Category: Neurology

Neurometabolites in anterior cingulate cortex in chronic fatigue syndrome: A magnetic resonance spectroscopy study at 7 Tesla

Abstract:

Background: Chronic fatigue syndrome (CFS) is a disorder characterized by prolonged physical and mental fatigue that cannot be explained by another established medical diagnosis. The anterior cingulate cortex (ACC) and putamen are two regions involved in frontal-striatal neural circuitry, which may be related to the pathophysiology of CFS. The aim of this study was to investigate the concentrations of neurometabolites, including glutamate, gamma-aminobutyric acid (GABA) and glutathione, in the ACC and putamen, using magnetic resonance spectroscopy (MRS) at 7 Tesla (7T). In addition, this study also aimed to evaluate resting-state functional connectivity in CFS with functional magnetic resonance imaging (fMRI).

Methods: This study involved 12 patients who met the Oxford criteria for CFS and 25 healthy controls. Participants rated themselves on the Chalder Fatigue Questionnaire (CFQ) and the Beck Depression Inventory (BDI). All participants had a single proton (1H) MRS and resting-state fMRI scan with a 7T Siemens MAGNETOM scanner (Siemens, Erlangen, Germany) with a Nova Medical 32 channel receive array head coil. Spectra were measured from voxels in the ACC (20 × 20 × 20 mm), putamen (10 × 16 × 20 mm) and occipital cortex (20 × 20 × 20 mm). Spectra were analysed with LCModel to obtain absolute concentrations of the neurochemicals. Differences in functional connectivity between CFS and healthy participants were tested using multivariate exploratory linear optimized decomposition into independent components (MELODIC) and dual regression.

Results: Concentrations of putamen glutamate and glutamate+glutamine (Glx) were increased in CFS while that of ACC GABA was decreased. Putamen Glx and ACC glutamine were negatively associated with the severity of self-reported fatigue. There were main effects of CFS diagnosis on glutathione (GSH) and total creatine, indicating decreases of these neurometabolites in all the regions studied in CFS patients. In addition, the CFS patients demonstrated elevated functional connectivity between the default mode network and right supracalcarine cortex, precuneus cortex and dorsolateral prefrontal cortex.

Conclusions: The increased putamen glutamate, decreased ACC GABA and elevated resting state functional connectivity of the default mode network suggest a hyperactive brain status in CFS. The global decrease of GSH and total creatine also suggest that CFS patients may have an abnormal bioenergetic status with higher oxidative stress.

Source: Chi Chen. Neurometabolites in anterior cingulate cortex in chronic fatigue syndrome: A magnetic resonance spectroscopy study at 7 Tesla. Oxford University Research Archive. September 22, 2017. (Open access article) https://ora.ox.ac.uk/objects/uuid:60ff242e-2ccd-4f23-ac7d-16553d864e8b

MEA Review: Grey and white matter differences in chronic fatigue syndrome

The ME Association of Great Britain has provided an excellent review of a recent study on brain matter abnormalities in ME/CFS patients. The study, Grey and white matter differences in Chronic Fatigue Syndrome – A voxel-based morphometry study, was conducted by Julia Newton’s group at Newcastle University. Below is an excerpt from Dr. Shepherd’s summary of the study. To read a full discussion, along with an excellent overview of brain pathology and the implications of these brain abnormalities, go HERE. You can download the full review as a PDF file.

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Comment from Dr Charles Shepherd, Hon Medical Adviser, ME Association:

This study was carried out in Newcastle by Professor Julia Newton and colleagues – a team who have not only achieved a long and distinguished record in ME/CFS research but also have access to patients who have been very carefully assessed from a clinical point of view. So, the results should be taken seriously.

As has been pointed out in this review, three of the main criticisms of previous neuroimaging studies involving people with ME/CFS is that the numbers involved have often been far too small; there has been a lack of information from other control groups that would be relevant in addition to the use of healthy controls; and that different imaging techniques have been used.  So, not surprisingly, the results are not always consistent.

Despite these caveats, these results clearly add weight to the findings from previous neuroimaging studies describing white matter abnormalities in ME/CFS but also raise the possibility of grey matter involvement in ME/CFS.

