Evidence browser

E2 ModerateCohortPEM not requiredCase-Control

A Cross-National Comparison of Myalgic Encephalomyelitis and Chronic Fatigue Syndrome at Tertiary Care Settings from the US and Spain.

Bhatia, Shaun, Olczyk, Nicole, Jason, Leonard A et al.·American journal of social sciences and humanities·2020

This study compared ME/CFS patients in the United States and Spain to see if the disease affects people differently depending on where they live. Researchers found that Spanish patients reported worse overall health and more severe symptoms, particularly pain and hormone-related problems, compared to American patients. The differences may be due to how each country handles disability benefits, how doctors view ME/CFS, and how easily patients can see specialists.

Processing of Laser-Evoked Potentials in Patients with Chronic Whiplash-Associated Disorders, Chronic Fatigue Syndrome, and Healthy Controls: A Case-Control Study.

Goudman, Lisa, Daenen, Liesbeth, Mouraux, Andre et al.·Pain medicine (Malden, Mass.)·2020

Researchers used a specialized brain test called laser-evoked potentials (LEPs) to measure how the nervous system responds to heat pain in ME/CFS patients, whiplash patients, and healthy people. The test involved brief laser pulses applied to the hand and foot while recording brain activity. The study found that ME/CFS patients' nervous systems responded to pain in basically the same way as healthy people, which suggests their pain-sensing pathways are working normally.

Pain and Sensitization

Cardiac Dimensions and Function Are Not Altered among Females with the Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Iversen, Per Ole, von Lueder, Thomas Gero, Kardel, Kristin Reimers et al.·Healthcare (Basel, Switzerland)·2020

Researchers used heart ultrasounds to check if the hearts of people with ME/CFS were structurally different or working differently than healthy people's hearts. They found no significant differences in heart size or function between the 16 women with ME/CFS and 10 healthy women they studied. This suggests that ME/CFS exercise intolerance and lactate buildup may not be caused by problems with how the heart itself is structured or functioning.

Confirmatory factor analysis of a myalgic encephalomyelitis and chronic fatigue syndrome stigma scale.

Terman, Julia M, Awsumb, Jessica M, Cotler, Joseph et al.·Journal of health psychology·2020

This study measured how much stigma (negative judgments and social shame) people with ME/CFS experience. Over 550 people with ME/CFS from around the world filled out a survey designed to assess stigma, feelings of isolation, and concerns about disclosing their illness. The researchers found that people with ME/CFS reported high levels of stigma and struggled with whether to tell others about their condition.

E2 ModerateCohortPEM requiredCross-Sectional

The Prevalence of Pediatric Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in a Community‑Based Sample.

Jason, Leonard A, Katz, Ben Z, Sunnquist, Madison et al.·Child & youth care forum·2020

Researchers studied over 10,000 children and teenagers in the Chicago area to find out how many have ME/CFS. They found that about 0.75% (roughly 1 in 133) young people have the condition, with higher rates among African American and Latino youth. Importantly, less than 5% of these children had been diagnosed before the study, meaning many young people with ME/CFS are going unrecognized by doctors.

Diagnostics

The Economic Impacts of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in an Australian Cohort.

Close, Shara, Marshall-Gradisnik, Sonya, Byrnes, Joshua et al.·Frontiers in public health·2020

This Australian study calculated how much ME/CFS costs patients, their families, and the healthcare system. Researchers surveyed people with ME/CFS and found the total annual cost was approximately $14.5 billion, including medical visits, treatments, medicines, and lost income. The study shows that ME/CFS places a heavy financial burden on individuals and society.

E2 ModerateCohortPEM requiredCross-Sectional

Two-Day Cardiopulmonary Exercise Testing in Females with a Severe Grade of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Comparison with Patients with Mild and Moderate Disease.

van Campen, C Linda Mc, Rowe, Peter C, Visser, Frans C·Healthcare (Basel, Switzerland)·2020

This study tested how exercise affects female ME/CFS patients with different disease severity levels. Researchers had 82 women complete exercise tests on two consecutive days and measured how much oxygen their bodies could use and how much work they could do. Patients with severe ME/CFS showed the biggest drop in exercise capacity between day one and day two, suggesting their bodies recover more poorly from physical activity.

Metabolic analysis of amino acids and vitamin B6 pathways in lymphoma survivors with cancer related chronic fatigue.

Fosså, Alexander, Smeland, Knut Halvor, Fluge, Øystein et al.·PloS one·2020

This study looked at blood chemicals called amino acids and B vitamins in lymphoma survivors who experienced lasting fatigue after cancer treatment. Researchers found that people with this fatigue had lower tryptophan (an amino acid) and signs of ongoing low-level immune activation and inflammation. The study suggests that persistent tiredness after lymphoma treatment may be caused by the body's immune system staying activated longer than expected.

BiomarkersImmune System

Clinically accessible tools for documenting the impact of orthostatic intolerance on symptoms and function in ME/CFS.

Lee, Jihyun, Wall, Pelle, Kimler, Chris et al.·Work (Reading, Mass.)·2020

This study looked at how much time ME/CFS patients can spend upright (standing or walking around) each day and how this relates to dizziness and other symptoms caused by orthostatic intolerance—a condition where symptoms get worse when standing or being active. Researchers compared 25 women with ME/CFS to 25 healthy women and found that ME/CFS patients spend far fewer hours upright and experience much worse symptoms that interfere with daily life. The study suggests that measuring upright hours and asking patients about orthostatic symptoms could be helpful tools for doctors diagnosing and managing ME/CFS.

