I had a "trigger" (car accident / contusion (aka dashboard injury)) when it got to my knees & legs. But when it spread to my shoulders/arms/hands in 2008 there was none. NONE. So you don't need a trigger for it to be CRPS. If it is, I hope they find something that works soon.

I couldn't stand Lyrica and my neurologist insisted I try this because it was supposed to be "better" than Neurontin. When I had taken my first dose, after a while, I got a terrible migraine triggered by a totally empty stomach feel and I had just eaten dinner (I was stuffed). Suddenly I felt as if I hadn't eaten in DAYS. Terrible; and of course that triggered a migraine. I couldn't take it, so back to the Neurontin it was.

I do fine pain wise on Neurontin & buprenorphine (but I have late stage CRPS in both legs).