Guillain–barré Syndrome

Basics

Description

  • Group of peripheral nerve disorders characterized by autoimmune demyelination and axonal degeneration of peripheral nerves usually leading to acute ascending paralysis
  • Humoral and cellular immune mediated
  • Leading cause of acute flaccid paralysis worldwide (since polio vaccination)
  • Triggered by antecedent bacterial/viral infection
  • Increasing incidence with advancing age, male gender
    • Average 1.1 per 100,000 per yr
  • Weakness reaches nadir at 2–4 wk
  • Spontaneous resolution occurs over weeks to months:
    • 80% full recovery at 1 yr
    • 20% unable to walk at 6 mo
    • 5% die of complications:
      • PE
      • Infection
      • Cardiac
  • Acute inflammatory demyelinating polyradiculoneuropathy (AIDP):
    • Most common form of Guillain–Barré syndrome (GBS; 90% of all GBS cases)
    • Demyelination sometimes accompanied by axonal loss
  • Other forms of GBS:
    • Acute motor axonal neuropathy (AMAN):
      • Pure motor axonal involvement
      • 67% seropositive for Campylobacter jejuni
      • Recovery often rapid
      • Often pediatric patients
    • Acute motor sensory axonal neuropathy (AMSAN):
      • Degeneration of myelinated motor and sensory nerves without significant inflammation or demyelination
      • Similar to AMAN, but also involves sensory nerves
    • Acute panautonomic neuropathy:
      • Very rare
      • Involves sympathetic and parasympathetic nerves
      • Postural hypotension, dysrhythmias, tachycardia, hypertension
      • Blurry vision, dry eyes, anhidrosis
      • Recovery gradual, often incomplete
    • Miller Fisher syndrome:
      • Rare
      • Rapidly evolving ataxia, areflexia, and ophthalmoplegia without weakness
      • Demyelination and inflammation of cranial nerves II and VI, spinal ganglia, and peripheral nerves
      • Resolves in 1–3 mo

Etiology

  • Postinfectious:
    • 2/3 with antecedent illness, usually respiratory or GI
    • Different autoantibodies associated with different subtypes
    • 1–3 wk between prodromal illness and neurologic symptoms
    • C. jejuni most common antecedent bacterial infection
    • Cytomegalovirus most common antecedent viral infection
    • Epstein–Barr virus, VZV, HIV, mycoplasma also associated
    • Emerging association with Zika virus, unclear if other viruses also necessary to precipitate GBS after Zika
    • Also emerging association with immune modulators (e.g., adalimumab)
    • Relationship to vaccines is questionable
    • Slightly increased risk ascribed to influenza vaccine
      • Incidence ∼2 cases per million vaccines given
      • Lower than risks associated with developing influenza
    • Case reports of GBS after meningococcal vaccine in adolescent
      • No definite association in larger studies

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