ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

721–740 of 746 studies

E3 PreliminaryMechanismPEM not requiredCross-Sectional

Corticomotor excitability and perception of effort during sustained exercise in the chronic fatigue syndrome.

Sacco, P, Hope, P A, Thickbroom, G W et al.·Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology·1999

This study examined whether the fatigue and exercise difficulty in ME/CFS comes from the brain and nervous system rather than just muscle weakness. Researchers used magnetic stimulation to measure how the motor cortex (the brain region controlling movement) responds during sustained muscle contractions in ME/CFS patients and healthy controls. They found that people with ME/CFS had shorter exercise endurance, felt more exhausted during effort, and showed different patterns of brain-to-muscle signaling compared to healthy people.

Post-Exertional Malaise

E3 PreliminaryCohortPEM unclearCase-Control

Managing chronic fatigue syndrome: overview and case study.

Jason, L A, Melrose, H, Lerman, A et al.·AAOHN journal : official journal of the American Association of Occupational Health Nurses·1999

This study explains 'envelope theory,' a practical approach where people with ME/CFS stay within their energy limits to avoid crashes and gradually build tolerance. By tracking energy levels over time, patients and doctors can better understand each person's unique patterns and what activities trigger setbacks.

Post-Exertional Malaise

E3 PreliminaryMechanismPEM not requiredMechanistic

Impaired oxygen delivery to muscle in chronic fatigue syndrome.

McCully, K K, Natelson, B H·Clinical science (London, England : 1979)·1999

This study found that muscles in people with ME/CFS are not receiving oxygen as quickly and efficiently as they should after exercise or when blood flow is temporarily stopped. The researchers measured how fast oxygen returns to calf muscles and found it took significantly longer in ME/CFS patients compared to healthy people. They also found that the muscles' ability to use oxygen for energy was reduced by about 20% in ME/CFS patients.

Post-Exertional Malaise

E3 PreliminaryCohortPEM not requiredCase-Control

The case history of an elite ultra-endurance cyclist who developed chronic fatigue syndrome.

Rowbottom, D G, Keast, D, Green, S et al.·Medicine and science in sports and exercise·1998

Researchers studied an elite cyclist who developed ME/CFS and tested his fitness before, during, and after his illness. His oxygen capacity and exercise performance dropped significantly during illness, but surprisingly remained low even after he felt clinically better. The authors suggest these fitness losses were due to prolonged inactivity from being sick rather than damage to his muscles' ability to use oxygen.

Post-Exertional Malaise

E3 PreliminaryReviewPEM not requiredReview-Narrative

Chronic fatigue syndrome: a literature review from a physiatric perspective.

Jain, S S, DeLisa, J A·American journal of physical medicine & rehabilitation·1998

This review examined over 200 scientific studies about ME/CFS to understand what we know about the condition, particularly focusing on thinking problems and exercise. The authors found that while patients often report cognitive difficulties, actual measured problems are subtle and mainly affect how quickly the brain processes complex information. Brain imaging studies suggest changes may occur in the white matter of the brain rather than in the muscles themselves.

Post-Exertional Malaise

E3 PreliminaryMechanismPEM not requiredMechanistic

Mouse running activity is lowered by Brucella abortus treatment: a potential model to study chronic fatigue.

Ottenweller, J E, Natelson, B H, Gause, W C et al.·Physiology & behavior·1998

Researchers infected mice with a killed bacterium to see if it would create a model similar to ME/CFS. The mice immediately stopped running and grooming after infection, then slowly recovered over 2-4 weeks—though some mice recovered faster than others. Interestingly, during recovery, the mice could only run for short periods at first before becoming exhausted, gradually building up their endurance over time.

Post-Exertional Malaise

E3 PreliminaryMechanismPEM not requiredObservational

Interleukin-1 beta, interleukin-1 receptor antagonist, and soluble interleukin-1 receptor type II secretion in chronic fatigue syndrome.

Cannon, J G, Angel, J B, Abad, L W et al.·Journal of clinical immunology·1997

This study examined whether people with ME/CFS have abnormal levels of immune signaling molecules (called interleukins) in their blood compared to healthy people. Researchers collected blood samples from women with ME/CFS and matched healthy controls at different points in their menstrual cycles, and tested how their immune cells responded to physical activity. The findings suggest that ME/CFS may involve differences in how the immune system communicates, possibly related to hormonal changes.

Immune SystemPost-Exertional Malaise

E3 PreliminaryReviewPEM not requiredReview-Narrative

Fatigue in the chronic fatigue syndrome: a cognitive phenomenon?

