I was on Topamax / "Stupamax" for 3 months. It initially worked, but totally pooped out 3 weeks ago. Now on Lamictal. Anyways, Topamax is known to cause problems with "trying to find the word" and "forgetfullness" I had both of these side effects and I usually don't get side effects from meds.
Topamax is also known to give kidney stones. I liked it initially because it curbed my appetite and made everything carbonated taste like poo. But after 3 months everything abruptly stopped and sent me into a world of hellish mood swings. Topamax works great for some people. I started at 50mg twice per day then got it upped to 100mg twice per day.

Wish you the best on it.