Phenytoin
"I am 37 years old and was diagnosed with epilepsy 5 weeks ago. I was put on the phenytoin capsules and take 300 mg at bedtime (which I take faithfully). Lately I've noticed my energy level has increased and I haven't had a seizure in 8 days, but I notice I wake up with a headache mostly to the back of my head. I also have been having so really weird dreams. It is 3 in the morning here and of course I awoke with a headache and a slightly stiffer neck. "