While sleeping one night I felt and intense pain while sleeping. Something akin to a friction burn but much more intense. As I was asleep , that's what I thought it was. The next day I felt nothing. That was six weeks ago. I have had occasions where I have brushed against things and felt the pain - fortunately, It only lasts for a second. When I tough my skin it feels numb. The sensation is similar to the feeling of the cheek after an injection at the dentist. I have not banged it or sustained any injury there.