I'm leaning towards the explanation you've gotten as it really does make the most sense, Koala.

The thing with the hug is that it is apparently due to spinal lesions. In my experience, when the hug comes on, there are several other sensations (as tkirk mentioned) that come on at the same time; sensitivity to touch, burning, numbness and it is often very, very intense.

I have had the hug on it's own, when I was in the final healing stages of a spinal lesion attack, that just felt like pressure with difficulty breathing (like heaviness on the chest). However, the only sharp pain that I've had associated to the hug is the way my skin felt. I've had no sharp pain internally.

It may be a spasm of some sort that you are experiencing, which I get BETWEEN my ribs, internally . . . that's not due to MS though, it's from Ulcerative Colitis.

The hug spasms don't feel like other spasm at all (to me). That's what they ARE, apparently, but the only indication that it is a spasm (for me) is little jittery feelings inside; nothing sharp, and nothing like the charlie horse spasms I get from spasticity in my legs.

Maybe others have experienced something similar to what you are saying though, and can relate. I would at least be getting that checked out for another potential cause though, if I were you . . .

Cherie