I have on a few occasions had this very sharp pain in the back of (right side) of my head, almost paralyzing for about 4-6 seconds. The first time it happened when a tried to throw a ball during a baseball game. It has been more frequent since then, once when lifting a heavy object, and now even when i turn my head too fast. I can feel it a little down the back of neck (right side) as well. Any ideas what it is??