Guillain-Barré Syndrome (GBS)
Introduction
Guillain Barré Syndrome (Gbs) is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
Overview
Guillain-Barré syndrome (GBS) is an acute, immune-mediated inflammatory polyradiculoneuropathy and the most common cause of acute flaccid paralysis worldwide. It is characterized by rapidly progressive, symmetrical ascending weakness and areflexia, typically developing over days to a few weeks following a preceding infection. GBS results from an autoimmune attack on the peripheral nervous system — either the myelin sheath (demyelinating subtypes) or the axon itself (axonal subtypes) — triggered by molecular mimicry between microbial antigens and ganglioside components of peripheral nerves. [@sejvar2011]
The incidence of GBS is approximately 1–2 per 100,000 person-years [@sejvar2011], affecting all age groups with a slight male [@yuki2012]
predominance. Two-thirds of patients report an antecedent respiratory or gastrointestinal infection in the 1–6 weeks before symptom onset. Campylobacter jejuni is the most [@fokke2014]
commonly identified trigger [@willison2016], [@yuki2012], followed by cytomegalovirus, [@hughes2007]
Epstein-Barr virus, Mycoplasma pneumoniae, and various other pathogens. GBS has also been associated with certain vaccines and, more recently, with SARS-CoV-2 infection and [@van1992]
COVID-19 vaccination (rare). Without treatment, the mortality rate is approximately 3–7%; with prompt treatment using intravenous immunoglobulin (IVIG) or plasmapheresis, most [@yuki2007]
patients recover substantially, though up to 20% remain significantly disabled [@shahrizaila2021]. [@shahrizaila2021]
--- [@doets2018]
Epidemiology
- Incidence: 1–2 per 100,000 person-years worldwide; no significant geographic variation
- Age: All ages affected; incidence increases with age (highest in adults >50 years)
- Sex: Slight male predominance (M:F ratio ~1.5:1)
- Seasonal variation: Minor peaks in winter (respiratory triggers) and summer (enteric triggers)
- Mortality: 3–7% even with optimal treatment; higher in elderly and those requiring mechanical ventilation
- Disability: ~20% of patients have persistent significant disability at 1 year; ~60% have full motor recovery
- Preceding infection: Identified in 60–70% of cases
Infectious Triggers
| Pathogen | Frequency | GBS Subtype Association | [@misawa2018]
|----------|-----------|------------------------| [@goodfellow2016]
| Campylobacter jejuni | 25–50% | AMAN, AMSAN (axonal forms), AIDP | [@walgaard2010]
| Cytomegalovirus (CMV) | 5–15% | AIDP (demyelinating) |
| Epstein-Barr virus (EBV) | 5–10% | AIDP |
| Mycoplasma pneumoniae | 5% | AIDP, cranial variants |
| Influenza virus | Variable | AIDP |
| Zika virus | Rare, epidemic-associated | AIDP |
| SARS-CoV-2 | Rare | AIDP, AMAN |
| Hepatitis E virus | Emerging | AIDP |
Classification and Subtypes
GBS encompasses several electrophysiologically and pathologically distinct subtypes:
Acute Inflammatory Demyelinating Polyradiculoneuropathy (AIDP)
- Most common subtype in Europe and North America (~85–90% of cases) [@doets2018]
- Autoimmune attack targets the [Schwann cell](/cell-types/schwann-cells) myelin sheath
- Segmental [demyelination](/mechanisms/demyelination) with macrophage infiltration, lymphocytic perivascular cuffs, and endoneurial edema
- Conduction block and slowed conduction velocities on nerve conduction studies
- Specific ganglioside antibody targets not consistently identified (unlike axonal forms)
Acute Motor Axonal Neuropathy (AMAN)
- More common in Asia and Central/South America (~30–65% in China, Japan)
- Strongly associated with Campylobacter jejuni infection
- Autoimmune attack targets axolemma of motor nerve fibers at nodes of Ranvier
- Anti-GM1 and anti-GD1a antibodies bind to gangliosides on the axonal membrane [@yuki2007], activate complement, and recruit macrophages to the periaxonal space
- May cause either reversible conduction failure (good prognosis) or axonal degeneration (poor prognosis)
- Motor nerve conduction studies show reduced CMAP amplitudes with preserved conduction velocity
Acute Motor-Sensory Axonal Neuropathy (AMSAN)
- Severe axonal variant affecting both motor and sensory axons
- Associated with anti-GM1, anti-GD1a antibodies
- Poor prognosis with prolonged recovery and significant residual deficits
- Often requires prolonged ventilatory support
Miller Fisher Syndrome (MFS)
- Classic triad: ophthalmoplegia, ataxia, and areflexia
- Associated with anti-GQ1b antibodies (>90% positive) [@yuki2007]
- GQ1b gangliosides are enriched in oculomotor nerve myelin, explaining the ophthalmoplegia
- Generally self-limited with good prognosis
- Accounts for ~5% of GBS in Western countries, up to 25% in Japan
Other Variants
- Pharyngeal-cervical-brachial (PCB) variant: Weakness of pharyngeal, neck, and arm muscles; anti-GT1a antibodies
- Acute pandysautonomia: Isolated autonomic neuropathy
- Bickerstaff brainstem encephalitis (BBE): Overlaps with MFS; involves brainstem — drowsiness, ophthalmoplegia, ataxia; anti-GQ1b positive
Pathophysiology
Molecular Mimicry
The central pathogenic mechanism in GBS is molecular mimicry: structural similarity between ganglioside epitopes on peripheral nerve membranes and lipooligosaccharide (LOS) or
other surface molecules of the inciting pathogen [@yuki2007], [@goodfellow2016]. This causes the immune system to generate antibodies against the pathogen that cross-react with self-gangliosides on nerve fibers.
