title: Prognostic factors for seizure outcome in patients with MRI-negative temporal lobe epilepsy: A meta-analysis and systematic review.
abstract: OBJECTIVE
  To perform a systematic review and meta-analysis to identify predictors of postoperative seizure freedom in patients with magnetic resonance imaging (MRI)-negative temporal lobe epilepsy.
  
  
  METHODS
  Publications were screened from electronic databases (MEDLINE, EMBASE), epilepsy archives, and bibliographies of relevant articles that were written in English. We recorded all possible risk factors that might predict seizure outcome after surgery. We calculated odds ratio (OR) with corresponding 95% confidence intervals (95% CI) of predictors for postoperative seizure freedom. Heterogeneity was assessed with I(2). All meta-analyses were performed using Review Manager.
  
  
  RESULTS
  Epilepsy duration (OR=2.57, 95% CI=1.21-5.47, p<0.05, I(2)=1%) and ictal or interictal electroencephalographic anomalies precisely localized in the ipsilateral temporal lobe (OR=3.89, 95% CI=1.66-9.08, p<0.01, I(2)=0 and OR=3.38, 95% CI=1.57-7.25, p<0.05, I(2)=0, respectively) were significantly associated with a higher rate of seizure freedom after surgery. However, the positron emission tomography (PET) results were not predictive of postoperative seizure freedom (OR=2.11, 95% CI=0.95-4.65, p=0.06, I(2)=0). No significant difference in seizure freedom was observed between the positive and negative pathology groups (OR=1.36, 95% CI=0.70-2.63, p=0.36, I(2)=0).
  
  
  CONCLUSIONS
  A shorter epilepsy duration and scalp electroencephalogram (EEG) signals localized precisely in the temporal lobe predicted a better seizure outcome in patients with MRI-negative temporal lobe epilepsy.
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Tiantan xili 6, Dongcheng, Beijing 100050, China; Beijing Key Laboratory of Neurostimulation, Tiantan xili 6, Dongcheng, Beijing 100050, China.
authors.forename: Xiu
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Tiantan xili 6, Dongcheng, Beijing 100050, China; Beijing Key Laboratory of Neurostimulation, Tiantan xili 6, Dongcheng, Beijing 100050, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Tiantan xili 6, Dongcheng, Beijing 100050, China; Beijing Key Laboratory of Neurostimulation, Tiantan xili 6, Dongcheng, Beijing 100050, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Beijing Neurosurgical Institute, Tiantan xili 6, Dongcheng, Beijing 100050, China; Beijing Key Laboratory of Neurostimulation, Tiantan xili 6, Dongcheng, Beijing 100050, China.
authors.forename: Wenhan
authors.initials: W
authors.lastname: Hu
authors.affiliation: Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Tiantan xili 6, Dongcheng, Beijing 100050, China; Beijing Key Laboratory of Neurostimulation, Tiantan xili 6, Dongcheng, Beijing 100050, China.
authors.forename: Xiaoqiu
authors.initials: X
authors.lastname: Shao
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Tiantan xili 6, Dongcheng, Beijing 100050, China; Beijing Key Laboratory of Neurostimulation, Tiantan xili 6, Dongcheng, Beijing 100050, China.
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Zhang
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Tiantan xili 6, Dongcheng, Beijing 100050, China; Beijing Key Laboratory of Neurostimulation, Tiantan xili 6, Dongcheng, Beijing 100050, China. Electronic address: zhangkai62035@163.com.
authors.forename: Kai
authors.initials: K
authors.lastname: Zhang
mesh_terms: D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data*
keywords: Epilepsy surgery; MRI negative; Meta-analysis; Temporal lobe epilepsy