title: FDG-positron emission tomography and invasive EEG: seizure focus detection and surgical outcome.
abstract: OBJECTIVE
  To study the value of [18F]2-deoxyglucose (FDG)-positron emission tomography when surface ictal EEG is nonlocalizing.
  
  
  METHODS
  FDG-PET scans were performed in 46 patients with complex partial seizures (CPS) not localized by ictal surface-sphenoidal video-EEG (VEEG) telemetry. Interictal PET was performed with continuous EEG monitoring, and images were analyzed with a standard template. Forty patients subsequently had subdural and 6 had depth electrodes (invasive EEG, IEEG); 22 had bilateral implants. A focus was detected in 40, and 35 had temporal lobectomy based on IEEG localization.
  
  
  RESULTS
  There was a close association between IEEG and PET localization (p < 0.01): 26 patients had relative unilateral temporal FDG-PET hypometabolism, all had congruent IEEG, and 18 of 23 were seizure-free after temporal lobectomy. Five patients had unilateral frontotemporal hypometabolism (3 of 5 were seizure-free), 1 had frontal hypometabolism, and 14 had no lateralized PET abnormality (4 of 7 were seizure-free). Patients who became seizure-free had significantly higher lateral temporal asymmetry index (AI). PET showed > or = 15% relative temporal hypometabolism (AI) in 12 of 22 patients with nonlateralized surface ictal VEEG and was capable of distinguishing between frontal and temporal foci in 16 of 24 patients with lateralized, but not localized, surface ictal video-EEG.
  
  
  CONCLUSIONS
  FDG-PET provides valuable data in patients with unlocalized surface ictal EEG and can reduce the number of patients who require IEEG studies. Quantitation is necessary for optimal PET interpretation.
authors.affiliation: Clinical Epilepsy Section, NINDS NIH, Bethesda, Maryland 20892, USA.
authors.forename: W H
authors.initials: WH
authors.lastname: Theodore
authors.forename: S
authors.initials: S
authors.lastname: Sato
authors.forename: C V
authors.initials: CV
authors.lastname: Kufta
authors.forename: W D
authors.initials: WD
authors.lastname: Gaillard
authors.forename: K
authors.initials: K
authors.lastname: Kelley
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism; D003847:Deoxyglucose / Q000031:analogs & derivatives; D003937:Diagnosis, Differential; D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000379:methods*; D004828:Epilepsies, Partial / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000601:surgery; D017029:Epilepsy, Complex Partial / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000601:surgery; D019788:Fluorodeoxyglucose F18; D007839:Functional Laterality; D005947:Glucose / Q000378:metabolism; D006801:Humans; D008991:Monitoring, Physiologic; D013686:Telemetry; D013702:Temporal Lobe / Q000601:surgery; D014055:Tomography, Emission-Computed; D016896:Treatment Outcome; D014743:Videotape Recording
chemical_list: D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose; D005947:Glucose