Neurology – Page 10 – American ME and CFS Society

Epstein-Barr Virus dUTPase Induces Neuroinflammatory Mediators: Implications for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

PURPOSE: Neuroinflammation is a common feature in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), affecting 85%-90% of all patients, yet the underlying mechanism or mechanisms responsible for the initiation and/or promotion of this process is largely unknown. Multiple reports, however, have suggested a role for Epstein-Barr virus (EBV), in particular, in ME/CFS, but its potential role, if any, in the neuroinflammatory process has not been addressed. In support of this premise, studies by our group have found that the EBV protein deoxyuridine triphosphate nucleotidohydrolase (dUTPase) induces anxiety and sickness behaviors in female mice. We also found that a small subset of patients with ME/CFS exhibited prolonged and significantly elevated neutralizing antibodies against EBV dUTPase protein in serum, which inversely correlated with ME/CFS symptoms. A larger ME/CFS case-control cohort study further confirmed that a significant percentage of patients with ME/CFS (30.91%-52.7%) were simultaneously producing antibodies against multiple human herpesviruses-encoded dUTPases and/or human dUTPase. Altogether, these findings suggest that EBV dUTPase protein may be involved in the neuroinflammatory process observed in ME/CFS. Thus, the aim of the present study was to determine whether the EBV dUTPase protein could contribute to neuroinflammation by altering the expression of genes involved with maintaining blood-brain barrier (BBB) integrity and/or modulating synaptic plasticity.

METHODS: With the use of human immortalized astrocytes, microglia, and cerebral microvascular endothelial cells, we conducted time-course (0-24 h) experiments with EBV dUTPase protein (10 μg/mL) to determine what effect(s) it may have on the expression of genes involved with BBB permeability, astrocytes and microglia cell function, tryptophan metabolism, and synaptic plasticity by quantitative reverse transcription polymerase chain reaction (qRT-PCR). In parallel, in vivo studies were conducted in female C57Bl/6 mice. Mice were injected by the intraperitoneal route with EBV dUTPase protein (10 μg) or vehicle daily for 5 days, and the brains were collected and processed for further qRT-PCR analysis of the in vivo effect of the dUTPase on the dopamine/serotonin and γ-aminobutyric acid/glutamate pathways, which are important for brain function, using RT2 Profiler PCR Arrays.

FINDINGS: EBV dUTPase protein altered the expression in vitro (12 of 15 genes and 32 of 1000 proteins examined) and in vivo (34 of 84 genes examined) of targets with central roles in BBB integrity/function, fatigue, pain synapse structure, and function, as well as tryptophan, dopamine, and serotonin metabolism.

IMPLICATIONS: The data suggest that in a subset of patients with ME/CFS, the EBV dUTPase could initiate a neuroinflammatory reaction, which contributes to the fatigue, excessive pain, and cognitive impairments observed in these patients.

Network structure underpinning (dys)homeostasis in chronic fatigue syndrome; Preliminary findings

Abstract:

INTRODUCTION: A large body of evidence has established a pattern of altered functioning in the immune system, autonomic nervous system and hypothalamic pituitary adrenal axis in chronic fatigue syndrome. However, the relationship between components within and between these systems is unclear. In this paper we investigated the underlying network structure of the autonomic system in patients and controls, and a larger network comprising all three systems in patients alone.

METHODS: In a sample of patients and controls we took several measures of autonomic nervous system output during 10 minutes of supine rest covering tests of blood pressure variability, heart rate variability and cardiac output. Awakening salivary cortisol was measured on each of two days with participants receiving 0.5mg dexamethasone during the afternoon of the first day. Basal plasma cytokine levels and the in vitro cytokine response to dexamethasone were also measured. Symptom outcome measures used were the fatigue impact scale and cognitive failures questionnaire. Mutual information criteria were used to construct networks describing the dependency amongst variables. Data from 42 patients and 9 controls were used in constructing autonomic networks, and 15 patients in constructing the combined network.

RESULTS: The autonomic network in patients showed a more uneven distribution of information, with two distinct modules emerging dominated by systolic blood pressure during active stand and end diastolic volume and stroke volume respectively. The combined network revealed strong links between elements of each of the three regulatory systems, characterised by three higher modules the centres of which were systolic blood pressure during active stand, stroke volume and ejection fraction respectively.

