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Objective To analyze longitudinal seizure outcomes following epilepsy surgery, including reoperations, in patients with intractable focal epilepsy. Methods Clinicoradiological characteristics of patients who underwent epilepsy surgery from 1995 to 2016 with follow‐up of ≥1 year were reviewed. In patients undergoing reoperations, the latest resection was considered the index surgery. The primary outcome was complete seizure freedom (Engel I) at last follow‐up. Potentially significant outcome variables were first identified using univariate analyses and then fit in multivariate Cox proportional hazards models. Results Of 898 patients fulfilling study criteria, 110 had reoperations; 92 had one resection prior to the index surgery and 18 patients had two or more prior resective surgeries. Two years after the index surgery, 69% of patients with no prior surgeries had an Engel score of I, as opposed to only 42% of those with one prior surgery, and 33% of those with two or more prior resections (P < .001). Among surgical outcome predictors, the number of prior epilepsy surgeries, female sex, lesional initial magnetic resonance imaging, no prior history of generalization, and pathology correlated with better seizure outcomes on univariate analysis. However, only sex (P = .011), history of generalization (P = .016), and number of prior surgeries (P = .002) remained statistically significant in the multivariate model. Significance Although long‐term seizure control is possible in patients with failed prior epilepsy surgery, the chances of success diminish with every subsequent resection. Outcome is additionally determined by inherent biological markers (sex and secondary generalization tendency), rather than traditional outcome predictors, supporting a hypothesis of “surgical refractoriness.”

is a second year epilepsy fellow at the Cleveland Clinic Foundation. SUMMARYObjective: We aim to develop a new scale that predicts seizure outcomes after resective epilepsy surgery. Methods: We retrospectively reviewed patients who underwent surgery for medically refractory epilepsy at our center between 1999 and 2012. Four predictive outcome indicators were selected: preoperative seizure frequency, history of generalized tonicclonic seizures, brain magnetic resonance imaging (MRI), and epilepsy duration. A score of 0 or 1 was given if the indicator was associated with poor or good outcome, respectively. A seizure freedom score (SFS) was calculated by adding these four categories (total score ranged from 0 to 4). A modified SFS (m-SFS) was then calculated with two additional outcome indicators: invasive electroencephalography (EEG) evaluation (IEI) (performed or not performed) and lobe of resection (temporal vs. extratemporal), for a score ranging from 0 to 6. Kaplan-Meier survival analysis was used to calculate the probability of seizure freedom in the overall group. Statistical significance was tested using the log-rank test and comparison of 95% confidence intervals (CIs). Results: The study population included 466 patients with 244 (52%) male. Seizure freedom rates were directly correlated with the SFS score: at 10 years, 36.9% of patients with SFS of 0 were seizure-free, as opposed to 45% for SFS = 1, 60% for SFS = 2, 72% for SFS 3 or above (p = 0.002). When calculated including the IEI and the localization, the score's performance improved: 24% of patients with a m-SFS of 0 were seizure-free at 10 years, as opposed to 38-59% for m-SFS = 1-3, and 75-79% for m-SFS of 4-6 (p < 0.001). Significance: An easily measurable seizure freedom score could be a reliable tool to synthesize multiple seizure outcome predictors into a single simple score to predict postoperative seizure freedom. This tool will help with patient and family counseling and estimation of surgical candidacy at both early (SFS) and advanced (m-SFS) stages of a surgical evaluation.

ObjectiveTo study the safety of antiepileptic drug (AED) withdrawal after temporal lobe epilepsy (TLE) surgery.MethodsWe reviewed patients who underwent TLE surgery from 1995 to 2011, collecting data on doses, dates of AED initiation, reduction, and discontinuation. Predictors of seizure outcome were defined using Cox-proportional hazard modeling and adjusted for, while comparing longitudinal seizure-freedom in patients for whom AEDs were unchanged after resection as opposed to reduced or stopped.ResultsA total of 609 patients (86% adults) were analyzed. Follow-up ranged from 0.5 to 16.7 years. Most (64%) had hippocampal sclerosis. Overall, 229 patients had remained on their same baseline AEDs, while 380 patients stopped (127 cases) or reduced (253 cases) their AEDs. Mean timing of the earliest AED change was shorter in patients with recurrent seizures (1.04 years) compared to those seizure-free at last follow-up (1.44 years; P-value 0.03). Whether AEDs were withdrawn 12 or 24 months after surgery, there was a 10–25% higher risk of breakthrough seizures within the subsequent 2 years. However, 70% of patients with seizure recurrence after AED discontinuation reachieved remission, as opposed to 50% of those whose seizures recurred while reducing AEDs (P = 0.0001). Long-term remission rates were similar in both AED discontinuation and “unchanged” groups (82% remission for AEDs withdrawn after 1 year and 90% for AEDs withdrawn after 2 years), while only 65% of patients whose recurrences started during AED reduction achieved a 2-year remission by last follow-up.InterpretationAED withdrawal increases the short-term risk of breakthrough seizures after TLE surgery, and may alter the long-term disease course in some patients.

Objectives: The objective of this cohort study was to compare neuropsychological outcomes following left temporal lobe resection (TLR) in patients with epilepsy who had or had not undergone prior invasive monitoring.Methods: Data were obtained from an institutional review board-approved, neuropsychology registry for patients who underwent epilepsy surgery at Cleveland Clinic between 1997 and 2013. A total of 176 patients (45 with and 131 without invasive EEG) met inclusion criteria. Primary outcome measures were verbal memory and language scores. Other cognitive outcomes were also examined. Outcomes were assessed using difference in scores from before to after surgery and by presence/absence of clinically meaningful decline using reliable change indices (RCIs). Effect of invasive EEG on cognitive outcomes was estimated using weighting and propensity score adjustment to account for differences in baseline characteristics. Linear and logistic regression models compared surgical groups on all cognitive outcomes.Results: Patients with invasive monitoring showed greater declines in confrontation naming; however, when RCIs were used to assess clinically meaningful change, there was no significant treatment effect on naming performance. No difference in verbal memory was observed, regardless of how the outcome was measured. In secondary outcomes, patients with invasive monitoring showed greater declines in working memory, which were no longer apparent using RCIs to define change. There were no outcome differences on other cognitive measures. Conclusions:Results suggest that invasive EEG monitoring conducted prior to left TLR is not associated with greater cognitive morbidity than left TLR alone. This information is important when counseling patients regarding cognitive risks associated with this elective surgery. Temporal lobe epilepsy is the most frequent type of epilepsy encountered in surgical centers, 1 and resective surgery is an effective treatment option for patients with drug-resistant seizures.