We have a TOS forum here on NT too, the useful sticky there has many of the top info sites listed so you can get a full idea of the many symptoms.
the useful sticky thread - {see post # 1 for a crash course}
http://neurotalk.psychcentral.com/thread84.html

Usually with TOS there is a job or work connection, or an injury of some sort like car accident, sports or falls, something that affected the upper body structures.
If you did have any of those factors I do suggest trying some sort of body work or adjustments and such just to make sure things are in alignment. Might be a simple fix or some help at the very least.

Some do have bony anomalies or extra cervical ribs that cause the impingement problems.
Also poor head, neck, shoulder postures can cause or be a factor with TOS.

if RSD is affecting the upper body {arms /hands etc} it is hard to tell the difference sometimes until you learn about both and read on both forums.

An advanced PT or expert chiro should be able to give you a full evaluation and give you some idea if you could have TOS also vs only RSD.

You pretty much have to ask them to check you for TOS and see how they respond - either they will say I can do that or give you a blank look LOL .
TOS is a supposed mystery to many - kind of like RSD is.