so i went to my NS yestarday and im more confused now then when i went in there ....... they told me i have a cavity in spinal cord he really did not tell me what thats means but he said thats why i have so much pain in my neck and ringing in my ears he said most people with cm dont need surgury but my other N thanks i need surgery so i dont know if there doing surgery or not i really dnt know whats going on so stressfull

That "cavity" is likely a syrinx (Syringomyelia) Depending on the surgeon a CM with a syrinx is often considered surgical irregardless of the size of the CM. More recently however they have learned that decompression with smaller syrinxes can actually lead to more problems.

Did he run any tests or have his staff do a function assesement? At the end of the day it is still a differential diagnoses not dependent on any particular piece of data. He is likely pulling everything together to make a recommendation. Do you have a follow-up appointment?