Is Passing Out Headaches And Migraines Related To Brain Disorder?

When I was an adolescent, I started having migraines and passing out from them. I was worked up and seen by a neurologist who said I have some sort of "brain disorder". As a child, it was not something for me to look in to but now that I am an adult, I am curious and can't find very much information on it. The passing out episodes have subsided for the most part but I still have very severe migraines. Any idea of what the condition is?