EEG arousals in normal sleep: variations induced by total and selective slow-wave sleep deprivation.
OBJECTIVE
Aim of the present study was to assess changes in arousal rates after selective slow-wave (SWS) and total sleep deprivations.


METHODS
Two-way mixed design comparing the arousal index (Al), as expressed by the number of EEG arousals divided by sleep duration, in totally or selectively sleep deprived subjects.


METHODS
Sleep laboratory.


METHODS
Nineteen normal male subjects [mean age=23.3 years (S.E.M.=0.55)].


METHODS
Al was measured in baseline nights and after selective SWS (N=10) and total sleep deprivation (N=9).


RESULTS
During the baseline nights AI values changed across sleep stages as follows: stage 1 > stage 2 and REM > SWS, but did not present any significant variations as a function of time elapsed from sleep onset. The recovery after deprivation showed a reduction in EEG arousals, more pronounced after total sleep deprivation; this decrease affected NREM but not REM sleep. During the baseline nights Al showed a close-to-significance negative correlation with REM duration, while during the recovery nights a significant positive relation with stage 1 duration was found.


CONCLUSIONS
The present results suggest that recuperative processes after sleep deprivation are also associated with a higher sleep continuity as defined by the reduction of EEG arousals.
De Gennaro
L
L
Department of Psychology, University of Rome La Sapienza, Italy. luigi.degennaro@uniroma1.it
Ferrara
M
M
Bertini
M
M
D000328:Adult; D001143:Arousal / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D004569:Electroencephalography; D006801:Humans; D008297:Male; D017286:Polysomnography; D012189:Retrospective Studies; D012890:Sleep / Q000502:physiology*; D012892:Sleep Deprivation / Q000175:diagnosis*; D012895:Sleep, REM / Q000502:physiology*