For example, Campylobacter jejuni strains associated with GBS express LOS structures that mimic GM1, GD1a, GD1b, GQ1b, and other gangliosides. Anti-ganglioside IgG antibodies bind to their targets on the peripheral nerve, activate the classical complement cascade, and initiate nerve injury through:
Complement-mediated membrane attack complex (MAC) deposition: Formation of MAC pores on nerve membranes causes ionic disruption and nerve dysfunction
Macrophage recruitment: Complement activation recruits macrophages that penetrate the basement membrane and strip myelin (in AIDP) or invade the periaxonal space (in AMAN)
Conduction block: Disruption of sodium channel clustering at nodes of Ranvier leads to reversible conduction failure
Wallerian degeneration: In severe axonal forms, the axon degenerates distal to the injury site ([Wallerian degeneration](/mechanisms/wallerian-degeneration)Immune Mechanisms
- Humoral immunity: Anti-ganglioside antibodies (IgG > IgM) are the primary effectors
- Complement activation: C3d and MAC deposits found on damaged nerve fibers; complement inhibitor (eculizumab) is under investigation
- T-cell involvement: CD4+ T-helper cells orchestrate the immune response; regulatory T-cell dysfunction may contribute to autoimmune breakdown of tolerance
- Blood-nerve barrier breakdown: Immune-mediated disruption of the blood-nerve barrier at nerve roots (where it is naturally weaker) allows immune cell infiltration, explaining the predilection for radiculopathy
Clinical Presentation
Classic Presentation
- Prodrome: 1–6 weeks after a respiratory or gastrointestinal illness
- Ascending weakness: Begins in the feet and legs, ascending to arms, trunk, and potentially cranial nerves over hours to days (nadir typically 2–4 weeks)
- Symmetry: Typically symmetric, though mild asymmetry is common early
- Areflexia: Loss of deep tendon reflexes, usually early in the course
- Sensory symptoms: Paresthesias, numbness, and neuropathic pain (often preceding weakness by days); typically less prominent than motor deficits
- Pain: Present in ~50–70% of patients; may be severe (back pain, radicular pain, neuropathic pain)
Respiratory Involvement
- ~25–30% of patients require mechanical ventilation due to respiratory muscle and/or diaphragm weakness
- Predictive factors: rapid progression, bulbar dysfunction, reduced forced vital capacity (FVC), bilateral facial weakness
- Respiratory failure is the leading cause of death in GBS
Autonomic Dysfunction
- Occurs in ~70% of patients to some degree
- Cardiovascular: Tachycardia, bradycardia, blood pressure fluctuations (hypertension and/or hypotension), arrhythmias
- Gastrointestinal: Ileus, constipation, urinary retention
- Sweating abnormalities: Anhidrosis or hyperhidrosis
- Autonomic dysfunction can cause sudden death (cardiac arrest) — requires ICU monitoring
Cranial Nerve Involvement
- Facial nerve (CN VII): Bilateral facial weakness in ~50% of patients
- Bulbar muscles: Dysphagia, dysarthria (10–20%)
- Oculomotor nerves: External ophthalmoplegia (particularly in Miller Fisher variant)
Clinical Course
Progressive phase: 1–4 weeks of worsening (nadir by 4 weeks in >90% of cases; by definition, progression beyond 8 weeks is CIDP)
Plateau phase: Days to weeks of stable deficits
Recovery phase: Gradual improvement over weeks to months; recovery is proximal-to-distal (reverse of onset)
Diagnosis
Clinical Criteria
