patients and a hybrid anterior cervical disc fusion and disc replacement in the third was associated with a marked improvement in myelopathic symptoms, resolution of lightheadedness and hemodynamic dysfunction, improvement in activity levels, and improvement in global ME/CFS symptoms.

Conclusions: The prompt post-surgical restoration of more normal function suggests that cervical spine stenosis contributed to the pathogenesis of refractory ME/CFS and orthostatic symptoms. The improvements following surgery emphasize the importance of a careful search for myelopathic examination findings in those with ME/CFS, especially when individuals with severe impairment are not responding to treatment.

Source: Rowe, P.C., Marden, C.L., Heinlein, S. et al. J Transl Med (2018) 16: 21. https://doi.org/10.1186/s12967-018-1397-7