Evidence browser

Postural orthostatic tachycardia syndrome in patients of orthostatic intolerance symptoms: an ambispective study.

Chouksey, Dinesh, Rathi, Pankaj, Sodani, Ajoy et al.·AIMS neuroscience·2021

This study looked at patients who experience dizziness, fainting, or heart racing when standing up—symptoms of a condition called POTS (Postural Orthostatic Tachycardia Syndrome). Researchers tested 246 patients with these symptoms and confirmed POTS in 40 of them using a special tilt-table test. Most POTS patients experienced fainting, lightheadedness, and heart palpitations, and nearly half also had a related condition causing fainting.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Are Circulating Fibroblast Growth Factor 21 and N-Terminal Prohormone of Brain Natriuretic Peptide Promising Novel Biomarkers in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome?

Domingo, Joan Carles, Cordobilla, Begoña, Ferrer, Roser et al.·Antioxidants & redox signaling·2021

This study looked for new blood markers that could help identify ME/CFS by measuring two proteins called FGF21 and NT-proBNP in patients and healthy people. The researchers found that ME/CFS patients had significantly higher levels of both proteins and showed signs of increased inflammation and oxidative stress (cellular damage). These findings suggest these proteins might be useful tools for diagnosing ME/CFS or developing new treatments.

BiomarkersImmune System

The impact of COVID-19 stress on pain and fatigue in people with and without a central sensitivity syndrome.

Koppert, Tim Y, Jacobs, Johannes W G, Lumley, Mark A et al.·Journal of psychosomatic research·2021

This study looked at whether pandemic-related stress made pain and fatigue worse in people with central sensitivity syndromes (conditions like ME/CFS and fibromyalgia) compared to those without these conditions. Researchers surveyed Dutch participants before COVID-19 (2018) and during the pandemic peak (2020), measuring stress levels, symptom severity, and psychological flexibility (the ability to adapt to difficult emotions). Surprisingly, the study found that while stress and symptom severity were generally linked, having a central sensitivity syndrome did not make people more vulnerable to stress-related symptom worsening.

Pain and Sensitization

E2 ModerateCohortPEM not requiredCase-Control

Comparative Survey of People with ME/CFS in Italy, Latvia, and the UK: A Report on Behalf of the Socioeconomics Working Group of the European ME/CFS Research Network (EUROMENE).

Brenna, Elenka, Araja, Diana, Pheby, Derek F H·Medicina (Kaunas, Lithuania)·2021

Researchers surveyed people with ME/CFS in Italy, Latvia, and the UK to understand how the disease affects their lives and finances. They found that ME/CFS has a serious impact on income and quality of life across all three countries, and that graded exercise therapy (a treatment commonly used in the UK) did not work for patients. The study also revealed differences in how doctors diagnose and treat ME/CFS depending on which country people live in.

Rome IV Functional Gastrointestinal Disorders and Health Impairment in Subjects With Hypermobility Spectrum Disorders or Hypermobile Ehlers-Danlos Syndrome.

Lam, Ching Y, Palsson, Olafur S, Whitehead, William E et al.·Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association·2021

This study compared stomach and digestive problems in people with hypermobility disorders (including hypermobile Ehlers-Danlos Syndrome) to a general population. Nearly all people with these hypermobility conditions (98%) had one or more functional gastrointestinal disorder, compared to less than half of the comparison group. People with hypermobility disorders also experienced many other widespread body symptoms and used healthcare services much more frequently.

E2 ModerateCohortPEM requiredLongitudinal

COVID-19 Symptoms Over Time: Comparing Long-Haulers to ME/CFS.

Jason, Leonard A, Islam, Mohammed, Conroy, Karl et al.·Fatigue : biomedicine, health & behavior·2021

This study compared how symptoms change over time in people with long COVID versus people with ME/CFS. Researchers asked 278 long-haulers to describe their current symptoms and symptoms from about 5 months earlier, and compared them to 502 ME/CFS patients. They found that long-haulers generally improved over time, with better sleep and less post-exertional malaise, but their brain fog and memory problems actually got worse. Long-haulers started off more symptomatic than ME/CFS patients but became less symptomatic over time, though orthostatic symptoms (dizziness when standing) remained similar in both groups.

