Page 141 - MEGIN Book Of Abstracts - 2023

60 months. Among 258 patients who were followed Canada; Department of Physiology, University of Toronto,
up for at least 12 months, 215 (83.3%) patients had a Canada; Department of Neurosurgery, Cincinnati Children's
favorable seizure outcome (Engel class I) after surgery, Hospital Medical Center, Cincinnati, OH, USA; Department of
and 43 (16.7%) patients had an unfavorable seizure Neurosurgery, University of Cincinnati College of Medicine,
outcome; longer duration of epilepsy, discordant Cincinnati, OH, USA
magnetoencephalography (MEG) findings, and acute
postoperative seizures were significantly included OBJECTIVE To clinically validate the connectivity-based
in the scoring system to predict unfavorable seizure magnetoencephalography (MEG) analyses to identify
outcomes, and in the scoring system, accumulated seizure onset zone (SOZ) with comparing to equivalent
scoring of 0-19 scores was recorded, which were finally current dipole (ECD).
grouped into three risk levels: low risk (risk < 30%), me-
dium risk (30% ≤ risk < 70%), and high risk (risk ≥ 70%). METHODS The ECD cluster was quantitatively analyzed
In addition, favorable neurological outcomes (mRS by calculating the centroid of the cluster and maximum
score 0-1) were recorded in 187 (72.5%) patients, while distance (the largest distance between all dipoles). The
unfavorable neurological outcomes were recorded in "primary hub" was determined by the highest eigen-
71 (27.5%) patients, which were significantly related to centrality. The distribution of nodes in the top 5% of
poor seizure control, older age at surgery, and longer eigenvector centrality values was quantified by gener-
duration of epilepsy and hospitalization time. ating the convex hull between each node.

SIGNIFICANCE The long-term surgical outcomes of RESULTS Thirty-one patients who underwent MEG,
LEAT after surgery were satisfactory. A scoring system stereotactic-EEG, and focal surgery were included.
for predicting unfavorable seizure outcomes with dif- The primary hub was significantly closer to the sEEG-
ferent risk levels was developed, which could partly defined SOZ compared to ECD (p = 0.009). The seizure
guide clinical treatments of LEAT. freedom positive and negative predictive values of
complete ECD cluster and primary hub resections did
Keywords: brain tumor, epilepsy surgery, neurological out- not significantly differ, although complete resection of
come, prognostic factor, seizure outcome the primary hub showed slightly better negative pre-
dictive value (ECD: 50.0% NPV, hub: 64.7% NPV). Both
Epilepsia open (2022), Vol. 7, No. 4 (36081402) (1 citation) quantitative ECD and functional connectivity analyses
suggested that spatially restricted dipole distributions
and higher connectivity in a smaller region correlate
Clinical validation of magnetoencephalography with better seizure outcomes.
network analysis for presurgical epilepsy evaluation
(2022) CONCLUSIONS Our findings suggest that MEG net-
work analysis could be a valuable complement to the
Fujiwara, Hisako; Kadis, Darren S; Greiner, Hansel M; ECD methods.
Holland, Katherine D; Arya, Ravindra; Aungaroon,
Gewalin; Fong, Susan L; Arthur, Todd M; Kremer, Kelly M; SIGNIFICANCE The results of this study are an impor-
Lin, Nan; Liu, Wei; Mangano, Francesco T; Skoch, Jesse; tant step towards using non-invasive neurophysiologic
Horn, Paul S; Tenney, Jeffrey R recordings to accurately define the epileptic network.

Division of Neurology, Cincinnati Children's Hospital Medical
Center, Cincinnati OH, USA; Department of Pediatrics, Uni-
versity of Cincinnati College of Medicine, Cincinnati, OH, USA.
Electronic address: [email protected]; Neurosci-
ences and Mental Health, Hospital for Sick Children, Toronto,

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