Hi and welcome to the Chiari forum.
I am so sorry u r having to deal with these symptoms and drs that know how to help.
I do not have hydrosyringomyelia, but I know form those that do it can indeed cause the pain and symptoms u mentioned.
http://www.medhelp.org/posts/Chiari-Malformation/LIST-OF-CHIARI-SPECIALISTS/show/1293483
Use the above link as a starting point to research drs that can be of more help to u and that understand ur condition a little more than the ones u have been dealing with.
The room spinning is vertigo...many with chiari do have this problem.
I do not know what to tell u other then try to get ur records to a chiari dr that can in turn inform ur drs so u can get the proper care.
"selma"