Guillain-Barré syndrome (GBS) is a rare, acute neurological disorder where the body's immune system mistakenly attacks its own peripheral nerves. This autoimmune response damages the nerve's protective covering (myelin sheath) or the nerve fibers (axons), disrupting the transmission of signals between the brain and the rest of the body.

1. GUILLAIN-BARRÉ
SYNDROME
DR. ASHIYA RASAK

2. Definition & Epidemiology
• Acute immune-mediated polyradiculoneuropathy (autoimmune
attack on peripheral nerves)
• Onset: Rapid (hours to days), peak weakness by 2 weeks (>90% by 4
weeks)
• Monophasic disorder: No relapse (distinguishes from CIDP)
• Triggers: Viral infections, Campylobacter jejuni, vaccinations,
pregnancy

3. Pathophysiology
• Molecular Mimicry: Pathogen
antigens cross-react with nerve
epitopes
• C. jejuni & GM1: LPS capsule
shares epitopes with GM1
ganglioside at nodes of Ranvier

6. Clinical Presentation
Prodrome: 1-4 weeks prior infection (URI, GI, or asymptomatic)
• First symptom: Paresthesias (tingling) in toes/fingertips
• Rapid progression: Ascending symmetric weakness (distal to proximal)
• Peak at 2-4 weeks: Leg weakness → arm weakness → facial/bulbar
• Respiratory involvement: 20-30% require mechanical ventilation
• Autonomic dysfunction: Labile BP, arrhythmias, sphincter dysfunction
• Sensory findings: Pain, stocking-glove distribution (usually mild)

8. ELECTROPHYSIOLOGICAL VARIANTS
AIDP (50-54%)
AMAN (18-20%)
AMSAN (17-18%)
Miller Fisher (5%)

10. ACUTE INFLAMMATORY DEMYELINATING POLYNEUROPATHY
• Pathology: Demyelination with secondary axonal loss; lymphocytic infiltration
• Associated Infections: EBV, CMV, respiratory viruses, some C. jejuni
• Characterized by Ascending paralysis, sensory involvement, preserved reflexes early
• NCS/EMG: Conduction blocks, multifocal slowing, prolonged F-waves, normal
amplitudes
• Prognosis: Better than axonal variants; 80-90% walk independently at 6 months

11. ACUTE MOTOR AXONAL NEUROPATHY
• Pathology: Motor axon targeting; minimal inflammatory infiltrate; no demyelination
• Epidemiology: Prevalent in Asia, Latin America (~20-60% in these regions)
• Associated Infections: Strongly associated with C. jejuni (poor prognostic factor)
• Rapid onset, motor-only weakness, severe presentation
• NCS/EMG: Reduced motor amplitudes, normal conduction velocity, prolonged F-waves
• Prognosis: Worse than AIDP; prolonged paralysis, 50-60% walk at 6 months

12. ACUTE MOTOR-SENSORY AXONAL NEUROPATHY
• Pathology: Motor AND sensory axon degeneration; Wallerian-like degeneration
• Epidemiology: 17-18% of GBS cases; more common in Asia
• Associated Infections: C. jejuni and other bacteria
• Severe sensorimotor loss, rapid progression, prolonged weakness
• NCS/EMG: Reduced motor AND sensory amplitudes, prolonged F-waves, fibrillations
• Prognosis: WORST variant; 30-40% walk at 6 months; higher mortality

13. MILLER FISHER SYNDROME (MFS)
• Classic Triad: Ophthalmoplegia + Ataxia + Areflexia
• Pathology: GQ1b ganglioside antibody-mediated; targets cranial nerves
• Epidemiology: ~5% of GBS spectrum; more common in Asia
• Descending weakness (unique to MFS), blurred vision, gait ataxia
• Antibody Testing: Anti-GQ1b antibodies in 80-90% (diagnostic)
• Prognosis: Better than classic GBS; most recover fully with treatment

14. RARE VARIANTS
• Pharyngeal-Cervical-Brachial (PCB): Facial, pharyngeal, neck weakness; restricted
distribution
• Pandysautonomic Variant: Pure autonomic symptoms (BP lability, arrhythmias, pupil
changes)
• Bifacial Weakness + Paresthesias (BFP): Bilateral facial paralysis with distal
paresthesias
• Pure Sensory GBS: Sensory ataxia only; rare; better prognosis
• Paraparetic GBS: Lower limb predominance; rare presentation

