Electrical Brain Stimulation to Reduce Epileptic Seizures

INCLUSION CRITERIA: Patients will be included under the following circumstances: Age between 18 to 80 years. Written informed consent is given by the patient. Epileptogenic focus in the temporal lobe or in the frontal lobe (unilateral or bilateral with dominant focus). Seizures are not completely responsive to medical treatment (8 or more seizures per month for at least 3 months) and patients have failed at least two anticonvulsant regimens in the past. The implantation of a vagus nerve stimulator will also be counted as anticonvulsant regimen. A stable anticonvulsant regimen (not more than three anticonvulsants) defined as unchanged dose or dose modifications lower than 20% in the last month (Blood levels of anticonvulsants will be measured at the beginning of the study, prior and after intervention, and after the study to assure that the type and dose of medication remains constant). For the vagus nerve stimulator, the stimulation parameters will have to be unchanged for at least one month. One antidepressant on a stable dose regimen for at least 1 month will be allowed. Mini-Mental-Status examination greater than or equal to 23 points. Commitment to participate in the long-term follow-up (up to 5 months). EXCLUSION CRITERIA: We will exclude patients if one of the following conditions applies: A history of any neurological illness other than the epilepsy. Acute symptomatic seizures (caused by brain tumor, acute stroke, intracranial hemorrhage, encephalitis) or psychogenic seizures. Generalized epilepsy or focal epilepsy with the epileptogenic zone outside the temporal lobe. A history of severe alcohol or drug abuse; psychiatric illness such as severe, clinically significant depression (as evaluated by BDI); poor motivational capacity; or severe language disturbances, particularly of receptive nature or with serious cognitive deficits. More than moderate uncontrolled medical problems (e.g., cardiovascular disease, active cancer or renal disease, any kind of end-stage pulmonary or cardiovascular disease, hypo/hyperthyroidism, severe diabetes, peripheral arteriopathy, or a deteriorated condition due to age, or other medical conditions as determined by the study physician, that would interfere with participation in this study). Increased intracranial pressure as evaluated by clinical means (presence of papilledema in eye ground exam, compressed sulci/ventricle on MRI scan). Previous implantation of metallic material (e.g., vascular clips, cochlear implant) in the cranium (except in the mouth), pacemaker, implanted medication pumps, neural stimulators. This does not apply for implantation of a vagus nerve stimulator (Cyberonics ® (Registered Trademark) [Registered Trademark] 100, 102 or 102R). Drug treatment acting primarily on the central nervous system (other than the regular anticonvulsant treatment and one antidepressant) that lowers the seizure threshold such as antipsychotic drugs (chlorpromazine, clozapine) or tricyclic antidepressants. Diseased or damaged skin over the face or scalp. Pregnancy.