CONCLUSIONS: CFS is a complex condition affecting physiological systems. It is important that novel analytical techniques are used to understand the abnormalities that lead to CFS. The underlying network structure of the autonomic system is significantly different to that of controls, with a small number of individual nodes being highly influential. The combined network suggests links across regulatory systems which shows how alterations in single nodes might spread throughout the network to produce alterations in other, even distant, nodes. Replication in a larger cohort is warranted.

Source: Clark JE, Ng WF, Rushton S, Watson S, Newton JL. Network structure underpinning (dys)homeostasis in chronic fatigue syndrome; Preliminary findings. PLoS One. 2019 Mar 25;14(3):e0213724. doi: 10.1371/journal.pone.0213724. eCollection 2019. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0213724 (Full article)

Neuroinflammation and Cytokines in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Critical Review of Research Methods

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is the label given to a syndrome that can include long-term flu-like symptoms, profound fatigue, trouble concentrating, and autonomic problems, all of which worsen after exertion. It is unclear how many individuals with this diagnosis are suffering from the same condition or have the same underlying pathophysiology, and the discovery of biomarkers would be clarifying.

The name “myalgic encephalomyelitis” essentially means “muscle pain related to central nervous system inflammation” and many efforts to find diagnostic biomarkers have focused on one or more aspects of neuroinflammation, from periphery to brain. As the field uncovers the relationship between the symptoms of this condition and neuroinflammation, attention must be paid to the biological mechanisms of neuroinflammation and issues with its potential measurement.

The current review focuses on three methods used to study putative neuroinflammation in ME/CFS: (1) positron emission tomography (PET) neuroimaging using translocator protein (TSPO) binding radioligand (2) magnetic resonance spectroscopy (MRS) neuroimaging and (3) assays of cytokines circulating in blood and cerebrospinal fluid. PET scanning using TSPO-binding radioligand is a promising option for studies of neuroinflammation. However, methodological difficulties that exist both in this particular technique and across the ME/CFS neuroimaging literature must be addressed for any results to be interpretable.

We argue that the vast majority of ME/CFS neuroimaging has failed to use optimal techniques for studying brainstem, despite its probable centrality to any neuroinflammatory causes or autonomic effects. MRS is discussed as a less informative but more widely available, less invasive, and less expensive option for imaging neuroinflammation, and existing studies using MRS neuroimaging are reviewed. Studies seeking to find a peripheral circulating cytokine “profile” for ME/CFS are reviewed, with attention paid to the biological and methodological reasons for lack of replication among these studies.

We argue that both the biological mechanisms of cytokines and the innumerable sources of potential variance in their measurement make it unlikely that a consistent and replicable diagnostic cytokine profile will ever be discovered.

Source: Michael B. VanElzakker, Sydney A. Brumfield and Paula S. Lara Mejia. Neuroinflammation and Cytokines in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Critical Review of Research Methods. Front. Neurol., 10 January 2019 | https://doi.org/10.3389/fneur.2018.01033 https://www.frontiersin.org/articles/10.3389/fneur.2018.01033/full?fbclid=IwAR3KxhofUaLakZRPNiyBliNHSlJvUOdsVqVf5cED_i6o5gF9MCbWxpeS298#h7 (Full article)

Evidence of widespread metabolite abnormalities in Myalgic encephalomyelitis/chronic fatigue syndrome: assessment with whole-brain magnetic resonance spectroscopy

Abstract:

Previous neuroimaging studies have detected markers of neuroinflammation in patients with Myalgic Encephalomyelitis /ChronicFatigue Syndrome (ME/CFS). Magnetic Resonance Spectroscopy (MRS) is suitable for measuring brain metabolites linked to inflammation, but has only been applied to discrete regions of interest in ME/CFS. We extended the MRS analysis of ME/CFS by capturing multi-voxel information across the entire brain.

Additionally, we tested whether MRS-derived brain temperature is elevated in ME/CFS patients. Fifteen women with ME/CFS and 15 age- and gender-matched healthy controls completed fatigue and mood symptom questionnaires and whole-brain echo-planar spectroscopic imaging (EPSI). Choline (CHO), myo-inositol (MI),lactate (LAC), and N-acetylaspartate (NAA) were quantified in 47 regions, expressed as ratios over creatine (CR), and compared between ME/CFS patients and controls using independent-samples t-tests. Brain temperature was similarly tested between groups.

