@dlgreene1 I am a spine surgery patient and I had vertigo when muscle spasms were independently rotating my C1 and C2. That stretches the vertebral arteries that run through the side of the cervical vertebrae which is part of the blood supply to the brain. I had dizziness bad enough that I fell over and couldn't stand up. Working with a physical therapist corrected that, and since my fusion surgery for C5/C6, it hasn't been much of an issue. I can recognize when I get some twisting which begins with a headache, earache, or jaw pain on one side, and I can check myself and get the tight side stretched out and get the vertebra aligned again. I also have thoracic outlet syndrome or TOS which makes one side of my neck tighter than the other, so it makes me a bit prone to this twisting of vertebrae. I have to be careful sleeping to maintain spine alignment, so I don't cause a muscle spasm.