Neurovascular dysfunction is a core, increasingly well-supported feature of Myalgic Encephalomyelitis (M.E.)
Neurovascular dysfunction is a core, increasingly well-supported feature of Myalgic Encephalomyelitis (M.E.), especially when M.E. is understood as a neurological disease rather than a fatigue condition.
What “Neurovascular” means
* Neuro-: the brain, spinal cord, and autonomic nervous system
* Vascular: blood vessels, blood flow, oxygen and nutrient delivery
Neurovascular dysfunction means the brain and nervous system are not getting or regulating blood flow properly, particularly during cognitive effort, upright posture, or exertion.
What goes wrong in M.E.
1. Impaired cerebral blood flow (CBF)
Multiple studies show reduced blood flow to the brain, especially:
* When upright (orthostatic stress)
* During cognitive tasks
* After exertion
This occurs even without meeting criteria for classic POTS, indicating a broader vascular control problem.
What this causes:
* Cognitive slowing and “brain fog”
* Word-finding difficulty
* Light and sound sensitivity
* Head pressure or headaches
* Reduced consciousness tolerance (needing to lie down)
2. Faulty blood vessel regulation
In healthy people, blood vessels:
* Dilate when tissues need oxygen
* Constrict appropriately to maintain pressure
In M.E., this regulation is unstable or delayed:
* Blood vessels may fail to dilate
* Or constrict at the wrong time
* Leading to oxygen extraction problems
This has been demonstrated in invasive cardiopulmonary exercise testing (iCPET) and vascular imaging studies.
3. Endothelial dysfunction
The endothelium (lining of blood vessels) plays a key role in:
* Nitric oxide signaling
* Immune-vascular communication
* Microcirculation
Evidence suggests endothelial signaling in M.E. is impaired, contributing to:
* Poor microvascular blood flow
* Tissue hypoxia despite normal oxygen levels in blood
* Exercise intolerance that cannot be explained by deconditioning
4. Neurovascular uncoupling
Normally, when a brain area becomes active, blood flow increases to match demand.
In M.E., this coupling appears broken:
* Cognitive effort does not reliably increase local blood flow
* The brain is forced to function in a relative energy-deficient state
This helps explain why:
* Thinking can cause post-exertional symptom exacerbation
* Cognitive PEM can be as severe as physical PEM
5. Interaction with autonomic dysfunction
Neurovascular dysfunction overlaps heavily with:
* Orthostatic intolerance
* Dysautonomia
* Abnormal heart rate and blood pressure control
But it is not limited to POTS and persists even when heart rate looks “normal.”
Why this matters clinically
Neurovascular dysfunction helps explain:
* Why patients worsen when upright
* Why exertion causes delayed crashes
* Why imaging can appear “normal” at rest
* Why symptoms are neurological, not psychological
It also explains why rest, recumbency, and pacing are not coping strategies—but physiological necessities.
Severe and Very Severe M.E.
In severe M.E., neurovascular impairment is often:
* More profound
* Present even at rest
* Associated with hypersensitivity, altered consciousness, and inability to tolerate minimal stimulation
This aligns with findings of marked cerebral hypoperfusion in bedbound patients.
Neurovascular dysfunction in M.E. means the brain is chronically under-supplied and poorly regulated, especially under stress. This is a biological, measurable failure of blood flow control, not a disorder of belief, effort, or mood.
https://pmc.ncbi.nlm.nih.gov/articles/PMC8607226
https://journal.chestnet.org/…/S0012-3692(22…/abstract
