MEA Research Roundup

ME/CFS and Long Covid Research: 21 – 27 February 2023 

The weekly research round-up includes recent publications about ME/CFS and Long Covid. We highlight the studies that have particularly caught our interest and follow these with the full list of publications together with their abstracts (summaries).


The ME Association maintains a comprehensive index of published research on ME/CFS and Long Covid that is free to use and updated weekly.

Audio Commentary by Dr Katrina Pears

ME/CFS Research Published 21 – 27 February 2023 

There’s been a mix of research this week, with four new ME/CFS studies but nineteen new Long Covid studies. 

A few small points of interest this week are in: 

  • Paper one (1) which looks at the terms/names used within ME/CFS research, revealing that Chronic Fatigue Syndrome is the predominant term used. Unfortunately, this is behind a paywall so we cannot read the full findings. 
  • Paper four (4) which is on anti-neutrophil cytoplasmic antibody associated vasculitis (AAV). It’s not the subject that we wanted to highlight but the format of the study. There are boxes which the authors clearly describe under the sub-headings: “evidence before this study, added value of this study and implications of all the available evidence”. I hope more journals that publish research adopt this style as it makes the study more accessible to readers. 

We have highlighted one of the ME/CFS studies in more detail below: 

Paper two (2) looks into establishing a marker for neurocognitive dysfunction. The study used the established Continuous Performance Test (CPT3™), which measures cognitive attention-related problems in just 14 minutes.  The research recruited 158 patients with ME/CFS and 67 Controls. There is an easy-to-understand list of all the features measured by the CPT3™ within the study, such as: sustained attention and response speed. 

ME/CFS patients were significantly different to controls in all measures the test analysed. Furthermore, cognitive impairment could be detected in all the main measures of the test, which are: inattentiveness, impulsivity, sustained attention, and vigilance. 

The results showed that ME/CFS patients had a worse indicator of inattentiveness, sustained attention, vigilance, impulsivity, slow reaction time, and more atypical scores. Interestingly, these measures are also associated with a likelihood of attention deficits disorders, like Attention Deficit Hyperactivity Disorder (ADHD). They found the most discriminative indicators of ME/CFS patients were Variability and Hit Reaction Time, which is a measure of response speed. 

There are a few points which could improve this study:  

  • It is unfortunate that there was a large imbalance of females to males in this study (145:13 in the ME/CFS group). The authors do not go into detail on the effect of gender other than that this significantly effects the cognitive function result.  
  • We do not know from this study if participants were recruited as there was concern over their cognitive function, i.e. they had reported brain fog at the clinic. 
  • There were no controlling factors for medication taken which could in turn affect cognitive function. 
  • It is difficult to interpret results from performance studies like this as participants know their function is being tested, it is hard to say how this will influence the results. 
  • Participants in this study were recruited from one clinic only, therefore, it would reinforce results to have comparisons across numerous clinics. 
  • It would also be interesting to see how a Long Covid group would compare. 
  • Furthermore, and most importantly, I think it is crucial to compare ME/CFS results to those with attention deficits disorders (due to the similar functioning shown in this study). It is important that these two groups can be clearly distinguished in a blinded test if this is to be used for diagnosis. 

Results from this study are not surprising as cognitive dysfunction is a well-known problem in ME/CFS, but this study differs in its size providing sound evidence for neurocognitive dysfunction in ME/CFS. Due to the methods used in this research, it would be hoped that this could be easily replicated and expanded. 

You may also be interested in reading this week Paper two (2) in the Long Covid reference section which shows structural brain changes in Long Covid. Dr Charles Shepherd has also provided a comment on this study. 

ME/CFS Research References and Abstracts  

1. Using Data Mining and Time Series to Investigate ME and CFS Naming Preferences 

Bhatia, S., & Jason, L. A.  

Journal of Disability Policy Studies, 0(0). 


There have been numerous iterations of naming convention specified for Myalgic Encephalomyelitis (ME) and Chronic Fatigue Syndrome (CFS). As health care turns to “big data” analytics to gain insights, the Google Trends database was mined to ascertain worldwide trends of public interest in several ME- and CFS-related search categories between 2004 and 2019.  

