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***LISTEN TO THE PODCAST HERE***

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DEFINITION

• Acute monophasic paralyzing illness usually provoked by a preceding event
  • Most commonly this is an infection (2/3rds of patients)
  • Other causes
    • Immunizations
      • Influenza, meningococcal (MCV4)
    • Surgery
    • Trauma
    • Medications
• Was considered to be a SINGLE condition, but now is recognized to be an umbrella term for a mix of many different variants
  • Acute inflammatory demyelinating polyradiculoneuropathy (AIDP)
    • Most common in the US (85-90%)
  • Miller Fisher syndrome (MFS)
  • Acute motor axonal neuropathy (AMAN)
  • Acute sensorimotor axonal neuropathy (AMSAN)

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EPIDEMIOLOGY

• 1-2 cases per 100,000 per year
• Incidence increases 20% with every 10-year increase in age after the first decade of life
• Slightly higher incidence in men than women

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PATHOGENSIS

• Molecular Mimicry
  • Antecedent event provokes an immune response, which produces antibodies that cross-reacts with nerve components due to the sharing of epitopes
    • If directed at Schwann cell surface membranes à AIDP
      • Infiltration of lymphocytes in the epineural and endoneural veins causing myelin degeneration at the dorsal and ventral roots
    • If directed at axonal membrane à AMAN and AMSAN
      • Attack is directed at the nodes of Ranvier of the ventral roots of the peripheral nerves
  • End result is blocking the neuro-electrical transmission of impulses
• Common infections
  • C. jejuni (most common)
  • HIV
  • H. influenza
  • M. pneumoniae
  • CMV

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CLINICAL FEATURES

• Ascending (distal to proximal) symmetric muscle weakness with absent deep tendon reflexes progressing over days to weeks
  • Weakness can vary from mild difficulty with walking to complete paralysis
  • Symptom peak at around 4 weeks
• Respiratory dysfunction – 10-30%
• Facial nerve palsies or oropharyngeal weakness – 50%
• Oculomotor – 15%
• Paresthesias – 80%
• Dysautonomia – 70%
  • Diarrhea, constipation, hyponatremia, bradycardia, urinary retention
• Variant Discrepancies
  • AMAN – preservation of deep tendon reflexes
  • AMSAN – more sensory disturbances
  • Miller Fisher – ophthalmoplegia with ataxia and areflexia

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DIAGNOSIS

• CSF Analysis
  • Albuminocytologic dissociation
    • Elevated protein with normal WBC
    • Present within first week and peaks at 3 weeks
    • Thought to be due to the increased permeability of the blood-nerve-barrier of the proximal roots
• Electrodiagnostic Studies (EMG and NCS)
  • Demyelinating forms
    • Decreased motor nerve conduction velocity
    • Prolonged distal motor latency
    • Complete conduction blocks
  • Axonal forms
    • Decreased distal motor and/or sensory amplitudes
  • Serial studies can be helpful since the condition can progress over time
• Antibodies
  • Specific autoantibodies can help differentiate variant subtypes
• MRI
  • Thickening and enhancement of the intrathecal spinal nerve roots and cauda equina

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DIAGNOSTIC CRITERIA

• Developed in 1978 and modified over the decades based on evolving research

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TREATMENT

• Supportive care
  • Respiratory support
    • Up to 30% will require ventilatory support
    • Impending respiratory arrest
      • FVC < 20 mL/kg
      • Maximum inspiratory pressure < 30 cmH2O
      • Maximum expiratory pressure < 40 cmH2O
    • Predictors of respiratory failure
      • Time of onset to admission < 7 days
      • Inability to cough, stand, lift elbows, or lift head
      • Elevated LFTs
      • Vital capacity < 60% predicted
    • Online tool to help predict
      • https://gbstools.erasmusmc.nl/prognosis-tool
  • Autonomic Dysfunction
    • Cardiovascular monitoring and support
      • Hypertension and hypotension
      • Bradycardia and tachydysrhythmias
    • Bowel and Bladder care
      • Urinary retention
      • Ileus management

• Disease-Modifying Treatment
  • Started within 4 weeks of symptom onset
  • Plasma exchange
    • Remove circulating autoantibodies
    • 4-6 treatments over 8-10 days
    • Complications
      • Hypotension, sepsis
  • IVIG
    • Interferes with production and function of cytokines, B-cells, and T-cells
    • 0.4 grams/kg/day for 5 days
    • Complications
      • Meningitis, rash, renal failure

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PROGNOSIS

• 60% will fully recover by 1 year
• 15% will have persistent severe motor problems
• 3-7% will succumb to the illness
  • 20% of patients requiring mechanical ventilation

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COTTAGE PHYSICIAN (1893)

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REFERENCES

1. Gibbons CH, Engstrom JW. Disorders of the Autonomic Nervous System. In: Jameson J, Fauci AS, Kasper DL, Hauser SL, Longo DL, Loscalzo J. eds. Harrison’s Principles of Internal Medicine, 20e. McGraw-Hill; Accessed May 09, 2021.
2. Diseases of the Peripheral Nerves. In: Ropper AH, Samuels MA, Klein JP, Prasad S. eds. Adams and Victor’s Principles of Neurology, 11e. McGraw-Hill; Accessed May 09, 2021.
3. Yuki N, Hartung HP. Guillain-Barré syndrome. N Engl J Med. 2012; 366(24):2294-304. [pubmed]
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6. Alshekhlee A, Hussain Z, Sultan B, Katirji B. Guillain-Barré syndrome: incidence and mortality rates in US hospitals. Neurology. 2008; 70(18):1608-13. [pubmed]
7. Fokke C, van den Berg B, Drenthen J, Walgaard C, van Doorn PA, Jacobs BC. Diagnosis of Guillain-Barré syndrome and validation of Brighton criteria. Brain. 2014; 137(Pt 1):33-43. [pubmed]
8. Hadden RD, Cornblath DR, Hughes RA, et al. Electrophysiological classification of Guillain-Barré syndrome: clinical associations and outcome. Plasma Exchange/Sandoglobulin Guillain-Barré Syndrome Trial Group. Ann Neurol. 1998; 44(5):780-8. [pubmed]
9. Lawn ND, Fletcher DD, Henderson RD, Wolter TD, Wijdicks EF. Anticipating mechanical ventilation in Guillain-Barré syndrome. Arch Neurol. 2001; 58(6):893-8. [pubmed]
10. Raphaël JC, Chevret S, Hughes RA, Annane D. Plasma exchange for Guillain-Barré syndrome. Cochrane Database Syst Rev. 2012; [pubmed]
11. Hughes RA, Swan AV, van Doorn PA. Intravenous immunoglobulin for Guillain-Barré syndrome. Cochrane Database Syst Rev. 2014; [PDF]