In reply to:

I think the scotoma itself is just the small area of disordered vision/blind spot. The migraine sufferer has "scintillating scomata;" macular problems will give a "central scotoma," etc.

Now I see (sorry, bad pun). I had a migrine once with scintillating scomata. It was truly horrible. I was in eighth grade, had this splitting headache all day, and ended up throwing up when I got home. Didn't even know what a migraine was at the time.

One of Oliver Sacks' books compares the drawings some historic nun made of her visions (I forget her name) to scintillating scomata, and he makes a pretty good case that she was in fact having migraines.