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)

 

A Study of the Protective Effect of Triticum aestivum L. in an Experimental Animal Model of Chronic Fatigue Syndrome

Abstract:

BACKGROUND: Oxidative stress plays a major role in the pathogenesis of chronic fatigue syndrome (CFS). Keeping in view the proven antioxidant activity of Triticum aestivum L., this study has been undertaken to explore the potential therapeutic benefit of this plant in the treatment of CFS.

OBJECTIVE: To study the protective effect of the ethanolic extract of the leaves of Triticum aestivum (EETA) in an experimental mice model of CFS.

MATERIALS AND METHODS: Five groups of albino mice (20-25 g) were selected for the study, with five animals in each group. Group A served as the naïve control and Group B served as the stressed control. Groups C and D received EETA (100 mg/kg and 200 mg/kg b.w.). Group E received imipramine (20 mg/kg b.w.). Except for Group A, mice in each group were forced to swim 6 min each for 7 days to induce a state of chronic fatigue. Duration of immobility was measured on every alternate day. After 7 days, various behavioral tests (mirror chamber and elevated plus maize test for anxiety, open field test for locomotor activity) and biochemical estimations (malondialdehyde [MDA] and catalase activity) in mice brain were performed.

RESULTS: Forced swimming in the stressed group resulted in a significant increase in immobility period, decrease in locomotor activity and elevated anxiety level. The brain homogenate showed significantly increased MDA and decreased catalase levels. The extract-treated groups showed significantly (P < 0.05) improved locomotor activity, decreased anxiety level, elevated catalase levels and reduction of MDA.

CONCLUSION: The study confirms the protective effects of EETA in CFS.

 

Source: Borah M, Sarma P, Das S. A Study of the Protective Effect of Triticum aestivum L. in an Experimental Animal Model of Chronic Fatigue Syndrome. Pharmacognosy Res. 2014 Oct;6(4):285-91. Doi: 10.4103/0974-8490.138251. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4166815/ (Full article)

 

Two age peaks in the incidence of chronic fatigue syndrome/myalgic encephalomyelitis: a population-based registry study from Norway 2008-2012

Abstract:

BACKGROUND: The aim of the current study was to estimate sex- and age-specific incidence rates of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) using population-based registry data. CFS/ME is a debilitating condition with large impact on patients and their families. The etiology is unknown, and the distribution of the disease in the general population has not been well described.

METHODS: Cases of CFS/ME were identified in the Norwegian Patient Register (NPR) for the years 2008 to 2012. The NPR is nationwide and contains diagnoses assigned by specialist health care services (hospitals and outpatient clinics). We estimated sex- and age-specific incidence rates by dividing the number of new cases of CFS/ME in each category by the number of person years at risk. Incidence rate ratios were estimated by Poisson regression with sex, age categories, and year of diagnosis as covariates.

RESULTS: A total of 5,809 patients were registered with CFS/ME during 2008 to 2012. The overall incidence rate was 25.8 per 100,000 person years (95% confidence interval (CI): 25.2 to 26.5). The female to male incidence rate ratio of CFS/ME was 3.2 (95% CI: 3.0 to 3.4). The incidence rate varied strongly with age for both sexes, with a first peak in the age group 10 to 19 years and a second peak in the age group 30 to 39 years.

CONCLUSIONS: Early etiological clues can sometimes be gained from examination of disease patterns. The strong female preponderance and the two age peaks suggest that sex- and age-specific factors may modulate the risk of CFS/ME.

 

Source: Bakken IJ, Tveito K, Gunnes N, Ghaderi S, Stoltenberg C, Trogstad L, Håberg SE, Magnus P. Two age peaks in the incidence of chronic fatigue syndrome/myalgic encephalomyelitis: a population-based registry study from Norway 2008-2012. BMC Med. 2014 Oct 1;12:167. doi: 10.1186/s12916-014-0167-5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4189623/ (full article)

Comment:

Cortisol output in adolescents with chronic fatigue syndrome: pilot study on the comparison with healthy adolescents and change after cognitive behavioural guided self-help treatment

Abstract:

OBJECTIVE: This study examined cortisol in adolescents with chronic fatigue syndrome (CFS) compared to healthy adolescents and changes in cortisol after cognitive behavioural guided self-help treatment. Exploratory analyses investigated the association between cortisol output and psychological variables.

METHODS: Salivary cortisol was measured upon awakening, at 15, 30, 45 and 60 min afterwards and at 12 noon, 4:00 p.m. and 8:00 p.m., in adolescents with CFS and healthy controls (HC). Groups were matched for age, gender, menarche status, menstrual cycle and awakening time. Twenty-four adolescents with CFS provided saliva samples six months after treatment. The main outcome measure was total salivary output over the day, calculated by area under the curve (AUC). The salivary awakening response was also assessed.

RESULTS: Cortisol output over the day was significantly lower in the CFS group (n=46) than in healthy controls (n=33). Within the CFS group, lower daily cortisol output was associated with higher self-reported perfectionist striving and prosocial behaviour. There were no significant group differences in the awakening response (n=47 CFS versus n=34 HC). After treatment, adolescents with CFS (n=21) showed a significant increase in daily cortisol output, up to normal levels.