Fry, A M, Martin, M·Journal of psychosomatic research·1996

This 1996 study examined whether the extreme tiredness experienced by people with ME/CFS comes from problems in the muscles or the brain's motor control. After reviewing existing research on muscle function and brain activity, the researchers concluded that the fatigue is not caused by physical muscle damage or weakness. Instead, they suggest that the brain may be processing fatigue signals in an unusual way, influenced by how people think about and interpret their symptoms.

Post-Exertional Malaise

E3 PreliminaryReviewPEM not requiredReview-Narrative

Use of exercise for treatment of chronic fatigue syndrome.

McCully, K K, Sisto, S A, Natelson, B H·Sports medicine (Auckland, N.Z.)·1996

This review looks at whether exercise can help people with ME/CFS feel better. While patients often report getting much sicker after even light activity, most studies find their muscles work normally on standard tests. The authors suggest exercise training might help, but caution that avoiding 'relapses' (crashes) is critical, and more research is needed to understand how exercise affects this illness.

Immune SystemPost-Exertional Malaise

E3 PreliminaryMechanismPEM not requiredCross-Sectional

Decreased postexercise facilitation of motor evoked potentials in patients with chronic fatigue syndrome or depression.

Samii, A, Wassermann, E M, Ikoma, K et al.·Neurology·1996

This study measured how the brain's motor cortex responds to exercise using magnetic stimulation in people with ME/CFS, depressed patients, and healthy controls. After exercise, healthy people showed a much stronger increase in brain activity (218%), while ME/CFS patients showed a weaker increase (126%), suggesting their brains may not respond as vigorously to physical exertion as they should.

Post-Exertional Malaise

E3 PreliminaryReviewPEM not requiredReview-Narrative

[Chronic fatigue syndrome--a review of the literature].

Hamre, H J·Tidsskrift for den Norske laegeforening : tidsskrift for praktisk medicin, ny raekke·1995

ME/CFS is a real medical condition that causes extreme tiredness, low-grade fevers, sore throats, and pain in joints and muscles, often starting after a flu-like illness. Exercise makes symptoms significantly worse. While doctors don't yet have a single blood test to diagnose it, research shows patients may have problems with brain blood flow, immune system issues, and mitochondrial (cellular energy) abnormalities.

Immune SystemPost-Exertional Malaise

E3 PreliminaryMechanismPEM unclearCross-Sectional

Effects of mild exercise on cytokines and cerebral blood flow in chronic fatigue syndrome patients.

Peterson, P K, Sirr, S A, Grammith, F C et al.·Clinical and diagnostic laboratory immunology·1994

Researchers tested whether light exercise (30 minutes of slow walking) would trigger abnormal immune and brain blood flow responses in ME/CFS patients compared to healthy people. They found that ME/CFS patients had higher levels of a specific immune protein (TGF-beta) both at rest and after exercise, and also showed changes in brain blood flow. These changes appeared larger in ME/CFS patients than in healthy controls, though the difference wasn't statistically significant.

Immune SystemPost-Exertional Malaise

E3 PreliminaryMechanismPEM not requiredObservational

Cytokine production and fatigue in patients with chronic fatigue syndrome and healthy control subjects in response to exercise.

Lloyd, A, Gandevia, S, Brockman, A et al.·Clinical infectious diseases : an official publication of the Infectious Diseases Society of America·1994

Researchers asked whether a specific immune response causes the fatigue that ME/CFS patients experience after exercise. They had patients and healthy people do a 30-minute hand-grip exercise and checked their blood for immune chemicals (cytokines) before, during, and after exercise. Surprisingly, they found no changes in these immune chemicals in either group, and patients actually reported feeling less fatigued after the exercise—the opposite of what happens in real life.

Immune SystemPost-Exertional Malaise

E3 PreliminaryMechanismPEM not requiredObservational

Acylcarnitine deficiency in chronic fatigue syndrome.

Kuratsune, H, Yamaguti, K, Takahashi, M et al.·Clinical infectious diseases : an official publication of the Infectious Diseases Society of America·1994

This study found that people with ME/CFS have lower levels of acylcarnitine, a substance that helps muscles produce energy, in their blood. Because acylcarnitine plays an important role in how muscles use energy, this deficiency might explain why ME/CFS patients experience fatigue, muscle pain, and weakness. Importantly, acylcarnitine levels tended to improve as patients recovered, suggesting it could be useful for tracking disease severity.

BiomarkersPost-Exertional Malaise

E3 PreliminaryReviewPEM not requiredReview-Narrative

Chronic fatigue syndrome: a diagnostic challenge for the laboratory.

Lanham, R J·Clinical laboratory science : journal of the American Society for Medical Technology·1994

This review examined what we know about ME/CFS, a condition characterized by extreme tiredness, pain, and thinking difficulties that come and go in cycles. While researchers don't yet know what causes ME/CFS, studies show that people with this condition often have unusual immune system test results. Currently, there is no single blood test or marker that can definitively diagnose ME/CFS, so doctors treat symptoms based on what each patient experiences.

