Outcome of Resective Surgery for Non-lesional Neocortical Temporal Lobe Epilepsy

ABSTRACT

BACKGROUND: Patients with neocortical temporal lobe epilepsy(NTLE) are reported to have less favorable outcome with anterior temporal lobectomy, and the prognostic factors for patients with non-lesional NTLE are not well defined. METHODS: We analyzed the multiple potential predictors of outcome for 26 consecutive medically intractable non-lesional NTLE patients who have had both extracranial and intracranial EEG monitoring during their presurgical evaluation prior to surgery age, age at seizure onset, sex, seizure semiology, seizure duration and frequency, an etiology, the site of the surgery, the region of intracranial ictal onset, intracranial amobarbital procedure, neuropsychology test, neuroimaging, multiple subpial transection(MST) and surgical pathology. The average follow up period was 37.0+/-11.1(range 20-60) months. The outcome factors analyzed were compared to two types of outcome group; seizure free group(class I) and persistent seizure group(class II-IV) according to Engel's classification. RESULTS: Seventeen of 26 non-lesional NTLE patients(65.4%) were seizure free during follow up. Intracranial ictal onset confined to anterior temporal region only significantly predicted seizure free(p<0.001). Earlier seizure onset(p=0.08) and resection without MST(p=0.10) tended to be seizure free, but not statistically significant. CONCLUSION: Patients with non-lesional NTLE can be a good candidate for a tailored anterior temporal neocorticectomy with/without MST after intracranial EEG monitoring and functional mapping.