Tag: 2015

The role of the hippocampus in the pathogenesis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a severe acquired illness characterized by a profound sensation of fatigue, not ameliorated by rest and resulting in a substantial decrease in the amount and quality of occupational, social and recreational activities.

Despite intense research, the aetiology and pathogenesis of ME/CFS is still unknown and no conclusive biological markers have been found. As a consequence, an accepted curative treatment is still lacking and rehabilitation programmes are not very effective, as few patients recover. Increased knowledge of the mechanisms leading to the emergence and maintenance of the illness is called for.

In this study, I will put forth an alternative hypothesis to explain some of the pathologies associated with ME/CFS, by concentrating on one of the major strategic organs of the brain, the hippocampus. I will show that the ME/CFS triggering factors also impact the hippocampus, leading to neurocognitive deficits and disturbances in the regulation of the stress system and pain perception. These deficits lead to a substantial decrease in activity and to sleep disorders, which, in turn, impact the hippocampus and initiate a vicious circle of increased disability.

Copyright © 2015 Elsevier Ltd. All rights reserved.

 

Source: Saury JM. The role of the hippocampus in the pathogenesis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Med Hypotheses. 2016 Jan;86:30-8. doi: 10.1016/j.mehy.2015.11.024. Epub 2015 Nov 27. https://www.ncbi.nlm.nih.gov/pubmed/26804593

 

Chronic fatigue syndrome (CFS) symptom-based phenotypes in two clinical cohorts of adult patients in the UK and The Netherlands

Abstract:

OBJECTIVE: Studies have provided evidence of heterogeneity within chronic fatigue syndrome (CFS), but few have used data from large cohorts of CFS patients or replication samples.

METHODS: 29 UK secondary-care CFS services recorded the presence/absence of 12 CFS-related symptoms; 8 of these symptoms were recorded by a Dutch tertiary service. Latent Class Analysis (LCA) was used to assign symptom profiles (phenotypes). Regression models were fitted with phenotype as outcome (in relation to age, sex, BMI, duration of illness) and exposure (in relation to comorbidities and patient-reported measures).

RESULTS: Data were available for 7041 UK and 1392 Dutch patients. Almost all patients in both cohorts presented with post-exertional malaise, cognitive dysfunction and disturbed/unrefreshing sleep, and these 3 symptoms were excluded from LCA. In UK patients, six phenotypes emerged: ‘full’ polysymptomatic (median 8, IQR 7-9 symptoms) 32.8%; ‘pain-only’ (muscle/joint) 20.3%; ‘sore throat/painful lymph node’ 4.5%; and ‘oligosymptomatic’ (median 1, IQR 0-2 symptoms) 4.7%. Two ‘partial’ polysymptomatic phenotypes were similar to the ‘full’ phenotype, bar absence of dizziness/nausea/palpitations (21.4%) or sore throat/painful lymph nodes (16.3%). Women and patients with longer duration of illness were more likely to be polysymptomatic. Polysymptomatic patients had more severe illness and more comorbidities. LCA restricted to 5 symptoms recorded in both cohorts indicated 3 classes (polysymptomatic, oligosymptomatic, pain-only), which were replicated in Dutch data.

CONCLUSIONS: Adults with CFS may have one of 6 symptom-based phenotypes associated with sex, duration and severity of illness, and comorbidity. Future research needs to determine whether phenotypes predict treatment outcomes, and require different treatments.

Copyright © 2015 Elsevier Inc. All rights reserved.

 

Source: Collin SM, Nikolaus S, Heron J, Knoop H, White PD, Crawley E. Chronic fatigue syndrome (CFS) symptom-based phenotypes in two clinical cohorts of adult patients in the UK and The Netherlands. J Psychosom Res. 2016 Feb;81:14-23. doi: 10.1016/j.jpsychores.2015.12.006. Epub 2015 Dec 23. https://www.ncbi.nlm.nih.gov/pubmed/26800634

 

Sleep quality and the treatment of intestinal microbiota imbalance in Chronic Fatigue Syndrome: A pilot study

Abstract:

Chronic Fatigue Syndrome (CFS) is a multisystem illness, which may be associated with imbalances in gut microbiota. This study builds on recent evidence that sleep may be influenced by gut microbiota, by assessing whether changes to microbiota in a clinical population known to have both poor sleep and high rates of colonization with gram-positive faecal Streptococcus, can improve sleep.

