Is keppra medication any good?

I started using 1000mg keppra three times a day a transition from Trileptal. The reason why I changed to keppra is bc my sodium was dropping and neuro said this would be better. Well the pain is back and you know how that is . I don't know if I should stick it out with keppra or go back to tripletail at 1800mg a day. Anyone using keppra? and im getting a mri and neuro suggest gamma knife surgery said 98% chance of success. Sounds pretty confident but the stories I read that doesn't seem to be the percentage. Thank you