Abstract Details

Title Post Ictal Generalized EEG suppression, Not Sleep State, is Associated with Peri-Ictal Respiratory Disturbances in Stereoelectroencephalography Recorded Perisylvian Seizures

Topic Sleep

Presentation(s) S6 - Sleep Medicine Highlights (4:42 PM-4:54 PM)

Poster/Presentation
Number 007

Background Seizure-related respiratory dysfunction may predispose to sudden unexpected death in epilepsy (SUDEP), yet existing studies are based largely on scalp recordings and lack comprehensive polysomnographic (PSG) signals. PGES (absence of EEG activity >10μV) is a proposed biomarker of SUDEP and most cases of SUDEP occur during sleep.

Objective

To identify peri-ictal respiratory disturbances associated with postictal generalized EEG suppression (PGES) and sleep.

Design/Methods

We studied respiratory changes in stereoelectroencephalography (SEEG)-recorded perisylvian seizures using a multimodal system integrating EEG and PSG signals including airflow, effort, SpO₂, and CO₂. Sleep state and PGES were defined by scalp electrodes (FZ/CZ). Interpretable recordings required SpO₂ and at least one airflow and effort channel. Respiratory events were scored during focal and generalized phases. Frequency and duration of events were compared by state and PGES status using two-sample t-test or Kruskal-Wallis test based on 0.05 significance level using SAS 9.4 software.

Results

61 seizures (29 patients) were included. Compared to seizures without PGES, PGES seizures (N=8) were associated with higher central event frequency (median [IQR]: 3.0[3.0,4.0] vs 1.0[1.0,1.0], P<0.001) and duration (76[63,94] vs 27[12.5,35] sec, P=0.010); higher ictal RR (mean±SD: 28.5±1.5 vs 24.6±4.6 bpm, P<0.001), pre-ictal-to-ictal RR change (8.1±3.2 vs 2.3±3.2 bpm, P<0.001) and pre-ictal-to-peak TcpCO₂change (16.4 [11.6,31.0] vs 2.2 [0.45,7.2] mmHg, P=0.023); and greater pre-ictal-to-nadir SPO₂ change (24.0 [23.0,24.4] vs 4.1 [2.4,11.0] %, P=0.033). However, PGES was not associated with sleep state. In contrast, sleep seizures (N=35) were differentiated from wake seizures only by lower pre-ictal (19.9±2.5 vs 24.1±3.1 bpm, P<0.001), ictal (22.6±4.3 vs 28.0±2.7 bpm, P<0.001), and postictal RR (24.7±5.22 vs 8.5±4.4 bpm, P=0.020), and higher pre-ictal TcpCO₂ (40.6[38.1, 42.6] vs 36.8[32.8, 39.5] mmHg, P=0.006).

Conclusions

PGES (and not sleep) in perisylvian seizures is associated with a host of respiratory disturbances, providing further support of its role as a biomarker of SUDEP.

Authors/Disclosures
Laura Mora Munoz, MD (Cleveland Clinic Foundation) PRESENTER	Dr. Mora Munoz has nothing to disclose.
	No disclosure on file
	No disclosure on file
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	No disclosure on file
Madeleine M. Grigg-Damberger, MD (University of New Mexico, Department of Neurology)	Dr. Grigg-Damberger has received personal compensation for serving as an employee of Oxford University Press. Dr. Grigg-Damberger has received personal compensation for serving as an employee of Up-to-date. Dr. Grigg-Damberger has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Journal of Clinical Sleep Medicine. Dr. Grigg-Damberger has received publishing royalties from a publication relating to health care.
Nancy R. Foldvary-Schaefer, DO, FAAN (Cleveland Clinic)	Dr. Foldvary-Schaefer has received personal compensation in the range of $10,000-$49,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Jazz. The institution of Dr. Foldvary-Schaefer has received research support from Jazz. The institution of Dr. Foldvary-Schaefer has received research support from Suven. The institution of Dr. Foldvary-Schaefer has received research support from Takeda. Dr. Foldvary-Schaefer has received publishing royalties from a publication relating to health care. Dr. Foldvary-Schaefer has received publishing royalties from a publication relating to health care.