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Abstracts

Patients Undergoing Intracranial EEG Monitoring have Fragmented and Poorly Consolidated Sleep

Abstract number : 3.138
Submission category : 2. Translational Research / 2A. Human Studies
Year : 2025
Submission ID : 274
Source : www.aesnet.org
Presentation date : 12/8/2025 12:00:00 AM
Published date :

Authors :
Presenting Author: Alexis Shindhelm, MS – University of Nebraska Medical Center

Haley Mendez, BS – University of Nebraska Medical Center
Abdallah Alsammani, PhD – Jacksonville University
Garnett Hegeman, BS – University of Michigan
William Stacey, MD, PhD – University of Michigan
Stephen Gliske, PhD – University of Nebraska Medical Center

Rationale: The occurrence of seizures and electrographic biomarkers of epilepsy, such as spikes and high frequency oscillations (HFOs), varies based on sleep stage. For patients undergoing intracranial EEG (iEEG) monitoring for seizure characterization and localization, this association presents both opportunities and challenges. Yet, the sleep architecture in this population remains poorly understood. Our objective is to address this gap in knowledge by characterizing sleep architecture during iEEG monitoring.

Methods: We characterized sleep architecture of multi-day, sleep-scored iEEG recordings from 58 subjects (9,815.91 hours) in the University of Michigan iEEG database compared to 116 age- and sex-matched control subjects (961.01 hours) from the open-access polysomnogram recordings in the Human Sleep Project (HSP) database.1 Since the HSP included overnight polysomnograms while the iEEG database includes 24-hour recordings, we selected 11:00 PM to 7:00 AM for a comparison window. We report the percentage of this 8-hour analysis time in each sleep stage and the median bout length per sleep stage. Statistical significance was assessed with the Wilcoxon rank-sum test. Due to paucity of N3 sleep in the iEEG recordings of subjects with epilepsy, we treated N2 and N3 as a single deep sleep stage.

Results: Patients’ overall sleep architecture from 11:00 PM to 7:00 AM was significantly different than the matched controls with less deep sleep (40.77% vs. 65.77%, p = 2.4 x 10-23), more REM sleep (14.75% vs. 14.64%, p = 3.8 x 10-21), and more time awake (35.57% vs. 11.52%, p = 2.4 x 10-26). Patients’ sleep was also highly fragmented with longer bouts of N1 sleep (1.05 vs 0.81 min, p = 8.0 x 10-4) and shorter bouts of N2 (2.56 vs. 3.76 min, p = 1.5 x 10-3) and REM (4.50 vs. 11.38 min, p = 6.0 x 10-7) sleep compared to the matched controls. Finally, patients’ sleep was poorly consolidated. For example, subjects with epilepsy had a much lower probability of being asleep (75.55% vs. 88.49%, p = 3.0 x 10-10) or in deep sleep (50.88% vs. 67.33%, p = 6.2 x 10-8) from 1:00 AM to 3:00 AM compared to the matched controls.

Conclusions: Patients undergoing iEEG monitoring experience highly disrupted, fragmented sleep. Our results highlight the critical need to account for disrupted sleep when considering the interplay between sleep, seizures, and epilepsy biomarkers, as common assumptions about the sleep architecture, duration, and time of day in general populations may not be applicable and would require more rigorous assessment.

Funding:

  • Sources of Funding 

  • 1. NIH R01-NS094399 and the Doris Duke Foundation #2015096 

  • 2. NIH K01-ES026839 

  • Reference 

    1. Westover, M. B., Moura Junior, V., Thomas, R., Cash, S., Nasiri, S., Sun, H., Gupta, A., Rosand, J., Ghanta, M., Ganglberger, W., Katwa, U., Stone, K., Zhang, Z., Ganjoo, G., Nassi PhD Candidate, T. E., Wei, R., Hwang, D., Trotti, L. M., Parekh, A.,…Rapoport, D. (2023). The Human Sleep Project (Version 2.0) [Dataset]. BDSP. https://doi.org/10.60508/QJBV-HG78 



Translational Research