Factors Related to the Clinical Outcomes of Surgery for Extra–Temporal Lobe Epilepsy: Long-Term Follow-Up Results

Background: Compared with temporal lobe epilepsy, the surgical outcome in extra–temporal lobe epilepsy (ETLE) is unsatisfactory. However, advances in diagnostic and surgical techniques have led to improved prognosis. This study investigated the outcomes and prognostic factors of ETLE based on long-term follow-up of patients undergoing surgical treatment for ETLE at a single institution. Methods: We retrospectively reviewed medical records of 58 patients with refractory ETLE who underwent resection between 2003 and 2015. Clinical outcome was evaluated by Engel classification. Parameters analyzed as prognostic factors were clarity of the lesion on magnetic resonance imaging, completeness of resection, and histologic diagnoses. Results: Of 58 patients (62.1%), 36 had a seizure-free state (Engel I) after surgery over a mean follow-up of 58 months. The most common pathology was cortical dysplasia (27 patients; 46.5%). In univariate analysis, only complete resection was a statistically significant prognostic factor (P = 0.001). Conclusions: Surgery is effective treatment for ETLE (79.4%, Engel I and II). Complete resection predicts more satisfactory results in patients with intractable ETLE.