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. — CFSMEATLAS
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.
Edwards, Charles C, Byrnes, Julia M, Broussard, Camille A et al. · Journal of translational medicine · 2025 · DOI
Quick Summary
Researchers tested whether a simple arm position exercise (holding arms overhead and opening/closing fists) could trigger symptoms in ME/CFS patients who struggle with overhead activities. They found that nearly all patients (97%) developed arm symptoms like pain, numbness, or heaviness during the test, and 41% also experienced whole-body symptoms like dizziness, brain fog, or a racing heart. This suggests that some ME/CFS patients may have nerve compression issues in their shoulders or neck that worsen with certain arm positions.
Why It Matters
Many ME/CFS patients report struggling with everyday activities like combing hair or reaching overhead, but this symptom has been understudied. This research suggests that nerve compression syndromes—which may be diagnosable and potentially treatable—could contribute to these difficulties. Identifying this subgroup could lead to targeted interventions and better understanding of ME/CFS heterogeneity.
Observed Findings
97% (62/64) of patients developed local upper limb symptoms during the abbreviated one-minute EAST, with symptom onset at a median of 20 seconds.
41% (26/64) of patients reported systemic symptoms including lightheadedness (19%), generalized fatigue (11%), cognitive fogginess, racing heart, and nausea.
The sample was predominantly female (95%) and young (median age 18 years), with 58% having evidence of joint hypermobility.
78% of eligible patients had ME/CFS, 20% had idiopathic chronic fatigue with orthostatic intolerance, and 1 had idiopathic chronic fatigue without orthostatic intolerance.
Inferred Conclusions
Brachial plexus involvement or thoracic outlet syndrome-like symptoms are provokable in a substantial proportion of patients with ME/CFS and chronic fatigue who report difficulty with arms-overhead activities.
Systemic symptoms triggered by the EAST maneuver may indicate broader physiological dysfunction beyond local nerve compression, suggesting interconnected pathophysiology involving cardiovascular and neurological systems.
The abbreviated one-minute EAST is sufficient to provoke symptoms and may be a useful clinical screening tool for this patient subgroup.
Remaining Questions
How prevalent are brachial plexus or thoracic outlet syndrome symptoms in unselected ME/CFS populations who do not report overhead difficulties?
What This Study Does Not Prove
This study does not establish that brachial plexus compression or thoracic outlet syndrome is common in the broader ME/CFS population, as it only enrolled patients who already reported overhead difficulties. It cannot determine causation or distinguish whether nerve compression causes systemic symptoms or is simply associated with them. The findings apply specifically to symptomatic adolescents and young adults and may not generalize to all ME/CFS patients.
Do local and systemic symptoms during EAST predict treatment response or prognosis, and what is the clinical significance of systemic symptoms provoked by this maneuver?
What is the relationship between brachial plexus involvement, joint hypermobility, and orthostatic intolerance in ME/CFS?
Can the EAST help identify a distinct ME/CFS subgroup with specific underlying pathophysiology, and would targeted interventions (e.g., physical therapy, surgical approaches) benefit this group?