Wernicke-Korsakoff syndrome is a brain disorder caused by thiamine deficiency. Wernicke-Korsakoff is actually two disorders. Wernicke disease involves damage to nerves in the central and peripheral nervous systems. It is often caused by malnutrition due to alcoholism. Korsakoff syndrome is characterized by memory problems and nerve damage. High doses of thiamine can improve muscle coordination and confusion, but rarely improves memory loss.