title: 1H-MRS imaging in intractable frontal lobe epilepsies characterized by depth electrode recording.
abstract: Presurgical evaluation of frontal lobe epilepsy (FLE) remains a challenging issue and frequently requires invasive depth electrode recording. In this study, we aimed at evaluating the potential usefulness of a non-invasive technique such as proton magnetic resonance spectroscopic imaging ((1)H-MRSI) in the presurgical evaluation of FLE and at investigating the potential electrophysiological correlates of the metabolic disturbances as defined by (1)H-MRSI. We compared the distribution of (1)H-MRSI abnormalities with the electrophysiological abnormalities defined by stereo-electroencephalography (SEEG) recording in 12 patients presenting with several subtypes of FLE. We also used 12 control subjects in order to obtain normative (1)H-MRSI data. We used a multilevel (1)H-MRSI protocol to better sample the principal regions of the frontal lobe. We also applied a metabolic mapping technique allowing a visual display of metabolic data. A significant decrease of both N-acetyl-aspartate/phosphocreatine-creatine and N-acetyl-aspartate/(choline-compounds + phosphocreatine-creatine) ratios was observed in regions involved in the epileptogenic zone (EZ) and/or the irritative zone (IZ) compared to regions without electrical abnormalities in the same patients (P = 0.044 and P = 0.018, respectively), and also compared to controls (P = 0.004 and P = 0.0001, respectively). No significant differences in metabolic ratios were observed between those regions involved in the EZ and those involved in the IZ only. Our results suggest a link between the relative decrease of N-acetyl-aspartate and the EZ as well as the IZ in FLE. Thus, multilevel (1)H-MRSI protocol may add pertinent information during the non-invasive presurgical evaluation of FLE.
authors.affiliation: Service de Neurophysiologie Clinique et Laboratoire de Neurophysiologie et Neuropsychologie, INSERM EMI 9926, Faculté de Médecine, Université de la Méditerranée, 27 Boulevard Jean Moulin, 13385 Marseille cedex 05, France. maxime.guye@ap-hm.fr
authors.forename: M
authors.initials: M
authors.lastname: Guye
authors.forename: J P
authors.initials: JP
authors.lastname: Ranjeva
authors.forename: Y
authors.initials: Y
authors.lastname: Le Fur
authors.forename: F
authors.initials: F
authors.lastname: Bartolomei
authors.forename: S
authors.initials: S
authors.lastname: Confort-Gouny
authors.forename: J
authors.initials: J
authors.lastname: Regis
authors.forename: P
authors.initials: P
authors.lastname: Chauvel
authors.forename: P J
authors.initials: PJ
authors.lastname: Cozzone
mesh_terms: D000293:Adolescent; D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D001931:Brain Mapping; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D004351:Drug Resistance; D004566:Electrodes; D004569:Electroencephalography; D004594:Electrophysiology; D017034:Epilepsy, Frontal Lobe / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D005625:Frontal Lobe / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010725:Phosphocreatine / Q000378:metabolism
chemical_list: D010725:Phosphocreatine; D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline