United Brachial Plexus Network, Inc.

Is Thoracic Oulet Syndrome a part of a Brachial Plexus Injury?

Yes, TOS is part of the Brachial Plexus:

Thoracic outlet syndrome (TOS) consists of a group of distinct disorders that affect the brachial plexus (nerves that pass into the arms from the neck), and/or the subclavian artery and vein (blood vessels that pass between the chest and upper extremity).

http://en.wikipedia.org/wiki/Thoracic_Outlet_Syndrome