title: Determinants of brain metabolism changes in mesial temporal lobe epilepsy.
abstract: To determine the main factors influencing metabolic changes in mesial temporal lobe epilepsy (MTLE) due to hippocampal sclerosis (HS).
  
  
  
  We prospectively studied 114 patients with MTLE (62 female; 60 left HS; 15- to 56-year-olds) with (18) F-fluorodeoxyglucose-positron emission tomography and correlated the results with the side of HS, structural atrophy, electroclinical features, gender, age at onset, epilepsy duration, and seizure frequency. Imaging processing was performed using statistical parametric mapping.
  
  
  
  Ipsilateral hypometabolism involved temporal (mesial structures, pole, and lateral cortex) and extratemporal areas including the insula, frontal lobe, perisylvian regions, and thalamus, more extensively in right HS (RHS). A relative increase of metabolism (hypermetabolism) was found in the nonepileptic temporal lobe and in posterior areas bilaterally. Voxel-based morphometry detected unilateral hippocampus atrophy and gray matter concentration decrease in both frontal lobes, more extensively in left HS (LHS). Regardless of the structural alterations, the topography of hypometabolism correlated strongly with the extent of epileptic networks (mesial, anterior-mesiolateral, widespread mesiolateral, and bitemporal according to the ictal spread), which were larger in RHS. Notably, widespread perisylvian and bitemporal hypometabolism was found only in RHS. Mirror hypermetabolism was grossly proportional to the hypometabolic areas, coinciding partly with the default mode network. Gender-related effect was significant mainly in the contralateral frontal lobe, in which metabolism was higher in female patients. Epilepsy duration correlated with the contralateral temporal metabolism, positively in LHS and negatively in RHS. Opposite results were found with age at onset. High seizure frequency correlated negatively with the contralateral metabolism in LHS.
  
  
  
  Epileptic networks, as assessed by electroclinical correlations, appear to be the main determinant of hypometabolism in MTLE. Compensatory mechanisms reflected by a relative hypermetabolism in the nonepileptic temporal lobe and in extratemporal areas seem more efficient in LHS and in female patients, whereas long duration, late onset of epilepsy, and high seizure frequency may reduce these adaptive changes.
authors.affiliation: Department of Neurosurgery, Sainte-Anne Hospital, Paris, France.|Paris Descartes University, Paris, France.|INSERM U 1129, Paris, France.|Department of Nuclear Medicine, SHFJ, CEA, Orsay, France.
authors.forename: Francine
authors.initials: F
authors.lastname: Chassoux
authors.affiliation: INSERM U 1000, Paris, France.|Psychiatry Department 91G16, Orsay Hospital, Paris Descartes University, Orsay, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Artiges
authors.affiliation: Department of Nuclear Medicine, INSERM U 1171, University Hospital of Lille, Lille, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Semah
authors.affiliation: Department of Nuclear Medicine, SHFJ, CEA, Orsay, France.|INSERM U 1023 IMIV, CEA, Paris-Sud University, Orsay, France.
authors.forename: Serge
authors.initials: S
authors.lastname: Desarnaud
authors.affiliation: Department of Neurosurgery, Sainte-Anne Hospital, Paris, France.|Paris Descartes University, Paris, France.|INSERM U 1129, Paris, France.
authors.forename: Agathe
authors.initials: A
authors.lastname: Laurent
authors.affiliation: Department of Neurosurgery, Sainte-Anne Hospital, Paris, France.|Paris Descartes University, Paris, France.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Landre
authors.affiliation: Department of Nuclear Medicine, SHFJ, CEA, Orsay, France.|INSERM U 1023 IMIV, CEA, Paris-Sud University, Orsay, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Gervais
authors.affiliation: Department of Neurosurgery, Sainte-Anne Hospital, Paris, France.|Paris Descartes University, Paris, France.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Devaux
authors.affiliation: Department of Nuclear Medicine, SHFJ, CEA, Orsay, France.|INSERM U 1023 IMIV, CEA, Paris-Sud University, Orsay, France.
authors.forename: Ourkia Badia
authors.initials: OB
authors.lastname: Helal
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000704:Analysis of Variance; D000927:Anticonvulsants / Q000627:therapeutic use; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D015331:Cohort Studies; D004833:Epilepsy, Temporal Lobe / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D012737:Sex Factors; D055815:Young Adult
chemical_list: D000927:Anticonvulsants; D019788:Fluorodeoxyglucose F18
keywords: Epileptic networks; Hippocampal sclerosis; Mesial temporal lobe epilepsy; Metabolism; PET