Lessons from a Severe Case of Fulminant Guillain–Barré Syndrome: A Case Report

Background and Clinical Significance: Guillain–Barré syndrome (GBS) can rarely progress to fulminant paralysis with loss of brainstem reflexes, mimicking coma or brain death despite preserved cortical function. Case Presentation: A 38-year-old man developed rapidly progressive weakness following a diarrheal illness, culminating in quadriplegia, areflexia, respiratory failure, and complete loss of brainstem reflexes within 72 h. Neuroimaging was unrevealing. EEG demonstrated preserved cerebral activity with an alpha coma pattern. Despite initial intravenous immunoglobulin therapy, neurological deterioration continued, prompting escalation to plasma exchange. Gradual recovery of brainstem reflexes and motor function ensued, followed by substantial functional improvement over nine months. This case highlights the diagnostic and prognostic challenges of fulminant GBS at the interface of peripheral and brainstem dysfunction. Neurophysiologic assessment and disciplined exclusion of central etiologies are essential. Timely immunotherapy and supportive care can lead to meaningful recovery even in extreme presentations. Conclusions: Fulminant GBS should be recognized as a potentially reversible cause of apparent coma, underscoring the importance of early diagnosis and aggressive treatment.