Wernicke-Korsakoff syndrome is a brain disorder, due to thiamine deficiency that has been associated with both Wernicke's encephalopathy and Korsakoff syndrome. The term refers to two different syndromes, each representing a different stage of the disease. Wernicke's encephalopathy represents the 'acute' phase and Korsakoff's syndrome represents the 'chronic' phase. However, they are used interchangeable in many sites. Wernicke's encephalopathy is characterized by confusion, abnormal stance and gait (ataxia), and abnormal eye movements (nystagmus). Korsakoff's syndrome is observed in a small number of patients. It is a type of dementia, characterized by memory loss and confabulation (filling in of memory gaps with data the patient can readily recall) and involvement of the heart, vascular, and nervous system. Wernicke-Korsakoff syndrome mainly results from chronic alcohol use, but also from dietary deficiencies, prolonged vomiting, eating disorders, systemic diseases (cancer, AIDS, infections), bariatric surgery, transplants, or the effects of chemotherapy. Studies indicate that there may be some genetic predisposition for the disease.Treatment involves supplementing the diet with thiamine. Wernicke encephalopathy is an acute syndrome and requires emergency treatment to prevent death and neurologic complications. In cases where the diagnosis is not confirmed, patients should still be treated while additional evaluations are completed. The disease is MONDO_0010198 (Wernicke-Korsakoff syndrome). Also known as: Korsakoff syndrome, Korsakoff's psychosis, Korsakoff's syndrome, Korsakov psychosis, Korsakov's psychosis.