Cerebral Blood Flow Is Reduced in Severe Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Patients During Mild Orthostatic Stress Testing: An Exploratory Study at 20 Degrees of Head-Up Tilt Testing

Abstract:

Introduction: In a study of 429 adults with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), we demonstrated that 86% had symptoms of orthostatic intolerance in daily life. Using extracranial Doppler measurements of the internal carotid and vertebral arteries during a 30-min head-up tilt to 70 degrees, 90% had an abnormal reduction in cerebral blood flow (CBF). A standard head-up tilt test of this duration might not be tolerated by the most severely affected bed-ridden ME/CFS patients. This study examined whether a shorter 15-min test at a lower 20 degree tilt angle would be sufficient to provoke reductions in cerebral blood flow in severe ME/CFS patients.

Methods and results: Nineteen severe ME/CFS patients with orthostatic intolerance complaints in daily life were studied: 18 females. The mean (SD) age was 35(14) years, body surface area (BSA) was 1.8(0.2) m2 and BMI was 24.0(5.4) kg/m2. The median disease duration was 14 (IQR 5-18) years. Heart rate increased, and stroke volume index and end-tidal CO2 decreased significantly during the test (p ranging from <0.001 to <0.0001). The cardiac index decreased by 26(7)%: p < 0.0001. CBF decreased from 617(72) to 452(63) mL/min, a 27(5)% decline. All 19 severely affected ME/CFS patients met the criteria for an abnormal CBF reduction.

Conclusions: Using a less demanding 20 degree tilt test for 15 min in severe ME/CFS patients resulted in a mean CBF decline of 27%. This is comparable to the mean 26% decline previously noted in less severely affected patients studied during a 30-min 70 degree head-up tilt. These observations have implications for the evaluation and treatment of severely affected individuals with ME/CFS.

Source: van Campen CLMC, Rowe PC, Visser FC. Cerebral Blood Flow Is Reduced in Severe Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Patients During Mild Orthostatic Stress Testing: An Exploratory Study at 20 Degrees of Head-Up Tilt Testing. Healthcare (Basel). 2020;8(2):E169. Published 2020 Jun 13. doi:10.3390/healthcare8020169 https://www.mdpi.com/2227-9032/8/2/169 (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)

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

The Abnormal Cardiac Index and Stroke Volume Index Changes During a Normal Tilt Table Test in ME/CFS Patients Compared to Healthy Volunteers, are Not Related to Deconditioning

Abstract:

1.1 Background. A small study in ME/CFS (Myalgic Encephalomyelitis/Chronic Fatigue Syndrome) patients undergoing tilt testing, showed that, despite a normal tilt test, stroke volumes and cardiac output were lower than in healthy volunteers. Moreover, it was suggested that this difference was related to deconditioning of patients. Aim of the study. We performed table testing in 150 ME/CFS patients. Stroke volumes and cardiac output were related to the severity of the disease.

1.2 Methods and results. In the patients the severity of the disease was clinically evaluated according to the ME criteria and scored as mild, moderate or severe disease. In a subgroup of 109 patients this clinical diagnosis was confirmed by the physical functioning score of the Rand-36 questionnaire. Significantly lower physical functioning scores (indicating worse functioning) were observed in the more severely affected patients. Stroke Volume Index (SVI) and Cardiac Index (CI) were measured by suprasternal aortic Doppler imaging in the supine position, prior to the tilt, and twice during the tilt. Thirty-seven healthy volunteers underwent the same tilt protocol. In all patients and all healthy volunteers, a normal heart rate and blood pressure response was observed during the tilt. The decreases in SVI and CI during the tilt was significantly larger in patients compared to the SVI and CI decrease in HV. The decrease in SVI and CI were similar and not significantly different between the mild, moderate, and severe ME groups.

1.3 Conclusions. During a normal tilt table test decreases in SVI and CI decrease are significantly greater in ME/CFS patients than in HV, consistent with previous work. The absence of differences between patients with mild, moderate, and severe ME/CFS suggests that the decreases in stroke volumes and cardiac output are not related to deconditioning. Other factors like decreased blood volumes and autonomic dysfunction may cause this difference in the hemodynamic response between ME/CFS patients and HV.

