Page 200 - MEGIN Book Of Abstracts - 2023

values were calculated for routine EEG, routine EEG plus non-invasively measure the epileptic network. We ret-
additional EEG and MEG. In addition, diagnostic gain rospectively identified pediatric and adult patients with
associated with MEG, relative to the other modalities, refractory focal epilepsy who underwent pre-surgical
was calculated. Secondary outcome was congruence of magnetoencephalography with subsequent intracra-
localization of epileptiform discharges between MEG nial electrographic monitoring. Magnetoencephalog-
and MRI or final clinical diagnosis. Based on a cohort of raphy tracings were visually reviewed, and interictal
138 patients, sensitivity and specificity was shown to epileptiform discharges ("spikes") were individually
be 31.6% and 78.4% for routine MEG, 31.6% and 100% marked. We then evaluated differences in whole-brain
for routine EEG, and 52.6% and 97.3% for routine EEG connectivity during brief epochs preceding the spikes
plus additional EEG, respectively. Routine MEG demon- and during the spikes using the Network-Based Sta-
strated a diagnostic gain of 16.8% compared to routine tistic to test differences at the network level. In six pa-
EEG and 9.5% compared to routine EEG plus additional tients with statistically-significant network differences,
EEG. In 35.7% of patients with a lesion on MRI that was we observed substantial overlap between the spike-
consistent with the final clinical diagnosis, MEG showed associated networks and electrographically active areas
epileptiform discharges in the same area. Routine MEG identified during intracranial monitoring (the spike-
may provide additional value during the initial diagno- associated network was 78% and 83% sensitive for
sis of epilepsy. intracranial electroencephalography-defined regions
in the irritative and seizure onset zones, respectively).
Keywords: diagnosis, epilepsy, magnetoencephalography, These findings support the neurobiological validity of
sensitivity the spike-associated network method. Assessment of
spike-associated networks has the potential to im-
Epileptic disorders: international epilepsy journal with prove surgical planning in epilepsy surgery patients by
videotape (2020), Vol. 22, No. 3 (32554358) (2 citations) identifying components of the epileptic network prior
to implantation.

Spike-associated networks and intracranial Keywords: epilepsy, functional connectivity, intracranial
electrographic findings (2020) electroencephalography, magnetoencephalography

Bear, Joshua J; Kirsch, Heidi E; Berman, Brian D; Epileptic disorders: international epilepsy journal with
Chapman, Kevin E; Tregellas, Jason R videotape (2020), Vol. 22, No. 3 (32554357) (2 citations)

Department of Pediatrics, Section of Neurology, Children's
Hospital Colorado, Aurora,, Department of Pediatrics, Univer- Identifying the epileptogenic zone by four non-
sity of Colorado Anschutz Medical Campus, Aurora; Depart- invasive imaging techniques versus stereo-EEG in
ment of Radiology and Biomedical Imaging, University of MRI-negative pre-surgery epilepsy patients (2020)
California, San Francisco,, Department of Neurology, Univer-
sity of California, San Francisco; Department of Neurology, Rossi Sebastiano, Davide; Tassi, Laura; Duran, Dunja;
University of Colorado Anschutz Medical Campus, Aurora; Visani, Elisa; Gozzo, Francesca; Cardinale, Francesco;
Department of Psychiatry, University of Colorado Anschutz Nobili, Lino; Del Sole, Angelo; Rubino, Annalisa; Dotta,
Medical Campus, Aurora,, Research Service, Rocky Mountain Sara; Schiaffi, Elena; Garbelli, Rita; Franceschetti,
Regional VA Medical Center, Aurora, USA Silvana; Spreafico, Roberto; Panzica, Ferruccio

ABSTRACT Functional connectivity is providing new Neurophysiology Unit, Fondazione IRCCS Istituto Neurologico
insights into the network nature of epilepsy with grow- Carlo Besta, Milan, Italy. Electronic address: davide.rossi@
ing clinical applications. Our objective was to validate istituto-besta.it; "Claudio Munari" Epilepsy Surgery Centre,
a novel magnetoencephalography-based method to Niguarda Hospital, Milan, Italy; Epilepsy Unit, Fondazione

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