I am a 56-year-old female and have had migraines since I was about 35. They are preceded by a muscle knot in my neck, mostly near the base of my ear (left or right leading to a headache on the same side). Sometimes applying pressure for 40 to 60 seconds will relieve the muscle knot and prevent the migraine. Usually has to be repeated several times a day. What causes the muscle knots? If I can find the source, could I prevent or end my migraines?