ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

321–340 of 380 studies

E3 PreliminaryBehavioralPEM not requiredMechanistic

Mental fatigue is linked with attentional bias for sad stimuli.

Watanabe, Kyosuke, Sasaki, Akihiro T, Tajima, Kanako et al.·Scientific reports·2019

When healthy people become mentally tired from doing difficult thinking tasks, their brains start paying more attention to sad and negative images. This study used computer tasks to measure how people's attention shifts before and after mental exhaustion. The findings suggest that fatigue changes how our brains process sad information, which may help explain why ME/CFS patients often struggle with mood-related challenges.

Cognitive Impairment

E3 PreliminaryReviewPEM requiredReview-Narrative

Understanding Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and the Emerging Osteopathic Approach: A Narrative Review.

Larrimore, Christopher, Ramnot, Amanda, Jaghab, Annmarie et al.·The Journal of the American Osteopathic Association·2019

This article reviews what scientists know about ME/CFS, including its symptoms, how it affects the body, and why it's hard to diagnose. The authors discuss both traditional medical approaches and osteopathic treatment (a type of hands-on therapy that focuses on the body's structure and function) as possible ways to help people with ME/CFS feel better. The review emphasizes that ME/CFS is a real, serious illness that deserves more awareness among doctors and better treatment options.

Cognitive ImpairmentImmune System

E3 PreliminaryTrialPEM not requiredRCT

Treatment for Gulf War Illness (GWI) with KPAX002 (methylphenidate hydrochloride + GWI nutrient formula) in subjects meeting the Kansas case definition: A prospective, open-label trial.

Holodniy, Mark, Kaiser, Jon D·Journal of psychiatric research·2019

Researchers tested a combination treatment called KPAX002—containing a stimulant medication (methylphenidate) plus vitamins and nutrients meant to support energy production in cells—in 17 people with Gulf War Illness. After 12 weeks, patients reported about 25% improvement in their overall symptoms, including better fatigue, brain fog, sleep, and pain. The treatment was generally safe and well-tolerated, though a larger, more rigorous study is needed to confirm these results.

Cognitive ImpairmentSleepPain and Sensitization

E3 PreliminaryReviewPEM not requiredReview-Narrative

Macrophagic myofasciitis-associated dysfunctioning: An update of neuropsychological and neuroimaging features.

Aoun Sebaiti, Mehdi, Abrivard, Marie, Blanc-Durand, Paul et al.·Best practice & research. Clinical rheumatology·2018

This review describes macrophagic myofasciitis (MMF), a condition associated with inflammatory lesions that may develop after certain vaccinations, and reports that patients with MMF often experience fatigue, pain, and cognitive problems. Brain imaging studies have shown altered activity patterns in several regions including the temporal lobes and cerebellum in some MMF patients. The authors interpret these findings as suggesting a central nervous system involvement, though the underlying mechanisms remain unclear and findings require replication.

Cognitive Impairment

E3 PreliminaryMechanismPEM unclearCross-Sectional

Brain function characteristics of chronic fatigue syndrome: A task fMRI study.

Shan, Zack Y, Finegan, Kevin, Bhuta, Sandeep et al.·NeuroImage. Clinical·2018

This study compared brain activity in ME/CFS patients and healthy people while they performed a challenging word-color matching task. ME/CFS patients were slower at the task, and their brains showed different patterns of activity—specifically, the brain signals were less complex and adaptive. The findings suggest that ME/CFS patients' brains may need to work harder or recruit more areas to handle cognitive challenges.

Cognitive Impairment

E3 PreliminaryReviewPEM unclearReview-Narrative

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

Hulens, Mieke, Rasschaert, Ricky, Vansant, Greet et al.·Journal of pain research·2018

This review paper proposes that ME/CFS, fibromyalgia, and a condition called idiopathic intracranial hypertension (IICH—where pressure builds up around the brain) may share similar underlying causes. All three conditions cause widespread pain, fatigue, cognitive problems, and other symptoms that could potentially be explained by increased pressure in the fluid surrounding the brain and spinal cord.

