What are the typical presentation and treatment of Guillain-Barré Syndrome (GBS)?

Presentation and Treatment of Guillain-Barré Syndrome (GBS)

Guillain-Barré syndrome (GBS) should be diagnosed in patients with rapidly progressive bilateral weakness of the legs and/or arms, absent or decreased tendon reflexes, and no CNS involvement, and treatment should be initiated promptly with either intravenous immunoglobulin (0.4 g/kg daily for 5 days) or plasma exchange (12-15 L in 4-5 exchanges over 1-2 weeks). 1, 2, 3

Clinical Presentation

Typical Features

• Progressive bilateral weakness that typically starts in the legs and ascends to arms and cranial muscles
• Decreased or absent deep tendon reflexes (a key distinguishing feature from other conditions like myasthenia gravis) 1, 2
• Distal paresthesias or sensory loss
• Progression to maximum disability within 2-4 weeks (rapid progression within 24 hours or after 4 weeks suggests alternative diagnoses) 1
• Relative symmetry of symptoms (though asymmetry can occur) 2

Associated Symptoms

• Dysautonomia (blood pressure/heart rate instability, pupillary dysfunction, bowel/bladder dysfunction) 1
• Pain (muscular, radicular, or neuropathic) - often severe and can precede weakness 1, 2
• Cranial nerve involvement (facial, glossopharyngeal, vagus nerves) 2, 4
• Respiratory insufficiency (occurs in approximately 20-30% of patients) 2, 4

Atypical Presentations

• Asymmetrical weakness
• Predominantly proximal or distal weakness
• Simultaneous onset in all limbs
• Severe pain preceding weakness
• Isolated cranial nerve dysfunction
• In young children: nonspecific features like pain, refusal to bear weight, irritability, meningism, or unsteady gait 1

Antecedent Events

• Approximately two-thirds of patients report an infection in the 4-6 weeks preceding onset 2
• Common triggers include:
  • Gastrointestinal infections (especially Campylobacter jejuni)
  • Respiratory infections
  • Cytomegalovirus (CMV)
  • Epstein-Barr virus (EBV) 5

Diagnostic Approach

Key Diagnostic Tests

1. Cerebrospinal Fluid (CSF) Examination

   • Typically shows albumino-cytological dissociation (elevated protein with normal cell count)
   • Note: Protein levels may be normal in 30-50% of patients in the first week 2

2. Electrodiagnostic Studies

   • Electromyography (EMG) and nerve conduction studies (NCS)
   • Shows sensorimotor polyradiculoneuropathy/polyneuropathy
   • Conduction velocity slowing and delayed F-wave latencies in 90% of patients 2, 4

3. Additional Testing

   • Anti-ganglioside antibody testing (limited value in typical GBS but anti-GQ1b antibodies found in up to 90% of Miller Fisher syndrome cases) 2
   • MRI in atypical cases to rule out other causes 2

Treatment

First-Line Treatment Options

1. Intravenous Immunoglobulin (IVIg)

   • Dosage: 0.4 g/kg/day for 5 consecutive days
   • Should be initiated as soon as possible after diagnosis
   • Recommended for patients unable to walk unaided within 2 weeks of symptom onset (can be considered up to 4 weeks) 1, 2, 3

2. Plasma Exchange (PE)

   • Alternative to IVIg
   • Dosage: 12-15 L in 4-5 exchanges over 1-2 weeks
   • Effective when initiated within 4 weeks of symptom onset 2, 3

Treatment Considerations

• IVIg is generally preferred over PE for practical reasons 6
• Corticosteroids are not recommended as monotherapy 2, 3
• Second IVIg course is not recommended for patients with poor prognosis 3
• Combined PE followed by IVIg is not recommended 3

Pain Management

• Consider gabapentinoids, tricyclic antidepressants, or carbamazepine 2, 3

Supportive Care

• Close monitoring of respiratory function
• Autonomic function monitoring
• Thromboembolism prophylaxis 2

Prognosis and Monitoring

Outcome Prediction

• The modified Erasmus GBS outcome score (mEGOS) can predict recovery 1, 2, 3
• The modified Erasmus GBS Respiratory Insufficiency Score (mEGRIS) assesses risk for requiring artificial ventilation 3

Recovery Timeline

• 60-80% of patients able to walk independently by 6 months 2
• Recovery can continue for >3 years after onset 1
• Approximately 20% of patients still unable to walk after 6 months 6

Complications and Mortality

• Mortality rate: 3-10% despite optimal treatment 2, 6
• Long-term complications may include persistent pain, fatigue, and other residual symptoms 2, 6

Special Considerations

• Treatment-related fluctuations (TRFs) occur in about 10% of patients within the first 8 weeks after IVIg, requiring repeated treatment 6
• Approximately 5% of patients initially diagnosed with GBS may develop chronic inflammatory demyelinating polyradiculoneuropathy with acute onset (A-CIDP) 6, 3
• Recurrence of GBS is rare (2-5% of patients) 1, 2

Clinical Pitfalls to Avoid

• Delaying treatment while awaiting diagnostic confirmation
• Failing to monitor respiratory function closely
• Misdiagnosing atypical presentations, especially in children
• Not recognizing pain as an early symptom that may precede weakness
• Overlooking the possibility of A-CIDP if progression continues beyond 8 weeks
• Using corticosteroids as monotherapy