Metabolic acidosis, due to the imbalance of the bodies buffering system and clearance of acid, it can resolve itself without medical intervention at times. However, it depends on how your tested values were that would determine treatment and monitoring of these values should continue over time for any changes.

I am not familiar with topiramate being the cause of it, (very limited knowledge there); however, in knowing how dehydrating this medication is, dehydration can be a cause of metabolic acidosis but is not the only cause. Perhaps these links might help. I wish you all the best, find the answers you are looking for and hope you feel better real soon.

Metabolic acidosis: MedlinePlus Medical Encyclopedia
Medscape: Medscape Access