ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

221–240 of 729 studies

E2 ModerateCohortPEM requiredCross-Sectional

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome is common in post-acute sequelae of SARS-CoV-2 infection (PASC): Results from a post-COVID-19 multidisciplinary clinic.

Bonilla, Hector, Quach, Tom C, Tiwari, Anushri et al.·Frontiers in neurology·2023

This study looked at 140 people suffering from long COVID symptoms and found that nearly half of them (43%) met the medical criteria for ME/CFS. Most patients had severe fatigue, brain fog, and unrefreshing sleep that lasted around 9-10 months on average. People with higher body weight and greater functional decline were more likely to develop the ME/CFS form of long COVID.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

Pediatric Post-Acute Sequelae of SARS-CoV-2 Infection.

Jason, Leonard A, Johnson, Madeline, Torres, Chelsea·Fatigue : biomedicine, health & behavior·2023

This study compared young people recovering from long COVID (PASC) with young people who have ME/CFS to understand how their symptoms differ. Researchers asked 19 parents about their child's symptoms during initial COVID infection and again later, then compared these to 19 young people with ME/CFS. Most PASC symptoms improved over time, but fatigue and sleep problems stayed high—similar to what ME/CFS patients experience.

SleepPost-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

Cardiopulmonary Profiling of Athletes with Post-Exertional Malaise after COVID-19 Infection-A Single-Center Experience.

Wernhart, Simon, Weihe, Eberhard, Totzeck, Matthias et al.·Journal of clinical medicine·2023

This study tested athletes who had lingering exercise problems and post-exertional malaise (feeling worse after physical activity) following COVID-19. Researchers used a special exercise test to measure how their hearts, lungs, and muscles responded to activity. They found that some athletes showed abnormal responses on these tests, particularly in how efficiently their bodies used oxygen during exercise, which may help identify who needs to limit their training intensity.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

Characterizing Sjögren-Associated Fatigue: A Distinct Phenotype from ME/CFS.

Kim, Laura, Kedor, Claudia, Buttgereit, Frank et al.·Journal of clinical medicine·2023

This study compared fatigue in people with Sjögren's syndrome (an autoimmune disease affecting moisture-producing glands) to fatigue in ME/CFS patients. While both groups experience severe tiredness, the researchers found important differences: Sjögren's patients recovered their muscle strength within an hour of activity, whereas ME/CFS patients typically experience worsening symptoms hours after exertion. Only a small portion of Sjögren's patients met ME/CFS diagnostic criteria, suggesting these are distinct conditions despite some symptom overlap.

Severe MEPost-Exertional Malaise

E2 ModerateDiagnosticPEM requiredCross-Sectional

Evaluating case diagnostic criteria for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): toward an empirical case definition.

Conroy, Karl E, Islam, Mohammed F, Jason, Leonard A·Disability and rehabilitation·2023

This study looked at how doctors diagnose ME/CFS by analyzing symptoms reported by over 2,300 patients from around the world. Researchers used statistical methods to identify which symptoms tend to occur together, then compared their findings to three existing diagnostic guidelines. They found that the symptoms cluster into seven main groups, with post-exertional malaise (worsening after activity), cognitive problems, and sleep issues being particularly important.

SleepPost-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

Focus on post-exertional malaise when approaching ME/CFS in specialist healthcare improves satisfaction and reduces deterioration.

Wormgoor, Marjon E A, Rodenburg, Sanne C·Frontiers in neurology·2023

This study looked at whether ME/CFS specialists in Norway were paying attention to post-exertional malaise (PEM)—the worsening of symptoms after physical or mental effort, which is a key feature of ME/CFS. They surveyed nearly 900 patients about their experiences in specialist clinics and hospitals. The results showed that when doctors focused on PEM and helped patients avoid overexertion, patients felt better, were more satisfied with their care, and were less likely to get worse after treatment.

Post-Exertional Malaise

E2 ModerateCohortPEM unclearObservational

Pattern of Post COVID Fatigue in Elderly Patients.

Gaber, Tarek A·Advances in rehabilitation science and practice·2023

This study looked at why older adults (especially those over 70) seem to report Long COVID fatigue less often than younger people. Rather than assuming older adults simply don't report symptoms, the researchers found that older people who do get post-COVID fatigue experience it differently—it doesn't seem to follow the typical pattern of getting worse after physical activity. The study suggests that changes in how aging bodies work (in immunity, metabolism, and genes) might explain why fatigue after COVID looks different in elderly patients.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredLongitudinal

One-year follow-up of young people with ME/CFS following infectious mononucleosis by Epstein-Barr virus.

Pricoco, Rafael, Meidel, Paulina, Hofberger, Tim et al.·Frontiers in pediatrics·2023

This study followed 25 young people (12 teenagers and 13 young adults) who developed ME/CFS after having infectious mononucleosis caused by Epstein-Barr virus. Researchers checked on their symptoms and quality of life at the start, 6 months, and 12 months later. Teenagers showed better improvement over the year, with more than half no longer meeting ME/CFS criteria, while young adults continued to have severe symptoms with little improvement.