There are several possible explanations for these findings but no clear answer has emerged in the paper.  Are they a primary feature of ME/CFS?  Or are they secondary to other factors – e.g. duration of illness, decrease in activity, severity of fatigue – that are related to having ME/CFS?  The only way to find out is through further research into what is clearly an interesting aspect of neuropathology in ME/CFS.

A fully referenced summary of all the key findings from both functional and structural neuroimaging studies in ME/CFS can be found in the Research section of the ME Association ‘An Exploration of the Key Clinical Issues’ available from our online shop.

You can read the rest of this brief summary HERE.

Grey and white matter differences in Chronic Fatigue Syndrome – A voxel-based morphometry study

Abstract:

OBJECTIVE: Investigate global and regional grey and white matter volumes in patients with Chronic Fatigue Syndrome (CFS) using magnetic resonance imaging (MRI) and recent voxel-based morphometry (VBM) methods.

METHODS: Forty-two patients with CFS and thirty healthy volunteers were scanned on a 3-Tesla MRI scanner. Anatomical MRI scans were segmented, normalized and submitted to a VBM analysis using randomisation methods. Group differences were identified in overall segment volumes and voxel-wise in spatially normalized grey matter (GM) and white matter (WM) segments.

RESULTS: Accounting for total intracranial volume, patients had larger GM volume and lower WM volume. The voxel-wise analysis showed increased GM volume in several structures including the amygdala and insula in the patient group. Reductions in WM volume in the patient group were seen primarily in the midbrain, pons and right temporal lobe.

CONCLUSION: Elevated GM volume in CFS is seen in areas related to processing of interoceptive signals and stress. Reduced WM volume in the patient group partially supports earlier findings of WM abnormalities in regions of the midbrain and brainstem.

Source: Finkelmeyer A, He J, Maclachlan L, Watson S, Gallagher P, Newton JL, Blamire AM. Grey and white matter differences in Chronic Fatigue Syndrome – A voxel-based morphometry study. Neuroimage Clin. 2017 Sep 28;17:24-30. doi: 10.1016/j.nicl.2017.09.024. ECollection 2018. https://www.ncbi.nlm.nih.gov/pubmed/29021956

Medial prefrontal cortex deficits correlate with unrefreshing sleep in patients with chronic fatigue syndrome

Abstract:

Unrefreshing sleep is a hallmark of chronic fatigue syndrome/myalgic encephalomyelitis (CFS). This study examined brain structure variations associated with sleep quality in patients with CFS. 38 patients with CFS (34.8 ± 10.1 years old) and 14 normal controls (NCs) (34.7 ± 8.4 years old) were recruited. All subjects completed the Hospital Anxiety and Depression Scale, Pittsburgh Sleep Quality Index (PSQI), and Chalder Fatigue Scale (CFQ) questionnaires. Brain MRI measures included global and regional grey and white matter volumes, magnetization transfer T1 weighted (MT-T1w) intensities, and T1 weighted (T1w) and T2 weighted spin echo signal intensities.

We performed voxel based group comparisons of these regional brain MRI measures and regressions of these measures with the PSQI and CFQ scales adjusted for age, anxiety and depression, and the appropriate global measure. In CFS patients, negative correlations were observed in the medial prefrontal cortex (mPFC) between PSQI and MT-T1w intensities (family-wise error corrected cluster, PFWE < 0.05) and between PSQI and T1w intensities (PFWE < 0.05). In the same mPFC location, both MT and T1w intensities were lower in CFS patients compared with NCs (uncorrected voxel P < 0.001).

This study is the first to report that brain structural differences are associated with unrefreshing sleep in CFS. This result refutes the suggestion that unrefreshing sleep is a misperception in CFS patients and further investigation of this symptom is warranted.

Source: Shan ZY, Kwiatek R, Burnet R, Del Fante P, Staines DR, Marshall-Gradisnik SM, Barnden LR. Medial prefrontal cortex deficits correlate with unrefreshing sleep in patients with chronic fatigue syndrome. NMR Biomed. 2017 Jun 29. doi: 10.1002/nbm.3757. [Epub ahead of print] http://onlinelibrary.wiley.com/doi/10.1002/nbm.3757/full

A Comparison of Neuroimaging Abnormalities in Multiple Sclerosis, Major Depression and Chronic Fatigue Syndrome (Myalgic Encephalomyelitis): is There a Common Cause?