3. Abbreviations

BMI : Body Mass Index

BSA : Body Surface Area

CFS : Chronic Fatigue Syndrome

CI : Cardiac Index

DBP : Diastolic Blood Pressure

HR : Heart Rate

HUT : Head-Up Tilt Test

HV : Healthy Volunteers

IOM : Institute of Medicine

MAP : Mean Blood Pressure

ME : Myalgic Encephalomyelitis

NMH : Neurally Mediated Hypotension

Normal BPHR : normal Blood Pressure and Heart Rate Response During HUT

OI : Orthostatic Intolerance

R36 Phys Funct : Rand-36 Physical Functioning Score

SBP : Systolic Blood Pressure

SVI : Stroke Volume Index

SVRI : Systemic Vascular Resistance Index

VTI : Time-Velocity Integral

Source: van Campen CMC, Visser FC (2018) The Abnormal Cardiac Index and Stroke Volume Index Changes During a Normal Tilt Table Test in ME/CFS Patients Compared to Healthy Volunteers, are Not Related to Deconditioning. J Thrombo Cir: JTC -107. DOI: 10.29011/ JTC -107. 000007 https://www.gavinpublishers.com/articles/Research-Article/Journal-of-Thrombosis-and-Circulation/The-Abnormal-Cardiac-Index-and-Stroke-Volume-Index-Changes-During-a-Normal-Tilt-Table-Test-in-ME-CFS-Patients-Compared-to-Healthy-Volunteers-are-Not-Related-to-Deconditioning (Full article)

Phenylephrine alteration of cerebral blood flow during orthostasis: effect on n-back performance in chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) with orthostatic intolerance is characterized by neurocognitive deficits and impaired working memory, concentration, and information processing. In CFS, upright tilting [head-up tilt (HUT)] caused decreased cerebral blood flow velocity (CBFv) related to hyperventilation/hypocapnia and impaired cerebral autoregulation; increasing orthostatic stress resulted in decreased neurocognition.

We loaded the baroreflex with phenylephrine to prevent hyperventilation and performed n-back neurocognition testing in 11 control subjects and 15 CFS patients. HUT caused a significant increase in heart rate (109.4 ± 3.9 vs. 77.2 ± 1.6 beats/min, P < 0.05) and respiratory rate (20.9 ± 1.7 vs. 14.2 ± 1.2 breaths/min, P < 0.05) and decrease in end-tidal CO2 (ETCO2; 42.8 ± 1.2 vs. 33.9 ± 1.1 Torr, P < 0.05) in CFS vs. control. HUT caused CBFv to decrease 8.7% in control subjects but fell 22.5% in CFS.

In CFS, phenylephrine prevented the HUT-induced hyperventilation/hypocapnia and the significant drop in CBFv with HUT (-8.1% vs. -22.5% untreated). There was no difference in control subject n-back normalized response time (nRT) comparing supine to HUT (106.1 ± 6.9 vs. 97.6 ± 7.1 ms at n = 4), and no difference comparing control to CFS while supine (97.1 ± 7.1 vs 96.5 ± 3.9 ms at n = 4). However, HUT of CFS subjects caused a significant increase in nRT (148.0 ± 9.3 vs. 96.4 ± 6.0 ms at n = 4) compared with supine.

Phenylephrine significantly reduced the HUT-induced increase in nRT in CFS to levels similar to supine (114.6 ± 7.1 vs. 114.6 ± 9.3 ms at n = 4). Compared with control subjects, CFS subjects are more sensitive both to orthostatic challenge and to baroreflex/chemoreflex-mediated interventions. Increasing blood pressure with phenylephrine can alter CBFv. In CFS subjects, mitigation of the HUT-induced CBFv decrease with phenylephrine has a beneficial effect on n-back outcome.

Copyright © 2014 the American Physiological Society.

 

Source: Medow MS, Sood S, Messer Z, Dzogbeta S, Terilli C, Stewart JM. Phenylephrine alteration of cerebral blood flow during orthostasis: effect on n-back performance in chronic fatigue syndrome. J Appl Physiol (1985). 2014 Nov 15;117(10):1157-64. doi: 10.1152/japplphysiol.00527.2014. Epub 2014 Oct 2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4233252/ (Full article)

 

Malfunctioning of the autonomic nervous system in patients with chronic fatigue syndrome: a systematic literature review

Abstract:

INTRODUCTION: It is hypothesised that the autonomic nervous system responds differently to various stressors in patients with chronic fatigue syndrome (CFS) compared with healthy controls. The goal is to systematically review the scientific literature addressing the functioning of the autonomic nervous system in patients with CFS.

MATERIALS AND METHODS: All studies that were identified through electronic databases (PubMed and Web of Science) were screened for eligibility based on the selection criteria and assessed (two independent raters) for methodological quality using a methodological checklist for case-control studies.

