HI,
I also have RSD in my foot and leg. I first recieved sympathetic blocks. Like your son they worked for a few hours. After this my doc did a epidural drip that sometimes will work when a block works any little bit. After a failed attempt with the epidural drip then we went with the SCS. My stim works great for the leg and foot pain but it is still cold and blue. The down side is that I have had three surgeries to change the placement of the battery because it would be prtruding once the swelling goes down. I now am scheduled for another surgery because the stiches that hold the battery in place have busted loose. The other down side to my experience is now I have Severe back pain due to all the surgeries. I wish your son the best and hope he can be pain free. I am 28 and was diagnosed when I was 26. Im sure I had it since I was in High School. I just know found a doctor who had any knowledge about RSD. If you have any questions about any thing please feel free to pm me or email me. I,ll email you so you will have mine if you ever want to talk about anything.