FFinalistSouthampton · 2027
Neurology
AKT · Neurology/Demyelinating & NMJ

Guillain-Barré syndrome

Acute immune-mediated demyelinating polyneuropathy (post-infective)

Overview

An acute, immune-mediated, ASCENDING demyelinating polyneuropathy, classically a few weeks after an infection (especially Campylobacter jejuni). Progressive symmetrical weakness with areflexia; the danger is respiratory failure and autonomic instability. Treated with IVIG or plasma exchange (NOT steroids).

Recognise

  • Progressive, symmetrical, ASCENDING weakness (legs then arms) with AREFLEXIA
  • ~1–3 weeks after a GI/respiratory infection (Campylobacter, CMV, EBV); mild sensory/paraesthesiae
  • Respiratory muscle weakness (monitor FVC); autonomic instability; cranial/bulbar involvement

Red flags

  • FALLING FVC (respiratory failure → ventilation), autonomic instability (arrhythmia, BP swings), bulbar weakness

Differentials & how to tell them apart

Chronic inflammatory demyelinating polyneuropathy (CIDP)same picture but develops/relapses over >8 weeks (chronic), steroid-responsive
Myasthenia gravisfatigable, ocular, NO areflexia, antibodies
Transverse myelitis / cord compressionsensory level + sphincter signs + UMN signs
BotulismDESCENDING paralysis, pupils involved
Hypokalaemia/periodic paralysiselectrolytes

Investigations

Clinical + nerve conduction studies (demyelination); LP shows ALBUMINOCYTOLOGICAL DISSOCIATION (raised protein, normal cell count); SERIAL FVC/spirometry to monitor respiratory function.

Management

IVIG (or plasma exchange) + respiratory monitoring (serial FVC); NOT steroids

  1. 1Admit; SERIAL FVC monitoring (the key safety measure — ventilate before crisis); IVIG or plasma exchange; VTE prophylaxis.Gate: Steroids do NOT work in GBS (unlike MS/CIDP); and a falling FVC, not oxygen saturation, is what flags impending respiratory failure → ICU/ventilation
  2. 2Supportive care, autonomic monitoring, rehabilitation; most recover well over months.
IV immunoglobulin (IVIG) — first-line
Plasma exchange — equivalent alternative
NOT steroids — steroids are ineffective in GBS (unlike CIDP/MS)

Key points

Ascending weakness + areflexia + recent infection + albuminocytological dissociation = GBS. Monitor FVC (not just sats). Treat with IVIG/plasma exchange — steroids do not help. Miller-Fisher variant = ophthalmoplegia + ataxia + areflexia (anti-GQ1b).

Monitor & prognosis

Serial FVC, autonomic status (ECG/BP), swallow, progression then recovery.

~80% recover well; respiratory failure and autonomic instability are the acute risks.

Source: NICE CKS; neurology guidance