Guillain-Barré Syndrome (GBS)

The most common form of neuromuscular paralysis in developed countries. Rapidly progressive inflammatory demyelinating peripheral neuropathy — can progress to paralysis, including respiratory paralysis, over 3–4 weeks.

Incidence in Australia is similar to the US (~1–2 per 100,000 annually), male:female ratio 2:1. Mortality <1%. Often affects young people with long life expectancy, making residual deficits an important cause of long-term disability. 80% recover without significant disability; 5% relapse. ~40% of patients require inpatient rehabilitation (especially those needing ventilatory support).

Aetiology and pathogenesis

Immune-mediated — acute fulminant demyelinating inflammatory polyneuropathy. T-lymphocyte sensitisation to peripheral myelin protein drives disease induction; lymphocytic infiltration causes patchy demyelination along peripheral nerves/nerve roots, impairing conduction (slowed velocity, conduction block). CSF protein rises in the second week of illness; the inflammatory process typically resolves and remyelination begins within 2–3 weeks.

~60% of patients have a preceding upper respiratory illness; ~27% have no identified preceding illness. Cytomegalovirus and Campylobacter jejuni infection are implicated in the axonal form of GBS.

Presentation

Symmetrical weakness, starting distally and progressing proximally; paraesthesia/pain in the limbs (less common). Reflexes depressed or absent; sensation usually intact.

Investigations

CSF protein elevated; abnormal motor nerve conduction studies.

Treatment

Acute setting: hospitalisation, respiratory support, and plasma exchange within the first 7 days of onset — shortens the time needing respiratory support and to independent walking, and is associated with better function at 6 months. IVIg also hastens recovery. Corticosteroids are not recommended — found ineffective and have fallen out of favour. Physiotherapy to prevent foot drop. Regular respiratory function monitoring; artificial ventilation may be required.

Rehabilitation and complications

~40% require inpatient rehabilitation (most are significantly disabled, often having needed ventilatory support acutely).

• Restrictive pulmonary function during REM sleep — poor inspiratory effort and secretion build-up (may have needed ventilation); needs chest physiotherapy and inspiratory training (incentive spirometry).
• DVT and PE — thromboprophylaxis.
• Dysautonomia — excessive sympathetic outflow with hypertension; patients are sensitive to vasoactive drugs, risking cardiac arrhythmia.
• Prolonged immobilisation — low blood volume causing postural hypotension, which can impede rehabilitation.
• Fatigue and pain — de-afferentation pain syndromes occur in 55–72%, driving fatigue/depression; OT-supervised desensitisation therapy for activities of daily living; antidepressants and neuropathic pain agents are commonly needed.