Time series analysis revealed that though “Chronic Fatigue Syndrome” remains the predominant search category in the ME and CFS field, the interest index declined at a rate of 2.77 per month during the 15-year study period.  

In the same time period, the interest index in “ME/CFS Hybrid” terms increased at a rate of 3.20 per month. Potential causal mechanisms for these trends and implications for patient sentiment analysis are discussed. 

2. The Conners Continuous Performance Test CPT3: Is it a reliable marker to predict neurocognitive dysfunction in Myalgic encephalomyelitis/chronic fatigue syndrome? 

Alegre-Martín J, Sanmartín-Sentañes R, Almirall M, Launois-Obregón P, Castro-Marrero J, Rodríguez-Urrutia A, Navarro-Sanchis JA and Ramos-Quiroga JA. 

Front. Psychol. 14:1127193 


Introduction: The main objective is to delimit the cognitive dysfunction associated with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/ CFS) in adult patients by applying the Continuous Performance Test (CPT3™). Additionally, provide empirical evidence on the usefulness of this computerized neuropsychological test to assess ME/CFS.  

Method: The final sample (n = 225; 158 Patients/67 Healthy controls) were recruited in a Central Sensitization Syndromes (CSS) specialized unit in a tertiary hospital. All participants were administered this neuropsychological test.  

Results: There were significant differences between ME/CFS and healthy controls in all the main measures of CPT3™. Mainly, patients had a worse indicator of inattentiveness, sustained attention, vigilance, impulsivity, slow reaction time, and more atypical T-scores, which is associated with a likelihood of having a disorder characterized by attention deficits, such as Attention Deficit Hyperactivity Disorder (ADHD). In addition, relevant correlations were obtained between the CPT3™ variables in the patient’s group. The most discriminative indicators of ME/ CFS patients were Variability and Hit Reaction Time, both measures of response speed.  

Conclusion: The CPT3™ is a helpful tool to discriminate neurocognitive impairments from attention and response speed in ME/CFS patients, and it could be used as a marker of ME/CFS severity for diagnosing or monitoring this disease. 

3. Health system support among patients with ME/CFS in Switzerland 

Tschopp R, König RS, Rejmer P, Paris DH.  

J Taibah Univ Med Sci. 2023 Jan 4;18(4):876-885. 


Objectives: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex chronic and debilitating multifactorial disease. Adequate patient care is challenged by poor knowledge among health care professionals and the historical misconception that the disease is psychological in nature. This study assessed the health-related challenges faced by patients with ME/CFS in Switzerland and examined whether they receive adequate health care. 

Methods: Quantitative and qualitative data were collected through a self-administered questionnaire between June and September of 2021, among 169 patients with ME/CFS in Switzerland. 

Results: The mean age at diagnosis was 38.8 years. Only one-third of ME/CFS affected children and youth were correctly diagnosed before their 18th birthday. The mean time from disease onset to diagnosis was 6.7 years, and patients had an average of 11.1 different appointments and 2.6 misdiagnoses.  

A poor diagnosis rate and insufficient disease knowledge among health professionals in Switzerland led 13.5% of the patients to travel abroad to seek a diagnosis. Most patients (90.5%) were told at least once that their symptoms were psychosomatic. Swiss patients expressed high dissatisfaction with the health system and indicated that physicians lacked knowledge regarding ME/CFS. Therapies prescribed by physicians or tried by patients, as well as their perceived efficacy, were described.  

Graded Exercise Therapy (GET) was perceived as harmful by patients, whereas pacing, complementary/alternative medicine, and dietary supplements and medications to alleviate symptoms were reported to be helpful to varying degrees. 

Conclusion: This study highlights that poor disease knowledge among health care providers in Switzerland has led to high patient dissatisfaction, and delays in ME/CFS diagnoses and prescription of inappropriate therapies, thus adding to patient distress and disease burden. 

4. Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and fibromyalgia: PR3-versus MPO-ANCA-associated vasculitis, an exploratory cross-sectional study 

Charmaine van Eeden, Naima Mohazab, Desiree Redmond, Elaine Yacyshyn, Alison Clifford, Anthony S. Russell, Mohammed S. Osman, and Jan Willem Cohen Tervaer. 

