Charlotte Stephens, Research Correspondent, ME Association.
We show below brief summaries of the research studies about ME/CFS that have been published in the last week, followed by the abstracts from those studies.
All research relating to ME/CFS can be located in the ME Association: Index of ME/CFS Published Research.
This extensive library of research is updated at the end of every month, and is correct to the end of August 2020. It is a free resource available to anyone.
The Index provides an A-Z of published research studies and selected key documents and articles, listed by subject matter, on myalgic encephalomyelitis, myalgic encephalopathy, and/or chronic fatigue syndrome (ME/CFS).
You can use it to easily locate and read any research in a particular area that you might be interested in, e.g. epidemiology, infection, neurology, post-exertional malaise etc.
You can also find the Research Index in the Research section of the website together with a list of Research Summaries that provide lay explanations of the more important and interesting work that has been published to date.
ME/CFS Research Published 28 August – 03 September 2020
This week, 5 new research studies have been published, highlights include:
- Two reviews from separate research groups at Bristol University and from Australia looking at neuroimaging studies in ME/CFS. Both reviews discovered that the most consistent finding was increased activations and additional brain area recruitment during cognitive tasks, measured using functional MRI imaging (investigating working memory, attention, reward and motivation, sensory information processing and emotional conflict).
- Researchers from Sweden hypothesised that hypermobility, intracranial hypertension (increased pressure in the brain), and craniocervical obstructions (abnormalities in the spinal column in the neck which may affect the flow of cerebrospinal fluid to and from the brain) may be common in ME/CFS patients and may explain many of the symptoms.
They looked at questionnaires, clinical assessments and MRI’s taken from 229 ME/CFS patients. Hypermobility was identified in 50% of participants. MRI of the brain was performed on 205 participants, of which 83% had signs of possible Intracranial hypertension (IH). MRI of the cervical spine was performed on 125 participants, of which 80% had craniocervical obstructions.
The researchers concluded that, compared to a general population, there is a large over-representation of hypermobility, signs of IH, and craniocervical obstructions in a proportion of ME/CFS patients. They recommended the need for future studies in this area and if their findings are confirmed, this could lead to new diagnostic and therapeutic approaches.
- Researchers from Australia conducted an economic impact study on ME/CFS and discovered it was potentially costing the Australian economy $14.5 billion (approx. £8 billion).
ME/CFS Research References and Abstracts
1. Almutairi B et al. (2020)
Using structural and functional MRI as a neuroimaging technique to investigate chronic fatigue syndrome/myalgic encephalopathy: a systematic review.
BMJ Open 10 (8).
Objective: This systematic review aims to synthesise and evaluate structural MRI (sMRI) and functional MRI (fMRI) studies in chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME).
Methods: We systematically searched Medline and Ovid and included articles from 1991 (date of Oxford diagnostic criteria for CFS/ME) to first April 2019. Studies were selected by predefined inclusion and exclusion criteria. Two reviewers independently reviewed the titles and abstracts to determine articles for inclusion, full text and quality assessment for risk of bias.
Results: sMRI studies report differences in CFS/ME brain anatomy in grey and white matter volume, ventricular enlargement and hyperintensities. Three studies report no neuroanatomical differences between CFS/ME and healthy controls. Task-based fMRI investigated working memory, attention, reward and motivation, sensory information processing and emotional conflict. The most consistent finding was CFS/ME exhibited increased activations and recruited additional brain regions. Tasks with increasing load or complexity produced decreased activation in task-specific brain regions.
Conclusions: There were insufficient data to define a unique neural profile or biomarker of CFS/ME. This may be due to inconsistencies in finding neuroanatomical differences in CFS/ME and the variety of different tasks employed by fMRI studies. But there are also limitations with neuroimaging.
All brain region specific volumetric differences in CFS/ME were derived from voxel-based statistics that are biased towards group differences that are highly localised in space. fMRI studies demonstrated both increases and decreases in activation patterns in CFS/ME, this may be related to task demand.