Abstract:

There is copious evidence of abnormalities in resting-state functional network connectivity states, grey and white matter pathology and impaired cerebral perfusion in patients afforded a diagnosis of multiple sclerosis, major depression or chronic fatigue syndrome (CFS) (myalgic encephalomyelitis). Systemic inflammation may well be a major element explaining such findings. Inter-patient and inter-illness variations in neuroimaging findings may arise at least in part from regional genetic, epigenetic and environmental variations in the functions of microglia and astrocytes.

Regional differences in neuronal resistance to oxidative and inflammatory insults and in the performance of antioxidant defences in the central nervous system may also play a role. Importantly, replicated experimental findings suggest that the use of high-resolution SPECT imaging may have the capacity to differentiate patients afforded a diagnosis of CFS from those with a diagnosis of depression. Further research involving this form of neuroimaging appears warranted in an attempt to overcome the problem of aetiologically heterogeneous cohorts which probably explain conflicting findings produced by investigative teams active in this field. However, the ionising radiation and relative lack of sensitivity involved probably preclude its use as a routine diagnostic tool.

Source: Morris G, Berk M, Puri BK. A Comparison of Neuroimaging Abnormalities in Multiple Sclerosis, Major Depression and Chronic Fatigue Syndrome (Myalgic Encephalomyelitis): is There a Common Cause? Mol Neurobiol. 2017 May 17. doi: 10.1007/s12035-017-0598-z. https://www.ncbi.nlm.nih.gov/pubmed/28516431 

CNS findings in chronic fatigue syndrome and a neuropathological case report

Abstract:

Chronic fatigue syndrome (CFS) is characterized as a persistent, debilitating complex disorder of unknown etiology, whereby patients suffer from extreme fatigue, which often presents with symptoms that include chronic pain, depression, weakness, mood disturbances, and neuropsychological impairment. In this mini review and case report, we address central nervous system (CNS) involvement of CFS and present neuropathological autopsy findings from a patient who died with a prior diagnosis of CFS.

Among the most remarkable pathological features of the case are focal areas of white matter loss, neurite beading, and neuritic pathology of axons in the white matter with axonal spheroids. Atypical neurons displaying aberrant sprouting processes in response to injury are observed throughout cortical gray and white matter. Abundant amyloid deposits identical to AD plaques with accompanying intracellular granular structures are observed as well. Neurofibrillary tangles are also present in the white matter of the frontal cortex, thalamus and basal ganglia.

Taken together, these neuropathological findings warrant further studies into CNS disease associated with CFS.

 

Source: Kimberly Ferrero, Mitchell Silver, Alan Cocchetto, Eliezer Masliah, Dianne Langford. CNS findings in chronic fatigue syndrome and a neuropathological case report. Journal of Investigative Medicine. DOI: 10.1136/jim-2016-000390 Published 6 April 2017. http://jim.bmj.com/content/early/2017/04/06/jim-2016-000390

 

Multimodal and simultaneous assessments of brain and spinal fluid abnormalities in chronic fatigue syndrome and the effects of psychiatric comorbidity

Abstract:

The purpose of this study was to investigate whether CFS patients without comorbid psychiatric diagnoses differ from CFS patients with comorbid psychiatric diagnoses and healthy control subjects in neuropsychological performance, the proportion with elevated spinal fluid protein or white cell counts, cerebral blood flow (CBF), brain ventricular lactate and cortical glutathione (GSH). The results of the study did not show any differences in any of the outcome measures between CFS patients with and without psychiatric comorbidity, thus indicating that psychiatric status may not be an exacerbating factor in CFS.

Importantly, significant differences were found between the pooled samples of CFS compared to controls. These included lower GSH and CBF and higher ventricular lactate and rates of spinal fluid abnormalities in CFS patients compared to healthy controls. Thirteen of 26 patients had abnormal values on two or more of these 4 brain-related variables.

These findings, which replicate the results of several of our prior studies, support the presence of a number of neurobiological and spinal fluid abnormalities in CFS. These results will lead to further investigation into objective biomarkers of the disorder to advance the understanding of CFS.

Copyright © 2017 Elsevier B.V. All rights reserved.

