I was on Topamax for about 5-6 months and I too had the same side effects of weight loss, pins and needles with numbness of my extremities, with trouble sleeping and also a loss of balance and persistent headache. My side effects did not go away. I went to my neuro and was changed to Zonegran due to the problems. My neuro said it was a similar drug to Topamax with less side effects. Things got better after the switch, but I continued to have some of the same problems, just to a lessor degree. Even now, I haven't regained the weight I lost.
My seizures were so much better on Topamax. I lost 15 pounds within that 5-6 months, but I understand that most people lose less than I did. Like the Topamax, I don't have much of an appetite or cravings for food with the Zonegran.
I suspect that if you can tolerate the med from the start, hopefully you will do well on it. It's always a trade off between how effective a drug works and if you can put up with the side effects. Good Luck... HUGS, Glenda
complex partial seizures since 22
lamictal 200mg 2x/d
zonegran 150mg 3/d