Craniocervical Instability

[Di1]

Any of you that have been diagnosed with a Craniocervical Instability (CCI)...can you tell me what diagnostic test confirmed this? I have been suffering for the past 18 mos with what totally seems like a CCI and has been confirmed by a PT that there is definitely something unstable in my occipital/sub-occipital area. He said that the alar and apical ligaments are definitely lax on the right side base of my skull (this all started after a chiropractor snapped my neck 3x/wk for 9 mos...so makes total sense to me that something could've happened) and that is where I feel all the issues. I can literally hear my skull shift as I move, a grinding noise, and it totally feels like my head is falling off my spine. I feel like to correct it a Dr would have to literally reposition my skull and then fuse it in place. This, along with all the sx you get with chiari. I've been told that my c-1 doesn't form a complete arch, I have a retroflexed odontoid and there is wear and tear at c-1-2 that wasn't there 6 mos ago. I am getting worse every day. None of the Drs believe it. I've had many flexion/extension xrays, CTs, MRIs and they all claim nothing is wrong. Is there imaging that can be done specifically in the area of the craniocervical junction?? On Thurs I have my 6-mo f/u with the neurosurgeon that did my last cervical fusion (c-5-7) in Feb and I plan to tell him that I am worse than ever and continue to fight him on the fact that there is a CCI, but I need to know if there is other testing that can be done. Why the heck wouldn't this show? I have argued the case that when they do the flex/exten xrays it's 1 second in time....if it's due to lax ligaments maybe I need to move a bit before it shifts out of position. I also argue that the other tests are always done while laying down with head supported so it wouldn't show up. I am just desperate for it to show on imaging b/c they won't believe me or the PT, despite his hands-on objective evaluation that clearly shows CCI.