First I'll let you look at this link about Neuro Stimulation for CRPS
It's written by the company my doctor's office uses, so it's got some marketing stuff, but it will give you an idea of what the end product will be.
When they do the trial or screening test, they don't implant anything. It's like inserting an epidural catheter from what I understand. I'll be mildly sedated for the insertion of the leads, but I'll be awake enough to tell my doctor what I'm feeling. This will help make sure that they cover the whole area of my pain.
I'll have five days to use the device with a special controller worn on my belt area. This way, I don't have to commit to the surgery to implant everything else (battery, stimulation system etc...). Anyway, I'll get to see if I can be more active, more comfortable and generally functioning better.