Sleep Spindles Predict Stress-Related Increases in Sleep Disturbances

Abstract

Background and Aim: Predisposing factors place certain individuals at higher risk for insomnia, especially in the presence of precipitating conditions such as stressful life events. Sleep spindles have been shown to play an important role in the preservation of sleep continuity. Lower spindle density might thus constitute an objective predisposing factor for sleep reactivity to stress. The aim of this study was therefore to evaluate the relationship between baseline sleep spindle density and the prospective change in insomnia symptoms in response to a standardized academic stressor.Methods: Twelve healthy students had a polysomnography recording during a period of lower stress at the beginning of the academic semester, along with an assessment of insomnia complaints using the insomnia severity index (ISI). They completed a second ISI assessment at the end of the semester, a period coinciding with the week prior to final examinations and thus higher stress. Spindle density, amplitude, duration, and frequency, as well as sigma power were computed from C4–O2 electroencephalography derivation during stages N2–N3 of non-rapid-eye-movement (NREM) sleep, across the whole night and for each NREM sleep period. To test for the relationship between spindle density and changes in insomnia symptoms in response to academic stress, spindle measurements at baseline were correlated with changes in ISI across the academic semester.Results: Spindle density (as well as spindle amplitude and sigma power), particularly during the first NREM sleep period, negatively correlated with changes in ISI (p < 0.05).Conclusion: Lower spindle activity, especially at the beginning of the night, prospectively predicted larger increases in insomnia symptoms in response to stress. This result indicates that individual differences in sleep spindle activity contribute to the differential vulnerability to sleep disturbances in the face of precipitating factors.

Sleep Spindles and Intellectual Ability: Epiphenomenon or Directly Related?

“…Furthermore, related studies also demonstrated that sleep spindles measured on a normal, quiet/undisturbed night of sleep were predictive of sleep quality on a subsequent night in a noisy environment (Dang-Vu et al, 2010). Moreover, baseline sleep spindles during a normal, quiet/undisturbed night of sleep could predict scores on the insomnia severity index during a disturbed night of sleep (Dang-Vu et al, 2015). In other words, sleep spindles from a normal, undisturbed night of sleep have predictive value (and are thus valid measures) of the continuity of sleep.…”

Studentų Psichoemocinės Būklės Ir Miego Kokybės Sąsajos

“…Nors Lietuvoje atliktų tyrimų, susijusių su studentų patiriamu nerimu, rezultatai skiriasi nuo užsienio literatūroje pateikiamų rezultatų, negalima paneigti nerimo problemos, o kartu ir nerimo įtakos miego kokybei [26]. Įrodyta, jog nemiga yra dažnesnė asmenims, turintiems depresijos ir nerimo simptomų [27]. Estijoje, Tartu universitete, atlikto tyrimo, kuriame dalyvavo 413 medicinos studentų, duomenimis, 21,9 proc.…”

The Accuracy, Night-to-Night Variability, and Stability of Frontopolar Sleep Electroencephalography Biomarkers

“…11 Additional phenotypes are emerging through the use of sleep biomarkers related to depressive and anxiety disorders and/or stress-related insomnia. 12,13 Critical cost-benefit analysis discussion remains paramount when the practitioner and patient decides if and what type of pharmacotherapeutic sleep agent is most appropriate for treating their respective sleep complaint. 14,15 Moreover, the United States Food and Drug Administration has continued to stress the importance of monitoring all classes of sleep aides due to concerns over safety and habituation 16,17 calling for the potential clinical value for repeated-measures dose-response EEG studies.…”

“…After rejection of periods when the absolute amplitude is ≥ 500 µV, the signals were notch filtered, and then infinite impulse response band pass-filtered to obtain 16 Hz samples of the power values for delta (1-3.5 Hz), Delta C (delta power corrected for ocular activity), theta (4-6.5 Hz), alpha (8-12 Hz), sigma (12)(13)(14)(15)(16), beta (18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28), and EMG bands ( > 40 Hz with a 80 Hz, 3 dB rolloff). A second set of power values was obtained after application of a 0.75-Hz highpass filter.…”