Long-term outcome of nonsurgical candidates with medically refractory localization-related epilepsy

Summary: Purpose: Epilepsy surgery can result in complete seizure remission rates of upto 80% in patients with mesial temporal sclerosis and unilateral seizures. The seizure-free rate after surgery for patients with extratemporal nonlesional epilepsy has ranged between 30% and 40%. Some patients with medically refractory localization-related epilepsy cannot be offered surgical resection because of inadequate localization of the epileptogenic zone, documentation of bilateral ictal onsets, or functionally important areas of cortex that prohibit resection. The short-term rate of complete remission with medications in temporal lobe epilepsy is poor. Less is known about remission rates in patients who are not surgical candidates. In this study, we evaluated the outcome of medical treatment in patients with medically refractory partial epilepsy who were evaluated for possible epilepsy surgery but deemed to be inadequate surgical candidates. Methods: A retrospective chart review and telephone survey with a self-rating questionnaire were completed for all patients who underwent epilepsy surgery evaluation but were not ultimately offered surgical treatment at the University of Michigan from 1990 through 1998. We assessed changes in seizure frequency and type, imaging characteristics, ictal recordings, interim medication history, and subjective changes in quality of life. Results: Thirty-four subjects were available for follow-up study, at an average of >4 years after surgical evaluation. A significant reduction in seizure frequency was noted at the time of follow-up compared with that at the time of surgical evaluation. Of patients, 21% achieved seizure remission and remained seizure free for an average of 2.5 years. Four of the seven seizurefree patients attributed their remission to new antiepileptic drugs (AEDs). On a global self-rating item, 15 of 34, or 44%, felt more or much more satisfied with their lives, and 41% felt their quality of life was stable. Conclusions: A surprisingly large number of patients we surveyed, with refractory partial epilepsy not eligible for surgical management, reported reduced seizure frequency at follow-up, and 21% were seizure free. Our findings suggest that the longterm prognosis in patients with refractory partial epilepsy who are not surgical candidates may be more positive than might be generally expected. Key Words: Epilepsy—Partial—Temporal lobe—Efficacy—Quality of life. Although the natural history of localization-related epilepsy is incompletely understood, recent data indicate that treatment response is likely to correlate with the etiology of the epilepsy. Temporal lobe epilepsy (TLE) with mesial temporal sclerosis (MTS) seems to be the most refractory to medical treatment (1), with the likelihood of complete remission ranging from 11% (2) to 42% (3). A better prognosis with medical management has been associated with other types of partial epilepsies. For instance, cryptogenic partial epilepsy remitted at a rate of 45% (2), and patients with lesional epilepsy secondary to arteriovenous malformations had a 78% chance of becoming seizure free (3). Other prognostic variables include age