Seizures
"I have been taking Keppra for 4 1/2 years, after head trauma from an auto accident caused me to have a seizure while in hospital.  I have experienced some minor occurances of side effects, but nothing compared to the problem I experienced while taking Dilantin, which caused me to lose my ability to reason, and to express myself, i.e. Dilantin made me an apparent idiot.  My greatest annoyance with Keppra is the rise in cost- 46% over these past 4 1/2 years."