E2 ModerateCohortPEM unclearObservational

Paediatric patients with myalgic encephalomyelitis/chronic fatigue syndrome value understanding and help to move on with their lives.

Rowe, Katherine·Acta paediatrica (Oslo, Norway : 1992)·2020

This study followed 784 young people (ages 6-18) with ME/CFS over 14 years at a specialized clinic in Melbourne. The patients received help with symptom management and personalized lifestyle plans adjusted to their severity of illness and individual circumstances. Most patients who responded said the management approach helped them regain control of their lives and stay socially connected and engaged in school.

E2 ModerateCohortPEM not requiredObservational

Association between quadrivalent human papillomavirus vaccination and selected syndromes with autonomic dysfunction in Danish females: population based, self-controlled, case series analysis.

Hviid, Anders, Thorsen, Nicklas M, Valentiner-Branth, Palle et al.·BMJ (Clinical research ed.)·2020

This study examined whether the HPV vaccine (used to prevent cervical cancer) was linked to ME/CFS, complex regional pain syndrome, or POTS in over 1.3 million Danish girls and women. Researchers found no evidence that the vaccine caused these conditions—the rates of these illnesses were similar whether or not girls received the vaccine.

E2 ModerateCohortPEM not requiredObservational

Parasympathetic activity is reduced during slow-wave sleep, but not resting wakefulness, in patients with chronic fatigue syndrome.

Fatt, Scott J, Beilharz, Jessica E, Joubert, Michael et al.·Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine·2020

This study found that people with ME/CFS have reduced calming nervous system activity during deep sleep, compared to healthy people. This overactive state during sleep—even when the brain should be resting—is linked to poor sleep quality and feeling unwell. The findings suggest that the body's inability to fully relax during sleep may be a key problem in ME/CFS.

E2 ModerateCohortPEM requiredObservational

Characterization of Post-exertional Malaise in Patients With Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Stussman, Barbara, Williams, Ashley, Snow, Joseph et al.·Frontiers in neurology·2020

This study asked 43 ME/CFS patients about post-exertional malaise (PEM)—the worsening of symptoms that happens after physical or mental activity. Patients described three main types of symptoms that get worse after exertion: exhaustion, trouble thinking clearly, and muscle/nerve problems. Most patients said their symptoms started within 24 hours after activity and felt worst around 3 days later, and they needed complete rest to recover.

E2 ModerateCohortPEM unclearObservational

Cognitive Function Declines Following Orthostatic Stress in Adults With Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

van Campen, C Linda M C, Rowe, Peter C, Verheugt, Freek W A et al.·Frontiers in neuroscience·2020

This study found that people with ME/CFS experience significant problems with memory and thinking speed after their body has been stressed by a tilt test (a medical test that checks how the body handles position changes). Specifically, when tested right after the tilt procedure, patients made more mistakes on memory tasks and responded much more slowly compared to before the test. This suggests that the physical stress of orthostatic intolerance directly worsens cognitive problems in ME/CFS.

Cytokine profiling of extracellular vesicles isolated from plasma in myalgic encephalomyelitis/chronic fatigue syndrome: a pilot study.

Giloteaux, Ludovic, O'Neal, Adam, Castro-Marrero, Jesús et al.·Journal of translational medicine·2020

This study looked at tiny particles called extracellular vesicles (EVs) in the blood of ME/CFS patients and compared them to healthy people. The researchers found that ME/CFS patients had more of these small particles, and the chemical messengers (cytokines) inside and around them showed unusual patterns of interaction that differed from healthy controls. This suggests that immune system signaling may be working differently in ME/CFS.

Immune System

Autonomic Phenotypes in Chronic Fatigue Syndrome (CFS) Are Associated with Illness Severity: A Cluster Analysis.

Słomko, Joanna, Estévez-López, Fernando, Kujawski, Sławomir et al.·Journal of clinical medicine·2020

This study looked at 131 ME/CFS patients to see if different types of autonomic nervous system problems (the system that controls heart rate, blood pressure, and digestion) exist. Researchers found four distinct patterns: some patients had sympathetic overactivity with dysfunction, some had sympathetic symptoms alone, some had parasympathetic issues, and some had an imbalance between the two systems. Patients with sympathetic overactivity had the most severe symptoms and worst quality of life, while those with balanced autonomic function were younger, less fatigued, and reported better quality of life.

Functional gastrointestinal disorders are increased in joint hypermobility-related disorders with concomitant postural orthostatic tachycardia syndrome.

Tai, Foong Way David, Palsson, Olafur S, Lam, Ching Y et al.·Neurogastroenterology and motility·2020

This study looked at people with joint hypermobility disorders (including Ehlers-Danlos syndrome) to understand how often they experience stomach and digestive problems. The researchers found that those who also have POTS (a condition affecting heart rate and blood pressure when standing) had significantly more digestive issues than those without POTS. The digestive problems remained worse in the POTS group even after accounting for other conditions like chronic fatigue syndrome.