Hi...well a syrinx can form after an injury, but with WC u will have to prove it is not a congenital condition as a syrinx can also form from a malformation of the skull ....called Chiari Malformation, this malformation causes the cerebral tonsils to herniate and block CSF flow...this causes the syrinx to form.
The condition of having a syrinx is also known as Syringomyelia.
Many times there is not much they can do for a syrinx as they tend to be too small for a shunt or stent....so, getting a brain MRI to see if ur syrinx was there and the injury just triggered symptoms to flare....
If u do have Chiari, they may suggest the decompression surgery to restore proper CSF flow in hopes the syrinx shrinks....
U may do well to research Syringomyelia and Chiari to locate Drs more informed on them and to do more testing for u....See the Chiari forum here on MedHelp -
http://www.medhelp.org/forums/show/257?camp=msc