Machine Learning Detects Pattern of Differences in Functional Magnetic Resonance Imaging (fMRI) Data between Chronic Fatigue Syndrome (CFS) and Gulf War Illness (GWI)

Abstract:

Background: Gulf War Illness (GWI) and Chronic Fatigue Syndrome (CFS) are two debilitating disorders that share similar symptoms of chronic pain, fatigue, and exertional exhaustion after exercise. Many physicians continue to believe that both are psychosomatic disorders and to date no underlying etiology has been discovered. As such, uncovering objective biomarkers is important to lend credibility to criteria for diagnosis and to help differentiate the two disorders.

Methods: We assessed cognitive differences in 80 subjects with GWI and 38 with CFS by comparing corresponding fMRI scans during 2-back working memory tasks before and after exercise to model brain activation during normal activity and after exertional exhaustion, respectively. Voxels were grouped by the count of total activity into the Automated Anatomical Labeling (AAL) atlas and used in an “ensemble” series of machine learning algorithms to assess if a multi-regional pattern of differences in the fMRI scans could be detected.

Results: A K-Nearest Neighbor (70%/81%), Linear Support Vector Machine (SVM) (70%/77%), Decision Tree (82%/82%), Random Forest (77%/78%), AdaBoost (69%/81%), Naïve Bayes (74%/78%), Quadratic Discriminant Analysis (QDA) (73%/75%), Logistic Regression model (82%/82%), and Neural Net (76%/77%) were able to differentiate CFS from GWI before and after exercise with an average of 75% accuracy in predictions across all models before exercise and 79% after exercise. An iterative feature selection and removal process based on Recursive Feature Elimination (RFE) and Random Forest importance selected 30 regions before exercise and 33 regions after exercise that differentiated CFS from GWI across all models, and produced the ultimate best accuracies of 82% before exercise and 82% after exercise by Logistic Regression or Decision Tree by a single model, and 100% before and after exercise when selected by any six or more models. Differential activation on both days included the right anterior insula, left putamen, and bilateral orbital frontal, ventrolateral prefrontal cortex, superior, inferior, and precuneus (medial) parietal, and lateral temporal regions. Day 2 had the cerebellum, left supplementary motor area and bilateral pre- and post-central gyri. Changes between days included the right Rolandic operculum switching to the left on Day 2, and the bilateral midcingulum switching to the left anterior cingulum.

Conclusion: We concluded that CFS and GWI are significantly differentiable using a pattern of fMRI activity based on an ensemble machine learning model.

Source: Provenzano D, Washington SD, Rao YJ, Loew M, Baraniuk J. Machine Learning Detects Pattern of Differences in Functional Magnetic Resonance Imaging (fMRI) Data between Chronic Fatigue Syndrome (CFS) and Gulf War Illness (GWI). Brain Sci. 2020;10(7):E456. Published 2020 Jul 17. doi:10.3390/brainsci10070456 https://www.mdpi.com/2076-3425/10/7/456 (Full text)

Brain studies show chronic fatigue syndrome and Gulf War illness are distinct conditions

CHICAGO (October 23, 2019) — Gulf War Illness (GWI) and chronic fatigue syndrome (CFS) share symptoms of disabling fatigue, pain, systemic hyperalgesia (tenderness), negative emotion, sleep and cognitive dysfunction that are made worse after mild exertion (postexertional malaise). Now, neuroscientists at Georgetown University Medical Center have evidence, derived from human brain studies, that GWI and CFS are two distinct disorders that affect the brain in opposing ways.

The findings, presented in two related studies at the annual meeting of the Society for Neuroscience (SFN) in Chicago, offer a new perspective on neurotoxicity and suggest that methods to effectively diagnose and treat these disorders could be developed, says the studies’ senior author, James Baraniuk, MD, a Georgetown professor of medicine.

GWI affects veterans of the 1990-1991 Persian Gulf War who were exposed to a toxic environment of nerve agents, pesticides and other neurotoxins, while the etiology of CFS is unknown. The overlapping symptoms suggest they may share some common mechanisms of disease.

