After a crush injury to my neck, my arm turned inwards and hurt like hell. No diagnosis for 7 years. My right arm stayed turned in for many years. cranial sacral work was the first treatment that started to help.

In trying to get a diagnosis, I had many invasive tests. I had an angiogram I think it was where they wanted to trace from my groin up my body down my arm.. Many yrs ago. Either way, the puncture in my leg spread the pain into my leg on the same side as my arm...

I went to a patient pain group, and RSD was being thrown around. I asked a woman what it was, and her response was it was what I had and after the meeting she would help me get to a doctor that could diagnose me.
That happened and got diagnosed. Back in the 1980's doctors did not recognize this disease.
My leg started to turn in. Then the other leg as that was affected years later.
I worked with a top cranial and other gentle modalities. My arm was also . My arm is still not perfect as it went so many years with no help.

An anesthologist from th e Netherlands taught me to use 4 % liquid lidocaine! and a 1 sided 6 in cutip, and go down the sinus cavity. I let the lidocaine rest on the nerve bundle to interrupt the abnormal sympathetic firing.
This block will shut down the upper body flares if done morning and evening.
So this is a wonderful block we can get right on.

So the sympathetic system fires abnormally. Yes, painful, but neurological.
Dystrophy, yes.
I think the 'reflex' ( in RSD) came in due to the nerve bundle ?

This disease also spreads throughout the whole body in time so in the CRPS it is not regional.