ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

361–380 of 404 studies

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 PreliminaryReviewPEM unclearReview-Narrative

Brain dysfunction as one cause of CFS symptoms including difficulty with attention and concentration.

Natelson, Benjamin H·Frontiers in physiology·2013

This study suggests that ME/CFS is not one single disease but rather multiple conditions with different underlying causes. By grouping patients based on specific characteristics—like whether they have psychiatric diagnoses, fibromyalgia, or blood pressure problems when standing—researchers found that different groups showed different types of brain dysfunction. This approach could help explain why some patients experience trouble with concentration and attention in different ways.

Autonomic Nervous SystemCognitive Impairment

E3 PreliminaryReviewPEM not requiredReview-Narrative

Neurocognitive impairment in childhood chronic fatigue syndrome.

Mizuno, Kei, Watanabe, Yasuyoshi·Frontiers in physiology·2013

This study examined how ME/CFS affects thinking and attention skills in children and teenagers. Researchers found that young people with ME/CFS have difficulty with tasks that require switching between activities or paying attention to multiple things at once. The brain regions responsible for these skills are still developing during childhood, and severe fatigue may slow down or disrupt this normal development.

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.

Autonomic Nervous SystemCognitive 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 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 PreliminaryMechanismPEM not requiredCross-Sectional

Postural neurocognitive and neuronal activated cerebral blood flow deficits in young chronic fatigue syndrome patients with postural tachycardia syndrome.

Stewart, Julian M, Medow, Marvin S, Messer, Zachary R et al.·American journal of physiology. Heart and circulatory physiology·2012

When people with ME/CFS try to stand upright or tilt backward, their brain doesn't get enough blood flow to think clearly, and their thinking problems get worse as their body position changes. In healthy people, brain blood flow increases during hard thinking tasks, but in ME/CFS patients, this normal response is broken—their brains don't increase blood flow when doing difficult mental tasks.

Autonomic Nervous SystemCognitive Impairment

E3 PreliminaryMechanismPEM not requiredObservational

Increasing orthostatic stress impairs neurocognitive functioning in chronic fatigue syndrome with postural tachycardia syndrome.

Ocon, Anthony J, Messer, Zachary R, Medow, Marvin S et al.·Clinical science (London, England : 1979)·2012

This study tested whether standing at increasing angles on a tilt table—a procedure that stresses the body's ability to maintain blood flow while upright—makes 'brain fog' worse in people with ME/CFS who also have POTS (a condition causing rapid heartbeat when standing). Researchers found that when people with CFS/POTS stood at steeper angles while doing concentration and memory tests, their performance got worse compared to healthy people, suggesting that orthostatic stress (the challenge of staying upright) does interfere with thinking and memory.

Autonomic Nervous SystemCognitive Impairment

E3 PreliminaryBehavioralPEM not requiredCross-Sectional

Metacognitive factors in chronic fatigue syndrome.

Maher-Edwards, Lorraine, Fernie, Bruce A, Murphy, Gabrielle et al.·Clinical psychology & psychotherapy·2012

This study explored how ME/CFS patients think about their thinking—specifically, their beliefs about analyzing and solving problems related to their symptoms. Researchers found that patients have both helpful and unhelpful thoughts about trying to understand their illness, and they often focus on either distracting themselves or monitoring their symptoms closely. The study suggests that these thought patterns may play a role in how ME/CFS symptoms develop or persist.

Cognitive Impairment

E3 PreliminaryMechanismPEM not requiredMechanistic

[Effect of electroacupuncture at Shenshu (BL 23) and Zusanli (ST 36) on the event-related potentials of chronic fatigue syndrome].

Cheng, Ci-Song, Zhu, Yi-Hui, Liang, Fan-Rong et al.·Zhongguo zhen jiu = Chinese acupuncture & moxibustion·2010

This study looked at whether acupuncture can help ME/CFS patients by examining brain wave patterns that reflect attention and thinking. Researchers compared brain signals in healthy people and ME/CFS patients at different times of day, then treated some ME/CFS patients with acupuncture. They found that acupuncture helped restore normal daily rhythms in brain activity and improved daytime thinking ability.

