I have both RSD and PN. I know my current pain doctor said a lot of the symptoms can be similar. The thing with PN is if you can find the cause behind it then you can treat that and many times the PN gets better. Before I was dx with RSD and I was dx with PN I was under similar treatments with meds and procedures. Though I do feel that the scs is more done on rsd but I could be wrong. The difference I notice though with the rsd is that I can't tolerate even touch often times or a wind blowing can feel like a gun shot. Hypersensitive.RSD can happen from an injury or trauma or it can be unknow the why it happens.