EEG source connectivity to localize the seizure onset zone in patients with drug resistant epilepsy
Date
2017-09
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
ENGLISH ABSTRACT: 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.
Description
CITATION: Staljanssens, W., et al . 2017. EEG source connectivity to localize the seizure onset zone in patients with drug resistant epilepsy. NeuroImage: Clinical, 16:689-698, doi:10.1016/j.nicl.2017.09.011
The original publication is available at http://www.sciencedirect.com
The original publication is available at http://www.sciencedirect.com
Keywords
Drug resistant epilepsy, Electroencephalography, Brain -- Diseases -- Diagnosis, Epilepsy -- Patients, Epilepsy -- Treatment, Drug resistance -- Epileptics
Citation
Staljanssens, W., et al . 2017. EEG source connectivity to localize the seizure onset zone in patients with drug resistant epilepsy. NeuroImage: Clinical, 16:689-698, doi:10.1016/j.nicl.2017.09.011