### EEG source connectivity to localize the seizure onset zone in patients with drug resistant epilepsy

Willeke Staljanssens UGent, Roel Van Holen UGent, Stefanie Gadeyne UGent, Evelien Carrette UGent, Alfred Meurs UGent, et al. (2017)
abstract
Electrical source imaging (ESI) from interictal scalp EEG is increasingly validated and used as a valuable tool in the presurgical evaluation of epilepsy as a reflection of the irritative zone. ESI of ictal scalp EEG to localize the seizure onset zone (SOZ) remains challenging. We investigated the value of an approach for ictal imaging using ESI and functional connectivity analysis (FC). Ictal scalp EEG from 111 seizures in 27 patients who had Engel class I outcome at least 1 year following resective surgery was analyzed. For every seizure, an artifact-free epoch close to the seizure onset was selected and ESI using LORETA was applied. In addition, the reconstructed sources underwent FC using the spectrum-weighted Adaptive Directed Transfer Function. This resulted in the estimation of the SOZ in two ways: (i) the source with maximal power after ESI, (ii) the source with the strongest outgoing connections after combined ESI and FC. Next, we calculated the distance between the estimated SOZ and the border of the resected zone (RZ) for both approaches and called this the localization error ((i) LEpow and (ii) LEconn respectively). By comparing LEpow and LEconn, we assessed the added value of FC. The source with maximal power after ESI was inside the RZ (LEpow = 0 mm) in 31% of the seizures and estimated within 10 mm from the border of the RZ (LEpow ≤ 10 mm) in 42%. Using ESI and FC, these numbers increased to 72% for LEconn = 0 mm and 94% for LEconn ≤ 10 mm. FC provided a significant added value to ESI alone (p < 0.001). ESI combined with subsequent FC is able to localize the SOZ in a non-invasive way with high accuracy. Therefore it could be a valuable tool in the presurgical evaluation of epilepsy.
author
organization
year
type
journalArticle (original)
publication status
in press
subject
keyword
Ictal imaging, EEG source imaging, Functional connectivity, Clinical EEG, Granger causality
journal title
NEUROIMAGE-CLINICAL
publisher
Elsevier BV
ISSN
2213-1582
DOI
10.1016/j.nicl.2017.09.011
language
English
UGent publication?
yes
classification
A1
id
8532269
handle
http://hdl.handle.net/1854/LU-8532269
date created
2017-09-26 07:04:54
date last changed
2017-09-28 13:33:59
@article{8532269,
abstract     = {Electrical source imaging (ESI) from interictal scalp EEG is increasingly validated and used as a valuable tool in the presurgical evaluation of epilepsy as a reflection of the irritative zone. ESI of ictal scalp EEG to localize the seizure onset zone (SOZ) remains challenging. We investigated the value of an approach for ictal imaging using ESI and functional connectivity analysis (FC). Ictal scalp EEG from 111 seizures in 27 patients who had Engel class I outcome at least 1 year following resective surgery was analyzed. For every seizure, an artifact-free epoch close to the seizure onset was selected and ESI using LORETA was applied. In addition, the reconstructed sources underwent FC using the spectrum-weighted Adaptive Directed Transfer Function. This resulted in the estimation of the SOZ in two ways: (i) the source with maximal power after ESI, (ii) the source with the strongest outgoing connections after combined ESI and FC. Next, we calculated the distance between the estimated SOZ and the border of the resected zone (RZ) for both approaches and called this the localization error ((i) LEpow and (ii) LEconn respectively). By comparing LEpow and LEconn, we assessed the added value of FC. The source with maximal power after ESI was inside the RZ (LEpow = 0 mm) in 31\% of the seizures and estimated within 10 mm from the border of the RZ (LEpow \ensuremath{\leq} 10 mm) in 42\%. Using ESI and FC, these numbers increased to 72\% for LEconn = 0 mm and 94\% for LEconn \ensuremath{\leq} 10 mm. FC provided a significant added value to ESI alone (p {\textlangle} 0.001). ESI combined with subsequent FC is able to localize the SOZ in a non-invasive way with high accuracy. Therefore it could be a valuable tool in the presurgical evaluation of epilepsy.},
author       = {Staljanssens, Willeke and Strobbe, Gregor and Van Holen, Roel and Keereman, Vincent and Gadeyne, Stefanie and Carrette, Evelien and Meurs, Alfred and Pittau, Francesca and Momjian, Shahan and Seeck, Margitta and Boon, Paul and Vandenberghe, Stefaan and Vulliemoz, Serge and Vonck, Kristl and van Mierlo, Pieter},
issn         = {2213-1582},
journal      = {NEUROIMAGE-CLINICAL },
keyword      = {Ictal imaging,EEG source imaging,Functional connectivity,Clinical EEG,Granger causality},
language     = {eng},
publisher    = {Elsevier BV},
title        = {EEG source connectivity to localize the seizure onset zone in patients with drug resistant epilepsy},
url          = {http://dx.doi.org/10.1016/j.nicl.2017.09.011},
year         = {2017},
}


Chicago
Staljanssens, Willeke, Gregor Strobbe, Roel Van Holen, Vincent Keereman, Stefanie Gadeyne, Evelien Carrette, Alfred Meurs, et al. 2017. “EEG Source Connectivity to Localize the Seizure Onset Zone in Patients with Drug Resistant Epilepsy.” Neuroimage-clinical .
APA
Staljanssens, W., Strobbe, G., Van Holen, R., Keereman, V., Gadeyne, S., Carrette, E., Meurs, A., et al. (2017). EEG source connectivity to localize the seizure onset zone in patients with drug resistant epilepsy. NEUROIMAGE-CLINICAL .
Vancouver
1.
Staljanssens W, Strobbe G, Van Holen R, Keereman V, Gadeyne S, Carrette E, et al. EEG source connectivity to localize the seizure onset zone in patients with drug resistant epilepsy. NEUROIMAGE-CLINICAL . Elsevier BV; 2017;
MLA
Staljanssens, Willeke, Gregor Strobbe, Roel Van Holen, et al. “EEG Source Connectivity to Localize the Seizure Onset Zone in Patients with Drug Resistant Epilepsy.” NEUROIMAGE-CLINICAL (2017): n. pag. Print.