title: Déjà-vu in temporal lobe epilepsy: metabolic pattern of cortical involvement in patients with normal brain MRI.
abstract: To contribute to the identification of brain regions involved in déjà-vu, we studied the metabolic pattern of cortical involvement in patients with seizures of temporal lobe origin presenting with or without déjà-vu. Using voxel-based analysis of 18FDG-PET brain scans, we compared glucose metabolic rate of 8 patients with déjà-vu, 8 patients without déjà-vu, and 20 age-matched healthy subjects. Patients were selected after comprehensive non-invasive presurgical evaluation, including normal brain MRI and surface electroclinical features compatible with unilateral temporal lobe epilepsy (TLE). Patients with and without déjà-vu did not differ in terms of age, gender, epilepsy lateralization, epilepsy onset, epilepsy duration, and other subjective ictal manifestations. TLE patients with déjà-vu exhibited ipsilateral hypometabolism of superior temporal gyrus and of parahippocampal region, in the vicinity of perirhinal/entorhinal cortex, in comparison either to healthy subjects or to TLE patients without déjà-vu (p<0.05 FDR-corrected). By contrast, no difference was found between patient subgroups for hypometabolism of hippocampus and amygdala. At an individual-level, in comparison to healthy subjects, hypometabolism of both parahippocampal region and superior temporal gyrus was present in 7/8 patients with déjà-vu. Hippocampal metabolism was spared in 3 of these 7 patients. These findings argue for metabolic dysfunction of a medial-lateral temporal network in patients with déjà-vu and normal brain MRI. Within the medial temporal lobe, specific involvement of the parahippocampal region, often in the absence of hippocampal impairment, suggests that the feeling of familiarity during seizures greatly depends on alteration of the recognition memory system.
authors.affiliation: Service Central de Biophysique et Médecine Nucléaire, CHU Timone & Centre Européen de Recherche en Imagerie Médicale, CERIMED & Centre d'Investigation Clinique, CIC, INSERM, Université de la Méditerranée, Marseille F-13000, France. eric.guedj@ap-hm.fr
authors.forename: Eric
authors.initials: E
authors.lastname: Guedj
authors.forename: Sandrine
authors.initials: S
authors.lastname: Aubert
authors.forename: Aileen
authors.initials: A
authors.lastname: McGonigal
authors.forename: Olivier
authors.initials: O
authors.lastname: Mundler
authors.forename: Fabrice
authors.initials: F
authors.lastname: Bartolomei
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D001931:Brain Mapping; D016022:Case-Control Studies; D003690:Deja Vu; D004833:Epilepsy, Temporal Lobe / Q000150:complications* / Q000473:pathology*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D007839:Functional Laterality; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008569:Memory Disorders / Q000209:etiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography / Q000379:methods; D055815:Young Adult
chemical_list: D019788:Fluorodeoxyglucose F18