Quandry, I did some research awhile back for a friend of mine who has chronic migraines. A newer treatment for some is acetylcholine. And, yes, there is a channelopathy component to some.

Google "migraine acetylcholine" and you'll find more info.

There are also autoimmune encephalopathies that can cause seizures and migraines.

Have you thought about seeing a geneticist?

Some people have triggers for their migraines such as MSG and other additives, tomatoes (which naturally have MSG), bright or flashing lights, changes in air pressure, being on a plane, changes in hydration and so many other things! It might be good for your family members and you to keep a journal of what you've eaten or been doing before migraines.

I no longer have them unless I eat tomatoes. They run in my family too.

Annie