Medtronic Deep Brain Stimulation (DBS) Therapy for Epilepsy Post-Approval Study (EPAS)

Inclusion Criteria: * Focal (partial) onset seizures (based on International League Against Epilepsy (ILAE) 2017 classification) that may or may not evolve to a bilateral tonic-clonic seizure (secondary generalization). The final determination shall be made by the Investigator based on a clinical description of the seizures and previous diagnostic testing that includes, at a minimum, video EEG (inpatient or ambulatory) that captured at least one ictal event * Anticipated average of 6 or more focal (partial) onset seizures per month during CMM phase, with no more than 30 consecutive seizure-free days during the CMM phase * Refractory to at least 3 antiepileptic drugs (AEDs) due to lack of effectiveness * Age 18 or older at the time of enrollment * Willing and able to complete the diary, with or without the assistance of a caregiver, in a reliable way as assessed by the clinical staff * Able to use the Patient Programmer with or without the assistance of a caregiver * Ability of the subject or legal representative to understand and provide signed consent for participating in the study * Willing and available to attend visits as scheduled and to comply with the study protocol Exclusion Criteria: * Generalized onset epilepsy type (based on International League Against Epilepsy (ILAE) 2017 classification) * Seizure frequency is too frequent that subject is unable to provide daily count in order to maintain a reliable seizure diary * Any episode of convulsive status epilepticus …