I had a bone spur in my sinus.  I had serious, life-altering migraines for 26 years.  It was spotted by my ENT when I had a sinus infection that would not respond to any antibiotics.  The ENT was suspicious when 99% of my migraine started around 3-5 am.  He hypothesized that my allergies pushed a nearby nerve onto the bone spur.  I never had another migraine after the surgery.  Instead of several migraines a week, I have not had a migraine in over 5 years.   Approximately a year before the start of the migraines, before seat belts, I was in an automobile accident where my face was smashed against the windshield and I was knocked unconscious.  I can only guess that might have been the cause of the bone spur.   Cate