I too suffer from migraines but I am not sure if it is from the MG or from APS (antiphospholipid Antibody Syndrome). I know that APS can cause them. Bummer part is because of the blood clotting I get I can't take percription Migraine medicine because they restrict the blood vessels in the brain. I can only take Excedrine Migraine (?) and take a nap. If I get it at the beginning, during the Auras I am okay, otherwise they can last days. Sounds, smells, and lights really bug me during them.
I was just recently diagnosed with MG so I am not sure how they are related. Thought all of my weakness was from headache and APS.