الفهرس 
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Abstract
Purpose: To analyze the electrophysiological changes of the postictal state and assess its relation to the outcome of epilepsy surgery in intractable temporal lobe epilepsy patients. Materials and methods A retrospective cohort study which was conducted in the Department of Epileptology, Tohoku University Hospital from 2010 to 2020. The study included 49 patients with TLE who underwent a detailed presurgical evaluation and sequential resective surgery for the unilateral probable epileptogenic temporal lobe with 1 year or more of follow-up. The interictal epileptiform distribution and those of the ictal and postictal epochs of the first focal impaired awareness seizure recorded in presurgical scalp EEG were reviewed. Patients were classified either with postoperative seizure-free status (Engel I) as group A or those with seizure persistence (Engel II-IV) as group B. Results: Of 49 patients, 33 (66%) patients were one-year seizure-free after surgery (group A). compared with group B, group A had a higher number of lateralized PPDA ( 71.9% versus 29.4%) and lesser number of bilateral PPDA (9.4% versus 64.7%) with high statistical difference between the 2 groups (p=0.001). Also, group A had a higher number of lateralized IEDs (78.1% versus 35.3% ) compared with group B and a lesser number of bilateral IEDs (15.6% versus 58.8%) with high statistical difference between the 2 groups (p=0.001). Conclusions : Analysis of postictal delta activity during presurgical evaluation yields valuable data on the localization of the epileptogenic zone Moreover, distribution of postictal slowing has an additional yield to interictal epileptiform discharge in predicting surgical outcomes in temporal lobe epilepsy. Therefore, we strongly recommend incorporating the assessment of interictal and postictal scalp EEG parameters (IEDs and PPDA) into the predictive scales of seizure outcomes after epilepsy surgery. Moreover, a combined analysis of both bilateral PPDA and bilateral IEDs showed significantly more often seizure persistence after surgery (p<0.0001). On the multivariable regression analysis, patients with bilateral IEDs and PPDA had 5.9- and 25.4-times higher odds to demonstrate the persistence of seizures within one year of surgery. Keywords: Interictal epileptiform distribution, postictal polymorphic delta activity, spatial distribution, surgical outcomes, temporal lobe epilepsy.