Page 210 - MEGIN Book Of Abstracts - 2023

on the authors' institutional experience in pursuing epilepsy surgery, outcome, pediatric epilepsy, presurgical
seizure-free surgical outcomes in children with medi- workup
cally refractory epilepsy.
Neurosurgical focus (2020), Vol. 48, No. 4 (32234993) (2
METHODS This was a retrospective, single-institution, citations)
observational cohort study of pediatric patients who
underwent evaluation and surgical treatment for medi-
cally refractory partial epilepsy between December Utility of magnetic source imaging in nonlesional
2003 and June 2016. During this interval, 108 children focal epilepsy: a prospective study (2020)
with medically refractory partial epilepsy underwent
evaluation for localization and resective epilepsy sur- Mohamed, Ismail Sidky; Toffa, Dènahin Hinnoutondji;
gery. Different noninvasive functional imaging modali- Robert, Manon; Cossette, Patrick; Bérubé, Arline-Aude;
ties, including ictal SPECT, FDG-PET, and magnetoen- Saint-Hilaire, Jean-Marc; Bouthillier, Alain; Nguyen,
cephalography-magnetic source imaging, were utilized Dang Khoa
to augment a standardized paradigm (electroen-
cephalography/semiology, MRI, and neuropsychology Neurology, University of Alabama, Birmingham, Alabama;
findings) for localization. Outcomes were evaluated at a Divisions of1Neurology and; Neuropsychology and Cogni-
minimum of 2 years (mean 7.5 years) utilizing area un- tion Research Center, Psychology Department, Université de
der the receiver operating characteristic curve analysis. Montréal, Quebec, Canada; and; Neurosurgery, Montreal
Localizing modalities and other clinical covariates were University Health Center, Université de Montréal, and
examined in relation to long-term surgical outcomes.
OBJECTIVE For patients with nonlesional refractory
RESULTS There was variation in the contribution of focal epilepsy (NLRFE), localization of the epileptogenic
each test, and no single presurgical workup modal- zone may be more arduous than for other types of
ity could singularly and reliably predict a seizure-free epilepsy and frequently requires information from mul-
outcome. However, concordance of presurgical modali- tiple noninvasive presurgical modalities and intracra-
ties yielded a high predictive value. No difference in nial EEG (icEEG). In this prospective, blinded study, the
long-term outcomes between inconclusive (normal authors assessed the clinical added value of magnetic
or diffusely abnormal) and abnormal focal MRI results source imaging (MSI) in the presurgical evaluation of
were found. Long-term survival analyses revealed a patients with NLRFE.
statistically significant association between seizure
freedom and patients with focal ictal EEG, early surgical METHODS This study prospectively included 57 con-
intervention, and no history of generalized convulsions. secutive patients with NLRFE who were considered for
epilepsy surgery. All patients underwent noninvasive
CONCLUSIONS Comprehensive preoperative evalua- presurgical evaluation and then MSI. To determine the
tion utilizing multiple noninvasive functional imaging surgical plan, discussion of the results of the presurgi-
modalities is not redundant and can improve pediatric cal evaluation was first undertaken while discussion
epilepsy surgical outcomes. participants were blinded to the MSI results. MSI results
were then presented. MSI influence on the initial man-
Keywords: AUC = area under the ROC curve, EEG = elec- agement plan was assessed.
troencephalography, MEG-MSI = magnetoencephalogra-
phy–magnetic source imaging, PMC = patient manage- RESULTS MSI results influenced patient management
ment conference, ROC = receiver operating characteristic, in 32 patients. MSI results led to the following changes
in surgical strategy in 14 patients (25%): allowing direct
surgery in 6 patients through facilitating the detection
of subtle cortical dysplasia in 4 patients and providing

 ontents  Index 189
C