Neurophysiologically Based Brain State Tracking and Modulation in Focal Epilepsy

Inclusion Criteria * Focal epilepsy, including seizures with and without impairment of consciousness, and secondarily generalized seizures: * Disabling seizure counts \>3 per month (Disabling seizures are those with significant negative impact on the patients life) * Drug resistance to \>2 appropriate seizure drugs with therapeutic serum concentrations * Not a good candidate for resective surgery or at significant risk for verbal memory decline as determined by our institution's multidisciplinary Epilepsy Surgery Committee. * For 3 months prior to enrollment, subject's anti-seizure medication dosages have been stable and subject has had at least 6 disabling (as defined in Inclusion Criteria 1) seizures per month, on average, with a seizure-free interval not to exceed 30 days. Seizures must be separated by a minimum of eight hours not to be considered part of a cluster. A cluster of seizures, for the purpose of this criterion, shall be considered a single seizure. * With the exception of epilepsy, subject must be medically and neurologically stable. * Mayo Clinic Epilepsy Surgery Committee approval for brain stimulation therapy obtained on clinical grounds and without reference to this protocol. * Age 18 to 75 * Ability and willingness to provide informed consent and participate in the study protocol. Subject is able to interpret and to respond, in accordance with the study protocol, to the advisory indicators provided by the device. * Subject has seizures that are d…