@natvlk I would recommend seeing a spine specialist and/or a physical therapist who has knowledge of rehabbing spine issues. When you get neck muscles spasms it can move your cervical vertebrae around which can cause dizziness. There are some spine issues that alter blood supply in the vertebral artery like Bow Hunter's syndrome. If you feel like you've eliminated other possibilities and no one knows, it could be a physical alignment problem that physical therapy may help. I am a spine surgery patient and have had muscle spasms cause dizziness.