Twenty-one CFS participants completed a 22- day open label trial. Faecal microbiota analysis was performed at baseline and at the end of the trial. Participants were administered erythromycin 400 mg b.d. for 6 days. Actigraphy and questionnaires were used to monitor sleep, symptoms and mood. Changes in patients who showed a clinically significant change in faecal Streptococcus after treatment (responders; defined as post-therapy distribution<6%) were compared to participants who did not respond to treatment.

In the seven responders, there was a significant increase in actigraphic total sleep time (p=0.028) from baseline to follow up, compared with non-responders. Improved vigour scores were associated with a lower Streptococcus count (ρ=-0.90, p=0.037). For both the responders and the whole group, poorer mood was associated with higher Lactobacillus.

Short term antibiotic treatment appears to be insufficient to effect sustainable changes in the gut ecosystem in most CFS participants. Some improvement in objective sleep parameters and mood were found in participants with reduced levels of gram-positive gut microbiota after antibiotic treatment, which is encouraging. Further study of possible links between gut microorganisms and sleep and mood disturbances is warranted.

 

Source: Jackson ML, Butt H, Ball M, Lewis DP, Bruck D. Sleep quality and the treatment of intestinal microbiota imbalance in Chronic Fatigue Syndrome: A pilot study. Sleep Sci. 2015 Nov;8(3):124-33. doi: 10.1016/j.slsci.2015.10.001. Epub 2015 Oct 23. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4688574/ (Full article)

 

Reduced gait automaticity in female patients with chronic fatigue syndrome: Case-control study

Abstract:

Patients with chronic fatigue syndrome (CFS) report difficulties walking for a prolonged period of time. This study compares gait automaticity between women with CFS and nondisabled controls. The “stops walking with eyes closed with secondary cognitive task” test is based on the classic “stops walking while talking” test but compares walking with eyes closed while performing a secondary cognitive task in a female CFS population (n = 34) and in female nondisabled controls (n = 38).

When initiating gate, 23.5% of patients with CFS looked toward the ground compared with only 2.6% of nondisabled controls. After 7 m, subjects were asked to close their eyes, and after another 7 m, they were asked, “How much is 100 minus 7?” Of the patients with CFS, 55.9% stopped walking compared with 5.3% of nondisabled controls. Less automated walking was observed in patients with CFS than in nondisabled controls (p < 0.001). The test-retest reliability is moderate for global stopping. This simple test observed reduced gait automaticity in patients with CFS for the first time. Dual tasking could be helpful to address the functional limitations found in this particular study.

 

Source: Eyskens JB, Nijs J, Wouters K, Moorkens G. Reduced gait automaticity in female patients with chronic fatigue syndrome: Case-control study. J Rehabil Res Dev. 2015;52(7):805-14. doi: 10.1682/JRRD.2014.11.0293. http://www.rehab.research.va.gov/jour/2015/527/JRRD-2014-11-0293.html (Full article)

 

Effect of Lixujieyu recipe in combination with Five Elements music therapy on chronic fatigue syndrome

Abstract:

OBJECTIVE: To observe the clinical effects of the Lixujieyu recipe combined with Five Elements music therapy on chronic fatigue syndrome (CFS) identified as the symptom patterns of liver stagnation and spleen deficiency in terms of Traditional Chinese Medicine.

METHODS: Patients with CFS were randomly divided into treatment group 1 (Lixujieyu recipe combined with Gong-Tune, n = 15); treatment group 2 (Lixujieyu recipe combined with Jiao-Tune, n = 15); treatment group 3 (Lixujieyu recipe combined with Yu-Tune, n = 15); treatment group 4 (Lixujieyu recipe combined with Shang-Tune, n = 15); treatment group 5 (Lixuiievu recipe combined with Zhi-Tune, n = 15); and the control group (Lixujieyu recipe alone, n = 15). Chinese medicine was given twice daily, and music was listened to for 45 minutes daily, 5 days a week. All patients were treated for 4 weeks. Patients were assessed via the Fatigue Scale, the Hamilton Depression Rating Scale, and the Hamilton Anxiety Rating Scale before and after treatment.

RESULTS: Treatment groups 1 and 2 had better effects on relieving the symptoms of physical fatigue related to anxiety and depression than the control group (P < 0.05).

CONCLUSION: Lixujieyu recipe combined with Gong-Tune or Jiao-Tune significantly relieved the symptoms of CFS.

