title: Surgical outcome in patients with MRI-negative, PET-positive temporal lobe epilepsy.
abstract: OBJECTIVE
  The purpose of this study was to determine the long-term surgical outcomes of magnetic resonance imaging (MRI)-negative, fluorodeoxyglucose positron emission tomography (FDG-PET)-positive patients with temporal lobe epilepsy (TLE) and compare them with those of patients with mesial temporal sclerosis (MTS).
  
  
  METHODS
  One hundred forty-one patients with TLE who underwent anterior temporal lobectomy were included in the study. The surgical outcomes of 24 patients with unilateral temporal hypometabolism on FDG-PET without an epileptogenic lesion on MRI were compared with that of patients with unilateral temporal hypometabolism on FDG-PET with MTS on MRI (n=117). The outcomes were compared using Engel's classification at 2 years after surgery. Clinical characteristics, unilateral interictal epileptiform discharges (IEDs), histopathological data and operation side were considered as probable prognostic factors.
  
  
  RESULTS
  Class I surgical outcomes were similar in MRI-negative patients and the patients with MTS on MRI (seizure-free rate at postoperative 2 years was 79.2% and 82% in the MRI-negative and MTS groups, respectively). In univariate analysis, history of febrile convulsions, presence of unilateral IEDs and left temporal localization were found to be significantly associated with seizure free outcome. Multivariate analysis revealed that independent predictors of a good outcome were history of febrile convulsions and presence of unilateral IEDs.
  
  
  CONCLUSIONS
  Our results suggest that epilepsy surgery outcomes of MRI-negative, PET positive patients are similar to those of patients with MTS. This finding may aid in the selection of best candidates for epilepsy surgery.
authors.affiliation: Gazi University, Faculty of Medicine, Department of Neurology, Ankara, Turkey. Electronic address: driremyildirim@yahoo.com.tr.
authors.forename: Irem Yıldırım
authors.initials: IY
authors.lastname: Capraz
authors.affiliation: Gazi University, Faculty of Medicine, Department of Neurosurgery, Ankara, Turkey.
authors.forename: Gökhan
authors.initials: G
authors.lastname: Kurt
authors.affiliation: Gazi University, Faculty of Medicine, Department of Nuclear Medicine, Ankara, Turkey.
authors.forename: Özgür
authors.initials: Ö
authors.lastname: Akdemir
authors.affiliation: Gazi University, Faculty of Medicine, Department of Pediatric Neurology, Ankara, Turkey.
authors.forename: Tugba
authors.initials: T
authors.lastname: Hirfanoglu
authors.affiliation: Gazi University, Faculty of Medicine, Department of Radiology, Ankara, Turkey.
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Oner
authors.affiliation: Guven Hospital, Department of Nuclear Medicine, Ankara, Turkey.
authors.forename: Tugba
authors.initials: T
authors.lastname: Sengezer
authors.affiliation: Gazi University, Faculty of Medicine, Department of Nuclear Medicine, Ankara, Turkey.
authors.forename: Lütfiye Ozlem Atay
authors.initials: LO
authors.lastname: Kapucu
authors.affiliation: Gazi University, Faculty of Medicine, Department of Pediatric Neurology, Ankara, Turkey.
authors.forename: Ayse
authors.initials: A
authors.lastname: Serdaroglu
authors.affiliation: Gazi University, Faculty of Medicine, Department of Neurology, Ankara, Turkey.
authors.forename: Erhan
authors.initials: E
authors.lastname: Bilir
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D007839:Functional Laterality; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D049268:Positron-Emission Tomography; D011379:Prognosis; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012640:Seizures / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D016896:Treatment Outcome; D014402:Tuberous Sclerosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology / Q000601:surgery
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: Electroencephalography; Epilepsy surgery; Fluorodeoxyglucose positron emission tomography; Magnetic resonance imaging; Medication-refractory epilepsy; Temporal lobe epilepsy