Neurology

Guillain-Barré syndrome

An acute immune-mediated polyradiculoneuropathy causing progressive symmetrical weakness, areflexia and potentially rapid respiratory or autonomic failure.

In a nutshell

GBS is an acute peripheral polyradiculoneuropathy causing progressive symmetrical weakness and areflexia, often after an infection. The emergency is respiratory or bulbar failure: admit, trend vital capacity and clinical respiratory function, involve critical care early, and treat significant or worsening disease with IV immunoglobulin or plasma exchange.

Classic presentation

Progressive symmetrical leg weakness with reduced or absent reflexes, paraesthesia or neuropathic pain and possible facial, bulbar or autonomic involvement after a recent diarrhoeal or respiratory illness.

Key points

GBS is a peripheral nerve process: weakness is usually symmetrical and progressive with hyporeflexia or areflexia.
Serial vital capacity or forced vital capacity and clinical bulbar assessment are more useful than oxygen saturation alone for anticipating respiratory failure.
CSF albuminocytological dissociation supports GBS but can be absent early; nerve-conduction studies support diagnosis and subtype.
Anti-GQ1b is most useful when Miller Fisher syndrome is suspected; routine antiganglioside testing has limited value in typical GBS.
IV immunoglobulin and plasma exchange are alternative disease-modifying treatments; corticosteroids are not recommended for GBS and routine sequential IVIG plus plasma exchange is not supported.
Rehabilitation, thrombosis prevention, pain management, autonomic monitoring and diagnostic reassessment are part of treatment, not optional extras.

First-line investigation

Serial respiratory and bulbar assessment with neurological examination, supported by lumbar puncture and nerve-conduction studies; do not delay escalation while waiting for a later supportive test.

Management

Admit and protect the airway

Admit urgently, assess swallow and cough, trend respiratory function and autonomic observations, and involve critical care before overt respiratory failure develops.^2,1

Confirm the pattern without delaying treatment

Use serial neurological examination with CSF and nerve-conduction studies as supportive tests; investigate atypical features and remember that early tests can be normal.^1,2

Use one evidence-based immunotherapy

Give specialist-directed IV immunoglobulin or plasma exchange for significant or worsening weakness, and do not use corticosteroids or routine sequential IVIG and plasma exchange.^1,2

Prevent secondary harm

Treat neuropathic pain, prevent venous thrombosis and pressure injury, support nutrition and communication, and monitor autonomic, cardiac, bowel, bladder and swallowing complications.^1,2,3

Rehabilitate and check for an alternative course

Provide multidisciplinary rehabilitation and reassess for treatment-related fluctuation, acute-onset CIDP or another diagnosis if deterioration continues beyond the expected acute phase.^1,2

Exam traps

Normal oxygen saturation does not exclude impending respiratory failure: trend vital capacity and assess cough, speech, swallow and work of breathing.
Normal CSF protein early in the illness does not exclude GBS.
A sensory level, marked asymmetry, early sphincter dysfunction or brisk reflexes should prompt reconsideration of spinal cord or another neurological disease.
Do not use corticosteroids as disease-modifying treatment for GBS.
Miller Fisher syndrome is the ophthalmoplegia, ataxia and areflexia variant, not simply an eye presentation of classical GBS.

Illustrations

Molecular mimicry in Guillain-Barré syndromeDiagram showing cross-reactive antibodies raised against an infectious antigen, such as Campylobacter jejuni, binding to structurally similar gangliosides on peripheral nerve myelin.PassFinals · original

Ascending pattern of weaknessBody diagram showing weakness beginning distally in the legs and progressing upward through the trunk, arms and, in severe cases, bulbar and respiratory muscles.PassFinals · original

Serial FVC monitoring trendGraph illustrating a falling forced vital capacity trend over days, shown as the trigger for escalation to respiratory support before oxygen saturation drops.PassFinals · original

Key sources

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.