NeurologyPEM-relevant

Severe ME

30 studies in the atlas

Severe and very severe ME/CFS leaves patients largely or completely housebound or bedbound. This population is critically under-represented in research because of the real barriers severe illness creates — inability to travel to study sites, tolerate assessment protocols, or withstand sensory stimulation. As a result, most findings summarised across the atlas are drawn from samples that under-include the most affected patients.

What we know

Severe ME/CFS is recognized as a distinct clinical presentation in major guidelines, including NICE 2021
Patients with severe ME/CFS are frequently excluded from research due to inability to travel, tolerate assessment protocols, or withstand sensory stimulation
This creates a significant evidence gap: the most affected patients are the least studied

What remains uncertain

Whether severe ME/CFS represents a distinct phenotype or an extreme end of the same spectrum remains debated
Home-based and remote assessment approaches may be necessary to include severe patients in future research
Early management focused on avoiding PEM triggers may be relevant to preventing progression, though direct evidence is limited

What is emerging

How many ME/CFS patients are severe (estimates vary, and population-level data is sparse)
Risk factors for progression from moderate to severe
Optimal care models for bedbound patients
Long-term outcomes and recovery prospects in severe cases

Start here

E0 ConsensusPEM required

Myalgic encephalomyelitis/chronic fatigue syndrome and fibromyalgia - overlap, differences, and emerging insights.

Murovska, Modra, Krumina, Angelika, Araja, Diana et al.·Journal of translational medicine·2026

ME/CFS and fibromyalgia are two different but often overlapping illnesses that cause severe fatigue, pain, and other debilitating symptoms. While they share many similarities, ME/CFS has a distinctive feature called post-exertional malaise—where activity makes symptoms dramatically worse for hours or days—while fibromyalgia does not. This review shows that the two conditions have different immune system patterns and may require different treatment approaches.

Severe ME

What we know

What remains uncertain

What is emerging

Myalgic encephalomyelitis/chronic fatigue syndrome and fibromyalgia - overlap, differences, and emerging insights.

Research Momentum

Top Studies

Understanding Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Physical Fatigue Through the Perspective of Immunosenescence.

Does the effect of cognitive behavior therapy for chronic fatigue syndrome (ME/CFS) vary by patient characteristics? A systematic review and individual patient data meta-analysis.

Myalgic encephalomyelitis/chronic fatigue syndrome and fibromyalgia - overlap, differences, and emerging insights.

Causes of symptoms and symptom persistence in long COVID and myalgic encephalomyelitis/chronic fatigue syndrome.

Key Pathophysiological Role of Skeletal Muscle Disturbance in Post COVID and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Accumulated Evidence.

The persistence of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) after SARS-CoV-2 infection: A systematic review and meta-analysis.

Posttreatment Lyme disease syndrome and myalgic encephalomyelitis/chronic fatigue syndrome: A systematic review and comparison of pathogenesis.

Fatigue in ANCA-associated vasculitis (AAV) and systemic sclerosis (SSc): similarities with Myalgic encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). A critical review of the literature.

Cytokine signature associated with disease severity in chronic fatigue syndrome patients

Deep sequencing of BCR heavy chain repertoires in myalgic encephalomyelitis/chronic fatigue syndrome.

Deficient butyrate-producing capacity in the gut microbiome is associated with bacterial network disturbances and fatigue symptoms in ME/CFS.

What is the current NHS service provision for patients severely affected by chronic fatigue syndrome/myalgic encephalomyelitis? A national scoping exercise.

Being homebound with chronic fatigue syndrome: A multidimensional comparison with outpatients.

Natural history of severe chronic fatigue syndrome.

Cardiopulmonary Exercise Testing Reveals Functional Limitations and Work Disability in Severe Post-COVID-19 and ME/CFS Patients.

Risk factors for severe post-COVID condition in children, adolescents, and young adults.

Post-exertional malaise in Long COVID: subjective reporting versus objective assessment.

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

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

Contested and neglected: Social and medical marginalization in severe Chronic Fatigue Syndrome.

A suffering body, hidden away from others: The experience of being long-term bedridden with severe myalgic encephalomyelitis/chronic fatigue syndrome in childhood and adolescence.

[Facts and myths about chronic fatigue syndrome].

Ensuring the Voice of the Very Severely Affected Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Patient Is Heard in Research-A Research Model.

The Impact of Severe ME/CFS on Student Learning and K-12 Educational Limitations.

Life-Threatening Malnutrition in Very Severe ME/CFS.

Experiences of Living with Severe Chronic Fatigue Syndrome/Myalgic Encephalomyelitis.

Severe ME in Children.

An Overview of Severe Myalgic Encephalomyelitis.

Mitochondrial Dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

COVID-19 and post-infectious myalgic encephalomyelitis/chronic fatigue syndrome: a narrative review.