CONCLUSION: The reduced daily cortisol output in adolescents with CFS is in line with adult findings. Associations between reduced cortisol output and two psychological variables-perfectionism and prosocial behaviour-are consistent with cognitive behavioural models of chronic fatigue syndrome. The mild hypocortisolism is reversible; cortisol output had returned to healthy adolescent levels by six months after cognitive behavioural guided self-help treatment.

Copyright © 2014 Elsevier Inc. All rights reserved.

 

Source: Rimes KA, Papadopoulos AS, Cleare AJ, Chalder T. Cortisol output in adolescents with chronic fatigue syndrome: pilot study on the comparison with healthy adolescents and change after cognitive behavioural guided self-help treatment. J Psychosom Res. 2014 Nov;77(5):409-14. doi: 10.1016/j.jpsychores.2014.08.018. Epub 2014 Sep 8.https://www.ncbi.nlm.nih.gov/pubmed/25260861

 

Use of single-nucleotide polymorphisms (SNPs) to distinguish gene expression subtypes of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME)

Abstract:

AIMS: We have reported gene expression changes in patients with chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) and the fact that such gene expression data can be used to identify subtypes of CFS/ME with distinct clinical phenotypes. Due to the difficulties in using a comparative gene expression method as an aid to CFS/ME disease and subtype-specific diagnosis, we have attempted to develop such a method based on single-nucleotide polymorphism (SNP) analysis.

METHODS: To identify SNP allele associations with CFS/ME and CFS/ME subtypes, we tested genomic DNA of patients with CFS/ME (n=108), patients with endogenous depression (n=17) and normal blood donors (n=68) for 504 human SNP alleles located within 88 CFS-associated human genes using the SNP Genotyping GoldenGate Assay (Illumina, San Diego, California, USA). 360 ancestry informative markers (AIM) were also examined.

RESULTS: 21 SNPs were significantly associated with CFS/ME compared with depression and normal groups. 148 SNP alleles had a significant association with one or more CFS/ME subtypes. For each subtype, associated SNPs tended to be grouped together within particular genes. AIM SNPs indicated that 4 subjects were of Asian origin while the remainder were Caucasian. Hierarchical clustering of AIM data revealed the relatedness between 2 couples of patients with CFS only and confirmed the overall heterogeneity of all subjects.

CONCLUSIONS: This study provides evidence that human SNPs located within CFS/ME associated genes are associated with particular genomic subtypes of CFS/ME. Further work is required to develop this into a clinically useful subtype-specific diagnostic test.

Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

 

Source: Shimosako N, Kerr JR. Use of single-nucleotide polymorphisms (SNPs) to distinguish gene expression subtypes of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME). J Clin Pathol. 2014 Dec;67(12):1078-83. doi: 10.1136/jclinpath-2014-202597. Epub 2014 Sep 19. https://www.ncbi.nlm.nih.gov/pubmed/25240059

 

Multiple Sclerosis/Chronic Fatigue Syndrome overlap: When two common disorders collide

Abstract:

INTRODUCTION: Fatigue is a major cause of disability and handicap in Multiple Sclerosis (MS) patients. The management of this common problem is often difficult. Chronic Fatigue Syndrome (CFS/ME) is another common cause of fatigue which is prevalent in the same population of middle aged females commonly affected by MS.

AIM: This report aims at examining the potential coexistence of MS and CFS/ME in the same patients.

METHOD: This is a retrospective study examining a cohort of MS patients referred for rehabilitation. The subjects were screened for CFS/ME symptoms.

RESULTS: Sixty-four MS patients (43 females) were screened for CFS/ME. Nine patients (14%) with a mean age 52 (SD 9.7) who were all females fulfilled the Fukuda criteria for diagnosis of CFS/ME. Their symptoms, including muscular and joint pain, malaise and recurrent headaches, were not explained by the pattern of their MS.

DISCUSSION: MS and CFS/ME are two common conditions with increased prevalence in middle aged females. As the diagnosis of CFS/ME is clinical with no positive clinical signs or investigations; it can be made with difficulty in the presence of another clear explanation for the disabling fatigue. Our results suggest that the two conditions may co-exist. Considering CFS/ME as a potential co-morbidity may lead to more focused and appropriate management.

 

Source: Gaber TA, Oo WW, Ringrose H. Multiple Sclerosis/Chronic Fatigue Syndrome overlap: When two common disorders collide. NeuroRehabilitation. 2014;35(3):529-34. doi: 10.3233/NRE-141146. https://www.ncbi.nlm.nih.gov/pubmed/25238862

 

High-throughput sequencing of plasma microRNA in chronic fatigue syndrome/myalgic encephalomyelitis

Abstract:

BACKGROUND: MicroRNAs (miRNAs) are known to regulate many biological processes and their dysregulation has been associated with a variety of diseases including Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME). The recent discovery of stable and reproducible miRNA in plasma has raised the possibility that circulating miRNAs may serve as novel diagnostic markers. The objective of this study was to determine the role of plasma miRNA in CFS/ME.

