Guillain-Barré syndrome
Formal Definition
An acute inflammatory demyelinating polyneuropathy characterized by progressive ascending weakness starting distally in the legs and progressing proximally, with areflexia, respiratory compromise, and autonomic dysfunction; typically preceded by a respiratory or GI infection (commonly Campylobacter jejuni or CMV); diagnosis is clinical supported by CSF albuminocytologic dissociation (elevated protein with normal cell count) and nerve conduction studies showing demyelination; treated with IVIg or plasmapheresis.
How It's Used on the Ward
"GBS" — the patient was fine 2 weeks ago and now can barely walk and is getting weaker by the day; starts in the feet, moves upward; the most dangerous part is respiratory — they can stop breathing, so monitor the FVC and NIF closely; often preceded by a stomach bug.
Example
""28-year-old male with 5 days of progressive ascending weakness — started as tingling in toes 2 weeks ago, now can barely stand, feet feel heavy, hands weak, facial weakness starting. Exam: areflexic in all extremities, ascending weakness to hip flexors, mild facial diplegia, no fever. No preceding trauma. 2 weeks ago: diarrheal illness resolved. CSF: protein 180 mg/dL (elevated), WBC 4 (normal), albuminocytologic dissociation. Nerve conduction: prolonged distal latencies, reduced conduction velocities, conduction block. Diagnosis: Guillain-Barré syndrome (AIDP variant). FVC 1.8L (monitor closely — at risk for respiratory failure). Started IVIg 0.4g/kg/day for 5 days. Monitor NIF q4h.""
Clinical Context
Variants: AIDP (most common, demyelinating), AMAN (axonal, motor only), AMSAN (axonal, motor+sensory). Classic presentation: ascending paralysis, areflexia, preceded by infection (Campylobacter jejuni 30%, CMV, EBV, Mycoplasma). Red flags requiring ICU: FVC <1.5L, NIF <-60 cm H2O (impending respiratory failure), rapid progression, severe bulbar weakness (risk of aspiration), autonomic dysfunction (HR variability loss, labile BP). Monitoring: FVC and NIF q4-8h. Treatment: IVIg (0.4g/kg/day x 5 days) or plasmapheresis (5 exchanges) — equally effective, IVIg preferred in most (easier to give). Steroids NOT effective. Complications: dysautonomia (arrhythmias, fluctuating BP, urinary retention), DVT/pulmonary embolism, pressure ulcers. Long-term: 80% walk at 6 months, 5% die, 10% have permanent disability. Variant: Miller Fisher syndrome (ophthalmoplegia, ataxia, areflexia).