Hello all, I've had this forum bookmarked for ages but up until this point didn't think I had much to offer in the way of help or advice.
I think I have told this story a few thousand times since, so I won't go through everything again. Instead I will offer the Coles version 
Since I was 13 or so I had been suffering from migraines, some of them downright nasty. Anyway fast forward 31 years later and my Internist gawd bless him has found the cure for mine. ** Knock wood**
For the last year I've had dangerously high blood pressure that was resistant to medication and whatever else my MD threw at it, anyway around last Aug of 2011, he sent me on to this Internist to try and get some answers. Well anyway it has taken countless blood tests and other exams including a CT scan of my kidneys and adrenal glands.
Earlier this month I was finally diagnosed with Adrenal Hyperplasia, it's a rare disorder. I was put on medication for it, and I haven't had one single migraine since June 6th of this year, that includes no impending sense of one, or getting woken up with one in the middle of the night.
I'm not saying this is the solution for everyone else here, but if you are still battling these nasty things I would strongly urge your doctor to get your Aldesterone levels checked. If they are elevated it will certainly be a factor in getting migraines. The med I am on blocks Aldesterone.