Immune SystemPost-Exertional Malaise

E3 PreliminaryMechanismPEM not requiredObservational

Effort syndrome: hyperventilation and reduction of anaerobic threshold.

Nixon, P G·Biofeedback and self-regulation·1994

This study focuses on a condition called 'effort syndrome,' which causes people to feel exhausted during physical activity. The researchers found that patients with effort syndrome breathe too heavily (hyperventilate), which changes the chemistry of their blood and makes their muscles tire much earlier than normal. By measuring breathing patterns during exercise, doctors can identify how much work each patient can do before their body runs out of chemical buffers.

Post-Exertional Malaise

E3 PreliminaryCohortPEM not requiredObservational

Human adjuvant disease revisited: a review of eleven post-augmentation mammoplasty patients.

Fenske, T K, Davis, P, Aaron, S L·Clinical and experimental rheumatology·1994

This study examined 11 women who developed widespread pain, fatigue, and joint symptoms after receiving silicone breast implants. The researchers found that 6 patients met criteria for fibromyalgia and 5 had chronic fatigue syndrome symptoms, but none had evidence of a traditional autoimmune disease. The authors suggest these cases should be classified as CFS or fibromyalgia rather than a unique implant-related disease.

Immune SystemPost-Exertional Malaise

E3 PreliminaryReviewPEM not requiredReview-Narrative

[Chronic fatigue syndrome--a defined unity?].

Rasmussen, A K, Andersen, V, Nielsen, H et al.·Ugeskrift for laeger·1994

This 1994 review examined what scientists knew about ME/CFS at that time, looking at whether a persistent virus or immune system problem caused the condition. The authors found that existing research did not consistently support either explanation, and that different studies often contradicted each other. They concluded that more careful research was needed to understand what actually causes ME/CFS and how to tell it apart from other illnesses.

Immune SystemPost-Exertional Malaise

E3 PreliminaryReviewPEM requiredReview-Narrative

Clinical presentation of chronic fatigue syndrome.

Komaroff, A L·Ciba Foundation symposium·1993

ME/CFS is a long-lasting illness that causes severe tiredness lasting at least six months, along with other symptoms like fever, sore throat, joint pain, and worsening after physical activity. While some symptoms can look like mental health conditions, ME/CFS has physical features—like sudden onset following a flu-like illness and post-exertional exhaustion—that suggest it involves real biological problems. This condition significantly impacts people's ability to work, study, and care for themselves.

Post-Exertional Malaise

E3 PreliminaryBehavioralPEM unclearConference-Abstract

Muscle histopathology and physiology in chronic fatigue syndrome.

Edwards, R H, Gibson, H, Clague, J E et al.·Ciba Foundation symposium·1993

Researchers examined muscle tissue from 108 ME/CFS patients and 22 healthy people using microscopes to look for structural damage, and tested muscle strength before and after exercise. They found no consistent muscle damage that explained fatigue symptoms, and muscle strength worked normally even after exercise. The study suggests ME/CFS is not caused by a primary muscle disease.

Post-Exertional Malaise

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Corticomotor excitability and perception of effort during sustained exercise in the chronic fatigue syndrome.

Managing chronic fatigue syndrome: overview and case study.

Impaired oxygen delivery to muscle in chronic fatigue syndrome.

The case history of an elite ultra-endurance cyclist who developed chronic fatigue syndrome.

Chronic fatigue syndrome: a literature review from a physiatric perspective.

Mouse running activity is lowered by Brucella abortus treatment: a potential model to study chronic fatigue.

Interleukin-1 beta, interleukin-1 receptor antagonist, and soluble interleukin-1 receptor type II secretion in chronic fatigue syndrome.

Fatigue in the chronic fatigue syndrome: a cognitive phenomenon?

Use of exercise for treatment of chronic fatigue syndrome.

Decreased postexercise facilitation of motor evoked potentials in patients with chronic fatigue syndrome or depression.

[Chronic fatigue syndrome--a review of the literature].

Effects of mild exercise on cytokines and cerebral blood flow in chronic fatigue syndrome patients.

Cytokine production and fatigue in patients with chronic fatigue syndrome and healthy control subjects in response to exercise.

Acylcarnitine deficiency in chronic fatigue syndrome.

Chronic fatigue syndrome: a diagnostic challenge for the laboratory.

Effort syndrome: hyperventilation and reduction of anaerobic threshold.

Human adjuvant disease revisited: a review of eleven post-augmentation mammoplasty patients.

[Chronic fatigue syndrome--a defined unity?].

Clinical presentation of chronic fatigue syndrome.

Muscle histopathology and physiology in chronic fatigue syndrome.

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