Newer AEDs and Drug-Resistant Epilepsy

Approximately 20-30% of patients with epilepsy have a form of refractory or drug-resistant epilepsy (DRE), that is defined as failure of adequate trials of two tolerated, appropriately chosen antiepileptic drugs (whether as monotherapies or in combination) to achieve sustained seizure freedom. All patients with DRE should be referred to multi-disciplinary or comprehensive epilepsy center. The first step of evaluation in such center is determination whether there is a true refractory epilepsy, i.e., ruling out the differential diagnoses of DRE. In the second step, seizure focus and type of seizures and/or syndromes as well as surgically remediable epilepsies (those with known pathophysiology, predictable natural history, and progressive features, e.g., developmental delay or interictal behavioral disorder) and surgically non-remediable cases are accurately defined. Patients who are not candidate for surgery, for example those with epileptogenic zone (EZ) in motor cortex or language areas, patients whose EZ overlaps with eloquent cortex, multifocal seizures and who are unwilling to surgery are managed by therapeutic options other than surgery including: trial of previously untried newer AEDs with lesser interactions, better efficacy and tolerability, with mechanism of action other than those of traditional antiepileptic drugs, corticosteroids, ketogenic diet and even trial of drugs in clinical development (experimental antiseizures) such as Cannabinoids, Everolimus and Ganaxolone. Tiziana G and coworkers (2019) reported that 12%-17 % of DREs became seizure free with the addition of a previously untried new AED. Complementary alternative medicine (CAM), such as behavioral therapy and Ayurvedic medicine are also the matters of concern. We herein, will review some of the newer AEDs such as zonisamide, lacosamide, rufinamide, stirioentol, eslicarbazepine, perampanel and retigabine.

Keywords:

Newer AED , Drug-resistance Epilepsy , Surgically non-remediable Epilepsies.