Gulliian bare syndrome
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"Guillain-Barre syndrome"[MeSH Terms]
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Guillain-Barré Syndrome (GBS)
Definition
Guillain-Barré syndrome is an acute, immune-mediated peripheral neuropathy characterized by rapidly progressive ascending muscle weakness, areflexia, and, in many cases, autonomic dysfunction. It is one of the most common life-threatening diseases of the peripheral nervous system, with an incidence of 0.81-1.89 cases per 100,000 persons per year worldwide. Incidence increases with age and is more prevalent in men.
Pathophysiology
About two-thirds of GBS cases are triggered by a preceding infection (typically 1-3 weeks before symptom onset). The infection generates microbe-specific T cells and antibodies that cross-react with antigens in the nerve sheath (molecular mimicry).
- Both T-cell-mediated and antibody-mediated mechanisms are involved, with T cells believed to play the dominant role
- Injury is most extensive in nerve roots and proximal nerve segments
- Associated with mononuclear cell infiltrates rich in macrophages
- In axonal variants (AMAN), autoimmune antibodies target GM1/GD1a and GalNAc-GD1a gangliosides
- In Miller-Fisher syndrome, anti-GQ1b antibodies attack cranial nerve-related structures
Common Triggers
| Type | Examples |
|---|---|
| Bacterial | Campylobacter jejuni (most common), Mycoplasma pneumoniae |
| Viral | Epstein-Barr virus, Cytomegalovirus, HIV, Herpes simplex, Zika virus, Chikungunya, SARS-CoV-2 |
| Non-infectious | Vaccinations, immune checkpoint inhibitors |
Subtypes and Variants
From Bradley and Daroff's Neurology in Clinical Practice:
Common Subtypes
| Subtype | Features |
|---|---|
| AIDP (Acute Inflammatory Demyelinating Polyradiculoneuropathy) | Most common in Europe/North America; demyelinating; ascending weakness |
| AMAN (Acute Motor Axonal Neuropathy) | Pure motor; associated with C. jejuni; summer epidemics in China |
| AMSAN (Acute Motor-Sensory Axonal Neuropathy) | Both motor + sensory fibers; severe, poor recovery |
Rare Variants
- Miller-Fisher Syndrome (MFS) - Classic triad: ophthalmoplegia, ataxia, and areflexia; anti-GQ1b antibody positive; accounts for 6% of GBS in the West, up to 18% in Taiwan
- Pharyngeal-cervical-brachial variant
- Paraparetic variant
- Bilateral facial palsy with paresthesias
Clinical Features
Required for Diagnosis (Brighton/Asbury-Cornblath Criteria)
- Progressive weakness of both legs and arms
- Areflexia or hyporeflexia
Supportive Clinical Features
- Progression over days to 4 weeks
- Relative symmetry of symptoms
- Mild sensory symptoms or signs
- Bifacial palsies
- Autonomic dysfunction (arrhythmias, BP fluctuations, bladder dysfunction)
- Absence of fever at onset
- Recovery beginning 2-4 weeks after progression ceases
Time Course
- Symptoms progress over several days, peaking at 2-4 weeks, then plateau
- ~5% of patients progress more rapidly, reaching maximum deficit within 72 hours
- Recovery may be protracted over months to years
Investigations
| Test | Finding |
|---|---|
| CSF | Elevated protein, <10 cells/μL (albuminocytological dissociation) - classic finding |
| Nerve Conduction Studies (NCS) | Conduction slowing or block (AIDP); reduced CMAP amplitudes (axonal) |
| Antibodies | Anti-GQ1b (MFS), anti-GM1 (AMAN; worse prognosis) |
| ECG | Arrhythmia screening |
| Pathogen screen | C. jejuni serology, CMV, EBV |
Respiratory Management (Critical Care)
GBS causes respiratory failure in 20-30% of cases, making it a leading cause of ICU admission.
"20-15-30" Rule for Intubation:
- Forced Vital Capacity (FVC) <20 mL/kg - consider ICU observation
- FVC <15 mL/kg - probable intubation needed
- Maximal Inspiratory Pressure (MIP) <-30 cm H₂O - indicates respiratory compromise
Hypercarbia is a late sign - do not rely on it alone.
The Erasmus GBS Respiratory Insufficiency Score (EGRIS) is a validated tool to predict need for early ICU admission based on weakness severity, symptom timing, and bulbar symptoms.
Mortality:
- Overall: <3-5% (previously 33% before positive-pressure ventilation)
- With mechanical ventilation: 14.3%
Treatment
| Treatment | Mechanism / Notes |
|---|---|
| Intravenous Immunoglobulin (IVIg) | Suppresses immune responses; first-line therapy |
| Plasmapheresis (plasma exchange) | Removes offending antibodies; equivalent efficacy to IVIg |
| Supportive care | Ventilatory support, DVT prophylaxis, pain management, physiotherapy |
| Steroids | NOT recommended - shown to be ineffective and may worsen outcomes |
IVIg and plasmapheresis are not combined as they show no additive benefit.
Prognosis
- Most patients recover with time after the initial acute phase
- Axonal degeneration on electrophysiology is associated with poorer recovery
- Anti-GM1 antibody positivity is associated with worse recovery
- About 20% of patients remain unable to walk unaided at 6 months
- ~5-10% have permanent severe disability
Key Distinction: GBS vs. CIDP
| Feature | GBS (acute) | CIDP (chronic) |
|---|---|---|
| Duration | <4 weeks to nadir | Progresses >2 months |
| Course | Monophasic | Relapsing-remitting or progressive |
| Treatment | IVIg/PE (short course) | Long-term steroids/IVIg/PE |
Sources:
- Bradley and Daroff's Neurology in Clinical Practice, Box 106.10-106.11 (Diagnostic criteria and subtypes)
- Robbins & Kumar Basic Pathology, p. 809 (Pathology and mechanisms)
- Miller's Anesthesia, 10e, p. 12034-12035 (ICU management and respiratory criteria)
Recent evidence (2024-2026): A 2026 systematic review (PMID 41038424) confirms physical exercise programs improve fatigue and functional capacity in GBS patients during rehabilitation - supporting early physiotherapy in the recovery phase.
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