Guillain-Barré syndrome commonly follows which of the following events?

• A. Recent infection
• B. Recent head trauma
• C. Recent vaccination
• D. Prolonged bed rest

Answer: (A)

Guillain-Barré syndrome is an autoimmune attack on the peripheral nerves that most often starts after an infection. The immune system, in responding to a recent infection (often a gastrointestinal illness from Campylobacter jejuni or a viral respiratory infection), can generate antibodies that cross-react with nerve components due to molecular mimicry. This misdirected immune response damages myelin or the nerve axons, slowing or blocking nerve conduction and producing the rapid, progressive weakness and areflexia seen in GBS. Although vaccines have been reported as rare preceding events, they are not the typical trigger. Head trauma or prolonged bed rest do not commonly precipitate GBS. So the most frequent antecedent event is a recent infection, typically occurring within a couple of weeks before symptoms begin.