TY - JOUR
T1 - High frequency oscillations are less frequent but more specific to epileptogenicity during rapid eye movement sleep
AU - Sakuraba, Rie
AU - Iwasaki, Masaki
AU - Okumura, Eiichi
AU - Jin, Kazutaka
AU - Kakisaka, Yosuke
AU - Kato, Kazuhiro
AU - Tominaga, Teiji
AU - Nakasato, Nobukazu
N1 - Funding Information:
This research was partially supported by a Grant-in-Aid for Scientific Research (No. 25462240 ) from the Japan Society for the Promotion of Science. The author MI was supported by the Takeda Science Foundation. We wish to thank Dr. Yoshiyuki Nishio for his comments and advice on the research approach.
Publisher Copyright:
© 2015 International Federation of Clinical Neurophysiology.
PY - 2016/1/1
Y1 - 2016/1/1
N2 - Objective: We hypothesized that high frequency oscillations (HFOs) are differently suppressed during rapid eye movement sleep (REM) between epileptogenic and less epileptogenic cortices, and that the suppressive effect can serve as a specific marker of epileptogenicity. Methods: Intracranial electroencephalography (EEG) was recorded in 13 patients with drug-resistant epilepsy. HFOs between 80 and 200 Hz were semi-automatically detected from total 15-min EEG epochs each for REM and slow wave sleep (SWS). z-Score of HFO occurrence rate was calculated from the baseline rate derived from non-epileptogenic cortex. Intracranial electrodes were labeled as REM dominant HFO (RdH) if REM z-score was greater than SWS z-score or as SWS dominant HFO (SdH) if SWS z-score was greater than REM z-score. Relationship of electrode location to the area of surgical resection was compared between RdH and SdH electrodes. Results: Out of 1070 electrodes, 101 were defined as RdH electrodes and 115 as SdH electrodes. RdH electrodes were associated with the area of resection in patients with postoperative seizure freedom (P < 0.001), but not in patients without seizure freedom. Conclusions: HFOs near the epileptogenic zone are less suppressed during REM. Significance: The less suppressive effect of REM may provide a specific marker of epileptogenicity.
AB - Objective: We hypothesized that high frequency oscillations (HFOs) are differently suppressed during rapid eye movement sleep (REM) between epileptogenic and less epileptogenic cortices, and that the suppressive effect can serve as a specific marker of epileptogenicity. Methods: Intracranial electroencephalography (EEG) was recorded in 13 patients with drug-resistant epilepsy. HFOs between 80 and 200 Hz were semi-automatically detected from total 15-min EEG epochs each for REM and slow wave sleep (SWS). z-Score of HFO occurrence rate was calculated from the baseline rate derived from non-epileptogenic cortex. Intracranial electrodes were labeled as REM dominant HFO (RdH) if REM z-score was greater than SWS z-score or as SWS dominant HFO (SdH) if SWS z-score was greater than REM z-score. Relationship of electrode location to the area of surgical resection was compared between RdH and SdH electrodes. Results: Out of 1070 electrodes, 101 were defined as RdH electrodes and 115 as SdH electrodes. RdH electrodes were associated with the area of resection in patients with postoperative seizure freedom (P < 0.001), but not in patients without seizure freedom. Conclusions: HFOs near the epileptogenic zone are less suppressed during REM. Significance: The less suppressive effect of REM may provide a specific marker of epileptogenicity.
KW - Epilepsy surgery
KW - High-frequency oscillations
KW - Intracranial electroencephalography
KW - Rapid eye movement sleep
KW - Seizure outcome
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U2 - 10.1016/j.clinph.2015.05.019
DO - 10.1016/j.clinph.2015.05.019
M3 - Article
C2 - 26073183
AN - SCOPUS:84930688142
VL - 127
SP - 179
EP - 186
JO - Electroencephalography and Clinical Neurophysiology - Electromyography and Motor Control
JF - Electroencephalography and Clinical Neurophysiology - Electromyography and Motor Control
SN - 1388-2457
IS - 1
ER -