If it is an inner ear issue yes it serves a CT or even X-ray of a spider should tell if there is deformities. It should be easy. Yes I believe the saccule is linked to balance bit of a leap of faith on my part I have not read any studies saying so but it is with most other animals so logic says yes it is.
Often people do try to sound scholarly and misuse terms, confuse definitions, or just plain ignore physics. I was hopeful that there is an article with at least some research into the cause of snake wobble. I am assuming, you, Skip, have also no of no such research? Pity that, I would like to know for certain. My thought is a neurological issue of some sort and not a balance issue. It looks like a spasticity and poor muscle control to me such as can some times be seen in stroke sufferers. Again just a guess on my part no evidence just observations.