Significant between-group differences were detected in several regions, most notably elevated CHO/CR in the left anterior cingulate (p < 0.001). Metabolite ratios in seven regions were correlated with fatigue (p < 0.05). ME/CFS patients had increased temperature in the right insula, putamen, frontal cortex, thalamus, and the cerebellum (all p < 0.05), which was not attributable to increased body temperature or differences in cerebral perfusion. Brain temperature increases converged with elevated LAC/CR in the right insula, right thalamus, and cerebellum (all p < 0.05). We report metabolite and temperature abnormalities in ME/CFS patients in widely distributed regions. Our findings may indicate that ME/CFS involves neuroinflammation.

Source: Christina Mueller, Joanne C. Lin, Sulaiman Sheriff, Andrew A. Maudsley, Jarred W. Younger. Evidence of widespread metabolite abnormalities in Myalgic encephalomyelitis/chronic fatigue syndrome: assessment with whole-brain magnetic resonance spectroscopy. Brain Imaging and Behavior. https://link.springer.com/epdf/10.1007/s11682-018-0029-4?author_access_token=rNZAi4Qn9MGbc1YywGoHCve4RwlQNchNByi7wbcMAY4otkELpwVAg-M9CJyul_kO-cT6SC717CxfcGOGfesdx7f1AhmYrPeCJukInpp-Dq7L6ew7TkRsW7LllmoDMoo7GAglGA7edR1iMan4xy8-LA%3D%3D (Full article)

Severe posterior hypometabolism but normal perfusion in a patient with CFS/ME

Abstract:

Chronic fatigue syndrome/myalgic encephalitis (CFS/ME) is a complex clinical condition defined by prolonged severe fatigue without medical or psychiatric causes, and by a subset of symptoms that mostly includes arthromyalgias, cognitive impairment, sleeping troubles, and unusual headaches [1]. Previous FDG-PET studies showed unspecific patterns of hypometabolism in the frontal and cingulate cortex in half of CFS patients compared to healthy controls [2].

We present 18F-FDG PET/MRI findings in a 21-year-old woman who fulfilled the criteria of CFS with a Fukuda score of 4. PET images (a) show severe and extensive hypometabolism in the posterior cortical regions (precuneus, parietal, temporal, and occipital), amygdalo-hippocampal complexes, and cerebellum. No structural abnormalities were found on T1 MPRAGE (b) or T2 FLAIR (c) MRI sequences. Interestingly, cerebral blood flow evaluated with Gadolinium first-pass method (d) was not decreased in these regions.

This peculiar pattern of hypometabolism was recently described in a large series of patients with aluminium-induced macrophagic myofasciitis (MMF) followed in our reference center [3]. However, the present patient had negative muscular biopsies for MMF. Neuropsychological testing showed severe impairment of short-term memory (immediate and working memory) in visual modality, and weakness of visual selective attention and executive functions, which are concordant with the pattern of hypometabolism. Finally, perfusion-metabolism uncoupling suggests that posterior hypometabolism may not be related to neuronal loss such as in degenerative diseases [4], but rather to an inflammatory or immunological process [5]. Further studies are warranted to investigate metabolism and perfusion using simultaneous PET/MRI in larger groups of patients with CFS/ME.

Source: S. Sahbai & P. Kauv & M. Abrivard & P. Blanc-Durand & M. Aoun-Sebati & B. Emsen & A. Luciani & J. Hodel & F-J. Authier & E. Itti. Severe posterior hypometabolism but normal perfusion in a patient with chronic fatigue syndrome/myalgic encephalomyelitis revealed by PET/MRI. Eur J Nucl Med Mol Imaging. 2018 Dec 14. doi: 10.1007/s00259-018-4229-3. [Epub ahead of print] https://forums.phoenixrising.me/index.php?threads/severe-posterior-hypometabolism-but-normal-perfusion-in-a-patient-with-cfs-me.62543/

The link between idiopathic intracranial hypertension, fibromyalgia, and chronic fatigue syndrome: exploration of a shared pathophysiology

Abstract:

PURPOSE: Idiopathic intracranial hypertension (IICH) is a condition characterized by raised intracranial pressure (ICP), and its diagnosis is established when the opening pressure measured during a lumbar puncture is elevated >20 cm H2O in nonobese patients or >25 cm H2O in obese patients. Papilledema is caused by forced filling of the optic nerve sheath with cerebrospinal fluid (CSF). Other common but underappreciated symptoms of IICH are neck pain, back pain, and radicular pain in the arms and legs resulting from associated increased spinal pressure and forced filling of the spinal nerves with CSF. Widespread pain and also several other characteristics of IICH share notable similarities with characteristics of fibromyalgia (FM) and chronic fatigue syndrome (CFS), two overlapping chronic pain conditions. The aim of this review was to compare literature data regarding the characteristics of IICH, FM, and CFS and to link the shared data to an apparent underlying physiopathology, that is, increased ICP.