Baraniuk was first to find unique physical changes in the brains of patients with GWI, and he and his colleagues have also found changes in brain chemistry between GWI and CFS. “This new work further emphasizes that chronic fatigue syndrome and Gulf War Illness are two very real, and very distinct, diseases of the brain,” he says.

The two SFN studies were led by investigators in Baraniuk’s lab. One, being presented by neuroscientist Stuart Washington, PhD, details how specific areas in the brain are affected by the disorders, and the second, led by student Haris Pepermintwala, MS, takes a deep dive into one of those areas, the brain stem, to illustrate the degree to which these conditions have differing effects.

Chronic fatigue syndrome/myalgic encephalomyelitis affects between 836,000 and 2.5 million Americans, according to a 2015 report by the National Academy of Medicine. Gulf War Illness developed in about one-third of the 697,000 veterans deployed to the 1990-1991 Persian Gulf War. Baraniuk says that during Operation Desert Storm, these veterans were exposed to combinations of nerve agents, pesticides and other toxic chemicals that may have triggered the chronic pain and cognitive and gastrointestinal problems.

Both GWI and CFS share common features: cognitive dysfunction, pain and fatigue primarily following physical exercise. To determine how these conditions affect brain function, investigators studied neuronal activation using functional MRI (fMRI) during a cognitive task a day before and a day after bicycle exercise stress tests in their different groups: 38 CFS patients, 80 GWI patients, and a control group of 23 healthy sedentary volunteers. Brain activation during a working memory task was compared between the pre- and post-exercise fMRI studies, and between CFS and GWI groups.

Before exercise, brain activation was similar between groups. However, after exercise the CFS group showed significantly increased activation of the midbrain, while GWI had the opposite effect, with decreased activation in this vital region of the arousal network. CFS also had increased activation in the insula. In contrast, GWI, but not CFS, had a decrease in activation of the cerebellum after exercise. The findings show that specific brain regions acted in opposing ways, representing a differentiation between GWI and CFS.

While these areas are involved in pain perception, among their many other tasks, “this doesn’t mean more or less activity is directly related to pain,” says Washington. “What it does show is that the two conditions are distinct from each other and involve different cellular/molecular mechanisms.”

The second study, led by Pepermintwala, looked more closely at specific regions within the brain stem and confirmed that CFS had significantly increased activation during the cognitive task after the exercise provocations, while GWI had significantly reduced activation.

These regions are involved in vital functions for instantaneous assessments of threats, predator-prey decisions, arousal, modulation of chronic pain, sleep and other neurobehavioral functions, Pepermintwala says. But after exercise, the CFS group had significantly increased activity in the majority of regions evaluated, while the GWI patients experienced significantly decreased activation.

The results support other research, conducted post-mortem in veterans with PTSD, suggesting that the brain stem in these veterans may have physical abnormalities, such as a loss of neurons, Pepermintwala says. “The midbrain is affected by the exercise and cognitive challenges, but CFS and GWI react in opposite ways, showing that they are related, but distinctly different disorders.”


For the study led by Washington, additional co-authors include Rakib Rahan, Richard Garner, Destie Provenzano, Kristina Zajur, Florencia Martinez Addiego, John VanMeter and Baraniuk.

For the study led by Pepermintwala, additional co-authors include Washington, Addiego, Rayhan and Baraniuk.

The authors report having no personal financial interests related to the studies.

These studies were supported by funding from The Sergeant Sullivan Circle, Barbara Cottone, Dean Clarke Bridge Prize, Department of Defense Congressionally Directed Medical Research Program (W81XWH-15-1-0679 and W81-XWH-09-1-0526), and the National Institute of Neurological Disorders and Stroke (R21NS088138 and RO1NS085131). The project has been funded in whole or in part with federal funds (UL1TR000101 previously UL1RR031975) from the National Center for Advancing Translational Sciences, National Institutes of Health, through the Clinical and Translational Science Awards Program.

VIDEO: Discovery Forum 2017 Highlights: ME/CFS and Gulf War Illness

The Solve ME/CFS Initiative presents highlights from Discovery Forum 2017 addressing the connections between Gulf War Illness and ME/CFS, featuring the presentation of Dr. Nancy Klimas of Nova Southeastern University. Dr. Klimas has more than 30 years of professional experience and has achieved international recognition for her research and clinical efforts in Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS) and Gulf War Illness (GWI).

