Neuroimmune Dysfunction in Myalgic Encephalomyelitis (M.E.)

Purpose

This page explains neuroimmune dysfunction in Myalgic Encephalomyelitis (M.E.), focusing on how abnormalities in the brain, immune system, autonomic nervous system, and circulation interact to produce the characteristic symptoms of the disease.

Key Points

1. Neuroimmune Dysfunction Overview

• M.E. involves a disruption between the nervous system and immune system
• The body becomes stuck in a chronic “sick state”
• This dysfunction affects energy production, circulation, and overall regulation

2. Brain Inflammation (Neuroinflammation)

• Activation of immune cells in the brain (microglia)
• Leads to symptoms such as:
  • Cognitive impairment (“brain fog”)
  • Sensory sensitivity (light, sound, touch)
  • Head pressure or headaches
  • Unrefreshing sleep

3. Immune System Dysregulation

• The immune system remains in a constant activated state
• Common findings include:
  • Elevated inflammatory cytokines
  • Viral reactivation (e.g. EBV, HHV-6)
  • Reduced natural killer (NK) cell function
• Contributes to:
  • Flu-like symptoms
  • Fatigue and malaise
  • Post-exertional symptom worsening

4. Autonomic Nervous System Dysfunction

• The autonomic nervous system (ANS) becomes unstable
• Affects regulation of:
  • Heart rate
  • Blood pressure
  • Digestion
  • Temperature
• Results from immune-related nerve dysfunction
• Leads to widespread dysregulation across the body

5. Cardiovascular and Circulatory Problems

Orthostatic Intolerance

• Difficulty maintaining blood flow when upright
• Includes:
  • POTS (rapid heart rate)
  • Neurally mediated hypotension (blood pressure drops)
• Symptoms:
  • Dizziness
  • Weakness
  • Nausea
  • Cognitive worsening when standing
  • Improvement when lying down

Reduced Cerebral Blood Flow

• Lower blood flow to the brain, especially when upright
• Contributes to:
  • Brain fog
  • Sensory overload
  • Post-exertional symptom worsening

Cardiac and Vascular Changes

• Some patients show:
  • Reduced cardiac output
  • Smaller heart size
  • Impaired oxygen delivery
• Endothelial dysfunction affects blood vessel regulation and circulation

6. Interaction Between Systems

• These systems form a self-reinforcing loop:
  1. Immune activation
  2. Autonomic dysfunction
  3. Impaired blood flow
  4. Reduced oxygen delivery
  5. Increased immune activation
• This loop helps explain:
  • Whole-body symptoms
  • Delayed crashes after exertion (PENE)
  • Partial improvement with rest but lack of full recovery

7. Multi-System Effects

• Dysregulation affects multiple systems simultaneously:
  • Neurological (brain fog, sensory issues)
  • Immune (flu-like symptoms)
  • Cardiovascular (dizziness, POTS)
  • Energy metabolism (post-exertional exhaustion)

8. Core Mechanism

• M.E. represents a failure of coordination between:
  • Brain
  • Immune system
  • Blood vessels
  • Autonomic nervous system
• The body becomes trapped in a maladaptive state of dysfunction

Target Audience

This information is intended for:

• People living with M.E.
• Carers and family members
• Healthcare professionals
• Researchers and advocates

Overall Outcome

This page highlights that neuroimmune dysfunction is central to M.E., driving widespread symptoms through interconnected disturbances in the brain, immune system, and circulation. Understanding these mechanisms helps:

• Explain the complexity of symptoms
• Support recognition of M.E. as a biological condition
• Guide research and clinical investigation
• Improve approaches to symptom management

Key Summary Statement

Neuroimmune dysfunction in M.E. reflects a breakdown in communication between the brain, immune system, and circulation, creating a self-perpetuating cycle of inflammation, impaired blood flow, and energy dysfunction.