TY - JOUR
T1 - Case Report
T2 - High-Gamma Oscillations on an Ictal Electroencephalogram in a Newborn Patient With Hypoxic–Ischemic Encephalopathy
AU - Takeuchi, Akihito
AU - Inoue, Takushi
AU - Nakamura, Makoto
AU - Kageyama, Misao
AU - Akiyama, Tomoyuki
AU - Kobayashi, Katsuhiro
N1 - Funding Information:
KK was supported by Grants-in-Aid from the Ministry of Education, Culture, Sports, Science and Technology, Japan [MEXT KAKENHI Grant Number 15H05874 (Non-linear Neuro-oscillology)] and by Health and Labour Research Grants from the Ministry of Health, Labour and Welfare, Japan (H26-nanchitou-ippan-051, and H29-nanchitou-ippan-010).
Publisher Copyright:
© Copyright © 2021 Takeuchi, Inoue, Nakamura, Kageyama, Akiyama and Kobayashi.
PY - 2021/10/1
Y1 - 2021/10/1
N2 - Fast oscillations (FOs) >40 Hz in electroencephalograms (EEGs) are associated with ictogenesis and epileptogenesis in adults and children with epilepsy. However, only a few previous studies showed FOs in neonates. Reported frequencies of such neonatal FOs were in the low-gamma (<60 Hz) band and, therefore, they were not high compared to those in pediatric patients. We herein report a newborn patient with severe hypoxic–ischemic encephalopathy (HIE), who showed pathological FOs with a frequency in the high-gamma band. She was born at a gestational age of 39 weeks 4 days by emergency cesarean section because of non-reassuring fetal status. She had focal motor seizures involving unilateral upper and lower limbs lasting for tens of seconds on days 0, 1, 4, 5, 8, and 9 and subclinical seizures on days 4–11. Phenobarbital (PB) was intravenously administered on days 0, 2, 4, 5, and 6. We found FOs that were superimposed on the ictal delta activities using visual inspection and time–frequency analysis on 8–11 days of age. Among them, we detected high-gamma (71.4–100 Hz) oscillations that appeared to be temporally independent of low-gamma activities in the ictal EEG on 11 days of age. To the best of our knowledge, this is one of the earliest reports showing pathological FOs with a frequency of >60 Hz in the high-gamma band in human neonatal seizures, which were previously observed in animal studies. Further studies are needed to elucidate the pathophysiology of ictal FOs in neonatal seizures.
AB - Fast oscillations (FOs) >40 Hz in electroencephalograms (EEGs) are associated with ictogenesis and epileptogenesis in adults and children with epilepsy. However, only a few previous studies showed FOs in neonates. Reported frequencies of such neonatal FOs were in the low-gamma (<60 Hz) band and, therefore, they were not high compared to those in pediatric patients. We herein report a newborn patient with severe hypoxic–ischemic encephalopathy (HIE), who showed pathological FOs with a frequency in the high-gamma band. She was born at a gestational age of 39 weeks 4 days by emergency cesarean section because of non-reassuring fetal status. She had focal motor seizures involving unilateral upper and lower limbs lasting for tens of seconds on days 0, 1, 4, 5, 8, and 9 and subclinical seizures on days 4–11. Phenobarbital (PB) was intravenously administered on days 0, 2, 4, 5, and 6. We found FOs that were superimposed on the ictal delta activities using visual inspection and time–frequency analysis on 8–11 days of age. Among them, we detected high-gamma (71.4–100 Hz) oscillations that appeared to be temporally independent of low-gamma activities in the ictal EEG on 11 days of age. To the best of our knowledge, this is one of the earliest reports showing pathological FOs with a frequency of >60 Hz in the high-gamma band in human neonatal seizures, which were previously observed in animal studies. Further studies are needed to elucidate the pathophysiology of ictal FOs in neonatal seizures.
KW - fast oscillations
KW - gamma
KW - hypoxic-ischemia encephalopathy
KW - ictal EEG
KW - neonatal seizure
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UR - http://www.scopus.com/inward/citedby.url?scp=85117163344&partnerID=8YFLogxK
U2 - 10.3389/fped.2021.679771
DO - 10.3389/fped.2021.679771
M3 - Article
AN - SCOPUS:85117163344
SN - 2296-2360
VL - 9
JO - Frontiers in Pediatrics
JF - Frontiers in Pediatrics
M1 - 679771
ER -