Does REM sleep contribute to subjective wake time in primary insomnia? A comparison of polysomnographic and subjective sleep in 100 patients

Department of Psychiatry and Psychotherapy, University Medical Center, Freiburg, Germany.
Journal of Sleep Research (Impact Factor: 3.35). 07/2008; 17(2):180-90. DOI: 10.1111/j.1365-2869.2008.00651.x
Source: PubMed


Primary insomnia (PI) is characterized by low subjective sleep quality which cannot always be verified using polysomnography (PSG). To shed light on this discrepancy, subjective estimates of sleep and PSG variables were compared in patients with PI and good sleeper controls (GSC). 100 patients with PI (age: 42.57 +/- 12.50 years, medication free for at least 14 days) and 100 GSC (41.12 +/- 13.99 years) with a sex distribution of 46 men and 54 women in each group were included. Both PSG and questionnaire variables showed clear impairments of sleep quality in PI compared with GSC. The arousal index within total sleep time was increased, which was mainly because of a strong increase within rapid eye movement (REM) sleep. Subjectively, more PI than GSC subjects estimated wake times longer than obtained from PSG. Linear modeling analysis of subjective wake time in terms of PSG parameters revealed that in addition to PSG defined wake time, REM sleep time contributed significantly to subjective wake time. This REM sleep contribution was larger for PI than for GSC subjects. The findings suggest that REM sleep-related processes might contribute to subjectively disturbed sleep and the perception of waking time in patients with PI.

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    • "In particular, the sample had a comparably low sleep efficiency and high number of awakenings [34]. However, in comparison with previous studies the present sample appears to be representative of other healthy participants of the sleep laboratory in Freiburg [35]. Second, it should be noted that, in the current study, PLMS was measured only during the first night. "
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    ABSTRACT: Background Normal sleep continuity and architecture show remarkable inter-individual variability. Previous studies suggest that brain morphology may explain inter-individual differences in sleep variables. Method Thirty-eight healthy subjects spent two consecutive nights at the sleep laboratory with polysomnographic monitoring. Furthermore, high-resolution T1-weighted MRI datasets were acquired in all participants. EEG sleep recordings were analyzed using standard sleep staging criteria and power spectral analysis. Using the FreeSurfer software for automated segmentation, 174 variables were determined representing the volume and thickness of cortical segments and the volume of subcortical brain areas. Regression analyses were performed to examine the relationship with polysomnographic and spectral EEG power variables. Results The analysis did not provide any support for the a-priori formulated hypotheses of an association between brain morphology and polysomnographic variables. Exploratory analyses revealed that the thickness of the left caudal anterior cingulate cortex was positively associated with EEG beta2 power (24–32 Hz) during REM sleep. The volume of the left postcentral gyrus was positively associated with periodic leg movements during sleep (PLMS). Conclusions The function of the anterior cingulate cortex as well as EEG beta power during REM sleep have been related to dreaming and sleep-related memory consolidation, which may explain the observed correlation. Increased volumes of the postcentral gyrus may be the result of increased sensory input associated with PLMS. However, due to the exploratory nature of the corresponding analyses, these results have to be replicated before drawing firm conclusions.
    Full-text · Article · Oct 2014 · PLoS ONE
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    • "Although participants reported worse subjective sleep quality in association with higher stress and somatic arousal on the interindividual level and with higher stress and cognitive arousal on the intraindividual level, this relationship does not seem to apply for actigraphy-assessed sleep data. Still this finding is not necessarily contradictory, as it is well-known that the subjective perception of impaired sleep is not always objectively measurable in actigraphic or PSG sleep data [63] [64] [65] [66]. Further, it might be possible that higher levels of stress and arousal might not yet influence actigraphic sleep measures in a young and healthy sample, but it could still constitute a factor preceding the development of subsequent sleep disturbances [35] [36] [37]. "
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    ABSTRACT: Objective Our study aimed to further elucidate the mediating role of presleep arousal in the relationship between daily stress and sleep by investigating subjective sleep quality and actigraphy-assessed sleep efficiency (SE) on both within- and between-participant levels in a sample of healthy young women. Methods Multilevel modelling was applied on electronically assessed data comprising 14 consecutive nights in 145 healthy young women to assess the relationship between daily stress; presleep (somatic and cognitive) arousal; and sleep on both levels, between participants and within participants across days. Results Higher levels of daily stress were consistently and significantly associated with higher levels of somatic and cognitive arousal. Somatic arousal mediated the relationship between daily stress and worsened subjective sleep quality on the between-participant level, while cognitive arousal mediated the relationship between daily stress and worsened subjective sleep quality on the within-participants level. Unexpectedly, healthy young women showed higher SE following days with above average stress with somatic arousal mediating this relationship. Conclusions Our data corroborate the role of presleep arousal mediating the relationship between daily stress and subjective sleep quality. Interestingly this effect was restricted to somatic arousal being relevant on interindividual levels and cognitive arousal on intraindividual levels. For young and healthy individuals who experience high stress and arousal, well-established cognitive-behavioral techniques could be useful to regulate arousal and prevent worse subjective sleep quality.
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    • "Based on the idea that REM sleep in insomnia is unstable and may contribute to sleep misperception [38], the increase in REM sleep observed during sleep restriction therapy could be interpreted as showing that sleep restriction consolidates REM sleep. Furthermore, one previous study found that REM sleep contributes to disrupt subjective perceptions of sleep and waking time [39]. Therefore, when the amount of REM sleep is increased and consolidated, it could contribute to the improvement of the subjective perception of sleep and wake time. "
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