 

Source: Zhang Z, Cai Z, Yu Y, Wu L, Zhang Y. Effect of Lixujieyu recipe in combination with Five Elements music therapy on chronic fatigue syndrome. J Tradit Chin Med. 2015 Dec;35(6):637-41. https://www.ncbi.nlm.nih.gov/pubmed/26742307

 

Abnormal resting state functional connectivity in patients with chronic fatigue syndrome: an arterial spin-labeling fMRI study

Abstract:

BACKGROUND: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating disorder characterized by severe fatigue and neurocognitive dysfunction. Recent work from our laboratory and others utilizing arterial spin labeling functional magnetic resonance imaging (ASL) indicated that ME/CFS patients have lower resting state regional cerebral blood flow (rCBF) in several brain areas associated with memory, cognitive, affective, and motor function. This hypoperfusion may underlie ME/CFS pathogenesis and may result in alterations of functional relationships between brain regions. The current report used ASL to compare functional connectivity of regions implicated in ME/CFS between patients and healthy controls (HC).

METHODS: Participants were 17 ME/CFS patients (Mage=48.88years, SD=12) fulfilling the 1994 CDC criteria and 17 age/sex matched HC (Mage=49.82years, SD=11.32). All participants underwent T1-weighted structural MRI as well as a 6-min pseudo-continuous arterial spin labeling (pCASL) sequence, which quantifies CBF by magnetically labeling blood as it enters the brain. Imaging data were preprocessed using SPM 12 and ASL tbx, and seed-to-voxel functional connectivity analysis was conducted using the CONN toolbox. All effects noted below are significant at p<0.05 with cluster-wise FDR correction for multiple comparisons.

RESULTS: ME/CFS patients demonstrated greater functional connectivity relative to HC in bilateral superior frontal gyrus, ACC, precuneus, and right angular gyrus to regions including precuneus, right postcentral gyrus, supplementary motor area, posterior cingulate gyrus, and thalamus. In contrast, HC patients had greater functional connectivity than ME/CFS in ACC, left parahippocampal gyrus, and bilateral pallidum to regions including right insula, right precentral gyrus, and hippocampus. Connectivity of the left parahippocampal gyrus correlated strongly with overall clinical fatigue of ME/CFS patients.

CONCLUSION: This is the first ASL based connectivity analysis of patients with ME/CFS. Our results demonstrate altered functional connectivity of several regions associated with cognitive, affective, memory, and higher cognitive function in ME/CFS patients. Connectivity to memory related brain areas (parahippocampal gyrus) was correlated with clinical fatigue ratings, providing supporting evidence that brain network abnormalities may contribute to ME/CFS pathogenesis.

Copyright © 2015 Elsevier Inc. All rights reserved.

 

Source: Boissoneault J, Letzen J, Lai S, O’Shea A, Craggs J, Robinson ME, Staud R. Abnormal resting state functional connectivity in patients with chronic fatigue syndrome: an arterial spin-labeling fMRI study. Magn Reson Imaging. 2016 May;34(4):603-8. doi: 10.1016/j.mri.2015.12.008. Epub 2015 Dec 18. https://www.ncbi.nlm.nih.gov/pubmed/26708036

 

Increased expression of activation antigens on CD8+ T lymphocytes in Myalgic Encephalomyelitis/chronic fatigue syndrome: inverse associations with lowered CD19+ expression and CD4+/CD8+ ratio, but no associations with (auto)immune, leaky gut, oxidative and nitrosative stress biomarkers

Abstract:

BACKGROUND: There is now evidence that specific subgroups of patients with Myalgic Encephalomyelitis / chronic fatigue syndrome (ME/CFS) suffer from a neuro-psychiatric-immune disorder. This study was carried out to delineate the expression of the activation markers CD38 and human leukocyte antigen (HLA) DR on CD4+ and CD8+ peripheral blood lymphocytes in ME/CFS.

METHODS: Proportions and absolute numbers of peripheral lymphocytes expressing CD3+, CD19+, CD4+, CD8+, CD38+ and HLA-DR+ were measured in ME/CFS (n=139), chronic fatigue (CF, n=65) and normal controls (n=40).

