Locked-in-like fulminant infantile Guillain-Barré syndrome associated with herpes simplex virus 1 infection

Introduction: Guillain-Barré syndrome (GBS) may rarely manifest as a peripheral locked-in syndrome. Methods: Clinical and instrumental features of a fulminant form of infantile GBS were assessed. Results: After 2 days of rhinitis, a 6-month-old infant was intubated in the emergency room for sudden-onset respiratory failure. Neurological examination showed generalized areflexic flaccid paralysis with no detectable interaction, which resembled a coma. Brain MRI was normal. Lumbar puncture showed pleocytosis (43 cells/mm³) and herpes simplex virus 1 (HSV1) PCR positivity. EEG showed normal sleep-wake cycles, and EMG demonstrated nerve inexcitability. Acyclovir and immunoglobulins provided no benefit. After 1 week, lumbar puncture showed albuminocytological dissociation (protein 217mg/dl). Plasmapheresis was then started, and progressive improvement occurred. At age 1 year, the child had recovered well with residual distal lower limb hyporeflexic weakness. Conclusions: A fulminant infantile GBS variant presenting as peripheral locked-in syndrome can be associated with HSV1 infection likely due to autoimmune cross-reactivity.