Surgical Treatments for Epilepsy

Abstract

An estimated 250,000 patients in the United States who have medically refractory epilepsy are candidates for epilepsy surgery, but only 2000 surgeries are done each year. If a patient fails trials with two or three antiepileptic drugs, the chances of controlling his or her seizures with medical therapy are quite low, and referral to a specialized epilepsy center is desirable. Patients with focal or secondarily generalized seizures are usually the best candidates for resective surgery, and complete control of seizures can be anticipated in 50% to 70% of patients who undergo a focal resection. Temporal lobectomy has the best outcome and the bestdocumented improvement in quality of life. Low-grade tumors, vascular lesions, and cortical dysplasias outside the temporal lobes can also be addressed successfully.The key to successful epilepsy surgery is multimodality localization of the seizure focus. Video-EEG recording of seizures with scalp plus or minus intracranial EEG plays a vital role. Advances in imaging technology, including receptor-ligand PET scans, ictal SPECT scans, and magnetic resonance spectroscopy can be used to guide the placement of intracranial EEG electrodes and may someday replace them altogether in identifying the area to be resected. In the future, devices for electrical stimulation, including vagus nerve stimulation and intracranial stimulation, may replace destructive methods, just as they have in the realm of movement disorders.Continuum Lifelong Learning Neurol 2007;13(4):152-176.

Extent of neocortical resection and surgical outcome of epilepsy: Intracranial EEG analysis

“…Among patients with medically refractory epilepsy, perhaps half are candidates for focal resective surgery (Thadani & Taylor, 2007). Many studies of the prognostic factors for surgical outcomes have been published during the last decade.…”

“…Many studies of the prognostic factors for surgical outcomes have been published during the last decade. Major determinants of outcome are complete resection of magnetic resonance imaging (MRI)–visible lesions or the epileptogenic zone (Tassi et al., 2002; Cohen‐Gadol et al., 2004; Fauser et al., 2004), underlying pathology (Berkovic et al., 1995; Tonini et al., 2004), the presence of a visible lesion on MRI (Hennessy et al., 2001; Tonini et al., 2004; Yun et al., 2006), and location of seizure focus (Téllez‐Zenteno et al., 2005; Thadani & Taylor, 2007). Although temporal lobe resection for mesial temporal lobe epilepsy (mTLE) is the most frequently performed surgical procedure and usually predicts a favorable prognosis, surgical outcome in cases of neocortical epilepsy is generally less satisfactory than for patients with mTLE (Engel et al., 2003; Tonini et al., 2004; Téllez‐Zenteno et al., 2005; Spencer & Huh, 2008).…”