Under-recognized Etiology of Altered Mental Status in a Patient with Alcoholism.

Wernicke's encephalopathy is an important condition for the emergency physician (EP) to consider in patients at risk for malnutrition. A 60-year-old man with history of alcoholism presented with word-finding difficulties, dysmetria, ataxia, and personality changes. After treatment with high-dose thiamine, his neurological status returned to his baseline. Although EPs routinely prescribe thiamine for patients with alcoholism, the common initial dose of 100 mg per day is likely subtherapeutic, and the population of patients at risk for malnutrition is much broader than only those with alcoholism, and includes those with cancer, anorexia nervosa, hyperemesis gravidarum, and others. EPs must be aware of this low-cost, readily available prophylaxis to prevent long-term neurological morbidity.