15. DIAGNOSIS: BRIGHTON CRITERIA

16. DIAGNOSIS: INVESTIGATIONS
Lumbar Puncture (CSF Analysis):
• Elevated protein (>400 mg/L) with normal cell count ("albuminocytologic dissociation")
• May be normal in first 10 days of illness
• Pleocytosis (>50 WBC) suggests alternate diagnosis (infection, malignancy)
Nerve Conduction Studies (NCS) & EMG:
• Normal in first week; characteristic findings after 1-2 weeks

18. NCS FINDINGS
Variant Key NCS Findings
AIDP
Prolonged Distal Latency,
Slow Conduction Velocity,
Prolonged/Absent F-waves.
Normal/Near-Normal Amplitudes.
AMAN
Low Compound Muscle AP Amplitudes.
Normal Sensory Nerve AP Amplitudes. Normal CV.
AMSAN
Low CMAP and SNAP Amplitudes.
Normal CV.
MFS
Normal NCS.
Absent/Prolonged F-waves/H-reflexes.

19. DIFFERENTIAL DIAGNOSIS
• Poliomyelitis: Similar weakness; but gray matter involvement, asymmetric,
fever present
• Spinal cord pathology: Upper motor neuron signs, sensory level, bladder
dysfunction
• Botulism: Descending paralysis, mydriasis, autonomic preservation
• Myasthenia Gravis: Ocular involvement first, fatigability, anticholinergic
responsiveness
• Acute Transverse Myelitis: Sensory level, sphincter involvement, MRI findings

22. MANAGEMENT: OVERVIEW & SUPPORTIVE CARE
• ICU Admission: For respiratory monitoring and autonomic support
• Vital Capacity Monitoring: Check forced vital capacity (FVC) regularly; intubate if <15 mL/kg or declining
• Continuous cardiac monitoring, fluid/vasopressor support for dysrhythmias
• DVT Prophylaxis: Compression stockings, sequential compression devices, anticoagulation if high risk
• Pain Management
• Early Rehabilitation: PT/OT, passive range of motion during paralysis

24. IMMUNOTHERAPY: IVIG (FIRST-LINE)
• Mechanism: Blocks complement, modulates antibodies, anti-inflammatory effects
• Dosing: 2 g/kg total body weight divided over 5 days (0.4 g/kg/day)
• Advantages: Convenient, widely available, fewer complications than plasma
exchange
• Side Effects: Renal dysfunction, headache, aseptic meningitis (rare)
• Timing: Most effective if started within 2 weeks of symptom onset; up to 4 weeks
considered

25. PLASMA EXCHANGE
• Mechanism: Removes circulating antibodies, immune complexes, complement
• Dosing: 5 exchanges over 7-14 days (1-1.5 plasma volumes per exchange)
• Indications: Preferred for nonambulant patients, renal failure, IVIG intolerance
• Disadvantages: Requires vascular access, more complications, logistically demanding

26. STEROIDS & ANTICOAGULATION
Corticosteroids:
• Monotherapy with steroids ALONE is NOT effective in GBS
Anticoagulation Prophylaxis:
• Indicated for all immobilized GBS patients (high VTE risk)
• Subcutaneous LMWH (enoxaparin 40 mg daily) or UFH
• Continue until ambulation or discharge

27. PROGNOSIS & LONG-TERM OUTCOMES
• Mortality: 3-7% (higher with respiratory involvement, AMSAN, advanced age)
• Recovery Timeline: 50% walk at 3 months; 70-80% at 6 months (AIDP); worse for axonal
variants
• 10-15% have permanent weakness; 20% chronic pain
• Recovery Phases: First 4 weeks most critical; recovery continues for months to years

28. MODIFIED ERASMUS GBS OUTCOME SCORE (MEGOS)

29. POST-GBS SYNDROME & REHABILITATION
• Post-GBS Syndrome: Persistent fatigue, weakness, pain in 10-20% of survivors
• Chronic Pain: Neuropathic pain; treated with gabapentin, pregabalin, tricyclics
• Autonomic Dysfunction: Persistent dysrhythmias, orthostatic hypotension
• Psychological Impact: Depression, anxiety
• Rehabilitation Focus: Early PT/OT prevents contractures; gradual strengthening

31. THANK YOU