Electrical control of epileptic seizures

Epilepsy is among the most common neurologic disorders, yet it is estimated that about one third of patients do not respond favorably to currently available drug treatments and up to 50% experience major side effects of these treatments. Although surgical resection of seizure foci can provide reduction or cessation of seizure incidents, a significant fraction of pharmacologically intractable seizure patients are not considered viable candidates for such procedures. Research advances in applying electrical stimulation as an alternative treatment for intractable epilepsy have been reported. The primary focus of these studies has been the search for optimized stimulation protocols by which to electrically suppress, revert or prevent seizures. In this review, the authors discuss some of the promising results that have been achieved. These results are organized in three broad categories based on how such protocols are generated. They focus on how information of the electrical activity in the brain is incorporated in the control schemes, namely: open loop, semiclosed loop, and closed loop protocols. Benefits, potential promises, and challenges of these different control techniques are discussed.