What Every ICU Doctor Must Know About Guillain-Barré Syndrome

Guillain-Barré syndrome remains the most common cause of acute flaccid tetraplegia globally, yet its management in the ICU setting requires nuanced understanding across diagnosis, monitoring, and treatment. This 2025 narrative review from the Neurology-ICU department at Pitié-Salpêtrière, published in Annals of Intensive Care, synthesizes current evidence with practical guidance for intensivists.

GBS is an immune-mediated polyneuropathy triggered in two-thirds of cases by a preceding infection. Six pathogens have been conclusively linked through case-control studies: Campylobacter jejuni (most common, especially in Asia), cytomegalovirus, Epstein-Barr virus, Hepatitis E virus, Mycoplasma pneumoniae, and Zika virus. Post-vaccination GBS is rare (~1/100,000), and the risk from influenza vaccination is lower than from influenza infection itself. Non-infectious triggers include immune checkpoint inhibitors, chemotherapy agents, and surgery.

Pathophysiology centers on molecular mimicry: microbial antigens structurally resemble gangliosides (GM1, GD1a) at nodes of Ranvier, prompting IgG antibody production that activates complement and recruits macrophages. Three electrophysiological subtypes emerge — AIDP (demyelinating, most common in Western countries), AMAN, and AMSAN (both axonal). AIDP features complement deposition and T-lymphocyte infiltration with reduced conduction velocity, while axonal subtypes show Na+/K+ ATPase blockade at Ranvier nodes. Emerging evidence implicates antibodies against paranodal proteins (neurofascin, contactin) in treatment-resistant cases initially resembling GBS.

Clinically, GBS progresses in three phases: ascent (typically under 4 weeks, 80% within 2 weeks), plateau, and recovery. Classical presentation involves ascending symmetric sensorimotor deficits, areflexia, and cranial nerve involvement. ICU admission is indicated for respiratory failure (20% need mechanical ventilation), bulbar dysfunction, or significant dysautonomia (blood pressure lability, arrhythmias, urinary retention). Diagnosis relies on clinical criteria supported by CSF showing albumin-cytological dissociation and nerve conduction studies; both may be normal early. Validated scores (EGOS, mEGOS, EGRIS) help predict ventilatory needs and prognosis.

Treatment with intravenous immunoglobulins (IVIg, 2 g/kg over 5 days) or therapeutic plasma exchange (TPE, 5 sessions) are equally effective and shorten disease duration; combination therapy provides no added benefit. Corticosteroids are ineffective and not recommended. Supportive ICU care — including careful ventilatory weaning, dysautonomia management, pain control, thromboprophylaxis, and nutritional support — is critical. Neurofilament light chains in CSF and plasma are emerging as prognostic biomarkers. Complement inhibitors (eculizumab, IgG-degrading enzyme) are under active investigation as targeted therapies. Mortality is below 5%, but up to 20% of patients retain significant disability at one year, underscoring the importance of early rehabilitation.