Korsakoff's Syndrome is a vitamin deficiency disease caused by a lack of thiamine (vitamin B1). The body requires only small amounts of this vitamin, so the syndrome is usually only found in people who are severely malnourished, or alcoholics who have almost no other food source. As House points out, this means that patients will almost certainly weigh less than 100 pounds or will have the red nose characteristic of the breakage of capillaries in alcoholics.