What is the onset and treatment of Guillain-Barré Syndrome (GBS)?

Guillain-Barré Syndrome: Onset and Treatment

Guillain-Barré Syndrome (GBS) typically presents with rapidly progressive bilateral weakness that reaches maximum disability within 2 weeks of onset, and treatment should be initiated promptly with either intravenous immunoglobulin (0.4 g/kg daily for 5 days) or plasma exchange (200-250 ml/kg in 4-5 exchanges over 1-2 weeks) for patients who cannot walk unaided. 1, 2

Clinical Onset and Presentation

Classic Presentation

• Rapidly progressive bilateral weakness of legs and/or arms
• Ascending pattern (distal to proximal progression)
• Onset reaches maximum disability within 2 weeks (alternative diagnoses should be considered if maximum disability occurs within 24 hours or after 4 weeks) 1
• Decreased or absent reflexes in most patients at presentation and almost all patients at nadir
• Typically preceded by infection in 4-6 weeks before onset (most commonly Campylobacter jejuni, Cytomegalovirus, Epstein-Barr virus, Mycoplasma pneumoniae, Hepatitis E virus, and Zika virus) 2

Atypical Presentations

• Weakness may be asymmetrical or predominantly proximal or distal
• Can start in legs, arms, or simultaneously in all limbs
• Severe diffuse pain or isolated cranial nerve dysfunction may precede weakness
• Young children (<6 years) may present with nonspecific features (poorly localized pain, refusal to bear weight, irritability) 1

Clinical Variants

• Pure motor variant (weakness without sensory signs)
• Bilateral facial palsy with paresthesias
• Pharyngeal-cervical-brachial weakness
• Paraparetic variant (limited to lower limbs)
• Miller Fisher syndrome (ophthalmoplegia, areflexia, and ataxia) 1

Diagnosis

Diagnostic Criteria

1. History of recent diarrhea or respiratory infection (increases likelihood)
2. CSF examination showing albuminocytological dissociation (increased protein with normal cell count)
   • Note: May be normal early in disease course
3. Electrophysiological studies to support diagnosis and distinguish subtypes
4. Consider anti-ganglioside antibody testing in atypical cases (particularly anti-GQ1b for Miller Fisher syndrome) 2, 3

Treatment

First-line Treatment Options

For patients within 2-4 weeks after onset who cannot walk unaided:

1. Intravenous Immunoglobulin (IVIg)

   • Dosage: 0.4 g/kg daily for 5 consecutive days
   • Preferred in most settings due to practical considerations 1, 2, 3

2. Plasma Exchange (PE)

   • Regimen: 200-250 ml/kg in 4-5 exchanges over 1-2 weeks
   • Equally effective as IVIg 1, 2, 3

Important Treatment Considerations

• Treatment should be initiated as soon as possible after diagnosis
• IVIg and PE are equally effective; choice often depends on availability and contraindications
• A second IVIg course is not recommended for patients with poor prognosis
• Corticosteroids alone are not effective and not recommended 2, 3
• Pain management may require gabapentinoids, tricyclic antidepressants, or carbamazepine 3

Monitoring and Supportive Care

Critical Monitoring

• Respiratory function: 20% of patients develop respiratory failure requiring mechanical ventilation
• Autonomic function: Monitor for blood pressure/heart rate instability, pupillary dysfunction, and bowel/bladder dysfunction
• Venous thromboembolism prophylaxis 1, 2

Prognosis

• Mortality rate: 3-10% despite best medical care
• Recovery: 60-80% of patients able to walk independently 6 months after onset
• Most improvement occurs in first year but can continue for >5 years
• Recurrence is rare (2-5% of patients) 1, 2

Common Pitfalls

1. Failure to recognize atypical presentations, especially in children
2. Delaying treatment while waiting for CSF abnormalities (may be normal early in disease)
3. Misdiagnosing treatment-related fluctuations (TRFs) as treatment failure
4. Failing to consider acute-onset chronic inflammatory demyelinating polyradiculoneuropathy (A-CIDP) if progression continues after 8 weeks (occurs in ~5% of patients initially diagnosed with GBS) 1, 3, 4

Long-term Management

• Use modified Erasmus GBS outcome score (mEGOS) to assess prognosis
• Anticipate that most patients will experience significant recovery, but some may have residual weakness or other complications
• Monitor for persistent fatigue and pain, which may require specific management 2, 3