Verapamil
"I was diagnosed with chronic migraine at 18 yrs old and put on topamax which helped until recently. I am 23 now and was in a car accident several months ago  started having vertigo, dizzy spells before a migraine, and almost everyday is a headache day. I went to a new neuro who started me on 120 mg verapamil, increased to 180 mg,then 240 mg at 240 mg the side effects were too much and am back to 180mg daily. It has def helped reduce vertigo. I still get some dizziness and lightheadedness every now and then. The migraines ate still almost every day. Waking up with a headache and going to sleep with a migraine many days."