Severe MEBiomarkersPost-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

An international survey of experiences and attitudes towards pacing using a heart rate monitor for people with myalgic encephalomyelitis/chronic fatigue syndrome.

Clague-Baker, Nicola, Davenport, Todd E, Madi, Mohammad et al.·Work (Reading, Mass.)·2023

This study asked 488 people with ME about their experiences using heart rate monitors to help manage their activity levels. Heart rate monitors can help you stay within a safe activity zone that doesn't trigger post-exertional malaise (the worsening of symptoms after activity). Most people in the study found that heart rate monitors helped them understand their condition better, reduce symptom severity, and even gradually increase what they could do—including returning to some work. However, people also reported challenges, so more research and better training for doctors is needed.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredCase-Control

Consequences of sarcolemma fatigue on maximal muscle strength production in patients with myalgic encephalomyelitis/chronic fatigue syndrome.

Retornaz, Frédérique, Stavris, Chloé, Jammes, Yves·Clinical biomechanics (Bristol, Avon)·2023

This study looked at whether problems with how muscle cells communicate during and after exercise might explain why people with ME/CFS have weak muscles. Researchers compared two groups of ME/CFS patients—those whose muscles showed electrical signal problems after exercise and those who didn't. They found that patients with these electrical problems had weaker grip strength both before and after exercise, and their symptoms got worse after physical activity.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredLongitudinal

Long-term symptom severity and clinical biomarkers in post-COVID-19/chronic fatigue syndrome: results from a prospective observational cohort.

Legler, Franziska, Meyer-Arndt, Lil, Mödl, Lukas et al.·EClinicalMedicine·2023

This study followed 106 people with long-term fatigue after COVID-19 for up to 20 months to see how they recovered over time. Researchers found that some patients met the diagnostic criteria for ME/CFS and had persistent, severe symptoms including fatigue and post-exertional malaise (worsening after activity), while others improved more substantially. Lower muscle strength at the start of illness was linked to ongoing symptoms, especially in those with ME/CFS.

BiomarkersImmune SystemPost-Exertional Malaise

E2 ModerateCohortPEM unclearObservational

Exercise intolerance associated with impaired oxygen extraction in patients with long COVID.

Norweg, Anna, Yao, Lanqiu, Barbuto, Scott et al.·Respiratory physiology & neurobiology·2023

This study looked at why people with long COVID struggle with exercise. Researchers tested 59 patients using a standard exercise test and found that their bodies were not extracting and using oxygen efficiently during activity. The patients also showed an unusual heart rate response during exercise. These findings suggest that problems with how the body produces and uses energy may be a key reason why long COVID patients experience fatigue and feel worse after exertion.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

Post-exertional malaise among people with long COVID compared to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Vernon, Suzanne D, Hartle, Megan, Sullivan, Karen et al.·Work (Reading, Mass.)·2023

This study looked at whether people with Long COVID experience post-exertional malaise (PEM)—a hallmark symptom of ME/CFS where symptoms get worse after physical or mental activity. Researchers surveyed 80 Long COVID patients and compared their experiences to 151 ME/CFS patients. Nearly all Long COVID patients reported having PEM, but the way they experienced it differed significantly from ME/CFS patients in terms of what triggered it, which symptoms appeared, and how to recover.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

Typing myalgic encephalomyelitis by infection at onset: A DecodeME study.

Bretherick, Andrew D, McGrath, Simon J, Devereux-Cooke, Andy et al.·NIHR open research·2023

This large study asked over 17,000 people with ME/CFS about their symptoms, when their illness started, and what health conditions they experience. The researchers found that ME/CFS is not one-size-fits-all: people whose ME/CFS began after an infection (like COVID-19 or glandular fever) reported different patterns of symptoms and other health problems compared to those whose illness started without a clear infection. The study also confirmed that women are more affected by ME/CFS than men, and discovered that women tend to have more additional health conditions alongside ME/CFS.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

Symptom-based clusters in people with ME/CFS: an illustration of clinical variety in a cross-sectional cohort.

Vaes, Anouk W, Van Herck, Maarten, Deng, Qichen et al.·Journal of translational medicine·2023

This study looked at whether people with ME/CFS can be grouped into different subtypes based on their specific combination of symptoms. Researchers asked 337 people with ME/CFS to report their symptoms and found 13 major groups, where people in each group shared similar patterns of symptom severity and frequency. While fatigue and post-exertional malaise (PEM) appeared in all groups, other symptoms varied—meaning people with ME/CFS experience the illness quite differently from one another.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredObservational

Recovery from Exercise in Persons with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Moore, Geoffrey E, Keller, Betsy A, Stevens, Jared et al.·Medicina (Kaunas, Lithuania)·2023

This study measured how long it takes people with ME/CFS to recover after exercise compared to healthy people. Researchers gave participants two exercise tests on consecutive days and tracked their symptoms for 10 days afterward. People with ME/CFS took an average of about 2 weeks to recover, while healthy controls recovered in just 2 days—showing that post-exertional malaise (the characteristic symptom flare after activity) lasts much longer in ME/CFS.