RESULTS: Twenty-seven case-control studies were included. The methodological quality varied between 50% and 71·4%. Some studies showed different responses to head-up tilt and other autonomous testing.

CONCLUSION: Although comparison between the included case-control studies was difficult, we can conclude that there are differences in autonomous response between patients with CFS and healthy controls. The heart rate dynamic response during the head-up tilt test differs between patients with CFS and healthy controls, supporting the increased prevalence of postural orthostatic tachycardia syndrome. The autonomic response can be useful for the diagnosis of CFS.

© 2014 Stichting European Society for Clinical Investigation Journal Foundation.

 

Source: Van Cauwenbergh D, Nijs J, Kos D, Van Weijnen L, Struyf F, Meeus M. Malfunctioning of the autonomic nervous system in patients with chronic fatigue syndrome: a systematic literature review. Eur J Clin Invest. 2014 May;44(5):516-26. doi: 10.1111/eci.12256. https://www.ncbi.nlm.nih.gov/pubmed/24601948

 

Relationship between autonomic cardiovascular control, case definition, clinical symptoms, and functional disability in adolescent chronic fatigue syndrome: an exploratory study

Abstract:

Chronic Fatigue Syndrome (CFS) is characterized by severe impairment and multiple symptoms. Autonomic dysregulation has been demonstrated in several studies. We aimed at exploring the relationship between indices of autonomic cardiovascular control, the case definition from Centers for Disease Control and Prevention (CDC criteria), important clinical symptoms, and disability in adolescent chronic fatigue syndrome.

38 CFS patients aged 12-18 years were recruited according to a wide case definition (ie. not requiring accompanying symptoms) and subjected to head-up tilt test (HUT) and a questionnaire. The relationships between variables were explored with multiple linear regression analyses. In the final models, disability was positively associated with symptoms of cognitive impairments (p<0.001), hypersensitivity (p<0.001), fatigue (p=0.003) and age (p=0.007).

Symptoms of cognitive impairments were associated with age (p=0.002), heart rate (HR) at baseline (p=0.01), and HR response during HUT (p=0.02). Hypersensitivity was associated with HR response during HUT (p=0.001), high-frequency variability of heart rate (HF-RRI) at baseline (p=0.05), and adherence to the CDC criteria (p=0.005). Fatigue was associated with gender (p=0.007) and adherence to the CDC criteria (p=0.04).

In conclusion, a) The disability of CFS patients is not only related to fatigue but to other symptoms as well; b) Altered cardiovascular autonomic control is associated with certain symptoms; c) The CDC criteria are poorly associated with disability, symptoms, and indices of altered autonomic nervous activity.

 

Source: Wyller VB, Helland IB. Relationship between autonomic cardiovascular control, case definition, clinical symptoms, and functional disability in adolescent chronic fatigue syndrome: an exploratory study. Biopsychosoc Med. 2013 Feb 7;7(1):5. doi: 10.1186/1751-0759-7-5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3570350/ (Full article)

 

Clonidine in the treatment of adolescent chronic fatigue syndrome: a pilot study for the NorCAPITAL trial

Abstract:

BACKGROUND: This pilot study (ClinicalTrials.gov ID: NCT01507701) assessed the feasibility and safety of clonidine in adolescent chronic fatigue syndrome (CFS). Specifically, we assessed clonidine dosage in relation to a) plasma concentration levels, b) orthostatic cardiovascular responses, and c) possible adverse effects.

FINDINGS: Five adolescent CFS patients (14-19 years old) received 50 μg clonidine twice per day during 14 days in an open, uncontrolled design. Plasma concentration of clonidine was assayed by standard laboratory methods. Changes in orthostatic cardiovascular responses were assessed by a 20o head-up tilt-test (HUT). Adverse effects were mapped by a questionnaire.After 14 days, C0 median (range) of clonidine was 0.21 (0.18-0.36) μg/L, and Cmax median (range) of clonidine was 0.41 (0.38-0.56) μg/L. Also, supine blood pressures and heart rate were lower during clonidine treatment, and the HUT response was closer to the normal response. No serious adverse effects were registered.

CONCLUSION: Clonidine 50 μg BID seems to be safe enough to proceed from a pilot study to a controlled trial in a select group of adolescents with CFS (ClinicalTrials.gov ID: NCT01040429).

