AutonomicPEM-relevant

Autonomic Nervous System

345 studies in the atlas

Autonomic dysfunction is among the most consistently reported abnormalities in ME/CFS. Studies document heart rate variability impairments, orthostatic intolerance, postural orthostatic tachycardia syndrome (POTS), and abnormal blood pressure regulation across patient populations. These findings reflect dysregulation of the autonomic nervous system — the network governing heart rate, blood pressure, and circulatory response to positional change. Research explores links between autonomic dysfunction, endothelial dysfunction, vascular tone, and impaired cerebral blood flow, suggesting a systemic vascular component to ME/CFS pathophysiology.

What we know

Orthostatic intolerance is reported by a majority of ME/CFS patients and can be demonstrated with tilt table testing
POTS has been documented in ME/CFS cohorts, particularly among younger patients
Reduced cerebral blood flow during upright posture has been observed in multiple studies
Altered heart rate variability has been reported, suggesting sympathetic-parasympathetic imbalance

What remains uncertain

Small fiber neuropathy, found in a subset of patients, may contribute to autonomic symptoms
Autoantibodies against adrenergic receptors have been reported in small studies and could play a role, though replication is needed
Blood volume reduction may contribute to orthostatic intolerance in some patients
The relationship between autonomic dysfunction and PEM is likely bidirectional, but the mechanisms are not well mapped

What is emerging

Whether autonomic dysfunction in ME/CFS is a primary driver of symptoms or a secondary consequence of other processes
Which assessment protocols are most appropriate for this patient population
Whether specific autonomic subtypes predict treatment response
Whether interventions such as vagus nerve stimulation or autonomic retraining have measurable benefit in ME/CFS specifically

Start here

E0 ConsensusPEM unclear

Systematic literature review: treatment of postural orthostatic tachycardia syndrome (POTS).

Schiweck, Nicole, Langer, Katharina, Maier, Andrea et al.·Clinical autonomic research : official journal of the Clinical Autonomic Research Society·2026

This review examined treatments for POTS (postural orthostatic tachycardia syndrome), a condition where your heart rate jumps significantly when you stand up, causing dizziness and fatigue. POTS is common in people with ME/CFS. The researchers looked at 45 studies and found that simple first-line treatments like compression socks, physical training, extra salt, and a vagus nerve stimulation device may help, while certain medications like ivabradine and beta-blockers also showed promise in some studies.

Research Momentum

340 publications over 34 years. Recent trend: steady (19/year over the last 3 years).

Top Studies

60 of 345, sorted by evidence level and year

E0ReviewPEM ?

Mapping cerebral blood flow in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and orthostatic intolerance: insights from a systematic review.

2025

Christopoulos, Elena M et al.·Journal of translational medicine

E0ReviewPEM ?

Objective sleep measures in chronic fatigue syndrome patients: A systematic review and meta-analysis.

2023

Mohamed, Abdalla Z et al.·Sleep medicine reviews·Meta-Analysis

E0ReviewPEM ?

A systematic review of neurological impairments in myalgic encephalomyelitis/ chronic fatigue syndrome using neuroimaging techniques.

2020

Maksoud, Rebekah et al.·PloS one·Systematic-Review

Autonomic Nervous System

What we know

What remains uncertain

What is emerging

Systematic literature review: treatment of postural orthostatic tachycardia syndrome (POTS).

Research Momentum

Top Studies

Mapping cerebral blood flow in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and orthostatic intolerance: insights from a systematic review.

Objective sleep measures in chronic fatigue syndrome patients: A systematic review and meta-analysis.

A systematic review of neurological impairments in myalgic encephalomyelitis/ chronic fatigue syndrome using neuroimaging techniques.

Evidence of altered cardiac autonomic regulation in myalgic encephalomyelitis/chronic fatigue syndrome: A systematic review and meta-analysis.

Cognitive Dysfunction in Chronic Fatigue Syndrome: a Review of Recent Evidence.

Malfunctioning of the autonomic nervous system in patients with chronic fatigue syndrome: a systematic literature review.

Dysautonomias: clinical disorders of the autonomic nervous system.

Chronic fatigue syndrome: what role does the autonomic nervous system play in the pathophysiology of this complex illness?

Systematic literature review: treatment of postural orthostatic tachycardia syndrome (POTS).

[Post-COVID: An inventory focusing on the key complaints PEM and POTS].

Systematic review: digital biomarkers of fatigue in chronic diseases.

Autoimmune Autonomic Neuropathy: From Pathogenesis to Diagnosis.

Understanding, diagnosing, and treating Myalgic encephalomyelitis/chronic fatigue syndrome - State of the art: Report of the 2nd international meeting at the Charité Fatigue Center.

Reduced Heart Rate Variability in Patients With Medically Unexplained Physical Symptoms: A Meta-Analysis of HF-HRV and RMSSD.

Sympathetic nervous system dysfunction in fibromyalgia, chronic fatigue syndrome, irritable bowel syndrome, and interstitial cystitis: a review of case-control studies.

Heart rate variability in patients with fibromyalgia and patients with chronic fatigue syndrome: a systematic review.

[Etiology of functional somatic syndromes].

