Suggest Treatment For Persistent Migraine

My 18- year old daughter has been suffering from continual migraines for app. 2 years. She has tried all conventional meds, including botox and holistic, like accupuncture, kinesiology, etc. without any relief. The only thing that helps is when she experiences a severe drop, like jumping off a cliff at the river or on a amusement park ride like supreme scream. It seems like the pressure of the drop makes the headache go away indefinitely. Based on this, can you make recommendations on other ways to help because jumping is not always practical. Thanks so much!