학술논문
Sleep-wake states change the interictal localization of candidate epileptic source generators
ORIGINAL ARTICLE
ORIGINAL ARTICLE
Document Type
Academic Journal
Author
Source
SLEEP. June 2022, Vol. 45 Issue 6, p1R, 13 p.
Subject
Language
English
ISSN
0161-8105
Abstract
Introduction Sleep and epilepsy are both phenomena generated by the brain, with interdependent effects and interactions. Sleep, as essential to survival as food and oxygen, is a recurrent physiological change [...]
Study Objectives: To compare estimated epileptic source localizations from 5 sleep-wake states (SWS): wakefulness (W), rapid eye movement sleep (REM), and non-REM 1-3. Methods: Electrical source localization (sLORETA) of interictal spikes from different SWS on surface EEG from the epilepsy monitoring unit at spike peak and takeoff, with results mapped to individual brain models for 75% of patients. Concordance was defined as source localization voxels shared between 2 and 5 SWS, and discordance as those unique to 1 SWS against 1-4 other SWS. Results: 563 spikes from 16 prospectively recruited focal epilepsy patients across 161 day-nights. SWS exerted significant differences at spike peak but not take-off. Source localization size did not vary between SWS. REM localizations were smaller in multifocal than unifocal patients (28.8% vs. 54.4%, p = .0091). All five SWS contributed about 45% of their localizations to converge onto 17.0 [+ or -] 15.5% voxels. Against any one other SWS, REM was least concordant (54.4% vs. 66.9%, p = .0006) and most discordant (39.3% vs. 29.6%, p = .0008). REM also yielded the most unique localizations (20.0% vs. 8.6%, p = .0059). Conclusions: REM was best suited to identify candidate epileptic sources. sLORETA proposes a model in which an 'omni-concordant core' of source localizations shared by all five SWS is surrounded by a 'penumbra' of source localizations shared by some but not all SWS. Uniquely, REM spares this core to 'move' source voxels from the penumbra to unique cortex not localized by other SWS. This may reflect differential intra-spike propagation in REM, which may account for its reported superior localizing abilities. Key words: rapid eye movement sleep; sleep activation; sleep wake states; epilepsy; seizures; epileptic generator; source localization; source generator; sLORETA; concordance
Study Objectives: To compare estimated epileptic source localizations from 5 sleep-wake states (SWS): wakefulness (W), rapid eye movement sleep (REM), and non-REM 1-3. Methods: Electrical source localization (sLORETA) of interictal spikes from different SWS on surface EEG from the epilepsy monitoring unit at spike peak and takeoff, with results mapped to individual brain models for 75% of patients. Concordance was defined as source localization voxels shared between 2 and 5 SWS, and discordance as those unique to 1 SWS against 1-4 other SWS. Results: 563 spikes from 16 prospectively recruited focal epilepsy patients across 161 day-nights. SWS exerted significant differences at spike peak but not take-off. Source localization size did not vary between SWS. REM localizations were smaller in multifocal than unifocal patients (28.8% vs. 54.4%, p = .0091). All five SWS contributed about 45% of their localizations to converge onto 17.0 [+ or -] 15.5% voxels. Against any one other SWS, REM was least concordant (54.4% vs. 66.9%, p = .0006) and most discordant (39.3% vs. 29.6%, p = .0008). REM also yielded the most unique localizations (20.0% vs. 8.6%, p = .0059). Conclusions: REM was best suited to identify candidate epileptic sources. sLORETA proposes a model in which an 'omni-concordant core' of source localizations shared by all five SWS is surrounded by a 'penumbra' of source localizations shared by some but not all SWS. Uniquely, REM spares this core to 'move' source voxels from the penumbra to unique cortex not localized by other SWS. This may reflect differential intra-spike propagation in REM, which may account for its reported superior localizing abilities. Key words: rapid eye movement sleep; sleep activation; sleep wake states; epilepsy; seizures; epileptic generator; source localization; source generator; sLORETA; concordance