Cognitive Impairment

E3 PreliminaryReviewPEM not requiredReview-Narrative

Fibromyalgia syndrome: a discussion of the syndrome and pharmacotherapy.

Smith, Howard S, Barkin, Robert L·American journal of therapeutics·2010

Fibromyalgia is a condition that causes widespread pain throughout the body, along with fatigue, sleep problems, brain fog, and mood changes. This article explains that fibromyalgia may share common features with ME/CFS and other conditions involving heightened pain sensitivity. While there is no cure, doctors can help manage symptoms through exercise, therapy, patient education, and specific medications.

Pain and SensitizationSleepCognitive Impairment

E3 PreliminaryCohortPEM not requiredCross-Sectional

Memory and attention problems in children with chronic fatigue syndrome or myalgic encephalopathy.

Haig-Ferguson, A, Tucker, P, Eaton, N et al.·Archives of disease in childhood·2009

This study looked at 20 children with ME/CFS who had memory and attention problems. Researchers asked the children, their parents, and teachers about these difficulties, and then gave the children a series of tests to measure how well they could focus, remember things, and process information. The children's test scores showed they had real difficulties with attention and memory compared to healthy children their age.

Cognitive Impairment

E3 PreliminaryBehavioralPEM not requiredCase-Control

Fixed belief in cognitive dysfunction despite normal neuropsychological scores: neurocognitive hypochondriasis?

Boone, Kyle Brauer·The Clinical neuropsychologist·2009

Some people with ME/CFS report serious cognitive problems in their daily life, but when given standard memory and thinking tests, their scores are completely normal. This study presents one case and suggests that some patients may worry excessively about cognitive problems that aren't actually measurable on formal tests—a condition the author calls 'neurocognitive hypochondriasis.' The study notes this pattern may occur in ME/CFS and several other conditions.

Cognitive Impairment

E3 PreliminaryReviewPEM not requiredReview-Narrative

Diagnostic and treatment challenges of chronic fatigue syndrome: role of immediate-release methylphenidate.

Valdizán Usón, José Ramón, Idiazábal Alecha, María Angeles·Expert review of neurotherapeutics·2008

This study explores whether a medication called methylphenidate (commonly known as Ritalin) might help people with ME/CFS who experience brain fog, memory problems, and difficulty concentrating. The authors reviewed existing research, including one small study showing positive results, and discussed how this medication works in the brain to boost focus and thinking speed. They suggest methylphenidate could be a promising treatment option worth further investigation for ME/CFS patients.

Cognitive Impairment

E3 PreliminaryReviewPEM not requiredReview-Narrative

Possible links between behavioral and physiological indices of tiredness, fatigue, and exhaustion in advanced cancer.

Olson, Karin, Turner, A Robert, Courneya, Kerry S et al.·Supportive care in cancer : official journal of the Multinational Association of Supportive Care in Cancer·2008

This paper proposes a new framework for understanding tiredness and fatigue in advanced cancer patients. The researchers suggest that cancer and its treatments stress the body, which then affects four key systems: thinking ability, sleep quality, nutrition, and muscle strength. They propose that problems in all four of these areas together—not just one alone—are what cause severe fatigue, and that studying how these systems interact could lead to better treatments.

SleepCognitive Impairment

E3 PreliminaryBehavioralPEM not requiredLongitudinal

Post concussion syndrome ebb and flow: longitudinal effects and management.

Rees, Roger J, Bellon, Michelle L·NeuroRehabilitation·2007

This study followed 20 adults who had lasting symptoms after a head injury (concussion) for an average of 3.35 years. Participants experienced fatigue, difficulty concentrating, mood changes, and sensitivity to noise. When they received counseling and therapy over two years, some symptoms like irritability improved, but many people still felt fundamentally changed and struggled with feelings of helplessness.

Cognitive Impairment

E3 PreliminaryReviewPEM unclearReview-Narrative

Violence, stress, and somatic syndromes.

