I'm new to this joint also :) but my experience with topomax is this..
I am on topamax 200mg daily, I had to build my way up to the dose. The side effects that I had are tingling in hands fingers numbness in face especially around mouth and nose,and weight loss i'd say about 25 pounds. As for the crying spells that others mentioned I had none of that it actually helped me with my depression and I was able to come off of prozac. I have been on it for over 6 months now and the tingling has gone away and the weightloss has platued...my my headaches have gone from 5-6 a week to 2 maybe 3 a week so it was made a great big difference in my life!! I take it a night before I go to bed.
I am also in transition between meds for acute headaches, I am supossed to be taking DHE injections but that are horrible so I put myself back on the Zomig nasal spray which doesn't take the headache away completely but gets me to a point were I can function. I just haven't made the appt with my Dr to get something else new..
I hope some of this info is helpfull..