Pain and SensitizationCognitive Impairment

E3 PreliminaryMechanismPEM unclearCross-Sectional

Task Related Cerebral Blood Flow Changes of Patients with Chronic Fatigue Syndrome: An Arterial Spin Labeling Study.

Staud, Roland, Boissoneault, Jeff, Craggs, Jason G et al.·Fatigue : biomedicine, health & behavior·2018

Researchers used advanced brain imaging to track blood flow while patients with ME/CFS and healthy people performed a challenging mental task. They found that while the overall amount of blood flowing to the brain was similar in both groups, specific brain regions showed different patterns when people were recovering from fatigue. In ME/CFS patients, fatigue improved when blood flow decreased in certain memory and attention areas, whereas in healthy people, fatigue improved when blood flow increased in those same areas.

Cognitive Impairment

E3 PreliminaryMechanismPEM unclearObservational

Open-label pilot for treatment targeting gut dysbiosis in myalgic encephalomyelitis/chronic fatigue syndrome: neuropsychological symptoms and sex comparisons.

Wallis, Amy, Ball, Michelle, Butt, Henry et al.·Journal of translational medicine·2018

This study tested whether treating an overgrowth of Streptococcus bacteria in the gut could help ME/CFS patients, particularly those with brain fog and sleep problems. Forty-four patients received alternating weeks of an antibiotic and a probiotic for 4 weeks. The treatment reduced the problematic bacteria and improved several symptoms including sleep quality, attention, and memory, though it did not significantly affect fatigue or mood.

Cognitive ImpairmentSleep

E3 PreliminaryDiagnosticPEM not requiredMethods-Paper

Psychometric Properties and Factor Structure of a Long and Shortened Version of the Cognitive and Behavioural Responses Questionnaire.

Ryan, Elizabeth G, Vitoratou, Silia, Goldsmith, Kimberley A et al.·Psychosomatic medicine·2018

This study tested a questionnaire designed to measure how people with ME/CFS think and behave in response to their illness—such as pushing through fatigue or avoiding activity. Researchers created a shorter, easier-to-use version of the original questionnaire by removing unnecessary questions while keeping the important ones. Both versions were found to be reliable and accurate tools for understanding these psychological responses.

Cognitive Impairment

E3 PreliminaryMechanismPEM not requiredCross-Sectional

Emotional conflict processing in adolescent chronic fatigue syndrome: A pilot study using functional magnetic resonance imaging.

Wortinger, Laura Anne, Endestad, Tor, Melinder, Annika Maria D et al.·Journal of clinical and experimental neuropsychology·2017

This study looked at how the brains of teenagers with ME/CFS process emotions and handle conflicting information. Researchers used brain imaging to watch what happened when young people with ME/CFS and healthy teenagers tried to identify emotions in faces while being distracted by conflicting words. Teenagers with ME/CFS showed weaker brain responses in areas that handle emotions and decision-making, and their brain activity was linked to how severe their fatigue was.

Cognitive Impairment

E3 PreliminaryBehavioralPEM not requiredLongitudinal

Neurocognitive improvements after best-practice intervention for chronic fatigue syndrome: Preliminary evidence of divergence between objective indices and subjective perceptions.

Cvejic, Erin, Lloyd, Andrew R, Vollmer-Conna, Uté·Comprehensive psychiatry·2016

This study tested whether a 12-week program combining graded activity and cognitive training could help ME/CFS patients with thinking and memory problems. Researchers measured improvements in two ways: by asking patients how they felt, and by giving them objective tests of mental performance. They found that patients showed real, measurable improvements in processing speed and accuracy on cognitive tests, and their stress response (measured by heart rate patterns) also improved.

Cognitive Impairment

E3 PreliminaryCohortPEM unclearCross-Sectional

Intrinsic Functional Hypoconnectivity in Core Neurocognitive Networks Suggests Central Nervous System Pathology in Patients with Myalgic Encephalomyelitis: A Pilot Study.

