I think this is a big debate with many of us.
I do know it spreads.....but if the research I've done is even half right, you can't predict where it will spread to. My research suggests it is a disorder of the entire nervous system. Not to mention sweat glands, skeletal system, circulatory system, etc.
I've had 2 doctors tell me it doesn't spread. Yet it started in my hand and has now spread into my fingers and past my wrist. This is the osteoporosis from being in a cast, but it is a side effect of an RSD limb being immobilized.
I would say it spreads......but I don't have a degree.
Hope this finds you having a "good" day. http://www.healthboards.com/ubb/heart.gif