 

Source: Natelson BH, Mao X, Stegner AJ, Lange G, Vu D, Blate M, Kang G, Soto E, Kapusuz T, Shungu DC. Multimodal and simultaneous assessments of brain and spinal fluid abnormalities in chronic fatigue syndrome and the effects of psychiatric comorbidity. J Neurol Sci. 2017 Apr 15;375:411-416. doi: 10.1016/j.jns.2017.02.046. Epub 2017 Feb 22. https://www.ncbi.nlm.nih.gov/pubmed/28320179

 

The Neuroinflammatory Etiopathology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating multi-systemic chronic illness of unknown etiology, classified as a neurological disorder by the World Health Organization (WHO). The symptomatology of the condition appears to emanate from a variety of sources of chronic neurological disturbance and associated distortions, and chronicity, in noxious sensory signaling and neuroimmune activation. This article incorporates a summary review and discussion of biomedical research considered relevant to this essential conception perspective. It is intended to provide stakeholders with a concise, integrated outline disease model in order to help demystify this major public health problem. The primary etiopathological factors presented are:

(A) Postural/biomechanical pain signaling, affecting adverse neuroexcitation, in the context of compression, constriction, strain, or damage of vertebral-regional bone and neuromuscular tissues;

(B) Immune mediated inflammatory sequelae, in the context of prolonged immunotropic neurotrophic infection-with lymphotropic/gliotropic/glio-toxic varieties implicated in particular;

(C) A combination of factors A and B. Sustained glial activation under such conditions is associated with oxidative and nitrosative stress, neuroinflammation, and neural sensitivity. These processes collectively enhance the potential for multi-systemic disarray involving endocrine pathway aberration, immune and mitochondrial dysfunction, and neurodegeneration, and tend toward still more intractable synergistic neuro-glial dysfunction (gliopathy), autoimmunity, and central neuronal sensitization.

 

Source: Glassford JA. The Neuroinflammatory Etiopathology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Front Physiol. 2017 Feb 17;8:88. doi: 10.3389/fphys.2017.00088. eCollection 2017. http://journal.frontiersin.org/article/10.3389/fphys.2017.00088/full (Full article)

 

Brain imaging reveals clues about chronic fatigue syndrome

A brain imaging study shows that patients with chronic fatigue syndrome may have reduced responses, compared with healthy controls, in a region of the brain connected with fatigue. The findings suggest that chronic fatigue syndrome is associated with changes in the brain involving brain circuits that regulate motor activity and motivation.

Compared with healthy controls, patients with chronic fatigue syndrome had less activation of the basal ganglia, as measured by fMRI (functional magnetic resonance imaging). This reduction of basal ganglia activity was also linked with the severity of fatigue symptoms.

According to the Centers for Disease Control and Prevention, chronic fatigue syndrome is a debilitating and complex disorder characterized by intense fatigue that is not improved by bed rest and that may be worsened by exercise or mental stress.

The results are scheduled for publication in the journal PLOS One.

“We chose the basal ganglia because they are primary targets of inflammation in the brain,” says lead author Andrew Miller, MD. “Results from a number of previous studies suggest that increased inflammation may be a contributing factor to fatigue in CFS patients, and may even be the cause in some patients.”

Miller is William P. Timmie professor of psychiatry and behavioral sciences at Emory University School of Medicine. The study was a collaboration among researchers at Emory University School of Medicine, the CDC’s Chronic Viral Diseases Branch, and the University of Modena and Reggio Emilia in Italy. The study was funded by the CDC.

The basal ganglia are structures deep within the brain, thought to be responsible for control of movements and responses to rewards as well as cognitive functions. Several neurological disorders involve dysfunction of the basal ganglia, including Parkinson’s disease and Huntington’s disease, for example.

In previous published studies by Emory researchers, people taking interferon alpha as a treatment for hepatitis C, which can induce severe fatigue, also show reduced activity in the basal ganglia. Interferon alpha is a protein naturally produced by the body, as part of the inflammatory response to viral infection. Inflammation has also been linked to fatigue in other groups such as breast cancer survivors.

“A number of previous studies have suggested that responses to viruses may underlie some cases of CFS,” Miller says. “Our data supports the idea that the body’s immune response to viruses could be associated with fatigue by affecting the brain through inflammation. We are continuing to study how inflammation affects the basal ganglia and what effects that has on other brain regions and brain function. These future studies could help inform new treatments.”

Treatment implications might include the potential utility of medications to alter the body’s immune response by blocking inflammation, or providing drugs that enhance basal ganglia function, he says.