Post-Exertional Malaise

E2 ModerateCohortPEM unclearObservational

Possible involvement of the autonomic nervous system in cervical muscles of patients with myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS).

Matsui, Takayoshi, Hara, Kazuhiro, Iwata, Makoto et al.·BMC musculoskeletal disorders·2021

This study looked at 1,226 hospitalized ME/CFS patients who received daily physical therapy focused on neck muscles. About 55% of patients recovered from ME/CFS after this treatment, and those who recovered showed changes in pupil size suggesting their nervous system function improved. The findings suggest that neck muscle problems and nervous system dysfunction may be connected in ME/CFS.

The antinuclear antibody dense fine speckled pattern and possible clinical associations: An indication of a proinflammatory microenvironment.

Lundgren, Mia C, Sapkota, Smarika, Peterson, Daniel J et al.·Journal of immunological methods·2021

This study looked at 425 patients who tested positive for a specific antibody pattern called ANA-DFS on a common autoimmune screening test. The researchers wanted to understand what conditions this pattern is associated with. They found that while some patients had known autoimmune diseases, many others had chronic fatigue syndrome, fibromyalgia, skin problems, or allergic conditions, suggesting this antibody pattern may indicate a generally inflamed immune system rather than one specific disease.

Immune System

BiomarkersPost-Exertional Malaise

Machine Learning Detects Pattern of Differences in Functional Magnetic Resonance Imaging (fMRI) Data between Chronic Fatigue Syndrome (CFS) and Gulf War Illness (GWI).

Provenzano, Destie, Washington, Stuart D, Rao, Yuan J et al.·Brain sciences·2020

This study used brain imaging (fMRI) and computer learning programs to see if people with ME/CFS and Gulf War Illness have different patterns of brain activity during memory tasks, both before and after exercise. Researchers found that computer programs could correctly distinguish between the two conditions about 75-82% of the time, and identified about 30-33 brain regions that showed different activation patterns between the two groups. This suggests that ME/CFS and Gulf War Illness may have measurable biological differences in how the brain works during cognitive tasks and recovery from exertion.

E2 ModerateDiagnosticPEM not requiredMethods-Paper

Joint Assessment of Equilibrium and Neuromotor Function: A Validation Study in Patients with Fibromyalgia.

Lomas-Vega, Rafael, Rodríguez-Almagro, Daniel, Peinado-Rubia, Ana Belén et al.·Diagnostics (Basel, Switzerland)·2020

Researchers created and tested a new 20-question tool to measure balance problems and nerve-muscle coordination in people with fibromyalgia. The tool was tested on 62 fibromyalgia patients, 22 older adults, and 24 healthy people. The results show the tool works well at identifying balance issues in fibromyalgia patients, especially problems related to head movements.

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 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.

Post-Exertional Malaise

Hemodynamics during the 10-minute NASA Lean Test: evidence of circulatory decompensation in a subset of ME/CFS patients.

Lee, Jihyun, Vernon, Suzanne D, Jeys, Patricia et al.·Journal of translational medicine·2020

This study tested a simple 10-minute standing test called the NASA Lean Test in ME/CFS patients to understand heart and blood vessel problems that cause dizziness and weakness. Researchers found that patients who became sick more recently (within 4 years) showed signs of circulation problems during the test—their hearts beat faster and their blood pressure changed abnormally—while those sick for over 10 years showed fewer of these changes. The NASA Lean Test appears to be a useful tool that doctors can use to diagnose and monitor these circulation problems.

E2 ModerateBehavioralPEM unclearObservational

The presence of overlapping quality of life symptoms in primary antibody deficiency (PAD) and chronic fatigue syndrome (CFS).

Bansal, Rhea A, Tadros, Susan, Bansal, Amolak S·Allergy, asthma, and clinical immunology : official journal of the Canadian Society of Allergy and Clinical Immunology·2020

This study looked at whether people with primary antibody deficiency (PAD)—a condition where the immune system doesn't make enough protective proteins—also experience ME/CFS-like symptoms. Researchers sent questionnaires to over 680 PAD patients and found that about 16% of those who responded had symptoms matching ME/CFS criteria, which is much higher than the general population. The study also found that sleep problems, fatigue, anxiety, and low mood were very common in PAD patients.

