Refractory Epilepsy

Unfortunately, 25–30% of people with epilepsy do not respond to adequate antiepileptic treatment and are said to suffer from “refractory epilepsy.” Although most people with refractory epilepsy have partial seizures, there is no definitive or all-inclusive definition of refractory epilepsy. Epilepsy can be considered medically intractable when satisfactory seizure control cannot be achieved with any of the potentially available effective antiepileptic drugs (AEDs), alone or in combination, at doses or levels not associated with unacceptable side effects (1). There is, however, no single step in the medical management of an adult or child with epilepsy after which he or she can be declared medically intractable. Several important factors must be considered before a patient can be deemed intractable. One is the definition of “satisfactory” seizure control. Different people will define satisfactory in vastly different ways, depending on their professional and social circumstances. In some highly functional and potentially productive persons, even a few seizures per year can ruin their lives, careers, and aspirations. The type of seizure and the percentage that occur only at night will also influence a person’s acceptance of a particular level of control. Unacceptable toxicity due to AEDs is also to some extent an individual matter; for example, the effect of sedation on the level of functioning in a professional environment. Overall, therefore, the refractory level must be assessed on an individual basis. Typically, patients fail to respond to AEDs for reasons other than a lack of efficacy, as noted in Table 1 (2). A proper seizure-type diagnosis is a crucial step in the successful management of epilepsy (“Diagnosis of Epilepsy,” pages 23–24). The choice of drug is determined by the type of epileptic syndrome (“Pharmacologic Treatment,” pages 33–34). Some AEDs are unsuitable for specific epilepsy types and syndromes. In addition, the possibility of pseudo-seizures has to be considered in any patient whose seizures are refractory. Another factor causing inadequate seizure control is poor patient compliance with prescribed AED treatment. Full understanding of the need to take the prescribed daily doses of AEDs and the necessary changes in lifestyle (e.g., to avoid seizures induced by sleep deprivation or alcohol) is critical for the success of therapy. At least 20% of patients with uncontrolled complex partial seizures may be expected to be noncompliant when they first present to an epilepsy clinic (3). REFRACTORY EPILEPSY IN CHILDREN