The researchers compared 18 patients diagnosed with chronic fatigue syndrome with 41 healthy volunteers. The 18 patients were recruited [not referred] based on an initial telephone survey followed by extensive clinical evaluations. The clinical evaluations, which came in two phases, were completed by hundreds of Georgia residents. People with major depression or who were taking antidepressants were excluded from the imaging study, although those with anxiety disorders were not.

For the brain imaging portion of the study, participants were told they’d win a dollar if they correctly guessed whether a preselected card was red or black. After they made a guess, the color of the card was revealed, and at that point researchers measured blood flow to the basal ganglia.

The key measurement was: how big is the difference in activity between a win or a loss? Participants’ scores on a survey gauging their levels of fatigue were tied to the difference in basal ganglia activity between winning and losing. Those with the most fatigue had the smallest changes, especially in the right caudate and the right globus pallidus, both parts of the basal ganglia.

Ongoing studies at Emory are further investigating the impact of inflammation on the basal ganglia, including studies using anti-inflammatory treatments to reduce fatigue and loss of motivation in patients with depression and other disorders with inflammation including cancer.

 

Source: Emory Health Sciences. “Brain imaging reveals clues about chronic fatigue syndrome.” ScienceDaily. ScienceDaily, 23 May 2014. https://www.sciencedaily.com/releases/2014/05/140523192427.htm

 

Toward a clearer diagnosis of chronic fatigue syndrome

Researchers at the RIKEN Center for Life Science Technologies, in collaboration with Osaka City University and Kansai University of Welfare Sciences, have used functional PET imaging to show that levels of neuroinflammation, or inflammation of the nervous system, are higher in patients with chronic fatigue syndrome than in healthy people.

Chronic fatigue syndrome, which is also known as myalgic encephalomyelitis, is a debilitating condition characterized by chronic, profound, and disabling fatigue. Unfortunately, the causes are not well understood.

Neuroinflammation — the inflammation of nerve cells — has been hypothesized to be a cause of the condition, but no clear evidence has been put forth to support this idea. Now, in this clinically important study, published in The Journal of Nuclear Medicine, the researchers found that indeed the levels of neuroinflammation markers are elevated in CFS/ME patients compared to the healthy controls.

The researchers performed PET scanning on nine people diagnosed with CFS/ME and ten healthy people, and asked them to complete a questionnaire describing their levels of fatigue, cognitive impairment, pain, and depression. For the PET scan they used a protein that is expressed by microglia and astrocyte cells, which are known to be active in neuroinflammation.

The researchers found that neuroinflammation is higher in CFS/ME patients than in healthy people. They also found that inflammation in certain areas of the brain — the cingulate cortex, hippocampus, amygdala, thalamus, midbrain, and pons — was elevated in a way that correlated with the symptoms, so that for instance, patients who reported impaired cognition tended to demonstrate neuroinflammation in the amygdala, which is known to be involved in cognition. This provides clear evidence of the association between neuroinflammation and the symptoms experienced by patients with CFS/ME.

Though the study was a small one, confirmation of the concept that PET scanning could be used as an objective test for CFS/ME could lead to better diagnosis and ultimately to the development of new therapies to provide relief to the many people around the world afflicted by this condition.

Dr. Yasuyoshi Watanabe, who led the study at RIKEN, stated, “We plan to continue research following this exciting discovery in order to develop objective tests for CFS/ME and ultimately ways to cure and prevent this debilitating disease.”

Journal Reference: Y. Nakatomi, K. Mizuno, A. Ishii, Y. Wada, M. Tanaka, S. Tazawa, K. Onoe, S. Fukuda, J. Kawabe, K. Takahashi, Y. Kataoka, S. Shiomi, K. Yamaguti, M. Inaba, H. Kuratsune, Y. Watanabe. Neuroinflammation in Patients with Chronic Fatigue Syndrome/Myalgic Encephalomyelitis: An 11C-(R)-PK11195 PET Study. Journal of Nuclear Medicine, 2014; DOI:10.2967/jnumed.113.131045

 

Source: RIKEN. “Toward a clearer diagnosis of chronic fatigue syndrome.” ScienceDaily. ScienceDaily, 4 April 2014. https://www.sciencedaily.com/releases/2014/04/140404085538.htm