TY - JOUR
T1 - Detection of seizure-associated high-frequency oscillations above 500 Hz
AU - Kobayashi, Katsuhiro
AU - Agari, Takashi
AU - Oka, Makio
AU - Yoshinaga, Harumi
AU - Date, Isao
AU - Ohtsuka, Yoko
AU - Gotman, Jean
N1 - Funding Information:
This study is supported in part by the Japan Epilepsy Research Foundation.
PY - 2010/2
Y1 - 2010/2
N2 - High-frequency oscillations (HFOs) of up to 500 Hz in EEG are considered to have close relation with ictogenesis. We had the unique opportunity to record a seizure in EEG with intracerebral macroelectrodes and a sampling frequency of 10 kHz. Considering the notion that faster HFOs are likely more ictogenic, we investigated this ictal EEG data to find if even faster HFOs were present. HFOs were investigated in interictal spikes and seizure activity using time-frequency spectra: t values corresponding to frequencies from 100 to 1000 Hz were obtained by comparison to the background and controlled by the false discovery rate (FDR). The seizure had a right hippocampal onset. HFOs up to 800 Hz as well as HFOs below 500 Hz built up in the hippocampal discharges more at the beginning of the seizure and during the preictal period than in the interictal period. These HFOs were visually confirmed in temporally expanded EEG traces. We demonstrated for the first time the existence of HFOs above 500 Hz and up to 800 Hz with intracerebral macroelectrodes in an epileptic patient; they occurred primarily in association with the seizure discharge. HFOs above 500 Hz possibly reflect facilitation of ictogenic neuronal hypersynchronization.
AB - High-frequency oscillations (HFOs) of up to 500 Hz in EEG are considered to have close relation with ictogenesis. We had the unique opportunity to record a seizure in EEG with intracerebral macroelectrodes and a sampling frequency of 10 kHz. Considering the notion that faster HFOs are likely more ictogenic, we investigated this ictal EEG data to find if even faster HFOs were present. HFOs were investigated in interictal spikes and seizure activity using time-frequency spectra: t values corresponding to frequencies from 100 to 1000 Hz were obtained by comparison to the background and controlled by the false discovery rate (FDR). The seizure had a right hippocampal onset. HFOs up to 800 Hz as well as HFOs below 500 Hz built up in the hippocampal discharges more at the beginning of the seizure and during the preictal period than in the interictal period. These HFOs were visually confirmed in temporally expanded EEG traces. We demonstrated for the first time the existence of HFOs above 500 Hz and up to 800 Hz with intracerebral macroelectrodes in an epileptic patient; they occurred primarily in association with the seizure discharge. HFOs above 500 Hz possibly reflect facilitation of ictogenic neuronal hypersynchronization.
KW - False discovery rate
KW - High-frequency oscillation
KW - Ictal EEG
KW - Mesial temporal lobe epilepsy
KW - Time-frequency analysis
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U2 - 10.1016/j.eplepsyres.2009.10.008
DO - 10.1016/j.eplepsyres.2009.10.008
M3 - Article
C2 - 19914804
AN - SCOPUS:75849132915
VL - 88
SP - 139
EP - 144
JO - Journal of Epilepsy
JF - Journal of Epilepsy
SN - 0920-1211
IS - 2-3
ER -