hi Blue,

I am making the assumption that they are talking about sympathetic nerve block done alongside the spine. This may give them a better idea but I do not think it can confirm or unconfirm a diagnosis. If the block works it tells you that you have sympathetically maintained pain. However, not everyone responds to the blocks and not all cases of CRPS have sympathetically maintained pain.

It WILL give you information, it may give relief and the steroid injection to the area may break the cycle somewhat if sympathetics are involved.