When drugs and surgery don't work

Epilepsy is a chronic disorder characterized by recurrent and unprovoked seizures (Dreifuss, 1987; Hauser & Hesdorffer, 1990). It is one of the most common neurologic disorders in the adult. The lifetime risk of developing epilepsy is 3.2% (Mattson, 1992). Approximately 90% of the incident cases in adults have symptomatic partial or localization-related epilepsy (Camfield & Camfield, 1996; Hauser & Hesdorffer, 1990; Hauser, 1992). The medial temporal lobe is the most epileptogenic region of the brain (Luby et al., 1995; Jeong et al., 1999; Wiebe et al., 2001). Pathologic lesions underlying the epileptogenic zone include mesial temporal sclerosis (MTS), tumor, vascular anomaly, malformations of cortical development (MCDs), and head trauma (Cascino et al., 1993; Radhakrishnan et al., 1998). The initial response to medication is of prognostic importance (Hauser, 1992). Patients with a remote symptomatic neurologic disease, foreign-tissue lesion, developmental delay, or abnormal neurologic examination are less likely to be rendered seizure-free. The goals of treatment are to render the individual seizure-free without producing antiepileptic drug (AED) toxicity, allowing the individual to become a participating and productive member of society (Engel & Ojemann, 1993). Despite the introduction of "newer" AEDs, nearly one-half of patients with partial epilepsy will not attain a seizure remission with pharmacotherapy (Kwan & Brodie, 2003). This discussion focuses on management of the adult patient with intractable partial seizure disorders that are medically refractory and may not be surgically remediable. It is estimated that 400,000 of the 2 million individuals with partial epilepsy in the United States have a medically refractory partial seizure disorder (Hauser & Hesdorffer, 1990; Hauser, 1992). An estimated 1,500 patients in the United States undergo epilepsy surgery each year. A UK study indicated that 30,000 patients develop epilepsy each year and approximately 6,000 have medically refractory seizures (Lhatoo et al., 2003). However, there are only about 400 epilepsy surgeries performed annually in the UK. Therefore, the number of patients with intractable partial epilepsy that is both medically refractory and possibly not a surgically remediable epileptic syndrome is significant.