RESULTS: The proportions of CD3+, CD8+, CD8+CD38+ and CD8+HLA-DR+ were significantly higher in ME/CFS patients than controls, while CD38+, CD8+CD38+, CD8+HLA-DR+ and CD38+HLA-DR+ were significantly higher in ME/CFS than CF. The percentage of CD19+ cells and the CD4+/CD8+ ratio were significantly lower in ME/CFS and CF than in controls. There were highly significant inverse correlations between the increased expression of CD38+, especially that of CD8+CD38+, and the lowered CD4+/CD8+ ratio and CD19+ expression. There were no significant associations between the flow cytometric results and severity or duration of illness and peripheral blood biomarkers of oxidative and nitrosative stress (O&NS, i.e. IgM responses to O&N modified epitopes), leaky gut (IgM or IgA responses to LPS of gut commensal bacteria), cytokines (interleukin-1, tumor necrosis factor-α), neopterin, lysozyme and autoimmune responses to serotonin.

CONCLUSIONS: The results support that a) increased CD38 and HLA-DR expression on CD8+ T cells are biomarkers of ME/CFS; b) increased CD38 antigen expression may contribute to suppression of the CD4+/CD8+ ratio and CD19+ expression; c) there are different immune subgroups of ME/CFS patients, e.g. increased CD8+ activation marker expression versus inflammation or O&NS processes; and d) viral infections or reactivation may play a role in a some ME/CFS patients.

 

Source: Maes M, Bosmans E, Kubera M. Increased expression of activation antigens on CD8+ T lymphocytes in Myalgic Encephalomyelitis/chronic fatigue syndrome: inverse associations with lowered CD19+ expression and CD4+/CD8+ ratio, but no associations with (auto)immune, leaky gut, oxidative and nitrosative stress biomarkers. Neuro Endocrinol Lett. 2015;36(5):439-46. https://www.ncbi.nlm.nih.gov/pubmed/26707044

 

Significant other behavioural responses and patient chronic fatigue syndrome symptom fluctuations in the context of daily life: An experience sampling study

Abstract:

OBJECTIVE: Significant other responses to patients’ symptoms are important for patient illness outcomes in chronic fatigue syndrome (CFS/ME); negative responses have been associated with increased patient depression, whilst increased disability and fatigue have been associated with solicitous significant other responses. The current study aimed to examine the relationship between significant other responses and patient outcomes within the context of daily life.

DESIGN: Experience Sampling Methodology (ESM).

METHOD: Twenty-three patients with CFS/ME and their significant others were recruited from specialist CFS/ME services. Sixty momentary assessments, delivered using individual San Francisco Android Smartphones, were conducted over a period of 6 days. All participants reported on affect, dyadic contact, and significant other responses to the patient. Patients reported on symptom severity, disability, and activity management strategies.

RESULTS: Negative significant other responses were associated with increased patient symptom severity and distress reported at the same momentary assessment; there was evidence of a potentially mediating role of concurrent distress on symptom severity. Patient-perceived solicitous responses were associated with reduced patient activity and disability reported at the same momentary assessment. Lagged analyses indicate that momentary associations between significant other responses and patient outcomes are largely transitory; significant other responses were not associated with any of the patient outcomes at the subsequent assessment.

CONCLUSION: The results indicate that significant other responses are important influences on the day-to-day experience of CFS/ME. Further research examining patient outcomes in association with specific significant other behavioural responses is warranted and future interventions that target such significant other behaviours may be beneficial. Statement of contribution What is already known on this subject? The existing literature has identified that significant other responses are important with respect to patient outcomes in CFS/ME. In particular, when examined cross-sectionally and longitudinally, negative and solicitous significant other responses are associated with poorer illness outcomes. This study is the first to examine the momentary associations between negative and solicitous responses, as reported by the patient and significant other, and patient-reported outcomes. An ESM paradigm was used to assess these temporal relationships within the context of participants’ daily life. What does this study add? Negative responses were associated with increased momentary patient distress and symptoms. Perceived solicitousness was associated with activity limitation but less perceived disability. The impact of significant other responses on patient outcomes was found to be transitory.

© 2015 The Authors. British Journal of Health Psychology published by John Wiley & Sons Ltd on behalf of British Psychological Society.

 

Source: Band R, Barrowclough C, Emsley R, Machin M, Wearden AJ. Significant other behavioural responses and patient chronic fatigue syndrome symptom fluctuations in the context of daily life: An experience sampling study. Br J Health Psychol. 2016 Sep;21(3):499-514. doi: 10.1111/bjhp.12179. Epub 2015 Dec 24. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4991278/ (Full article)

 

Changes in Gut and Plasma Microbiome following Exercise Challenge in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a disease characterized by intense and debilitating fatigue not due to physical activity that has persisted for at least 6 months, post-exertional malaise, unrefreshing sleep, and accompanied by a number of secondary symptoms, including sore throat, memory and concentration impairment, headache, and muscle/joint pain.