Exercise – induced changes in cerebrospinal fluid miRNAs in Gulf War Illness, Chronic Fatigue Syndrome and sedentary control subjects

Abstract:

Gulf War Illness (GWI) and Chronic Fatigue Syndrome (CFS) have similar profiles of pain, fatigue, cognitive dysfunction and exertional exhaustion. Post-exertional malaise suggests exercise alters central nervous system functions. Lumbar punctures were performed in GWI, CFS and control subjects after (i) overnight rest (nonexercise) or (ii) submaximal bicycle exercise. Exercise induced postural tachycardia in one third of GWI subjects (Stress Test Activated Reversible Tachycardia, START). The remainder were Stress Test Originated Phantom Perception (STOPP) subjects. MicroRNAs (miRNA) in cerebrospinal fluid were amplified by quantitative PCR. Levels were equivalent between nonexercise GWI (n = 22), CFS (n = 43) and control (n = 22) groups. After exercise, START (n = 22) had significantly lower miR-22-3p than control (n = 15) and STOPP (n = 42), but higher miR-9-3p than STOPP. All post-exercise groups had significantly reduced miR-328 and miR-608 compared to nonexercise groups; these may be markers of exercise effects on the brain. Six miRNAs were significantly elevated and 12 diminished in post-exercise STARTSTOPP and control compared to nonexercise groups. CFS had 12 diminished miRNAs after exercise. Despite symptom overlap of CFS, GWI and other illnesses in their differential diagnosis, exercise-induced miRNA patterns in cerebrospinal fluid indicated distinct mechanisms for post-exertional malaise in CFS and START and STOPP phenotypes of GWI.

Source: James N. Baraniuk & Narayan Shivapurkar. Exercise – induced changes in cerebrospinal fluid miRNAs in Gulf War Illness, Chronic Fatigue Syndrome and sedentary control subjects. Scientific Reports 7, Article number: 15338 (2017) doi:10.1038/s41598-017-15383-9    https://www.nature.com/articles/s41598-017-15383-9 (Full article)

Brain chemistry study shows chronic fatigue syndrome, Gulf War illness as unique disorders

WASHINGTON — Researchers at Georgetown University Medical Center have found distinct molecular signatures in two brain disorders long thought to be psychological in origin — chronic fatigue syndrome (CFS) and Gulf War Illness (GWI).

In addition, the work supports a previous observation by GUMC investigators of two variants of GWI. The disorders share commonalities, such as pain, fatigue, cognitive dysfunction and exhaustion after exercise.

Their study, published in Scientific Reports, lays groundwork needed to understand these disorders in order to diagnosis and treat them effectively, says senior investigator, James N. Baraniuk, MD, professor of medicine at Georgetown University School of Medicine. Narayan Shivapurkar, PhD, assistant professor of oncology at the medical school worked with Baraniuk on the research.

The changes in brain chemistry — observed in levels of miRNAs that turn protein production on or off — were seen 24 hours after riding a stationary bike for 25 minutes.

“We clearly see three different patterns in the brain’s production of these molecules in the CFS group and the two GWI phenotypes,” says Baraniuk. “This news will be well received by patients who suffer from these disorders who are misdiagnosed and instead may be treated for depression or other mental disorders.”

Chronic fatigue syndrome affects between 836,000 and 2.5 million Americans, according to a National Academy of Medicine report. The disorder was thought to be psychosomatic until a 2015 review of 9,000 articles over 64 years of research pointed to unspecified biological causes. Still, no definitive diagnosis or treatment is available.

Gulf War Illness has developed in more than one-fourth of the 697,000 veterans deployed to the 1990-1991 Persian Gulf War, Baraniuk and his colleagues have reported in earlier work.

Gulf War veterans were exposed to combinations of nerve agents, pesticides and other toxic chemicals that may have triggered the chronic pain, cognitive, gastrointestinal and other problems, Baraniuk says. Although the mechanisms remain unknown, the study provides significant insights into brain chemistry that can now be investigated.