Post-Exertional Malaise

E2 ModerateCohortPEM unclearLongitudinal

Predictors of impaired functioning among long COVID patients.

Jason, Leonard A, Dorri, Joseph A·Work (Reading, Mass.)·2023

This study followed Long COVID patients from their first two weeks of illness through about five months later to understand which early symptoms predict worse long-term outcomes. Researchers found that people who experienced problems with their autonomic nervous system (heart rate, blood pressure, temperature control) and stomach issues early on were more likely to have difficulty returning to work and family life. The same early symptoms were also linked to developing ME/CFS.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

Two symptoms can accurately identify post-exertional malaise in myalgic encephalomyelitis/chronic fatigue syndrome.

Davenport, Todd E, Chu, Lily, Stevens, Staci R et al.·Work (Reading, Mass.)·2023

This study found that asking patients about just two specific symptoms can accurately identify post-exertional malaise (PEM), the key feature of ME/CFS. Researchers had people with ME/CFS and healthy controls exercise twice, 24 hours apart, and report their symptoms at different times. The most reliable symptoms for identifying PEM were cognitive problems (brain fog), worsening function, and loss of positive feelings or mood.

Post-Exertional Malaise

E2 ModerateCohortPEM unclearObservational

Prolonged indoleamine 2,3-dioxygenase-2 activity and associated cellular stress in post-acute sequelae of SARS-CoV-2 infection.

Guo, Lihui, Appelman, Brent, Mooij-Kalverda, Kirsten et al.·EBioMedicine·2023

This study found that people with long-COVID have persistent activity of an enzyme called IDO2 in their blood cells and brain tissue, months or years after initial infection. This enzyme breaks down tryptophan (an amino acid) into other compounds that may trigger cellular stress and energy problems. The researchers also discovered that blocking a specific receptor (called AHR) could stop this process in laboratory tests, suggesting a potential treatment target.

Energy MetabolismImmune SystemPost-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

Do diagnostic criteria for ME matter to patient experience with services and interventions? Key results from an online RDS survey targeting fatigue patients in Norway.

Kielland, Anne, Liu, Jing, Jason, Leonard A·Journal of health psychology·2023

This study surveyed 660 people with ME/CFS in Norway to understand how different diagnostic criteria and symptoms affect their experiences with treatments and healthcare services. Most patients reported that available interventions had little benefit or made them feel worse. The researchers found that post-exertional malaise (a hallmark symptom where activity makes fatigue and other symptoms worse) was strongly linked to how patients tolerated different treatments, suggesting this symptom should be a key consideration when recommending interventions.

Post-Exertional Malaise

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Evidence Atlas

Evidence browser

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome is common in post-acute sequelae of SARS-CoV-2 infection (PASC): Results from a post-COVID-19 multidisciplinary clinic.

Pediatric Post-Acute Sequelae of SARS-CoV-2 Infection.

Cardiopulmonary Profiling of Athletes with Post-Exertional Malaise after COVID-19 Infection-A Single-Center Experience.

Characterizing Sjögren-Associated Fatigue: A Distinct Phenotype from ME/CFS.

Evaluating case diagnostic criteria for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): toward an empirical case definition.

Focus on post-exertional malaise when approaching ME/CFS in specialist healthcare improves satisfaction and reduces deterioration.

Pattern of Post COVID Fatigue in Elderly Patients.

One-year follow-up of young people with ME/CFS following infectious mononucleosis by Epstein-Barr virus.

An international survey of experiences and attitudes towards pacing using a heart rate monitor for people with myalgic encephalomyelitis/chronic fatigue syndrome.

Consequences of sarcolemma fatigue on maximal muscle strength production in patients with myalgic encephalomyelitis/chronic fatigue syndrome.

Long-term symptom severity and clinical biomarkers in post-COVID-19/chronic fatigue syndrome: results from a prospective observational cohort.

Exercise intolerance associated with impaired oxygen extraction in patients with long COVID.

Post-exertional malaise among people with long COVID compared to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Typing myalgic encephalomyelitis by infection at onset: A DecodeME study.

Symptom-based clusters in people with ME/CFS: an illustration of clinical variety in a cross-sectional cohort.

Recovery from Exercise in Persons with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Predictors of impaired functioning among long COVID patients.

Two symptoms can accurately identify post-exertional malaise in myalgic encephalomyelitis/chronic fatigue syndrome.

Prolonged indoleamine 2,3-dioxygenase-2 activity and associated cellular stress in post-acute sequelae of SARS-CoV-2 infection.

Do diagnostic criteria for ME matter to patient experience with services and interventions? Key results from an online RDS survey targeting fatigue patients in Norway.

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