Before I was dx with PN/RSD I had an injection in the original area before my condition spread which was my inner ankle/foot with what sounds like similar. It was a block and also anesthetic. I could not tolerate that now and for some conditions like mine an injection into the area of the condition is not good. Everyone is different. At that time though the area was numb from it but I still could feel pain if that makes sense.
I wonder and maybe someone else could give insight and maybe it does not work for PN as I got mine for the and it did not work but why sympathetic blocks are not used?