Has anyone suggested Piriformis Syndrome? This is where the sciatic nerve become compressed by the priformis muscle. This is VERY hard to diagnose, and from what i understand, they can't see it by an MRI. I don't know why. That's why it's so often overlooked. And I really don't know what the treatment is, unless it's physical therapy, to release the sciatic nerve.
You might ask your doctor about this, to see if it's a possibility. It sounds like it could be. It can't hurt to ask, since all other options have been looked at. Best of luck and God bless! Hugs, Lee
PS -- PLEASE LET US KNOW, OK???