0218 Changes in sleep architecture and topography of sleep EEG slow wave activity following acute wake extension in early adolescence

Abstract

Abstract Introduction A progression of peak sleep EEG slow wave activity (SWA; EEG power 0.5-4Hz) from posterior to anterior expression reflects brain development. Further, increased EEG SWA after extended wakefulness is a marker of sleep pressure. However, it is unclear whether recovery sleep SWA in later youth is expressed in a similar scalp topography as typical sleep. Using experimental wake-extension, we investigated homeostatic changes in sleep architecture and SWA topography in early adolescence. Methods Twenty-two young adolescents (M±SD: 12.03±1.14y, 12F) participated in two consecutive laboratory stays after at least a week of at-home actigraphy-monitored stabilization (9.5h in bed). A baseline night (BSL; 9.5h 21:00-06:30) was followed by wake-extension (WE) to 02:30 and a 4h recovery sleep opportunity (RS; 02:30-06:30), each monitored by polysomnography including a 25-channel EEG array. The current analyses examined R&K sleep architecture at BSL and RS. SWA in RS was compared to the first 4h of BSL in two ways: (1) absolute NREM power (µV2); (2) an index (TI) of the topographical distribution of midline SWA (FPz-AFz-Fz-FCz-Cz-CPz-Pz-POz-Oz) providing a score of 1 to 9 indicating frontal to occipital peak distribution. Results WE significantly altered RS sleep architecture, including an increase in slow-wave sleep (%TST) versus BSL (M±SD BSL: 26.76±5.69%, RS: 51.65±7.83%, t(21)=-17.09, p<.001, d=-3.65). SWA was also significantly greater in RS (channel-averaged SWA BSL: 11883.50±5142.17 µV2, RS: 18955.82±7451.20 µV2, t(21)=-8.67, p<.001) with 22/25 individual electrodes meeting Bonferroni-corrected significance (ps<.001). Finally, we observed a small frontal shift (t(21)=2.39, p=.027, d=.51) of maximal SWA in RS (TI: 4.46±2.58; i.e., FCz/Cz) compared to BSL (5.32±2.78, i.e., Cz/CPz). Conclusion These data indicate robust sleep homeostasis in young adolescents after wake extension, expressed as increased SWA across the scalp. The findings also add to existing literature by indicating that SWA topography may also be sensitive to homeostatic challenge. Specifically, a baseline centroparietal locus of maximal SWA typical to this age became more frontocentral in recovery sleep. This anterior shift may reflect a homeostatic need over developmentally sensitive prefrontal cortex. Next steps will assess how individual responses may reflect a child’s neurodevelopment (e.g., inattention symptoms) or manifested behavior after wake extension and recovery sleep. Support (if any) K01MH109854, P20GM139743, R01HD103655