Thanks. Luckily I was home when the vertigo hit. Now that I know that it's possible, I will be careful any time I'm feeling any other migraine symptoms.

As I've thought about it more, I remembered that a few years ago I used to get brief dizzy spells when I would tilt my head back to look up. Tilting my head back down made them go away.

Saturday night I fell asleep in front of the TV -- could not keep my eyes open no matter how hard I tried. After about an hour I woke up and went to bed, and slept until 11:30 the next day, about 11 hours in all. I'm hoping that marked the last phase of the migraine. I'm feeling better now.