First of all sincerely my heart goes out to you!
Mine started in left arm and hand (broken wrist surgery) and was caught fairly early, by the grace of a WONDERFULphysical therapist.
I too am fearing the spread because I can now feel the pain further up my arm.
I can not imagine having it confirmed in all limbs and back. Do you think it has anything to do with the SCS surgery or maybe it spreads anyway?
Kevscar talked about spreading happening to 77% of RSD/CRPS anyway.

We need more awareness and research for this monster disease! So many questions! What makes it spread, what prevents it, what slows it?

The things that help me cope are nerve blocks, P.T., moderate consitent activity (but not to point of pain) warm epsom salt baths, THIS SUPPORT GROUP. Vitamin C 1000 mg. and 500 mg. per day is recommended by my PM Dr. to help prevent spread.
I try to borrow from a young girl's quote. "Living with CRPS, not dying with CRPS".