title: Combining ESI, ASL and PET for quantitative assessment of drug-resistant focal epilepsy.
abstract: When localization of the epileptic focus is uncertain, the epileptic activity generator may be more accurately identified with non-invasive imaging techniques which could also serve to guide stereo-electroencephalography (sEEG) electrode implantation. The aim of this study was to assess the diagnostic value of perfusion magnetic resonance imaging with arterial spin labeling (ASL) in the identification of the epileptogenic zone, as compared to the more invasive positron-emission tomography (PET) and other established investigation methods for source imaging of electroencephalography (EEG) data. In 6 patients with drug-resistant focal epilepsy, standard video-EEG was performed to identify clinical seizure semeiology, and high-density EEG, ASL and FDG-PET to non-invasively localize the epileptic focus. A standardized source imaging procedure, low-resolution brain electromagnetic tomography constrained to the individual matter, was applied to the averaged spikes of high-density EEG. Quantification of current density, cerebral blood flow, and standardized uptake value were compared over the same anatomical areas. In most of the patients, source in the interictal phase was associated with an area of hypoperfusion and hypometabolism. Conversely, in the patients presenting with early post-ictal discharges, the brain area identified by electrical source imaging (ESI) as the generating zone appeared to be hyperperfused. In 2 patients in whom the focus remained uncertain, the postoperative follow-up showed the disappearance of epileptic activity. As an innovative and more comprehensive approach to the study of epilepsy, the combined use of ESI, perfusion MRI, and PET may play an increasingly important role in the non-invasive evaluation of patients with refractory focal epilepsy.
authors.affiliation: Department of Neurological, and Movement Sciences, Section of Neurology, University of Verona, Italy. Electronic address: silviafrancesca.storti@univr.it.
authors.forename: Silvia Francesca
authors.initials: SF
authors.lastname: Storti
authors.affiliation: Department of Neurological, and Movement Sciences, Section of Neurology, University of Verona, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Boscolo Galazzo
authors.affiliation: Department of Neurological, and Movement Sciences, Section of Neurology, University of Verona, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Del Felice
authors.affiliation: Department of Neuroradiology, AOUI of Verona, Verona, Italy.
authors.forename: Francesca Benedetta
authors.initials: FB
authors.lastname: Pizzini
authors.affiliation: Department of Neurophysiology, Foundation IRCCS San Camillo Hospital, Venice, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Arcaro
authors.affiliation: Department of Neurophysiology, Foundation IRCCS San Camillo Hospital, Venice, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Formaggio
authors.affiliation: Epilepsy Surgery Center, Niguarda Hospital, Milan, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Mai
authors.affiliation: Department of Neurological, and Movement Sciences, Section of Neurology, University of Verona, Italy; Department of Neurophysiology, Foundation IRCCS San Camillo Hospital, Venice, Italy; Clinical Neurophysiology and Functional Neuroimaging Unit, AOUI of Verona, Verona, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Manganotti
mesh_terms: D000328:Adult; D003952:Diagnostic Imaging; D004351:Drug Resistance; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000175:diagnosis* / Q000188:drug therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D059906:Neuroimaging / Q000379:methods*; D049268:Positron-Emission Tomography; D013113:Spin Labels
chemical_list: D013113:Spin Labels
keywords: ASL; ESI; Epilepsy; Multimodal imaging approach; PET