However, fMRI signal cannot differentiate between neural excitation and inhibition or function-specific neural processing. Many studies have small sample sizes and did not control for the heterogeneity of this clinical population.
We suggest that with robust study design, subgrouping and larger sample sizes, future neuroimaging studies could potentially lead to a breakthrough in our understanding of the disease.
2. Bragee B et al. (2020)
Signs of Intracranial Hypertension, Hypermobility, and Craniocervical Obstructions in Patients With Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.
Frontiers in Neurology 11.
The pathophysiology of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is unknown. In this study, we test the hypothesis that hypermobility, signs of intracranial hypertension (IH), and craniocervical obstructions may be over-represented in patients with ME/CFS and thereby explain many of the symptoms.
Our study is a retrospective, cross-sectional study, performed at a specialist clinic for referred patients with severe ME/CFS as defined by the Canada Consensus Criteria. The first 272 patients with ME/CFS were invited to participate, and 229 who provided prompt informed consent were included.
Hypermobility was assessed using the Beighton Score. IH was assessed indirectly by the quotient of the optic nerve sheet diameter (ONSD)/eyeball transverse diameter on both sides as measured on magnetic resonance imaging (MRI) of the brain. We also included assessment of cerebellar tonsil position in relation to the McRae line, indicating foramen magnum. Craniocervical obstructions were assessed on MRI of the cervical spine. Allodynia was assessed by quantitative sensory testing (QST) for pain in the 18 areas indicative of fibromyalgia syndrome (FMS). A total of 190 women, mean age 45 years, and 39 males, mean age 44 years, were included.
Hypermobility was identified in 115 (50%) participants. MRI of the brain was performed on 205 participants of whom 112 (55%) had an increased ONSD and 171 (83%) had signs of possible IH, including 65 (32%) who had values indicating more severe states of IH. Cerebellar tonsils protruding under the McRae line into the foramen magnum were identified in 115 (56%) of the participants.
MRI of the cervical spine was performed on 125 participants of whom 100 (80%) had craniocervical obstructions. Pain at harmless pressure, allodynia, was found in 96% of the participants, and FMS was present in 173 participants or 76%. Compared to a general population, we found a large overrepresentation of hypermobility, signs of IH, and craniocervical obstructions.
Our hypothesis was strengthened for future studies on the possible relation between ME/CFS symptoms and hypermobility, IH, and craniocervical obstructions in a portion of patients with ME/CFS. If our findings are confirmed, new diagnostic and therapeutic approaches to this widespread neurological syndrome should be considered.
3. Close S et al. (2020)
The Economic Impacts of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in an Australian Cohort.
Frontiers in Public Health 8: 420.
Objectives: This study aims to estimate direct and indirect health economic costs associated with government and out-of-pocket (OOP) expenditure based on health care service utilization and lost income of participants and carers, as reported by Australian Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) patient survey participants.
Design: A cost of illness study was conducted to estimate Australian cost data for individuals with a ME/CFS diagnosis as determined by the Canadian Consensus Criteria (CCC), International Consensus Criteria (ICC), and the 1994 CDC Criteria (Fukuda).
Setting and participants: Survey participants identified from a research registry database provided self-report of expenditure associated with ME/CFS related healthcare across a 1-month timeframe between 2017 and 2019.
Main outcome measures: ME/CFS related direct annual government health care costs, OOP health expenditure costs, indirect costs associated with lost income and health care service use patterns.
Results: The mean annual cost of health care related expenditure and associated income loss among survey participants meeting diagnostic criteria for ME/CFS was estimated at $14.5 billion.
For direct OOP and Government health care expenditure, high average costs were related to medical practitioner attendance, diagnostics, natural medicines, and device expenditure, with an average attendance of 10.6 referred attendances per annum and 12.1 GP visits per annum related specifically to managing ME/CFS.
Conclusions: The economic impacts of ME/CFS in Australia are significant. Improved understanding of the illness pathology, diagnosis, and management, may reduce costs, improve patient prognosis and decrease the burden of ME/CFS in Australia.