This study focused on spinal fluid of CFS, GWI and control subjects who agreed to have a lumbar puncture. Spinal taps before exercise showed miRNA levels were the same in all participants. In contrast, miRNA levels in spinal fluid were significantly different after exercise. The CFS, control and two subtypes of GWI groups had distinct patterns of change. For example, CFS subjects who exercised had reduced levels of 12 different mRNAs, compared to those who did not exercise.

The miRNA changes in the two GWI subtypes add to other differences caused by exercise. One subgroup developed jumps in heart rate of over 30 beats when standing up that lasted for two to three days after exercise. Magnetic resonance imaging showed they had smaller brainstems in regions that control heart rate, and did not activate their brains when doing a cognitive task. In contrast, the other subgroup did not have any heart rate or brainstem changes, but did recruit additional brain regions to complete a memory test. The two groups were as different from each other as they were from the control group.

Finding two distinct pathophysiological miRNA brain patterns in patients reporting Gulf War disease “adds another layer of evidence to support neuropathology in the two different manifestations of Gulf War disease,” he says.

Baraniuk adds that miRNA levels in these disorders were different from the ones that are altered in depression, fibromyalgia, and Alzheimer’s disease, further suggesting CFS and GWI are distinct diseases.

###

The study was supported by funding from The Sergeant Sullivan Center, Dr. Barbara Cottone, Dean Clarke Bridge Prize, Department of Defense Congressionally Directed Medical Research Program (CDMRP) W81XWH-15-1-0679, and National Institute of Neurological Diseases and Stroke R21NS088138 and RO1NS085131.

Baraniuk and Shivapurkar are named as inventors on a patent application that has been filed by Georgetown University related to the technology described.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Gulf War Illness patients exhibit increased humoral responses to the Herpesviruses-encoded dUTPase: Implications in disease pathophysiology

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Gulf War Illness (GWI) are debilitating diseases with overlapping symptomology and there are currently no validated tests for definitive diagnosis of either syndrome. While there is evidence supporting the premise that some herpesviruses may act as possible triggers of ME/CFS, the involvement of herpesviruses in the pathophysiology of GWI has not been studied in spite of a higher prevalence of ME/CFS in these patients.

We have previously demonstrated that the deoxyuridine triphosphate nucleotidohydrolases (dUTPase) encoded by Epstein-Barr virus (EBV), human herpesvirus-6 (HHV-6), and varicella-zoster virus (VZV) possess novel functions in innate and adaptive immunity. The results of this study demonstrate that a significant percentage of patients with ME/CFS (30.91-52.7%) and GWI (29.34%) are simultaneously producing antibodies against multiple human herpesviruses-encoded dUTPases and/or the human dUTPase when compared to controls (17.21%). GWI patients exhibited significantly higher levels of antibodies to the HHV-6 and human dUTPases than controls (p = 0.0053 and p = 0.0036, respectively), while the ME/CFS cohort had higher anti-EBV-dUTPase antibodies than in both GWI patients (p = 0.0008) and controls (p < 0.0001) as well as significantly higher anti-human dUTPase antibodies than in controls (p = 0.0241).

These results suggest that screening of patients’ sera for the presence of various combinations of anti-dUTPase antibodies could be used as potential biomarkers to help identify/distinguish patients with these syndromes and better direct treatment. This article is protected by copyright. All rights reserved.

Source: Halpin P, Williams MV, Klimas NG, Fletcher MA, Barnes Z, Ariza ME.Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Gulf War Illness patients exhibit increased humoral responses to the Herpesviruses-encoded dUTPase: Implications in disease pathophysiology. J Med Virol. 2017 Mar 17. doi: 10.1002/jmv.24810. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/28303641

 

Cytokine expression provides clues to the pathophysiology of Gulf War illness and myalgic encephalomyelitis

Abstract:

Gulf War illness (GWI) is a chronic disease of unknown etiology characterized by persistent symptoms such as cognitive impairment, unexplained fatigue, pervasive pain, headaches, and gastrointestinal abnormalities. Current reports suggest that as many as 200,000 veterans who served in the 1990-1991 Persian Gulf War were afflicted. Several potential triggers of GWI have been proposed including chemical exposure, toxins, vaccines, and unknown infectious agents. However, a definitive cause of GWI has not been identified and a specific biological marker that can consistently delineate the disease has not been defined.

