Wernicke Encephalopathy Secondary to Intractable Vomiting as the Initial Presentation of an Obstructive Duodenal Tumor: A Case Report

Abstract

Wernicke encephalopathy is an acute neurological disorder caused by thiamine deficiency and is often under-recognised in patients without chronic alcohol misuse. Prolonged vomiting and impaired nutritional intake may rapidly deplete thiamine stores and precipitate neurological deterioration. We report a 76-year-old woman with no history of chronic alcohol use who presented with persistent, intractable vomiting and subsequently developed severe dizziness, generalised weakness, truncal ataxia, and acute confusion. Brain magnetic resonance imaging demonstrated bilateral symmetrical lesions consistent with Wernicke encephalopathy, and the serum thiamine concentration was 40 nmol/L. Immediate high-dose parenteral thiamine produced rapid neurological improvement. Initial contrast-enhanced abdominal computed tomography and two standard upper gastrointestinal endoscopic examinations were non-diagnostic, apart from gastric stasis. Because distal duodenal obstruction remained suspected, a third examination was performed with a paediatric colonoscope. This revealed a large exophytic intraluminal stenosing tumour in the distal duodenum. Endoscopic biopsies showed a duodenal adenoma with high-grade dysplasia. Following multidisciplinary assessment, the patient underwent a palliative gastrojejunostomy. The postoperative course was uneventful, with resolution of vomiting, abdominal pain, and neurological symptoms. This case emphasises that Wernicke encephalopathy should be considered in patients with prolonged vomiting and new neurological manifestations, even without alcohol misuse. Persistent obstructive symptoms and gastric stasis after non-diagnostic standard endoscopy should prompt evaluation of the distal duodenum using an appropriate alternative endoscopic approach.