Transcranial Magnetic Stimulation to Treat Epilepsy

This study will use transcranial magnetic stimulation, or TMS (described below), to treat epilepsy in certain patients whose seizures persist despite optimum medical treatment. TMS used in this study is intended to lessen the number of seizures a patient has by decreasing excitability of the brain in the region where the seizures originate. Patients between 5 and 65 years of age who have had epilepsy for two or more years and have had at least one seizure a week for at least 6 months may be eligible for this 18-week study. Their seizures must come from a neocortical focus-that is, near the surface of the brain. Candidates will be selected from the NIH Epilepsy clinic and will be screened with an electroencephalogram (EEG), magnetic resonance imaging (MRI) scans, and blood tests. Participants will keep a diary of the seizures they experience over an 8-week period. After the 8 weeks, they will come to the NIH outpatient clinic for 6 consecutive days for the following procedures: * Day 1: A regular clinic visit, plus 6 hours of video-EEG recording (described below) * Days 2 through 5: Video-EEG monitoring and TMS as follows: 8:00 - 11: 00 a.m. 3 hours video-EEG monitoring 11:00 - 12:30 p.m. TMS (includes set-up time; actual stimulation time lasts 30 minutes) 12:30 - 3:00 p.m. Lunch + rest 3:00 - 4:30 p.m. TMS 4:30 - 7:30 p.m. 3 hours video-EEG monitoring (On the fifth day, subjects will have 6 hours of video-EEG monitoring in the afternoon instead of 3 hours.) Participants will be randomly assigned to one of two TMS groups. One group will have TMS delivered in a way that is thought to have a chance of reducing seizures; the other will have sham, or placebo, stimulation. When the TMS sessions are completed, participants will keep a diary of their seizures for another 8 weeks. Transcranial Magnetic Stimulation For TMS, an insulated wire coil is placed on the subject's scalp. A brief electrical current passes through the coil, creating a magnetic pulse that t