Recently I was asked by a student to talk about yoga and migraines. So I have done some research. This blog entry is about the Mahashirsha Mudra "Gesture of the Great Head" that is for headache and tension relief (according to Mudras for Healing and Transformation.) This mudra helps relieve tension around the face, jaw an eyes which may provide relief from tension headaches. It may also ease symptoms from TMJ dysfunction. This mudra is also know for "instilling a sense of release" and helps us "let go of worry and anxiety". This release and letting go may also help headaches especially those that come from an anxious, tight mind and body.
How to: Tuck your ring fingers into your palms. Bring the tip of your thumb to the tips of the index and middle fingers. Extend your little fingers out as much as possible. Rest your hands in your lap with palms facing upward. Relax your shoulders back and down with your crown towards the ceiling. Concentrate on your breathing, especially on your exhale. Mudras for Healing and Transformation suggests the following verse to say while holding this mudra: "My exhaling breath allows me to release stress and tension from my entire body."
Please let me know how this works for you!