Zinn, Marcie L, Zinn, Mark A, Jason, Leonard A·Applied psychophysiology and biofeedback·2016

Researchers used EEG brain scans to measure electrical activity and communication between brain regions in 9 ME/CFS patients and 9 healthy controls. They found that people with ME/CFS had weaker electrical activity in the back of the brain and reduced communication between three important brain networks that help with thinking, attention, and rest. These differences suggest that ME/CFS involves measurable changes in how the brain works.

Cognitive Impairment

E3 PreliminaryDiagnosticPEM unclearMethods-Paper

Maximizing potential impact of experimental research into cognitive processes in health psychology: A systematic approach to material development.

Hughes, Alicia M, Gordon, Rola, Chalder, Trudie et al.·British journal of health psychology·2016

This paper is a guide for researchers on how to properly design experiments that test whether people with conditions like ME/CFS have unconscious biases in how they pay attention to and interpret information about their illness. The authors explain that many past studies used different, untested materials, making it hard to compare results. They provide a step-by-step process and practical tools to help researchers create better, standardized materials for these types of studies.

Cognitive Impairment

E3 PreliminaryMechanismPEM not requiredCross-Sectional

Less efficient and costly processes of frontal cortex in childhood chronic fatigue syndrome.

Mizuno, Kei, Tanaka, Masaaki, Tanabe, Hiroki C et al.·NeuroImage. Clinical·2015

This study looked at how children with ME/CFS use their brains when doing challenging thinking tasks. When performing two tasks at once (like sorting letters while reading a story), children with ME/CFS had to activate much larger areas of their brains compared to healthy children. This suggests their brains work harder and less efficiently to accomplish the same tasks, which may contribute to the exhaustion they experience.

Cognitive Impairment

E3 PreliminaryCohortPEM not requiredObservational

A prospective, proof-of-concept investigation of KPAX002 in chronic fatigue syndrome.

Kaiser, Jon D·International journal of clinical and experimental medicine·2015

This small study tested a combination treatment called KPAX002, which pairs a stimulant medication (methylphenidate) with nutrients thought to support energy production in cells. Fifteen people with ME/CFS took this combination for 12 weeks, and researchers measured changes in fatigue and concentration problems using standard questionnaires. Most participants (87%) showed meaningful improvement in fatigue, and the treatment was generally safe and well tolerated.

Cognitive Impairment

E3 PreliminaryDiagnosticPEM requiredMethods-Paper

Accurate diagnosis of myalgic encephalomyelitis and chronic fatigue syndrome based upon objective test methods for characteristic symptoms.

Twisk, Frank Nm·World journal of methodology·2015

ME and CFS are often treated as the same condition, but they are actually different illnesses with some overlapping symptoms. ME has specific features like muscle weakness, brain fog, heart and circulation problems, and especially a distinctive symptom called post-exertional malaise—where patients feel much worse after even small amounts of activity. Because many ME/CFS symptoms feel subjective, some doctors have questioned whether they are real physical problems, but this article argues that objective medical tests can measure key symptoms and help doctors diagnose these conditions more accurately.

Cognitive Impairment

E3 PreliminaryMechanismPEM not requiredMechanistic

Phenylephrine alteration of cerebral blood flow during orthostasis: effect on n-back performance in chronic fatigue syndrome.

Medow, Marvin S, Sood, Shilpa, Messer, Zachary et al.·Journal of applied physiology (Bethesda, Md. : 1985)·2014

Many ME/CFS patients experience dizziness and cognitive problems when standing up because blood flow to the brain decreases. This study tested whether a medication called phenylephrine, which raises blood pressure, could help restore brain blood flow and improve thinking tasks during standing. The researchers found that phenylephrine reduced the brain blood flow drop and helped ME/CFS patients perform better on memory tests while upright.

Autonomic Nervous SystemCognitive Impairment

E3 PreliminaryMechanismPEM not requiredMechanistic

[Effect of acupuncture intervention on learning-memory ability and cerebral superoxide dismutase activity and malonaldehyde concentration in chronic fatigue syndrome rats].