RESULTS: Using Illumina high-throughput sequencing we identified 19 miRNAs that were differentially expressed in the plasma of CFS/ME patients in comparison to non-fatigued controls. Following RT-qPCR analysis, we were able to confirm the significant up-regulation of three miRNAs (hsa-miR-127-3p, hsa-miR-142-5p and hsa-miR-143-3p) in the CFS/ME patients.

CONCLUSION: Our study is the first to identify circulating miRNAs from CFS/ME patients and also to confirm three differentially expressed circulating miRNAs in CFS/ME patients, providing a basis for further study to find useful CFS/ME biomarkers.

 

Source: Brenu EW, Ashton KJ, Batovska J, Staines DR, Marshall-Gradisnik SM. High-throughput sequencing of plasma microRNA in chronic fatigue syndrome/myalgic encephalomyelitis. PLoS One. 2014 Sep 19;9(9):e102783. doi: 10.1371/journal.pone.0102783. ECollection 2014. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4169517/ (Full article)

 

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

Abstract:

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

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

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

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

 

Source: Wyller VB, Fagermoen E, Sulheim D, Winger A, Skovlund E, Saul JP. Orthostatic responses in adolescent chronic fatigue syndrome: contributions from expectancies as well as gravity. Biopsychosoc Med. 2014 Sep 15;8:22. doi: 10.1186/1751-0759-8-22. eCollection 2014. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4166398/ (Full article)

 

Tryptophan depletion in chronic fatigue syndrome, a pilot cross-over study

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) is still an enigmatic disorder. CFS can be regarded as a complex disorder with tremendous impact on lives of CFS-patients. Full recovery without treatment is rare. A somatic explanation for the fatigue is lacking. There is clinical and experimental evidence implicating enhanced serotonergic neurotransmission in CFS.

Genetic studies and imaging studies support the hypothesis of upregulated serotonin system in CFS. In line with the hypothesis of an increased serotonergic state in CFS, we performed a randomised clinical trial investigated the effect of 5-HT3 receptor antagonism in CFS. No benefit was found of the 5-HT3 receptor antagonist ondansetron compared to placebo.To further investigate the involvement of serotonin in CFS we performed a placebo controlled cross over pilot study investigating the effect of Acute Tryptophan Depletion.

FINDINGS: Five female CFS-patients who met the US Center for Disease Control and Prevention criteria for CFS were recruited. There were two test days, one week apart. Each participant received placebo and ATD. To evaluate the efficacy of the ATD procedure tryptophan and the large neutral amino acids were measured. The outcome measures were fatigue severity, concentration and mood states. ATD resulted in a significant plasma tryptophan to large neutral amino acid ratio reduction of 96%. There were no significant differences in fatigue-, depression and concentration between the placebo- and ATD condition.

CONCLUSIONS: These first five CFS-patients did not respond to the ATD procedure. However, a much larger sample size is needed to draw final conclusions on the hypothesis of an increased serotonergic state in the pathophysiology of CFS.

TRIAL REGISTRATION: ISRCTN07518149.

 

Source: The GK, Verkes RJ, Fekkes D, Bleijenberg G, van der Meer JW, Buitelaar JK. Tryptophan depletion in chronic fatigue syndrome, a pilot cross-over study. BMC Res Notes. 2014 Sep 16;7:650. doi: 10.1186/1756-0500-7-650. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4176591/ (Full article)

 

Prevalence and predictors of recovery from chronic fatigue syndrome in a routine clinical practice

Abstract:

Cognitive behavioural therapy (CBT) is one of the treatments of choice for patients with chronic fatigue syndrome (CFS). However, the factors that predict recovery are unknown. The objective of this study was to ascertain the recovery rate among CFS patients receiving CBT in routine practice and to explore possible predictors of recovery.

Recovery was defined as no longer meeting Oxford or CDC criteria for CFS measured at 6 months follow-up. A composite score representing full recovery additionally included the perception of improvement, and normal population levels of fatigue and of physical functioning. Logistic regression was used to examine predictors of recovery.

Predictors included age, gender, cognitive and behavioural responses to symptoms, work and social adjustment, beliefs about emotions, perfectionism, anxiety and depression at baseline. At 6 months follow-up 37.5% of the patients no longer met either the Oxford or the CDC criteria for CFS while 18.3% were fully recovered.

Multivariate analyses showed that worse scores on the work and social adjustment scale, unhelpful beliefs about emotions, high levels of depression and older age were associated with reduced odds for recovery. Recovery rates in this routine practice were comparable to previous RCTs. There was a wide spectrum of significant predictors for recovery.

Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

 

Source: Flo E, Chalder T. Prevalence and predictors of recovery from chronic fatigue syndrome in a routine clinical practice. Behav Res Ther. 2014 Dec;63:1-8. doi: 10.1016/j.brat.2014.08.013. Epub 2014 Aug 26. http://www.sciencedirect.com/science/article/pii/S0005796714001429 (Full article)