The dull pain starts behind your eye, like it always does when you are stressed and overtired. You know that a migraine is developing, and start to wonder how you will manage this one. Grandma always told you to turn off the lights and apply hot compresses to your forehead. Your co-worker swears by her megadoses of Vitamin B Complex. You love the convenience of over-the-counter combination analgesics with caffeine. You have heard of prescription nasal sprays, pain killers classified as controlled substances, and even something about injectable bacterial toxins. There are as many choices for...