 

Source: Fagermoen E, Sulheim D, Winger A, Andersen AM, Vethe NT, Saul JP, Thaulow E, Wyller VB. Clonidine in the treatment of adolescent chronic fatigue syndrome: a pilot study for the NorCAPITAL trial. BMC Res Notes. 2012 Aug 7;5:418. doi: 10.1186/1756-0500-5-418. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3461473/ (Full article)

 

Impaired cardiovascular response to standing in chronic fatigue syndrome

Abstract:

BACKGROUND: Impaired skeletal muscle metabolism is recognized in chronic fatigue syndrome (CFS). This study examined the relationship between skeletal and cardiac muscle function and symptoms on standing in CFS using magnetic resonance spectroscopy (MRS) and impedance cardiography.

MATERIALS AND METHODS: Phosphocreatine (PCr)/adenosine triphosphate (ATP) ratio by cardiac MRS, PCr/ADP and proton efflux by muscle MRS were performed in 12 CFS (Fukuda) and 8 controls. Head up tilt (HUT) and cardiac contractility (left ventricular work index, LVWI) (n = 64 CFS and matched controls) were found. Fatigue impact was accessed by Fatigue Impact Scale and orthostatic symptoms by Orthostatic Grading Scale (OGS).

RESULTS: Cardiac PCr/ATP correlated with measures of muscle bioenergetic function (half-time PCr recovery [kappa = -0.71, P = 0.005] and half-time ADP recovery [kappa = -0.60, P = 0.02]) suggesting that the muscle and cardiac bioenergetic function correlate in CFS. Four of 12 (33.3%) CFS patients had PCr/ATP values consistent with significant cardiac impairment. Those with impaired cardiac energy metabolism had significantly reduced maximal and initial proton efflux rates (P < 0.05). Cardiac PCr/ATP ratio correlated with myocardial contractility (LVWI) in response to standing (P = 0.03). On HUT, LVWI on standing was significantly higher in CFS (P = 0.05) with symptoms on standing (OGS) occurring in 61/64 (95%) (vs. 25/64 [39%] controls; P < 0.0001). OGS scores were significantly higher in those with abnormal LVWI responses to standing (P = 0.04), with the LVWI on standing correlating with OGS scores (r(2) = 0.1; P = 0.03). HUT was positive in 19 (32%).

CONCLUSIONS: Skeletal muscle and cardiac bioenergetic abnormalities associate in CFS. Cardiac bioenergetic metabolism associates with increase in cardiac contractility on standing. Haemodynamic assessment in CFS is well tolerated and safe with a high diagnostic yield comparable with unexplained syncope.

 

Source: Hollingsworth KG, Jones DE, Taylor R, Blamire AM, Newton JL. Impaired cardiovascular response to standing in chronic fatigue syndrome. Eur J Clin Invest. 2010 Jul;40(7):608-15. doi: 10.1111/j.1365-2362.2010.02310.x. Epub 2010 May 23. https://www.ncbi.nlm.nih.gov/pubmed/20497461

 

A matched case control study of orthostatic intolerance in children/adolescents with chronic fatigue syndrome

Abstract:

This study aimed to define cardiovascular and heart rate variability (HRV) changes following head-up tilt (HUT) in children/adolescents with chronic fatigue syndrome (CFS) in comparison to age- and gender-matched controls.

Twenty-six children/adolescents with CFS (11-19 y) and controls underwent 70-degree HUT for a maximum of 30 min, but returned to horizontal earlier at the participant’s request with symptoms of orthostatic intolerance (OI) that included lightheadedness.

Using electrocardiography and beat-beat finger blood pressure, a positive tilt was defined as OI with 1) neurally mediated hypotension (NMH); bradycardia (HR <75% of baseline), and hypotension [systolic pressure (SysP) drops >25 mm Hg)] or 2) postural orthostatic tachycardia syndrome (POTS); HR increase >30 bpm, or HR >120 bpm (with/without hypotension).

Thirteen CFS and five controls exhibited OI generating a sensitivity and specificity for HUT of 50.0% and 80.8%, respectively. POTS without hypotension occurred in seven CFS subjects but no controls. POTS with hypotension and NMH occurred in both. Predominant sympathetic components to HRV on HUT were measured in CFS tilt-positive subjects.

In conclusion, CFS subjects were more susceptible to OI than controls, the cardiovascular response predominantly manifest as POTS without hypotension, a response unique to CFS suggesting further investigation is warranted with respect to the pathophysiologic mechanisms involved.

 

Source: Galland BC, Jackson PM, Sayers RM, Taylor BJ. A matched case control study of orthostatic intolerance in children/adolescents with chronic fatigue syndrome. Pediatr Res. 2008 Feb;63(2):196-202. https://www.ncbi.nlm.nih.gov/pubmed/18091356