Topamax was a total disaster for me. I went up to 400mg per day, and the only result was almost total loss of brain function. A year later, I am still not back to my previous mental abilities. I'm now taking Lyrica, 100mg in the morning, 50mg at night. I was put on it by a supposed "migraine/headache" specialist, who turned out to be pretty much a regular neurologist. She told me that my problem was way beyond her area of expertise. Great. I searched long and hard to find her, just to be told that she didn't know how to help me. She did put me on the Lyrica, but after four months, I haven't had any reduction in migraines. I haven't noticed any side effects, but with all the medication I take, I doubt I'd notice unless it was a very major symptom. My Pain doctor, who doesn't do anything other than give me epidurals for my back, said he thinks it should help with my migraines. WRONG!!! Good luck with it yourself. I'm sure it must be helping somebody.
Let us know how it goes.