0324 Effect of Sleep Restriction on Sleep Electroencephalogram Waveforms in Adolescents

Abstract

Abstract Introduction Over the past 18 years, our laboratory has been carrying out longitudinal studies of sleep and sleep need across adolescence. Our current study uses a dose-response design to examine daytime performance and sleep EEG after varied sleep durations. Here we present results for 1-30 Hz EEG power in NREM and REM sleep. Methods Home EEG recording in children 10-16 years old (N=77, mean age = 13.2). Adhering to their habitual rise time participants kept an assigned TIB schedule of 7, 8.5, or 10 hours for four consecutive nights. Participants completed all three conditions each year of the 3 year study. EEG recordings from the fourth night of each condition were scored and analyzed with FFT. Results Reducing TIB from 10 to 7 hours effectively decreased total sleep time (TST) from an average of 531 min to an average of 407 min. Decreasing TIB (from 10 to 7 h) produced a small increase (4.6%, p=0.0004) in delta (1-4 Hz) power and a larger decrease (9.0%, p=0.0032) in alpha (8-11 Hz) power in the first 5 h of NREM sleep. In REM periods 2 and 3, the same TIB reduction also increased (12.1%, p<0.0001) delta power and decreased (14.2%, p<0.0001) alpha power. Decreasing TIB reduced (11%, p<0.0001) sigma (11-15 Hz) power in the first 5h of NREM sleep and reduced (28%, p<0.0001) all night NREM sigma energy. Conclusion Reducing TST changes EEG power in several frequency bands. The increase in NREM delta power, expected from homeostatic models, may be too small to be biologically significant. The larger loss of sigma power may be of greater consequence. Sigma frequency activity is an indicator of sleep spindles which have been affected in aging, learning, memory and psychopathology. The sigma response to sleep restriction could be used to study these relations. Support PHS grant R01 HL116490 supported this work.