I have a sharp pain (on the right side) that comes and goes in my head. It's behind my ear, above the large bone in back of my skull. The very sharp, stabbing pain hits and then no pain and about 10 sec. later it stabs pain again. A pain pill takes away the pain for about 20-24 hrs. My mother told me that she had the exact same thing over 20 yrs ago when she went outside to clean off her car on a very windy, cold day in winter with nothing on her head. She went to emergency and they x-rayed, blood tests and found nothing wrong. What is this?