METHODS: Data in the literature regarding these three conditions were compared and linked to the hypothesis of the shared underlying physiopathology of increased cerebrospinal pressure.

RESULTS: The shared characteristics of IICH, FM, and CFS that can be caused by increased ICP include headaches, fatigue, cognitive impairment, loss of gray matter, involvement of cranial nerves, and overload of the lymphatic olfactory pathway. Increased pressure in the spinal canal and in peripheral nerve root sheaths causes widespread pain, weakness in the arms and legs, walking difficulties (ataxia), and bladder, bowel, and sphincter symptoms. Additionally, IICH, FM, and CFS are frequently associated with sympathetic overactivity symptoms and obesity. These conditions share a strong female predominance and are frequently associated with Ehlers-Danlos syndrome.

CONCLUSION: IICH, FM, and CFS share a large variety of symptoms that might all be explained by the same pathophysiology of increased cerebrospinal pressure.

Source: Hulens M, Rasschaert R, Vansant G, Stalmans I, Bruyninckx F, Dankaerts. The link between idiopathic intracranial hypertension, fibromyalgia, and chronic fatigue syndrome: exploration of a shared pathophysiology. J Pain Res. 2018 Dec 10;11:3129-3140. doi: 10.2147/JPR.S186878. eCollection 2018. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6292399/ (Full article)

VIDEO: Jarred Younger, PhD | How Brain Inflammation Causes ME/CFS

Jarred Younger studied Psychophysiology at the University of Tennessee in Knoxville in 2003. He then completed postdoctoral fellowships in pain medicine and neuroimaging at Arizona State University and Stanford University before joining the faculty at Stanford in 2009. In 2014, he transferred to the University of Alabama at Birmingham, where he currently directs the Neuroinflammation, Pain and Fatigue Laboratory. His lab uses neuroimaging, immune monitoring, and clinical trial techniques to develop new diagnostic tests and treatments for pain and fatigue disorders.

You can read the full transcript HERE.

Hyperintense sensorimotor T1 spin echo MRI is associated with brainstem abnormality in chronic fatigue syndrome

Abstract:

We recruited 43 Chronic Fatigue Syndrome (CFS) subjects who met Fukuda criteria and 27 healthy controls and performed 3T MRI T1 and T2 weighted spin-echo (T1wSE and T2wSE) scans. T1wSE signal follows T1 relaxation rate (1/T1 relaxation time) and responds to myelin and iron (ferritin) concentrations. We performed MRI signal level group comparisons with SPM12. Spatial normalization after segmentation was performed using T2wSE scans and applied to the coregistered T1wSE scans.

After global signal-level normalization of individual scans, the T1wSE group comparison detected decreased signal-levels in CFS in a brainstem region (cluster-based inference controlled for family wise error rate, PFWE= 0.002), and increased signal-levels in large bilateral clusters in sensorimotor cortex white matter (cluster PFWE < 0.0001). Moreover, the brainstem T1wSE values were negatively correlated with the sensorimotor values for both CFS (R2 = 0.31, P = 0.00007) and healthy controls (R2= 0.34, P = 0.0009), and the regressions were co-linear.

This relationship, previously unreported in either healthy controls or CFS, in view of known thalamic projection-fibre plasticity, suggests brainstem conduction deficits in CFS may stimulate the upregulation of myelin in the sensorimotor cortex to maintain brainstem – sensorimotor connectivity. VBM did not find group differences in regional grey matter or white matter volumes. We argued that increased T1wSE observed in sensorimotor WM in CFS indicates increased myelination which is a regulatory response to deficits in the brainstem although the causality cannot be tested in this study. Altered brainstem myelin may have broad consequences for cerebral function and should be a focus of future research.

Source: Barnden LR, Shan ZY, Staines DR, Marshall-Gradisnik S, Finegan K, Ireland T, Bhuta S. Hyperintense sensorimotor T1 spin echo MRI is associated with brainstem abnormality in chronic fatigue syndrome. Neuroimage Clin. 2018;20:102-109. doi: 10.1016/j.nicl.2018.07.011. Epub 2018 Jul 11. https://www.ncbi.nlm.nih.gov/pubmed/30497131

Brain abnormalities in myalgic encephalomyelitis/chronic fatigue syndrome: Evaluation by diffusional kurtosis imaging and neurite orientation dispersion and density imaging

Abstract:

BACKGROUND: Diffusional kurtosis imaging (DKI) and neurite orientation dispersion and density imaging (NODDI) metrics provide more specific information regarding pathological changes than diffusion tensor imaging (DTI).