As good as it gets? A meta-analysis and systematic review of methodological quality of heart rate variability studies in functional somatic disorders.

Central nervous system abnormalities in fibromyalgia and chronic fatigue syndrome: new concepts in treatment.

Autonomic nervous system derangement in fibromyalgia syndrome and related disorders.

Controlled exposures to volatile organic compounds in sensitive groups.

Chronic pain and fatigue syndromes: overlapping clinical and neuroendocrine features and potential pathogenic mechanisms.

Decreased Heart Rate Variability Is Associated with Increased Fatigue Across Different Medical Populations: A Systematic Review.

Heart rate variability in patients with somatic symptom disorders and functional somatic syndromes: A systematic review and meta-analysis.

Postural tachycardia syndrome and other forms of orthostatic intolerance in Ehlers-Danlos syndrome.

Effects of acupuncture and moxibustion on heart rate variability in chronic fatigue syndrome patients: Regulating the autonomic nervous system in a clinical randomized controlled trial.

Assessing fatigue in myalgic encephalomyelitis/chronic fatigue syndrome patients before and after treatment with bright light therapy: A prospective randomized controlled crossover study.

Compression Stockings Improve Cardiac Output and Cerebral Blood Flow during Tilt Testing in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) Patients: A Randomized Crossover Trial.

Cerebral blood flow is reduced in ME/CFS during head-up tilt testing even in the absence of hypotension or tachycardia

Acupuncture and Moxibustion have Different Effects on Fatigue by Regulating the Autonomic Nervous System: A Pilot Controlled Clinical Trial.

Ubiquinol-10 supplementation improves autonomic nervous function and cognitive function in chronic fatigue syndrome.

Effects of low-dose clonidine on cardiovascular and autonomic variables in adolescents with chronic fatigue: a randomized controlled trial.

Home orthostatic training in chronic fatigue syndrome--a randomized, placebo-controlled feasibility study.

Combination therapy with hydrocortisone and fludrocortisone does not improve symptoms in chronic fatigue syndrome: a randomized, placebo-controlled, double-blind, crossover study.

Fludrocortisone acetate to treat neurally mediated hypotension in chronic fatigue syndrome: a randomized controlled trial.

A preliminary placebo-controlled crossover trial of fludrocortisone for chronic fatigue syndrome.

The Use of Heart Rate Variability-Biofeedback (HRV-BF) as an Adjunctive Intervention in Chronic Fatigue Syndrome (CSF/ME) in Long COVID: Results of a Phase II Controlled Feasibility Trial.

Understanding concussion in myalgic encephalomyelitis/chronic fatigue syndrome: Findings from the 2023 National Health Interview study.

Provocation of brachial plexus and systemic symptoms during the elevated arm stress test in individuals with myalgic encephalomyelitis/chronic fatigue syndrome or idiopathic chronic fatigue.

Diagnosis of chronic fatigue syndrome using beat-to-beat autonomic measurements.

Awareness and Perception of Myalgic Encephalomyelitis and Chronic Fatigue Syndrome Among Pain Specialists: A Questionnaire-Based Study.

Low Vasopressin in Myalgic Encephalomyelitise/Chronic Fatigue Syndrome.

Autonomic Dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Findings from the Multi-Site Clinical Assessment of ME/CFS (MCAM) Study in the USA.

The Relation Between Cardiac Output and Cerebral Blood Flow in ME/CFS Patients with a POTS Response During a Tilt Test.

Two Different Hemodynamic Responses in ME/CFS Patients with Postural Orthostatic Tachycardia Syndrome During Head-Up Tilt Testing.

Plasma Neurofilament Light Chain: A Potential Biomarker for Neurological Dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Do people with ME/CFS and joint hypermobility represent a disease subgroup? An analysis using registry data.

The Cardiac Output-Cerebral Blood Flow Relationship Is Abnormal in Most Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Patients with a Normal Heart Rate and Blood Pressure Response During a Tilt Test.

Phenylephrine alters phase synchronization between cerebral blood velocity and blood pressure in ME/CFS with orthostatic intolerance.

Effects of whole-body cryotherapy and static stretching are maintained 4 weeks after treatment in most patients with chronic fatigue syndrome.

Repetitive transcranial magnetic stimulation ameliorates symptoms in patients with myalgic encephalomyelitis (chronic fatigue syndrome).

Comparison of a 20 degree and 70 degree tilt test in adolescent myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) patients.

Skin Temperature Circadian Rhythms and Dysautonomia in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: The Role of Endothelin-1 in the Vascular Tone Dysregulation.

Autonomic Nervous System Regulation Effects of Epipharyngeal Abrasive Therapy for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Associated With Chronic Epipharyngitis.

Orthostatic chronotropic incompetence in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Worsening Symptoms Is Associated with Larger Cerebral Blood Flow Abnormalities during Tilt-Testing in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Orthostatic Intolerance and Chronotropic Incompetence in Patients With Myalgic Encephalomyelitis or Chronic Fatigue Syndrome.

Influence of end-tidal CO2 on cerebral blood flow during orthostatic stress in controls and adults with myalgic encephalomyelitis/chronic fatigue syndrome.

Psychogenic Pseudosyncope: Real or Imaginary? Results from a Case-Control Study in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) Patients.