My second flare, which occurred long before my diagnosis, was vertigo exactly like you describe. No
balance issues, just constant room-spinning sensation. It was HORRIBLE, and I banned myself from driving for about a week because of it. It just makes it impossible to stay oriented in space when moving your head, and when driving, you constantly have to turn your head.
Since it was before my diagnosis, I had no treatment for that flareo. Still, it resolved itself completely in about 3 weeks.