Results of Epilepsy Surgery: Still So Much to Learn
Authors: Bergen Donna C. 
Published: May 2006

Predicting Long-Term Seizure Outcome after Resective Epilepsy Surgery: The Multicenter Study Spencer SS, Berg AT, Vickrey BG, Sperling MR, Bazil CW, Shinnar S, Langfitt JT, Walczak TS, Pacia SV Neurology 2005;65(6):912–918 Background In a seven-center prospective observational study of resective epilepsy surgery, the authors examined probability and predictors of entering 2-year remission and the risk of subsequent relapse. Methods Patients aged 12 years and over were enrolled at time of referral for epilepsy surgery, and underwent standardized evaluation, treatment, and follow-up procedures. The authors defined seizure remission as 2 years completely seizure-free after hospital discharge with or without auras, and relapse as any seizures after 2-year remission. The authors examined type of surgery, seizure, clinical and demographic variables, and localization study results with respect to prediction of seizure remission or relapse, using χ2 and proportional hazards analysis. Results Of 396 operated patients, 339 were followed over 2 years, and 223 (66%) experienced 2-year remission, not significantly different between medial temporal (68%) and neocortical (50%) resections. In multivariable models, only absence of generalized tonic–clonic seizures and presence of hippocampal atrophy were significantly and independently associated with remission, and only in the medial temporal resection group. Fifty-five patients relapsed after 2-year remission, again not significantly different between medial temporal (25%) and neocortical (19%) resections. Only delay to remission predicted relapse, and only in medial temporal patients. Conclusion Hippocampal atrophy and a history of absence of generalized tonic clonic seizures were the sole predictors of 2-year remission, and only for medial temporal resections. Antiepileptic Drug Withdrawal after Successful Surgery for Intractable Temporal Lobe Epilepsy Kim YD, Heo K, Park SC, Huh K, Chang JW, Choi JU, Chung SS, Lee BI Epilepsia 2005;46(2):251–257 Purpose To investigate the prognosis related to antiepileptic drug (AED) discontinuation after successful surgery for intractable temporal lobe epilepsy. Methods The clinical courses after temporal lobectomies (TLs) were retrospectively analyzed in 88 consecutive patients. All the patients had TLs as the only surgical procedure, and they had been followed up for longer than 3 years. AED discontinuation was attempted if the patient had been seizure free without aura for ≥1 year during the follow-up period. Results Sixty-six (75%) patients achieved complete seizure freedom for ≥1 year; 28 patients were seizure free immediately after surgery (immediate success); and 38 patients became seizure free after some period of recurrent seizures (delayed success). AED discontinuation was attempted in 60 (91%) of 66 patients with a successful outcome. In 13 (22%) patients, seizure relapse developed during AED reduction ( n = 60), and in 7 (12%) patients after discontinuation of AEDs ( n = 38). The seizure recurrence rate was not different between the immediate- and delayed-success groups. Among 20 patients with seizure relapse related to AED tapering, 9 (45%) of them regained seizure freedom after reinstitution of AED treatment, and AEDs were eventually discontinued in 6 of them. Seizures that recurred after complete AED discontinuation had a better prognosis than did the seizures that recurred during AED reduction (seizure freedom in 86% vs 23%). At the final assessment, 54 (61%) patients had been seizure free ≥1 year; 37 without AEDs and 17 with AEDs. The successful discontinuation of AEDs was more frequent for patients with a younger age at the time of surgery and for those patients with shorter disease duration. Conclusions Our results suggest that seizure freedom without aura at ≥1 year is a reasonable indication for the attempt at AED discontinuation. The subsequent control of recurrent seizures was excellent, especially if seizures relapsed after the complete discontinuation of AEDs. Younger age at the time of surgery and a shorter disease duration seem to affect successful AED discontinuation for a long-term period.