Abstract
An older woman developed acute progressive limb weakness associated with pain, paraesthesia and falls 2 weeks after receiving a respiratory syncytial virus (RSV) vaccine. Initial examination and imaging suggested alternative diagnoses, including cervical spondylotic disease and cerebrovascular pathology and early neurophysiology was non-diagnostic. During admission, she deteriorated with urinary retention, areflexia and type 2 respiratory failure requiring intubation and ventilation and was commenced on intravenous immunoglobulin (IVIG). Cerebrospinal fluid analysis later demonstrated albumin-cytologic dissociation and repeat nerve conduction studies confirmed an acute inflammatory demyelinating polyradiculoneuropathy consistent with Guillain-Barré syndrome (GBS). She improved following intensive care and IVIG, with partial recovery of limb strength and functional status and was discharged to a rehabilitation facility. This case illustrates a rare but important possible association between RSV vaccination and GBS; highlights the diagnostic challenges of early presentations with non-specific symptoms and inconclusive investigations; and emphasises the need for serial assessment and early escalation of care to optimise patient outcomes.