Oh my goodness! I get the exact snapping rubber band thing in my neck when I turn my head, and have never known how to even describe it. I sort of see stars for a second. And it is very intense. That fits perfectly! But I'm undiagnosed, so let me know if you find out that it's a form of L'Hermitte's.
If the pressure goes around your ribs, it could be the MS "hug"