• The primary efficacy objective is to demonstrate that the reduction in the seizure rate in the active group is greater than in the control group. [ Time Frame: At the end of the three-month blinded phase ] [ Designated as safety issue: No ]
  

• A safety objective is to characterize the adverse events experienced with the Medtronic DBS system stimulating the anterior nucleus in patients with epilepsy. [ Time Frame: Through the long-term follow-up phase ] [ Designated as safety issue: Yes ]
  
• A safety objective is to characterize the incidence of sudden unexplained death in epilepsy (SUDEP) with the Medtronic DBS system stimulating the anterior nucleus in patients with refractory epilepsy. [ Time Frame: Through the long-term follow-up phase ] [ Designated as safety issue: Yes ]
  
• To demonstrate that the proportion of responders in the active group is greater than in the control group. [ Time Frame: At the end of the three-month blinded phase ] [ Designated as safety issue: No ]
  
• To demonstrate that the mean percentage of seizure-free days and maximum length of seizure-free intervals in the active group is greater than in the control group. [ Time Frame: At the end of the three-month blinded phase ] [ Designated as safety issue: No ]
  
• To demonstrate that the proportion of treatment failures in the active group is less than in the control group. [ Time Frame: At the end of the three-month blinded phase ] [ Designated as safety issue: No ]
  

Medtronic, Inc. is sponsoring an investigational study of the Intercept™ Epilepsy Control System, the company's direct brain stimulation therapy for patients with refractory epilepsy. Epilepsy is a condition that affects 2.3 million Americans, and about one-third of these patients is refractory, or continues to experience seizures despite a wide range of treatment options.

The prospective, randomized, double-blind trial uses existing technology to test whether bilateral stimulation of the anterior nucleus of the thalamus can safely and effectively reduce seizure frequency in patients with epilepsy. It includes enrollment of 158 patients at 17 sites in the U.S. A minimum of 102 patients will be implanted and monitored for 13 months following implant, with long-term follow-up until the device is approved or the study is stopped.

Patients in the active group, who will receive neurostimulation, will be monitored for a reduction in seizure rates compared to the control group, who will not receive neurostimulation during the three-month double-blind phase. After the double-blind phase, all patients will receive neurostimulation.

Candidates for the trial are adults with partial-onset epilepsy for whom at least three antiepileptic drugs have proven ineffective. They will have had an average of six or more seizures per month. Candidates will continue to receive their epilepsy medications while participating in the trial.

Direct brain stimulation therapy has already received approval in the United States, Europe, Canada, and Australia for the treatment of Essential Tremor and Parkinson's disease. Direct brain stimulation is not approved for the treatment of epilepsy.