I am not an expert on this condition, so please think of these comments as only general musings. While I was a Resident, however, I did spend some time working with a Surgeon who dealt with this condition quite a bit.
As you probably already know it involves the dysfunction of a nerve - usually after a minor trauma to the nerve - that results in a hyperalgesic (pain out of keeping with the stimulus) response to the affected area. There seem to be varying degrees of the condition and in the worst cases the affected area becomes discolored and cool, and can be so sensitive to the touch that folks can feel even light touches as excruciating pain.
There are some medications that are specifically intended to target pain from malfunctioning nerves (neuropathic pain), and these tend to be tried first, but they can be of little benefit to people with the worst forms of complex regional pain syndrome, which also goes by the name reflex sympathetic dystrophy just to complicate things needlessly.
The Surgeon I worked with performed a relatively new type of procedure where he would implant spinal stimulators to try and relieve the pain of those with the worst form of the condition. These stimulators would activate the sensory part of the spinal cord corresponding to the patient's site of pain and replace the pain with a sort of buzzing sensation, which in theory patients would find more tolerable. The whole thing was meant to work on the gate theory of pain - the idea that essentially we can only really feel any one thing at a time and when subjected to multiple sensory stimuli we tend to block some out.
As I recall, and this was about 5 years back, there weren't any large studies that validated this treatment. The condition itself is so rare, it would probably be very hard to study it in large groups.
Of the folks I saw who had the nerve stimulators implanted (4 or 5 patients), some had a great response, while others noticed no improvement. All of them were usually at their wits end by the time they saw this surgeon and were willing to try just about anything. And of course as with any procedure, I would recommend asking a Surgeon what their individual rates of success and complication rates were.
I hope these general comments are helpful. Feel free to send me a personal message if you had any specific follow-up questions.
M.