seizure prevention
"I have nightmares, weight loss (went from 128 to 118 in a few weeks, which is a lot for me), dizziness.  Also "the spins" whenever I lay down, which is when my body feels stable but the whole world spins (kind of like being drunk and lying down). 

No seizures yet but they aren't that common to begin with (1x/year) and I've only been on lamotrigine for a few months.  I'm at 300mg/day now and trying to get up to 400mg.  Dizziness is pretty bad right now, that rocking feeling you get after being on a boat.  I feel that."