The diagnosis of GBS is primarily clinical, based on the Brighton Collaboration criteria [@fokke2014]:
- Bilateral, flaccid weakness of limbs
- Decreased or absent deep tendon reflexes in weak limbs
- Monophasic illness course with time between onset and nadir of 12 hours to 28 days
- No identified alternative diagnosis
Investigations
| Test | Findings in GBS |
|------|-----------------|
| [Nerve conduction studies/EMG](/diagnostics/emg-nerve-conduction) | AIDP: Prolonged distal latencies, slowed conduction velocities, conduction block, temporal dispersion. AMAN: Reduced CMAPs with preserved velocities. May be normal in first week. |
| Cerebrospinal fluid (CSF) | Albuminocytologic dissociation: elevated protein (>0.45 g/L) with normal cell count (<10 cells/μL). Present in ~80% after first week [@yuki2012]. |
| Anti-ganglioside antibodies | Anti-GM1, anti-GD1a (AMAN); anti-GQ1b (MFS, BBE). Negative results do not exclude GBS. |
| MRI of spine | Gadolinium enhancement of cauda equina nerve roots (sensitive but not specific). Useful to exclude structural compression. |
| Pulmonary function tests | Serial FVC and negative inspiratory force (NIF) monitoring — critical for predicting ventilatory failure [@walgaard2010]. |
Differential Diagnosis
- Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP): Similar but chronic/relapsing (>8 weeks progression)
- Transverse myelitis / spinal cord compression: UMN signs, bladder dysfunction, sensory level
- Myasthenia gravis: Fluctuating weakness, ocular predominance, decremental response on repetitive nerve stimulation
- Botulism: Descending paralysis, pupillary dilation
- West Nile virus / poliomyelitis: Asymmetric, pure motor, CSF pleocytosis
- [multiple sclerosis](/diseases/multiple-sclerosis): CNS involvement, brain lesions on MRI
- Tick paralysis: History of tick attachment; rapid improvement after tick removal
- Critical illness neuropathy/myopathy: ICU setting; elevated CK in myopathy
Treatment
First-Line Therapies
Both IVIG and plasmapheresis are equally effective [@hughes2007], [@van1992] and should be initiated promptly (within 2 weeks of symptom onset for maximum benefit):
Intravenous Immunoglobulin (IVIG):
- Dose: 0.4 g/kg/day for 5 consecutive days (total 2 g/kg)
- Mechanism: Modulates Fc receptors, neutralizes pathogenic antibodies, inhibits complement activation, provides anti-idiotypic antibodies
- Preferred in many centers due to ease of administration and fewer access-related complications
- Most effective in AIDP; also beneficial in AMAN
Plasmapheresis (Plasma Exchange, PE):
- Protocol: Typically 5 exchanges over 1–2 weeks (total ~250 mL/kg)
- Mechanism: Removes circulating pathogenic antibodies, complement factors, and inflammatory mediators
- Equally effective to IVIG; cost-effective in resource-limited settings
- Requires central venous access; hemodynamic instability can be a contraindication
Combined IVIG + PE: No proven additive benefit; not recommended over either therapy alone.
Corticosteroids: Not effective in GBS (unlike CIDP) and are not recommended.
Emerging Therapies
- Eculizumab: Complement C5 inhibitor; prevents MAC formation. Phase II/III trials in severe GBS showed mixed results but remains under investigation [@misawa2018].
- Efgartigimod (Vyvgart): Neonatal Fc receptor (FcRn) inhibitor that accelerates IgG catabolism, thereby rapidly reducing pathogenic antibody levels. Promising emerging therapy based on its success in myasthenia gravis.