PURPOSE: To detect microstructural abnormalities in myalgic encephalomyelitis (ME) / chronic fatigue syndrome (CFS) patients by using DKI and NODDI metrics.

STUDY TYPE: Prospective.

POPULATION: Twenty ME/CFS patients and 23 healthy controls were recruited.

FIELD STRENGTH/SEQUENCE: Three-b value DWI (b-values = 0, 1000, and 2000 sec/mm2 ) and 3D T1 -weighted images were at 3.0T.

ASSESSMENT: Mean kurtosis (MK), neurite density index (NDI), orientation dispersion index (ODI), fractional anisotropy (FA), and mean diffusivity (MD) were calculated.

STATISTICAL TESTING: The two-sample t-test analysis in SPM12 software was used to compare the differences between ME/CFS and control groups.

RESULTS: In the ME/CFS patients, we observed significant FA decreases in the genu of the corpus callosum and the anterior limb of the right internal capsule (P < 0.05), but no significant difference in MD (P = 0.164); there were also significant MK decreases in the right frontal area, anterior cingulate gyrus, superior longitudinal fasciculus (SLF), and left parietal area (P < 0.05). Significant NDI decreases were observed in the right posterior cingulate gyrus, SLF, and left frontal area of the ME/CFS patients (P < 0.05). Significant ODI decreases were seen in the bilateral occipital areas, right superior temporal gyrus, the anterior limb of internal capsule, and the posterior cingulate gyrus (P < 0.05), and significant ODI increases were revealed in the bilateral occipital and right temporal areas (P < 0.05).

DATA CONCLUSION: Right SLF abnormalities may be a diagnostic marker for ME/CFS.

LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018.

Source: Kimura Y, Sato N, Ota M, Shigemoto Y, Morimoto E, Enokizono M, Matsuda H, Shin I, Amano K, Ono H, Sato W, Yamamura T. Brain abnormalities in myalgic encephalomyelitis/chronic fatigue syndrome: Evaluation by diffusional kurtosis imaging and neurite orientation dispersion and density imaging. J Magn Reson Imaging. 2018 Nov 14. doi: 10.1002/jmri.26247. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/30430664

Associations between clinical symptoms, plasma norepinephrine and deregulated immune gene networks in subgroups of adolescent with Chronic Fatigue Syndrome

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) is one of the most important causes of disability among adolescents while limited knowledge exists on genetic determinants underlying disease pathophysiology.

METHODS: We analyzed deregulated immune-gene modules using Pathifier software on whole blood gene expression data (29 CFS patients, 18 controls). Deconvolution of immune cell subtypes based on gene expression profile was performed using CIBERSORT. Supervised consensus clustering on pathway deregulation score (PDS) was used to define CFS subgroups. Associations between PDS and immune, neuroendocrine/autonomic and clinical markers were examined. The impact of plasma norepinephrine level on clinical markers over time was assessed in a larger cohort (91 patients).

RESULTS: A group of 29 immune-gene sets was shown to differ patients from controls and detect subgroups within CFS. Group 1P (high PDS, low norepinephrine, low naïve CD4+ composition) had strong association with levels of serum C-reactive protein and Transforming Growth Factor-beta. Group 2P (low PDS, high norepinephrine, high naïve CD4+ composition) had strong associations with neuroendocrine/autonomic markers. The corresponding plasma norepinephrine level delineated 91 patients into two subgroups with significant differences in fatigue score.

CONCLUSION: We identified 29 immune-gene sets linked to plasma norepinephrine level that could delineate CFS subgroups. Plasma norepinephrine stratification revealed that lower levels of norepinephrine were associated with higher fatigue. Our data suggests potential involvement of neuro-immune dysregulation and genetic stratification in CFS.

Source: Nguyen CB, Kumar S, Zucknick M, Kristensen VN, Gjerstad J, Nilsen H, Wyller VB. Associations between clinical symptoms, plasma norepinephrine and deregulated immune gene networks in subgroups of adolescent with Chronic Fatigue Syndrome. Brain Behav Immun. 2018 Nov 9. pii: S0889-1591(18)30796-7. doi: 10.1016/j.bbi.2018.11.008. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/30419269