Crofford, Leslie J·Trauma, violence & abuse·2007

This review article examines how experiences of violence and stress may trigger or worsen conditions like ME/CFS, fibromyalgia, and irritable bowel syndrome—illnesses that involve pain, exhaustion, mood changes, memory problems, and sleep issues. The authors explain that stress affects the brain and body's hormone and nervous system function, which may make people more vulnerable to developing these conditions. Understanding this connection could help us recognize how violence exposure affects long-term health.

Pain and SensitizationSleepCognitive Impairment

E3 PreliminaryMechanismPEM not requiredCross-Sectional

Functional neuroimaging correlates of mental fatigue induced by cognition among chronic fatigue syndrome patients and controls.

Cook, Dane B, O'Connor, Patrick J, Lange, Gudrun et al.·NeuroImage·2007

This study used brain imaging to see how the brains of ME/CFS patients and healthy people respond during mentally tiring tasks. Researchers found that feelings of mental fatigue were linked to activity in specific brain regions during a difficult memory task, and that ME/CFS patients showed greater brain activity in these areas compared to healthy controls, even though they were doing the same task.

Cognitive Impairment

E3 PreliminaryTrialPEM not requiredRCT

Effects of elevated plasma tryptophan on brain activation associated with the Stroop task.

Morgan, Rhian M, Parry, Allyson M M, Arida, Ricardo M et al.·Psychopharmacology·2007

This study looked at how a dietary supplement called tryptophan affects the brain's activity during mental tasks in people experiencing central fatigue (like in ME/CFS). Researchers used brain imaging to watch what happens when people take tryptophan versus a placebo while doing a challenging attention test. They found that tryptophan slowed down responses and changed brain activity patterns in several regions, particularly in areas related to awareness and processing information.

Cognitive Impairment

E3 PreliminaryReviewPEM not requiredReview-Narrative

[School phobia and childhood chronic fatigue syndrome (CCFS)].

Tomoda, Akemi·Nihon rinsho. Japanese journal of clinical medicine·2007

This review examines childhood chronic fatigue syndrome (CCFS), a serious condition where children experience extreme tiredness that cannot be explained by other medical or mental health problems. Children with CCFS often struggle with memory and concentration, sleep problems, and symptoms related to their nervous system. The authors suggest that CCFS may involve changes in how the brain functions, which could explain why patients experience fatigue, thinking difficulties, and memory problems.

Autonomic Nervous SystemCognitive Impairment

← Previous Next 20 studies →

Or browse by topic

PEM Immune Neuro Metabolic Biomarkers Severe ME Long COVID Cognitive

Evidence Atlas

Evidence browser

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

Brain dysfunction as one cause of CFS symptoms including difficulty with attention and concentration.

Neurocognitive impairment in childhood chronic fatigue syndrome.

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

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

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

Postural neurocognitive and neuronal activated cerebral blood flow deficits in young chronic fatigue syndrome patients with postural tachycardia syndrome.

Increasing orthostatic stress impairs neurocognitive functioning in chronic fatigue syndrome with postural tachycardia syndrome.

Metacognitive factors in chronic fatigue syndrome.

[Effect of electroacupuncture at Shenshu (BL 23) and Zusanli (ST 36) on the event-related potentials of chronic fatigue syndrome].

Fibromyalgia syndrome: a discussion of the syndrome and pharmacotherapy.

Memory and attention problems in children with chronic fatigue syndrome or myalgic encephalopathy.

Fixed belief in cognitive dysfunction despite normal neuropsychological scores: neurocognitive hypochondriasis?

Diagnostic and treatment challenges of chronic fatigue syndrome: role of immediate-release methylphenidate.

Possible links between behavioral and physiological indices of tiredness, fatigue, and exhaustion in advanced cancer.

Post concussion syndrome ebb and flow: longitudinal effects and management.

Violence, stress, and somatic syndromes.

Functional neuroimaging correlates of mental fatigue induced by cognition among chronic fatigue syndrome patients and controls.

Effects of elevated plasma tryptophan on brain activation associated with the Stroop task.

[School phobia and childhood chronic fatigue syndrome (CCFS)].

Curated Collections

Neuroinflammation Evidence

Metabolism & Mitochondria

Biomarkers

PEM-Specific Research