Page 193 - MEGIN Book Of Abstracts - 2023

Keywords: BETS, EEG, Hippocampus, MEG, Magnetic poor outcomes of class III-V to group B (6 patients).
source imaging (MSI), Small sharp spikes (SSS) The number of post-VNS MEG spikes was significantly
reduced compared to pre-VNS MEG spikes in group A,
Clinical neurophysiology: official journal of the but not in group B. Group A showed significantly higher
International Federation of Clinical Neurophysiology preoperative PBS than group B. Postoperative ITD
(2020), Vol. 131, No. 12 (32988727) (6 citations) significantly decreased in 5 patients who underwent
corpus callosotomy compared to 10 patients without.

Secondary epileptogenesis on gradient magnetic- CONCLUSION GMFT can detect the inter- and intra-
field topography correlates with seizure outcomes hemispheric spreading of spikes with high spatiotem-
after vagus nerve stimulation (2020) poral resolution on the brain surface. Frequent inter-
ictal MEG spikes propagating bilaterally on GMFT may
Okamura, Akitake; Otsubo, Hiroshi; Hashizume, Akira; reflect a favorable seizure outcome after VNS. GMFT
Kagawa, Kota; Katagiri, Masaya; Seyama, Go; Kurisu, can identify dependent secondary epileptogenic spikes
Kaoru; Iida, Koji responding to VNS, which may be used to control gen-
eralized seizures in a subset of patients with pharmaco-
Department of Neurosurgery, Graduate School of Biomedical resistant epilepsy.
and Health Sciences, Hiroshima University, Hiroshima, Japan;
Epilepsy Center, Hiroshima University Hospital, Hiroshima, Keywords: Bilateral spreading, Dependent spikes, Gradient
Japan; Division of Neurology, Department of Pediatrics, The magnetic field topography, Magnetoencephalography,
Hospital for Sick Children, Toronto, Canada; Department of Secondary epileptogenesis, Vagus nerve stimulation
Neurosurgery, Chugoku Rosai Hospital, Hiroshima, Japan;
Department of Neurosurgery, Graduate School of Biomedical Epilepsy research (2020), Vol. 167 (32987243) (2 citations)
and Health Sciences, Hiroshima University, Hiroshima, Japan;
Epilepsy Center, Hiroshima University Hospital, Hiroshima,
Japan. Electronic address: [email protected] Awake state-specific suppression of primary
somatosensory evoked response correlated with
OBJECTIVE To determine the correlation between duration of temporal lobe epilepsy (2020)
secondary unilateral or bilateral spreading on gradient
magnetic-field topography (GMFT) before and after va- Ishida, Makoto; Jin, Kazutaka; Kakisaka, Yosuke; Kanno,
gus nerve stimulation (VNS), and postoperative seizure Akitake; Kawashima, Ryuta; Nakasato, Nobukazu
outcomes.
Department of Epileptology, Tohoku University Graduate
METHODS We analyzed pre- and post-VNS magne- School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai,
toencephalography (MEG) in 15 patients with VNS Miyagi, 980-8575, Japan; Collaborative Laboratory of Elec-
implants. We applied McHugh classification to evaluate tromagnetic Neurophysiology, Tohoku University Graduate
seizure outcomes. GMFT visualized the spatiotemporal School of Medicine, Sendai, Miyagi, Japan. [email protected].
spread of the gradient magnetic field from MEG (>300 ac.jp; Institute of Development, Aging and Cancer, Tohoku
fT/cm) before and after the spike peak. We compared University, Sendai, Miyagi, Japan
the proportion of bilaterally spreading (PBS) MEG
spikes and seizure outcomes. We also compared the in- ABSTRACT Epilepsy is a network disease. The primary
terhemispheric time difference (ITD) between patients somatosensory cortex (S1) is usually considered to
with and without corpus callosotomy. be intact, but could be subclinically disturbed based
on abnormal functional connectivity in patients with
RESULTS We allocated patients with favorable seizure temporal lobe epilepsy (TLE). We aimed to investigate if
outcomes of class I and II to group A (9 patients) and the S1 of TLE is abnormally modulated. Somatosensory

 ontents  Index 172
C