Acute Inflammatory Demyelinating Polyneuropathy (AIDP)


  • Rapid onset polyneuropathy that manifests most often with ascending weakness and numbness that can involve the respiratory and facial musculature also
  • Usually preceded by infectious illness a few weeks prior, some flu vaccination associations



  •  Acute, progressive extremity weakness, weak or absent reflexes, and potentially subjective sensatory changes
  • Often, infectious symptoms precede AIDP symptoms by a few weeks
    • There are a TON of variants of AIDP, with some having cranial nerve weakness early, proximal weakness, sensory ataxia, primarily sensory loss, or rapid muscle weakness; do not use lack of classic ascending weakness to dismiss the idea of AIDP
    • Sensory loss is common in an ascending pattern too



  • LP – albuminocytologic dissociation = high protein & normal cell count
    • One exception is HIV, which can cause AIDP but also have a high cell count and high protein count
  • EMG/NCS – shows a demyelinating pattern (temporal dispersion and decreased conduction velocities). This can be normal in the first few days and may need to be repeated 2 weeks after if the diagnosis is not clear
  • Differential diagnosis: spinal cord lesions can mimic GBS including with areflexia, LEMS, sometimes MG, acute HIV or HCV, viral myelitis (entero/West Nile)



  • ABCs! NIF at baseline then Q4-6 hours
    • NIF < -30 with good effort generally warrants ICU monitoring
  •  IVIG or PLEX (PLEX requires central line)
  • Can get worse if you give them steroids