To describe a severe Campylobacter-associated, anti-GQ1b–positive Bickerstaff brainstem encephalitis (BBE) case with respiratory failure, incomplete response to IVIg/corticosteroids, improvement after plasma exchange, and concern for possible recurrence.

BBE is a rare anti-GQ1b spectrum disorder characterized by ataxia, ophthalmoplegia, and encephalopathy. Early cerebrospinal fluid and neuroimaging studies may be unrevealing despite rapid neurologic deterioration.

Retrospective case report.

A previously healthy 27-year-old Japanese man presented with acute ataxia, dysmetria, and bilateral hand paresthesias following a febrile diarrheal illness. Initial CT head and cerebrospinal fluid were non-inflammatory (WBC 1, protein 30 mg/dL), and early MRI was nonlocalizing. Within 72 hours, he developed profound encephalopathy, generalized areflexia, bulbar dysfunction, and respiratory failure requiring mechanical ventilation. EEG evolved from normal to diffuse slowing. MRI brain and spine remained negative for acute lesions or nerve root enhancement, though cerebellar-predominant atrophy was noted. Stool testing confirmed Campylobacter infection. Collateral history revealed a similar severe childhood episode in Japan requiring intubation, reportedly termed cerebellitis/encephalitis, with complete recovery. He received high-dose corticosteroids and IVIg for 5 days but had persistent bulbar/neuromuscular impairment and failed initial extubation. Plasma exchange was initiated with subsequent neurologic improvement, including improved command following, symmetric limb strength ≥4+/5, and successful extubation. Serum anti-GQ1b IgG returned strongly positive (1:3200), confirming BBE. Residual ophthalmoplegia and areflexia persisted at discharge.

This case highlights severe seropositive BBE with initially bland CSF and nonlocalizing neuroimaging, reinforcing that normal early studies do not exclude fulminant anti-GQ1b spectrum disease. Improvement after plasma exchange following incomplete response to IVIg/corticosteroids supports considering escalation in severe presentations. A remote similar episode and cerebellar atrophy raise concern for possible recurrent anti-GQ1b spectrum disease, though the relationship between episodes remains uncertain.