Guillain-Barré Syndrome

Heterogenous autoimmune disease of peripheral nerves, usually following an infection or other immune stimulus, that leads to rapid onset ascending flaccid paralysis and sensory dysfunction. Can be divided into:

Epidemiology and Risk Factors

Pathophysiology

Variable depending on the subtype of GBS. Postulated mechanisms include:

  • Antibody-mediated nerve injury
    Molecular mimicry between the microbial antigen and nerve surface gangliosides.

Aetiology

Precipitating conditions include:

  • Infection
    • Bacterial
      • Campylobacter jejuni
        25-40%. Strong association with axonal GBS and Miller-Fisher Syndrome.
      • Haemophilius spp.
      • Mycoplasma spp.
    • Viral
      • CMV
      • VZV
      • EBV
      • HIV
      • Mumps
      • Influenza A
      • Parainfluenza
      • Hepatitis E
  • Immune
    • Vaccinations
      Difficult to disentangle from baseline risk. Case reports include:
      • Influenza
      • TB
      • Tetanus
      • Typhoid

Clinical Manifestations

Prodromal illness:

  • Usually mild
  • Within the last 8 weeks
    • Peak at 2 weeks prior

Neuropathy:

  • Paraesthesiae
    • ~50%
    • Distal
    • Usually mild
  • Motor
    • Initial weakness, progressing to flaccid paralysis
    • Hyporeflexia, progressing to areflexia
  • Cranial nerves
    • ~45%
    • Most common:
      • Facial
      • Glossopharyngeal
      • Vagus
  • Autonomic dysfunction
    • Common
    • Significant cause of morbidity and mortality

Diagnostic Approach and DDx

Factors favouring GBS:

  • Progressive weakness that is:
    • Bilateral
    • In both arms and legs
  • Areflexia
  • Autonomic dysfunction
  • Pain
  • Protein in CSF

Factors favouring alternative diagnosis:

  • Respiratory failure disproportionate to limb weakness
  • Febrile
  • Persistent bladder or bowel dysfunction
  • Spinal cord sensory level
  • Asymmetry of motor signs

Differential diagnoses of weakness include:

  • Brainstem
    • CVA
    • Locked-in syndrome
  • Spinal cord
    • Transverse myelitis
    • Mass effect
      • Tumour
      • Haemorrhage
  • Peripheral nerve
    • GBS
    • CIN
    • Toxins
      • Arsenic
      • Thallium
  • NMJ
    • Neuromuscular blockade
    • MG
    • Lambert-Eaton syndrome
    • Toxins
      • Organophosphate
      • Botulism
  • Muscle
    • Steroid myopathy
    • Alcoholic myopathy
    • Polymyositis
    • Dermatomyositis
    • Toxic myopathy
    • CIM

Investigations

Impending respiratory failure suggested on PFTs by:

  • VC <20 mL/kg
  • Max inspiratory pressure <-30 cmH20
  • Max expiratory pressure <40 cmH20

Bedside:

Laboratory:

Imaging:

Other:

  • LP
    • ↑ CSF protein >0.4g/dL
      In >90%.
    • Low/normal CSF cell count
  • Nerve conduction studies
    • Reinforce diagnosis
    • Differentiate between demyelinating and axonal subtypes

Management

  • Early immunotherapy with either:
    • Immunoglobulin
    • Plasma exchange

Specific therapy:

  • Pharmacological
    • Immunoglobulin
      • 2g/kg IV
      • 10% relapse, with good response to further course
      • ↓ Need for mechanical ventilation
      • ↓ Duration of mechanical ventilation
      • Equivalent to plasma exchange
        Preferred due to convenience.
  • Procedural
    • Plasma exchange
      • Within 7 days of onset
        • 4 exchanges of 1-2 volumes over 1-2 weeks
        • Albumin preferable to FFP
  • Physical

Supportive care:

Avoid suxamethonium for intubation, as with other neuromuscular disorders.

  • A
    • Intubation
      If bulbar dysfunction.
    • Early tracheostomy as long duration of ventilation is expected
  • B
    • Chest physiotherapy
    • Respiratory function (VC) monitoring with PFTs
      More reliable than blood gases.
    • Mechanical ventilation
  • G
    • Feeding
      • PN only if EN precluded by paralytic ileus

Disposition:

Preventative:

Marginal and Ineffective Therapies

  • Steroids
    Both low and high-dose corticosteroids have no effect on outcome, and may slow recovery.

Anaesthetic Considerations

Complications

  • Death
    5-8%.
  • A
    • Aspiration
  • B
    • Respiratory failure
      30% require ventilation.
  • C
    • Haemodynamic instability
      • Orthostatic hypotension
      • Paroxysmal hypertension
      • Sinus tachycardia
      • Bradycardia
      • Ventricular arrhythmias
  • F
    • Urinary retention
  • G
    • Paralytic ileus

Prognosis

Usual course:

  • Nadir at 2-4 weeks
  • Resolution over weeks-months
    • 70% functional independence at 1 year
      Further improvement seen for 18 months/2 years.
    • 20% minor limitations

Good prognostic factors include:

  • Early treatment
  • Early avoidance of complications

Poor prognostic factors:

  • Age >60
  • Rapid progression
    Quadriparesis in <7 days.
  • Mechanical ventilation
  • Diarrheal illness prodrome

Key Studies

References

  1. Bersten, A. D., & Handy, J. M. (2018). Oh’s Intensive Care Manual. Elsevier Gezondheidszorg.