Can Extra Vertebrae Cause Migraine Problem?

Hi there, I have chronic migraines, to the point where it is almost everyday. I had x-rays which revealed i have an extra vertabrae at the base of my neck, both dies, only half formed - would this be the cause of the migraines? Have been to drs + neurologists who have me on an anti-depressant to relax the muscles but dont know about these ribs as i have only just discovered it.