Myalgic encephalomyelitis (ME) is a disease with similar and overlapping symptomology, and subjects diagnosed with GWI typically fit the diagnostic criteria for ME. For these reasons, GWI is often considered a subgroup of ME.

To explore this possibility and identify immune parameters that may help to understand GWI pathophysiology, we measured 77 serum cytokines in subjects with GWI and compared these data to that of subjects with ME as well as healthy controls.

Our analysis identified a group of cytokines that identified ME and GWI cases with sensitivities of 92.5% and 64.9%, respectively. The five most significant cytokines in decreasing order of importance were IL-7, IL-4, TNF-α, IL-13, and IL-17F. When delineating GWI and ME cases from healthy controls, the observed specificity was only 33.3%, suggesting that with respect to cytokine expression, GWI cases resemble control subjects to a greater extent than ME cases across a number of parameters. These results imply that serum cytokines are representative of ME pathology to a greater extent than GWI and further suggest that the two diseases have distinct immune profiles despite their overlapping symptomology.

Copyright © 2014 Elsevier Ltd. All rights reserved.

 

Source: Khaiboullina SF, DeMeirleir KL, Rawat S, Berk GS, Gaynor-Berk RS, Mijatovic T, Blatt N, Rizvanov AA, Young SG, Lombardi VC. Cytokine expression provides clues to the pathophysiology of Gulf War illness and myalgic encephalomyelitis. Cytokine. 2015 Mar;72(1):1-8. doi: 10.1016/j.cyto.2014.11.019. Epub 2014 Dec 13. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4410698/ (Full article)

 

A role for homeostatic drive in the perpetuation of complex chronic illness: Gulf War Illness and chronic fatigue syndrome

Erratum in

  • PLoS One. 2014;9(4):e94161.
  • PLoS One. 2014;9(6):e100355.

Abstract:

A key component in the body’s stress response, the hypothalamic-pituitary-adrenal (HPA) axis orchestrates changes across a broad range of major biological systems. Its dysfunction has been associated with numerous chronic diseases including Gulf War Illness (GWI) and chronic fatigue syndrome (CFS). Though tightly coupled with other components of endocrine and immune function, few models of HPA function account for these interactions.

Here we extend conventional models of HPA function by including feed-forward and feedback interaction with sex hormone regulation and immune response. We use this multi-axis model to explore the role of homeostatic regulation in perpetuating chronic conditions, specifically GWI and CFS. An important obstacle in building these models across regulatory systems remains the scarcity of detailed human in vivo kinetic data as its collection can present significant health risks to subjects. We circumvented this using a discrete logic representation based solely on literature of physiological and biochemical connectivity to provide a qualitative description of system behavior. This connectivity model linked molecular variables across the HPA axis, hypothalamic-pituitary-gonadal (HPG) axis in men and women, as well as a simple immune network. Inclusion of these interactions produced multiple alternate homeostatic states and sexually dimorphic responses.

Experimental data for endocrine-immune markers measured in male GWI subjects showed the greatest alignment with predictions of a naturally occurring alternate steady state presenting with hypercortisolism, low testosterone and a shift towards a Th1 immune response. In female CFS subjects, expression of these markers aligned with an alternate homeostatic state displaying hypocortisolism, high estradiol, and a shift towards an anti-inflammatory Th2 activation. These results support a role for homeostatic drive in perpetuating dysfunctional cortisol levels through persistent interaction with the immune system and HPG axis. Though coarse, these models may nonetheless support the design of robust treatments that might exploit these regulatory regimes.

 

Source: Craddock TJ, Fritsch P, Rice MA Jr, del Rosario RM, Miller DB, Fletcher MA, Klimas NG, Broderick G. A role for homeostatic drive in the perpetuation of complex chronic illness: Gulf War Illness and chronic fatigue syndrome. PLoS One. 2014 Jan 8;9(1):e84839. doi: 10.1371/journal.pone.0084839. ECollection 2014. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3885655/ (Full article)

 

Migraine in gulf war illness and chronic fatigue syndrome: prevalence, potential mechanisms, and evaluation

Abstract:

OBJECTIVE: To assess the prevalence of headache subtypes in Gulf War Illness (GWI) and Chronic Fatigue Syndrome (CFS) compared to controls.