The Lancet Regional Health – Americas 2023;20: 100460. 


Background: Persistent fatigue is a common complaint in ANCA-vasculitis (AAV) patients and has a profound impact on patient’s quality of life. The symptoms associated with this fatigue mirror those found in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and fibromyalgia.  

Etiologic and pathophysiologic differences exist between PR3- and MPO-ANCA disease, yet differences in their fatigue manifestations have not been well researched. We compared fatigue and its associations in healthy controls, AAV patients and fibromyalgia controls.  

Methods: The Canadian consensus criteria were used for ME/CFS diagnosis, and American College of Rheumatology criteria for fibromyalgia diagnosis. Factors such as cognitive failure, depression, anxiety, and sleep disturbances were assessed by patient reported questionnaires. Clinical factors such as BVAS, vasculitis damage index, CRP and BMI were also collected.  

Findings: Our AAV cohort comprised 52 patients, with a mean age of 44.7 (20–79), 57% (30/52) of the patients were female. We found 51.9% (27/52) of patients fulfilled the diagnostic criteria for ME/CFS, with 37% (10/27) of those having comorbid fibromyalgia. Rates of fatigue were higher in MPO-ANCA patients, than in PR3-ANCA patients, and their symptoms were more similar to the fibromyalgia controls.  

Fatigue in PR3-ANCA patients was related to inflammatory markers. These differences may be due to the varied pathophysiology of the PR3- and MPO-ANCA serotypes.  

Interpretation: A large proportion of AAV patients suffer from debilitating fatigue consequential enough to meet the diagnostic criteria for ME/CFS. Fatigue associations were not the same between PR3- and MPO-ANCA patients, suggesting that the underlying mechanisms may be different. Future studies should consider ANCA serotype, as further research may inform different clinical treatment strategies for AAV patients suffering from ME/CFS. 

Long-COVID Research References  

  1. Gastrointestinal and Hepatobiliary Symptoms and Disorders with Long (Chronic) COVID Infection 
  1. Structural brain changes in patients with post-COVID fatigue: a prospective observational study 
  1. Cardiac abnormalities in Long COVID 1-year post-SARS-CoV-2 infection 
  1. Cohort profile: A Québec-based plasma donor biobank to study COVID-19 immunity (PlasCoV) 
  1. Organ and cell-specific biomarkers of Long-COVID identified with targeted proteomics and machine learning 
  1. A Systematic Review & Metaethnography of the lived experiences of long COVID patients  
  1. Identification of the pathogenic relationship between Long COVID and Alzheimer's disease by bioinformatics methods 
  1. High Prevalence of Alternative Diagnoses in Children and Adolescents with Suspected Long COVID—A Single Center Cohort Study 
  1. Cystatin-c May Indicate Subclinical Renal Involvement, While Orosomucoid Is Associated with Fatigue in Patients with Long-COVID Syndrome 
  1. Prevalence and clinical features of long COVID from omicron infection in children and adults 
  1. Potential of Black Seeds (Nigella Sativa) in the Management of Long COVID or Post-acute Sequelae of COVID-19 (PASC) and Persistent COVID-19 Symptoms – An Insight 
  1. Management of long-COVID-19 patients with sleep disorders: practical advice to general practitioners 
  1. Assessment of Exercise Capacity of Individuals with Long COVID: A Cross-sectional Study 
  1. Pain and Clinical Presentation: A Cross-Sectional Study of Patients with New-Onset Chronic Pain in Long-COVID-19 Syndrome 
  1. Social Stigma, Mental Health, Stress, and Health-Related Quality of Life in People with Long COVID 
  1. Long COVID: An unpredicted multisystem syndrome of COVID-19 disease 
  1. Predictors of Long-COVID-19 and its Impact on Quality of Life: Longitudinal Analysis at 3, 6 and 9 Months after Discharge from a Portuguese Centre 
  1. Investigating brain cortical activity in patients with post-COVID-19 brain fog 
  1. Persistent SARS-CoV-2 Infection, EBV, HHV-6 and Other Factors May Contribute to Inflammation and Autoimmunity in Long COVID 

Dr Katrina Pears,
Research Correspondent.
The ME Association.

Dr Katrina Pears - MEA Research Correspondent
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