4. Shan Z et al. (2020)
Neuroimaging characteristics of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): a systematic review.
Journal of Translational Medicine 18 (1): 335.
Background: Since the 1990s, neuroimaging has been utilised to study Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), a debilitating illness with unknown aetiology.
While brain abnormalities in ME/CFS have been identified, relatively little is known regarding which specific abnormalities are consistently observed across research groups and to what extent the observed abnormalities are reproducible.
Method: To identify consistent and inconsistent neuroimaging observations in ME/CFS, this retrospective and systematic review searched for studies in which neuroimaging was used to investigate brain abnormalities in ME/CFS in Ovid MEDLINE, PubMed (NCBI), and Scopus from January 1988 to July 2018. A qualitative synthesis of observations was performed to identify brain abnormalities that were consistently and inconsistently reported.
Results: 63 full-text articles were included in the synthesis of results from 291 identified papers. Additional brain area recruitment for cognitive tasks and abnormalities in the brain stem are frequent observations in 11 and 9 studies using different modalities from different research teams respectively.
Also, sluggish blood oxygenation level-dependent (BOLD) signal responses to tasks, reduced serotonin transporters, and regional hypometabolism are consistent observations by more than two research teams.
Single observations include abnormal brain tissue properties, regional metabolic abnormalities, and association of brain measures with ME/CFS symptoms. Reduced resting cerebral blood flow and volumetric brain changes are inconsistent observations across different studies.
Conclusion: Neuroimaging studies of ME/CFS have frequently observed additional brain area recruitment during cognitive tasks and abnormalities in the brain stem.
The frequent observation of additional brain area recruitment and consistent observation of sluggish fMRI signal response suggest abnormal neurovascular coupling in ME/CFS.
5. Van Deuren S et al. (2020)
Fatigue-Related Cognitive-Behavioral Factors in Survivors of Childhood Cancer: Comparison with Chronic Fatigue Syndrome and Survivors of Adult-Onset Cancer.
Journal of Adolescent and Young Adult Oncology [Epub ahead of print].
Purpose: Cancer-related fatigue is a burdensome late effect of cancer treatment. A pilot study showed the effectiveness of cognitive-behavioral therapy (CBT) in fatigued survivors of childhood cancer (CCS).
The aim of this study is to investigate whether the six cognitive-behavioral factors that are addressed during CBT differ in CCS compared with patients with chronic fatigue syndrome (CFS) and survivors of adult-onset cancer (ACS). Levels of self-esteem, optimism, and depressive symptoms, variables that are also related to fatigue, were also compared between groups.
Methods: Retrospective analyses were performed on 34 CCS (ages 11–42 years), 102 patients with CFS, and 95 ACS who were referred for evaluation of severe fatigue. Fatigue severity, possible cognitive-behavioral fatigue maintaining factors, depressive symptoms, self-esteem, and optimism were assessed using questionnaires and actigraphy.
Results: No significant differences were found in the factors coping with the experience of having had cancer, fear of cancer recurrence, physical activity, and in levels of self-esteem and optimism. CCS attributed their fatigue significantly more often to psychosocial causes and reported fewer problems in sleep/rest compared with patients with CFS. Compared with ACS, CCS reported significantly more social support, more problems in sleep/rest, and more depressive symptoms.
Conclusions: There is substantial overlap in cognitive-behavioral factors that can maintain fatigue between CCS and CFS patients or ACS. Also differences were found regarding attribution of fatigue, the sleep/rest pattern, social support, and depressive symptoms that might have clinical implications when CBT for fatigue is provided to CCS.
The ME Association
Please support our vital work
We are a national charity working hard to make the UK a better place for people whose lives have been devastated by an often-misunderstood neurological disease.
If you would like to support our efforts and ensure we are able to inform, support, advocate and invest in biomedical research, then please donate today.
Just click the image opposite or visit our JustGiving page for one-off donations or to establish a regular payment. You can even establish your own fundraising event.
ME Association Registered Charity Number 801279