BACKGROUND: Approximately, 25% of the military personnel who served in the 1990-1991 Persian Gulf War have developed GWI. Symptoms of GWI and CFS have considerable overlap, including headache complaints. Migraines are reported in CFS. The type and prevalence of headaches in GWI have not been adequately assessed.

METHODS: 50 GWI, 39 CFS and 45 controls had structured headache evaluations based on the 2004 International Headache Society criteria. All subjects had history and physical examinations, fatigue and symptom related questionnaires, measurements of systemic hyperalgesia (dolorimetry), and assessments for exclusionary conditions.

RESULTS: Migraines were detected in 64% of GWI (odds ratio = 11.6 [4.1-32.5]) (mean [±95% CI]) and 82% of CFS subjects (odds ratio = 22.5 [7.8-64.8]) compared to only 13% of controls. There was a predominance of females in the CFS compared to GWI and controls. However, migraine status was independent of gender in GWI and CFS groups (x (2) = 2.7; P = 0.101). Measures of fatigue, pain, and other ancillary criteria were comparable between GWI and CFS subjects with and without headache.

CONCLUSION: The high prevalence of migraine in CFS was confirmed and extended to GWI subjects. GWI and CFS may share dysfunctional central pathophysiological pathways that contribute to migraine and subjective symptoms. The high migraine prevalence warrants the inclusion of a structured headache evaluation in GWI and CFS subjects, and treatment when present.

 

Source: Rayhan RU, Ravindran MK, Baraniuk JN. Migraine in gulf war illness and chronic fatigue syndrome: prevalence, potential mechanisms, and evaluation. Front Physiol. 2013 Jul 24;4:181. doi: 10.3389/fphys.2013.00181. ECollection 2013. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3721020/ (Full article)

 

A comparison of sex-specific immune signatures in Gulf War illness and chronic fatigue syndrome

Abstract:

BACKGROUND: Though potentially linked to the basic physiology of stress response we still have no clear understanding of Gulf War Illness (GWI), a debilitating condition presenting complex immune, endocrine and neurological symptoms. Here we compared male (n = 20) and female (n = 10) veterans with GWI separately against their healthy counterparts (n = 21 male, n = 9 female) as well as subjects with chronic fatigue syndrome/ myalgic encephalomyelitis (CFS/ME) (n = 12 male, n = 10 female).

METHODS: Subjects were assessed using a Graded eXercise Test (GXT) with blood drawn prior to exercise, at peak effort (VO2 max) and 4-hours post exercise. Using chemiluminescent imaging we measured the concentrations of IL-1a, 1b, 2, 4, 5, 6, 8, 10, 12 (p70), 13, 15, 17 and 23, IFNγ, TNFα and TNFβ in plasma samples from each phase of exercise. Linear classification models were constructed using stepwise variable selection to identify cytokine co-expression patterns characteristic of each subject group.

RESULTS: Classification accuracies in excess of 80% were obtained using between 2 and 5 cytokine markers. Common to both GWI and CFS, IL-10 and IL-23 expression contributed in an illness and time-dependent manner, accompanied in male subjects by NK and Th1 markers IL-12, IL-15, IL-2 and IFNγ. In female GWI and CFS subjects IL-10 was again identified as a delineator but this time in the context of IL-17 and Th2 markers IL-4 and IL-5. Exercise response also differed between sexes: male GWI subjects presented characteristic cytokine signatures at rest but not at peak effort whereas the opposite was true for female subjects.

CONCLUSIONS: Though individual markers varied, results collectively supported involvement of the IL-23/Th17/IL-17 axis in the delineation of GWI and CFS in a sex-specific way.

 

Source: Smylie AL, Broderick G, Fernandes H, Razdan S, Barnes Z, Collado F, Sol C, Fletcher MA, Klimas N. A comparison of sex-specific immune signatures in Gulf War illness and chronic fatigue syndrome. BMC Immunol. 2013 Jun 25;14:29. doi: 10.1186/1471-2172-14-29. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3698072/ (Full article)