Case Report: A rare case of concurrent diabetic ketoacidosis and severe acute pancreatitis, followed by Guillain-Barré syndrome and Wernicke's encephalopathy.

The coexistence of diabetic ketoacidosis (DKA) and severe acute pancreatitis (SAP) is a life-threatening metabolic emergency complicated by multiple organ dysfunction syndrome. The sequential development of Guillain-Barré syndrome (GBS) and Wernicke's encephalopathy (WE) in such critically ill patients is exceedingly rare and prone to missed diagnosis. A 26-year-old obese male was admitted with unconsciousness after excessive cola ingestion. He was diagnosed with DKA, SAP, pneumonia, sepsis. During hospitalization, the patient developed progressive visual impairment, dysphagia, hoarseness, and ophthalmoplegia. Neurological examination revealed diminished to absent tendon reflexes. Typical albumin-cytologic dissociation was detected in cerebrospinal fluid. Cranial magnetic resonance imaging showed characteristic hyperintense signals in the mammillary bodies and periaqueductal region, accompanied by reduced serum vitamin B1 levels, consistent with WE. The patient was eventually diagnosed with overlapping GBS and WE. He received repeated intravenous immunoglobulin therapy and thiamine supplementation. The patient's neurological function gradually recovered and he was discharged in stable condition. Critical illness-related systemic inflammation, metabolic derangements and infection can induce GBS, while inadequate thiamine supplementation and heightened consumption result in severe thiamine deficiency complicated by WE. Close neurological monitoring, timely thiamine supplementation, and standardized immunotherapy contribute to favorable clinical outcomes.