Sleep

Guided graded Exercise Self-help for chronic fatigue syndrome: patient experiences and perceptions.

Cheshire, Anna, Ridge, Damien, Clark, Lucy et al.·Disability and rehabilitation·2020

This study looked at what patients experienced when they tried a guided exercise self-help program (GES) for ME/CFS. Some patients improved while others got worse. The researchers found that people who improved tended to be more motivated and faced fewer obstacles, while those who worsened had been sick longer, had other health conditions, and experienced symptom flare-ups from the exercise. The study suggests that the booklet alone isn't enough—patients need support from healthcare professionals who understand ME/CFS, especially during the difficult early weeks when improvements haven't started yet.

Post-Exertional Malaise

E2 ModerateBehavioralPEM not requiredCross-Sectional

Assessing functioning in adolescents with chronic fatigue syndrome: psychometric properties and factor structure of the School and Social Adjustment Scale and the Physical Functioning Subscale of the SF36.

Loades, M E, Vitoratou, S, Rimes, K A et al.·Behavioural and cognitive psychotherapy·2020

This study tested two short questionnaires to measure how much ME/CFS affects young people's daily activities—both at school and socially, and their physical abilities. The researchers found that both questionnaires work well, are reliable, and accurately capture the impact of the illness. These tools could help doctors and researchers better track how adolescents with ME/CFS are functioning over time.

Cognitive factors are associated with disability and pain, but not fatigue among physiotherapy attendees with persistent pain and fatigue.

Thompson, Dave P, Antcliff, Deborah, Woby, Steve R·Physiotherapy·2020

This study looked at how thoughts and beliefs affect pain, disability, and fatigue in people with long-term pain and exhaustion who were receiving physiotherapy. Researchers found that how confident people felt about managing their condition (self-efficacy) and how much they catastrophized (worried excessively) about their symptoms were linked to pain levels and disability, but surprisingly were not linked to fatigue levels.

Pain and Sensitization

Reductions in Cerebral Blood Flow Can Be Provoked by Sitting in Severe Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Patients.

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

This study tested whether a simple sitting test could detect blood flow problems in the brains of severely ill ME/CFS patients. Researchers found that 90% of severe ME/CFS patients had significant drops in brain blood flow when sitting upright—dropping by about 24.5%—while healthy people's brain blood flow barely changed. This sitting test was easier to tolerate than standard tilt tests and could be useful for diagnosing blood flow problems in the most severely affected patients.

E2 ModerateCohortPEM requiredCross-Sectional

The role of low-grade inflammation in ME/CFS (Myalgic Encephalomyelitis/Chronic Fatigue Syndrome) - associations with symptoms.

Jonsjö, Martin A, Olsson, Gunnar L, Wicksell, Rikard K et al.·Psychoneuroendocrinology·2020

This study looked at whether low-level inflammation in the blood is connected to ME/CFS symptoms like exhaustion after activity, brain fog, muscle pain, and flu-like illness. Researchers tested 53 ME/CFS patients for various inflammatory markers and found that several of these markers were associated with cognitive problems and pain, though they were surprisingly less connected to post-exertional fatigue. Interestingly, the connection between inflammation and symptoms was different for men and women in some cases.

BiomarkersImmune SystemCognitive ImpairmentPost-Exertional Malaise

Cerebral blood flow is reduced in ME/CFS during head-up tilt testing even in the absence of hypotension or tachycardia: A quantitative, controlled study using Doppler echography.

van Campen, C Linda M C, Verheugt, Freek W A, Rowe, Peter C et al.·Clinical neurophysiology practice·2020

This study measured blood flow to the brain in ME/CFS patients while they were tilted upright for 30 minutes. Researchers found that blood flow to the brain dropped significantly more in ME/CFS patients (24-29%) compared to healthy people (7%), even in patients whose heart rate and blood pressure stayed normal. The more symptoms patients experienced from standing, the greater their blood flow reduction.