Refractory or Drug-Resistant Epilepsy: Epilepsy is considered refractory, or drug-resistant, when seizures are not adequately controlled by antiepileptic drug therapy or when intolerable side effects from drug therapy prevent patients from continuing with treatment. One study shows that once an AED is unsuccessful controlling seizures, the chances of successful treatment with subsequent AEDs are significantly reduced. In 2009, the International League Against Epilepsy (ILAE) published a consensus statement defining drug resistant epilepsy as "failure of adequate trials of two tolerated and appropriately chosen and used AED schedules…to achieve sustained freedom."
Adjunctive Therapy: A treatment option that is prescribed for use in combination with other treatment options; also referred to as “add on” therapy.
AEDs: Antiepileptic Drugs are prescribed to treat seizures associated with epilepsy. There are approximately 20 AEDs currently available worldwide.
Seizures: A change in function related to abnormal electrical activity in the brain. Intermittent bursts of electrical energy sometimes interrupt the normal flow of electrical impulses between nerve cells. This interruption can affect consciousness, muscle control, bodily movements or sensations. Seizures are classified in the following two types:
Partial Seizures: Partial seizures start in a particular area or areas of the brain.
Generalized Seizure: The source of a primary generalized seizure cannot be identified. They appear to involve the whole brain from the beginning.
SUDEP: Sudden Unexplained Death in Epilepsy, a death for which no cause can be found except for the individual having had a history of epilepsy.
Vagus Nerve: The vagus nerve is a cranial nerve and serves as one of the primary communication pathways between the body and the brain. It has both motor and sensory functions.