- Complement inhibitors: C1-esterase inhibitor, anti-C5 antibodies under investigation
- IdeS (imlifidase): Endopeptidase that cleaves IgG; ultra-rapid antibody removal under early investigation
Supportive Care
- ICU monitoring: Serial respiratory monitoring (FVC, NIF) — intubate if FVC <20 mL/kg or declining rapidly
- Thromboprophylaxis: DVT/PE prophylaxis in immobilized patients
- Pain management: Gabapentin, pregabalin, opioids, carbamazepine for neuropathic pain
- Nutrition: Enteral nutrition if dysphagia present; PEG if prolonged
- Rehabilitation: Early physiotherapy; prolonged inpatient rehabilitation for severely affected patients
- Autonomic management: Continuous cardiac monitoring; temporary pacing for symptomatic bradycardia; vasopressors/antihypertensives for blood pressure instability
- Psychological support: Anxiety and depression are common; psychological counseling recommended
Prognosis
- Mortality: 3–7% even with optimal treatment; mainly from respiratory failure, cardiac arrest (autonomic dysfunction), pulmonary embolism, or nosocomial infections
- Recovery: ~80% of patients walk independently at 6 months; ~60% achieve full motor recovery at 1 year [@shahrizaila2021]
- Residual deficits: ~20% have persistent significant disability at 1 year; fatigue is the most common long-term complaint (60–80% of survivors)
- Prognostic factors for poor outcome: Age >60, preceding diarrheal illness (Campylobacter), rapid progression, need for ventilation, low CMAP amplitudes (axonal involvement), high Erasmus GBS Outcome Score (EGOS)
- Recurrence: ~2–5% lifetime recurrence risk (rare)
- Post-GBS fatigue: Severe fatigue occurs in up to 80% of survivors, lasting years and significantly impairing quality of life
See Also
- [Schwann Cells](/cell-types/schwann-cells)
- [Electromyography and Nerve Conduction Studies](/diagnostics/emg-nerve-conduction)
- [Neurodegenerative Diseases](/diseases)
External Links
- [NINDS: Guillain-Barré Syndrome](https://www.ninds.nih.gov/health-information/disorders/guillain-barre-syndrome)
- [GBS/CIDP Foundation International](https://www.gbs-cidp.org/)
- [CDC: Guillain-Barré Syndrome](https://www.cdc.gov/guillain-barre/index.html)
- [OMIM: Guillain-Barré Syndrome](https://omim.org/entry/139393)
Background
The study of Guillain Barré Syndrome (Gbs) has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
Recent Research (2024-2026)
Recent advances in Guillain-Barré Syndrome (GBS) have focused on understanding disease mechanisms, identifying biomarkers, and developing novel therapeutic approaches. Key developments include:
- Genetic studies: Identification of new genetic risk factors and mechanistic insights
- Biomarker research: Development of diagnostic and prognostic biomarkers
- Therapeutic approaches: Investigation of novel treatment strategies
- Clinical trials: Ongoing Phase I-III trials for new therapies
Allen Brain Atlas Resources
- [Allen Brain Atlas - Gene Expression](https://human.brain-map.org/) - Search for gene expression data across brain regions
- [Allen Brain Atlas - Cell Types](https://celltypes.brain-map.org/) - Explore neuronal cell type taxonomy
- [Allen Brain Atlas - Aging, Dementia & TBI](https://aging.brain-map.org/) - Data on aging and traumatic brain injury
- [BrainSpan Atlas of the Developing Human Brain](https://brainspan.org/) - Developmental gene expression data
References
[Unknown, Willison HJ, Jacobs BC, van Doorn PA. Guillain-Barré syndrome. Lancet. 2016;388(10045):717-727. [DOI (2016)](https://doi.org/10.1016/S0140-6736(16)
[Sejvar JJ, et al., Population incidence of Guillain-Barré syndrome: a systematic review and meta-analysis. Neuroepidemiology. 2011;36(2):123-133. [DOI (2011)](https://doi.org/10.1159/000324710)
[Unknown, Yuki N, Hartung HP. Guillain-Barré syndrome. N Engl J Med. 2012;366(24):2294-2304. [DOI (2012)](https://doi.org/10.1056/NEJMra1114525)
[Fokke C, et al, Diagnosis of Guillain-Barré syndrome and validation of Brighton criteria (2014))
[Hughes RAC, et al, Immunotherapy for Guillain-Barré syndrome: a systematic review (2007))
[Unknown, Van der Meché FGA, Schmitz PIM. A randomized trial comparing intravenous immune globulin and plasma exchange in Guillain-Barré syndrome. N Engl J Med. 1992;326(17):1123-1129. [DOI (1992)](https://doi.org/10.1056/NEJM199204233261705)
[Unknown, Yuki N. Ganglioside mimicry and peripheral nerve disease. Muscle Nerve. 2007;35(6):691-711. [DOI (2007)](https://doi.org/10.1002/mus.20762)
[Unknown, Shahrizaila N, Lehmann HC, Kuwabara S. Guillain-Barré syndrome. Lancet. 2021;397(10280):1214-1228. [DOI (2021)](https://doi.org/10.1016/S0140-6736(21)
[Doets AY, et al., Regional variation of Guillain-Barré syndrome. Brain. 2018;141(10):2866-2877. [DOI (2018)](https://doi.org/10.1093/brain/awy232)
[Misawa S, et al., Safety and efficacy of eculizumab in Guillain-Barré syndrome: a multicentre, double-blind, randomised phase 2 trial. Lancet Neurol. 2018;17(6):519-529. [DOI (2018)](https://doi.org/10.1016/S1474-4422(18)
[Unknown, Goodfellow JA, Willison HJ. Guillain-Barré syndrome: a century of progress. Nat Rev Neurol. 2016;12(12):723-731. [DOI (2016)](https://doi.org/10.1038/nrneurol.2016.172)
[Walgaard C, et al., Prediction of respiratory insufficiency in Guillain-Barré syndrome. Ann Neurol. 2010;67(6):781-787. [DOI (2010)](https://doi.org/10.1002/ana.21976)