ABSTRACT
Morbid obesity is a curable systemic disease that can cause several complications, including hypertension, diabetes mellitus, and osteoarthritis. However, it is not easy to control solely by conservative management. Bariatric surgeries, such as sleeve gastrectomy and gastric banding, are recently developed treatments that are applied to patients with morbid obesity in Korea. However, gastric surgery can cause surgical or metabolic complications, such as thiamine deficiency, which can lead to Wernicke's encephalopathy. This metabolic complication presents with typical symptoms of confusion, ophthalmoplegia, nystagmus, and ataxia. In this case report, we present a case of Wernicke's encephalopathy, which developed slowly following sleeve gastrectomy in a patient with morbid obesity.