 Migraine and the skin sensitivity that accompanies it can go away in minutes after a nerve block, which is a procedure involving an injection of a small amount of a local anesthetic next to a nerve to the skin, causing an area of skin to become numb. We have also noticed that light sensitivity goes away quickly after a nerve block. We would like to see how quickly this happens and how long the benefit of nerve block lasts. We are interested to see if these effects are due to the injection itself or due to the lidocaine. 