Page 159 - MEGIN Book Of Abstracts - 2023

Department of Biomedical Engineering, Carnegie Mellon Uni- Children, Toronto, ON, Canada; The Division of Neuroimag-
versity, USA; University of Pittsburgh Comprehensive Epilepsy ing, Department of Diagnostic Imaging, The Hospital for Sick
Center (UPCEC), University of Pittsburgh Medical School, USA; Children Toronto ON, Canada; The Division of Neurology, De-
Department of Biomedical Engineering, Carnegie Mellon partment of Pediatrics, McMaster Children's Hospital, Hamil-
University, USA. Electronic address: [email protected] ton, ON, Canada. Electronic address: [email protected]

ABSTRACT Non-invasive MEG/EEG source imaging PURPOSE To investigate the utility of Low Density (LD)
provides valuable information about the epileptogenic Electrical Source Imaging (ESI) to model the ictal onset
brain areas which can be used to aid presurgical plan- zone (IOZ) for the surgical work up of children with
ning in focal epilepsy patients suffering from drug- medically refractory epilepsy.
resistant seizures. However, the source extent estima-
tion for electrophysiological source imaging remains METHODS This was a retrospective review of 12
to be a challenge and is usually largely dependent patients from a district and regional pediatric epilepsy
on subjective choice. Our recently developed algo- center, who underwent focal resections between 2014
rithm, fast spatiotemporal iteratively reweighted edge and 2019. ESI was generated using the Curry 8 soft-
sparsity minimization (FAST-IRES) strategy, has been ware, incorporating T1 Magnetic Resonance Imaging
shown to objectively estimate extended sources from (MRI) scans and scalp electroencephalogram (EEG) re-
EEG recording, while it has not been applied to MEG cordings. Concordance of the ictal LD-ESI localizations
recordings. In this work, through extensive numerical to the epileptogenic zone was assessed by comparing
experiments and real data analysis in a group of focal the location of the ictal LD-ESI to the focal resection
drug-resistant epilepsy patients' interictal spikes, we margins on neuroimaging and noting the post-oper-
demonstrated the ability of FAST-IRES algorithm to ative outcomes at one year. Localizations determined
image the location and extent of underlying epilepsy by ictal LD-ESI were also compared to interictal LD-ESI,
sources from MEG measurements. Our results indicate positron emission tomography (FDG-PET) and interictal
the merits of FAST-IRES in imaging the location and magnetoencephalography (MEG).
extent of epilepsy sources for pre-surgical evaluation
from MEG measurements. RESULTS Ictal ESI correctly localized the ictal onset
zone in 4/6 patients, with all four being seizure free at
Keywords: Electrophysiological source imaging (ESI), one year. Similarly, interictal ESI localized the irritative
Epilepsy, Magnetoencephalography (MEG), Source extent zone in 7/9 patients with focal resections, with 6/7
imaging being seizure free at one year. Additionally, we ob-
served ictal ESI to be concordant to interictal ESI in 5/6
NeuroImage. Clinical (2022), Vol. 33 (34864288) (1 citation) patients. Ictal ESI and interictal ESI were concordant to
interictal MEG in 3/6 patients. Ictal ESI was concordant
with FDG-PET in 6/7 cases.
Low density electrical source imaging of the ictal
onset zone in the surgical evaluation of children CONCLUSION IOZ source localization through LD-ESI
with epilepsy (2021) is a promising complementary method of assessing
the epileptogenic focus in children. These findings may
Thurairajah, Arun; Freibauer, Alexander; support the inclusion of ictal LD-ESI within the pre-
RamachandranNair, Rajesh; Whitney, Robyn; Jain, surgical evaluation of children to supplement current
Puneet; Donner, Elizabeth; Widjaja, Elysa; Jones, Kevin C diagnostic tools.

The Division of Neurology, Department of Pediatrics, Mc- Keyword: Ictal Low Density Electrical Source Imaging
Master Children's Hospital, Hamilton, ON, Canada; Division
of Neurology, Department of Pediatrics, The Hospital for Sick Epilepsy research (2021), Vol. 178 (34784573) (2 citations)

 ontents  Index 138
C