In patients with post-exertional malaise, significant worsening of symptoms occurs following physical exertion and exercise challenge serves as a useful method for identifying biomarkers for exertion intolerance. Evidence suggests that intestinal dysbiosis and systemic responses to gut microorganisms may play a role in the symptomology of ME/CFS. As such, we hypothesized that post-exertion worsening of ME/CFS symptoms could be due to increased bacterial translocation from the intestine into the systemic circulation.

To test this hypothesis, we collected symptom reports and blood and stool samples from ten clinically characterized ME/CFS patients and ten matched healthy controls before and 15 minutes, 48 hours, and 72 hours after a maximal exercise challenge. Microbiomes of blood and stool samples were examined.

Stool sample microbiomes differed between ME/CFS patients and healthy controls in the abundance of several major bacterial phyla. Following maximal exercise challenge, there was an increase in relative abundance of 6 of the 9 major bacterial phyla/genera in ME/CFS patients from baseline to 72 hours post-exercise compared to only 2 of the 9 phyla/genera in controls (p = 0.005). There was also a significant difference in clearance of specific bacterial phyla from blood following exercise with high levels of bacterial sequences maintained at 72 hours post-exercise in ME/CFS patients versus clearance in the controls.

These results provide evidence for a systemic effect of an altered gut microbiome in ME/CFS patients compared to controls. Upon exercise challenge, there were significant changes in the abundance of major bacterial phyla in the gut in ME/CFS patients not observed in healthy controls. In addition, compared to controls clearance of bacteria from the blood was delayed in ME/CFS patients following exercise. These findings suggest a role for an altered gut microbiome and increased bacterial translocation following exercise in ME/CFS patients that may account for the profound post-exertional malaise experienced by ME/CFS patients.

 

Source: Shukla SK, Cook D, Meyer J, Vernon SD, Le T, Clevidence D, Robertson CE, Schrodi SJ, Yale S, Frank DN. Changes in Gut and Plasma Microbiome following Exercise Challenge in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). PLoS One. 2015 Dec 18;10(12):e0145453. doi: 10.1371/journal.pone.0145453. ECollection 2015. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4684203/ (Full article)

 

The Many Neuroprogressive Actions of Tryptophan Catabolites (TRYCATs) that may be Associated with the Pathophysiology of Neuro-Immune Disorders

Abstract:

Many, if not all, chronic medical, neurodegenerative and neuroprogressive illnesses are characterised by chronic immune activation, oxidative and nitrosative stress (O&NS) and systemic inflammation. These factors, notably elevated pro-inflammatory cytokines, activate indoleamine 2,3-dioxygenase (IDO) leading to an upregulated tryptophan catabolite (TRYCAT) pathway of tryptophan degradation in the periphery and in the brain. In such conditions the TRYCAT pathway becomes the predominant system for tryptophan degradation in all body compartments.

In this paper we review the pathways whereby TRYCATs may play a role in neuro-inflammatory and neuroprogressive disease. Thus chronic activation of the TRYCAT pathway leads to the production of a range of neuroactive, neuroprotective and neurotoxic TRYCATs. Some TRYCATs such as quinolinic acid act as potent neurotoxins which inhibit ATP production by mitochondria, provoke increases in O&NS, disrupt neuron glial communication and blood brain barrier integrity, induce apoptosis of glial cells, directly damage neurons and function as a N-methyl D-aspartate (NMDA) receptor agonist.

Other TRYCATs such as kynurenic acid function as antagonists of NMDA, α- amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid and kainate receptors and act to regulate levels of glutamate and dopamine.

The neuroprotective functions of this TRYCAT are likely exercised via engagement with alpha7 nicotinic acetylcholine and aryl hydrocarbon receptors but the neuroprotective effects stemming from elevated kynurenic acid levels come at the price of severely compromised neurocognitive function and emotional processing. Other TRYCATS also possess neurotoxic or neuroprotective properties via pro-oxidant and antioxidant effects.

Here we discuss the involvement of the above mentioned TRYCAT pathways in schizophrenia, Alzheimer’s disease and chronic fatigue syndrome.

Source: Morris G, Carvalho AF, Anderson G, Galecki P, Maes M. The Many Neuroprogressive Actions of Tryptophan Catabolites (TRYCATs) that may be Associated with the Pathophysiology of Neuro-Immune Disorders. Curr Pharm Des. 2016;22(8):963-77. https://www.ncbi.nlm.nih.gov/pubmed/26667000