Liu, Chang-zheng, Lei, Bo·Zhen ci yan jiu = Acupuncture research·2013

Researchers tested whether acupuncture could help rats with chronic fatigue syndrome (CFS) learn and remember better. They found that acupuncture improved memory performance in fatigued rats and also increased protective molecules in the brain while reducing harmful ones, suggesting acupuncture may work by protecting brain cells from oxidative damage.

Cognitive Impairment

E3 PreliminaryDiagnosticPEM not requiredMethods-Paper

Self-regulatory fatigue in chronic multisymptom illnesses: scale development, fatigue, and self-control.

Nes, Lise Solberg, Ehlers, Shawna L, Whipple, Mary O et al.·Journal of pain research·2013

This study created a new questionnaire to measure a specific type of mental tiredness called self-regulatory fatigue—the exhaustion that comes from having to constantly manage your thoughts, emotions, and behaviors. Researchers gave this 18-question test to nearly 300 people with chronic illnesses like fibromyalgia and ME/CFS, along with standard fatigue and self-control tests. They found that this mental tiredness is related to, but distinct from, physical fatigue—suggesting it's a separate problem worth measuring and understanding.

Cognitive Impairment

E3 PreliminaryReviewPEM not requiredReview-Narrative

Caught in the thickness of brain fog: exploring the cognitive symptoms of Chronic Fatigue Syndrome.

Ocon, Anthony J·Frontiers in physiology·2013

ME/CFS causes cognitive difficulties that patients often describe as "brain fog"—a feeling of foggy thinking, slow mental processing, and trouble concentrating. This review suggests brain fog may result from reduced blood flow to the brain combined with the physical stress of standing (which worsens symptoms in many patients), plus the extra mental effort required to complete tasks. Understanding these overlapping factors could help explain why cognitive symptoms feel so exhausting.

Cognitive ImpairmentAutonomic Nervous System

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Mental fatigue is linked with attentional bias for sad stimuli.

Understanding Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and the Emerging Osteopathic Approach: A Narrative Review.

Treatment for Gulf War Illness (GWI) with KPAX002 (methylphenidate hydrochloride + GWI nutrient formula) in subjects meeting the Kansas case definition: A prospective, open-label trial.

Macrophagic myofasciitis-associated dysfunctioning: An update of neuropsychological and neuroimaging features.

Brain function characteristics of chronic fatigue syndrome: A task fMRI study.

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

Task Related Cerebral Blood Flow Changes of Patients with Chronic Fatigue Syndrome: An Arterial Spin Labeling Study.

Open-label pilot for treatment targeting gut dysbiosis in myalgic encephalomyelitis/chronic fatigue syndrome: neuropsychological symptoms and sex comparisons.

Psychometric Properties and Factor Structure of a Long and Shortened Version of the Cognitive and Behavioural Responses Questionnaire.

Emotional conflict processing in adolescent chronic fatigue syndrome: A pilot study using functional magnetic resonance imaging.

Neurocognitive improvements after best-practice intervention for chronic fatigue syndrome: Preliminary evidence of divergence between objective indices and subjective perceptions.

Intrinsic Functional Hypoconnectivity in Core Neurocognitive Networks Suggests Central Nervous System Pathology in Patients with Myalgic Encephalomyelitis: A Pilot Study.

Maximizing potential impact of experimental research into cognitive processes in health psychology: A systematic approach to material development.

Less efficient and costly processes of frontal cortex in childhood chronic fatigue syndrome.

A prospective, proof-of-concept investigation of KPAX002 in chronic fatigue syndrome.

Accurate diagnosis of myalgic encephalomyelitis and chronic fatigue syndrome based upon objective test methods for characteristic symptoms.

Phenylephrine alteration of cerebral blood flow during orthostasis: effect on n-back performance in chronic fatigue syndrome.

[Effect of acupuncture intervention on learning-memory ability and cerebral superoxide dismutase activity and malonaldehyde concentration in chronic fatigue syndrome rats].

Self-regulatory fatigue in chronic multisymptom illnesses: scale development, fatigue, and self-control.

Caught in the thickness of brain fog: exploring the cognitive symptoms of Chronic Fatigue Syndrome.

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