TY - JOUR
T1 - Epileptogenic high-frequency oscillations skip the motor area in children with multilobar drug-resistant epilepsy
AU - Iimura, Yasushi
AU - Jones, Kevin
AU - Hattori, Kyoko
AU - Okazawa, Yushi
AU - Noda, Atsuko
AU - Hoashi, Kana
AU - Nonoda, Yutaka
AU - Asano, Eishi
AU - Akiyama, Tomoyuki
AU - Go, Cristina
AU - Ochi, Ayako
AU - Snead, O. Carter
AU - Donner, Elizabeth J.
AU - Rutka, James T.
AU - Drake, James M.
AU - Otsubo, Hiroshi
N1 - Funding Information:
Drs. Yasushi Iimura and Hiroshi Otsubo were supported by EpLink ? the Epilepsy Research Program of the Ontario Brain Institute (OBI). The OBI is an independent non-profit corporation, funded partially by the Ontario government. The opinions, results, and conclusions are those of the authors, and no endorsement by the OBI is intended or should be inferred.
Publisher Copyright:
© 2017 International Federation of Clinical Neurophysiology
PY - 2017/7/1
Y1 - 2017/7/1
N2 - Objective Subtotal hemispherectomy involves the resection of multiple lobes in children with drug-resistant epilepsy, skipping the motor area (MA). We determined epileptogenicity using the occurrence rate (OR) of high-frequency oscillations (HFOs) and the modulation index (MI), demonstrating strength of coupling between HFO and slow wave. We hypothesized that epileptogenicity increased over the multiple lobes but skipped the MA. Methods We analyzed 23 children (14 subtotal hemispherectomy; 9 multilobar resections). Scalp video-EEG and magnetoencephalography were performed before surgery. We analyzed the OR(HFO) and MI(5 phases=0.5–8 Hz) on electrodes of total area, resection areas, and MA. We compared the data between good [International League Against Epilepsy (ILAE) class I–II] and poor (III–VI) seizure outcome groups. Results ILAE class Ia outcome was achieved in 18 children. Among the MI(5 phases) in the resection areas, MI(3–4 Hz) was the highest. The OR(HFO) and MI(3–4 Hz) in both total area and resection areas were significantly higher in the good seizure outcome group than in the poor outcome group. The OR(HFO) and MI(3–4 Hz) in resection areas were significantly higher than in the MA. Conclusions Our patients with multilobar drug-resistant epilepsy showed evidence of multifocal epileptogenicity that specifically skipped the MA. Significance This is the first study demonstrating that the electrophysiological phenotype of multifocal epilepsy specifically skips the MA using OR(HFO) and MI(3–4 Hz).
AB - Objective Subtotal hemispherectomy involves the resection of multiple lobes in children with drug-resistant epilepsy, skipping the motor area (MA). We determined epileptogenicity using the occurrence rate (OR) of high-frequency oscillations (HFOs) and the modulation index (MI), demonstrating strength of coupling between HFO and slow wave. We hypothesized that epileptogenicity increased over the multiple lobes but skipped the MA. Methods We analyzed 23 children (14 subtotal hemispherectomy; 9 multilobar resections). Scalp video-EEG and magnetoencephalography were performed before surgery. We analyzed the OR(HFO) and MI(5 phases=0.5–8 Hz) on electrodes of total area, resection areas, and MA. We compared the data between good [International League Against Epilepsy (ILAE) class I–II] and poor (III–VI) seizure outcome groups. Results ILAE class Ia outcome was achieved in 18 children. Among the MI(5 phases) in the resection areas, MI(3–4 Hz) was the highest. The OR(HFO) and MI(3–4 Hz) in both total area and resection areas were significantly higher in the good seizure outcome group than in the poor outcome group. The OR(HFO) and MI(3–4 Hz) in resection areas were significantly higher than in the MA. Conclusions Our patients with multilobar drug-resistant epilepsy showed evidence of multifocal epileptogenicity that specifically skipped the MA. Significance This is the first study demonstrating that the electrophysiological phenotype of multifocal epilepsy specifically skips the MA using OR(HFO) and MI(3–4 Hz).
KW - Epileptic spasms
KW - Modulation index (MI)
KW - Motor area
KW - Pathological high-frequency oscillations
KW - Phase-amplitude coupling
KW - Subtotal hemispherectomy
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U2 - 10.1016/j.clinph.2017.03.031
DO - 10.1016/j.clinph.2017.03.031
M3 - Article
C2 - 28521267
AN - SCOPUS:85019183490
VL - 128
SP - 1197
EP - 1205
JO - Electroencephalography and Clinical Neurophysiology - Electromyography and Motor Control
JF - Electroencephalography and Clinical Neurophysiology - Electromyography and Motor Control
SN - 1388-2457
IS - 7
ER -