@jetsetter Cervicogenic headaches can be generated from the spine. If your vertebrae are out of alignment just a bit, or twisted or tilted or if they slip forward, etc that puts extra pressure on the muscles between the neck and head and causes pain and muscle spasms. It can also cause vertigo. All of that happened to me because of a herniated cervical disc. Your physical therapist should be able to assess if your neck is out of alignment. If you have not been evaluated by a spine specialist, you may want to do that and get some imaging. If you have had a whiplash in the past, there can be changes going on with the spine even years later. I had a spinal fusion which solved these problems and gave me back quality of life.