Wernicke–Korsakoff Syndrome

Abstract Wernicke–Korsakoff syndrome refers to a life‐threatening encephalopathy due to inadequate supply of thiamine (vitamin B1) to the brain. It is a combination of Wernicke encephalopathy (WE), an acute neuropsychiatric disorder fully responsive to prompt and adequate thiamine replacement, and Korsakoff syndrome (KS), the chronic, irreversible form of WE that does not remit with thiamine treatment. Thiamine deficiency can occur in any condition of unbalanced nutrition that lasts for 2–3 weeks. These include poor nutrition, chronic alcohol misuse, loss of thiamine owing to recurrent vomiting or malabsorption, increased thiamine requirements owing to chronic diseases, prolonged and excessive carbohydrate intake and gastrointestinal surgical procedures, in particular, patients after bariatric surgery. The diagnosis is clinical and is mainly supported by the dramatic improvement of neurological signs to parenteral thiamine. Neuroimaging studies are useful to confirm the diagnosis of both WE and KS. Patients with suspected thiamine deficiency should be treated immediately with parenteral thiamine at the doses deemed to be effective in the treatment of WE and prevention of KS. Key Concepts: Thiamine deficiency can occur in a myriad of clinical settings that include malnutrition, malabsorption and increased metabolism and in patients following bariatric surgery. A thiamine deficiency that lasts for 2 to 3 weeks leads to Wernicke encephalopathy, an acute, life‐threatening disorder that is a medical emergency. Wernicke encephalopathy is fully responsive to prompt and adequate thiamine replacement. Untreated or inadequately treated Wernicke encephalopathy may lead to Korsakoff syndrome, a chronic amnesic encephalopathy that does not remit with thiamine treatment. The goal of treatment of Wernicke encephalopathy is the immediate administration of high doses of parenteral thiamine deemed sufficient to prevent Korsakoff syndrome.