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

Abstract

<div class="section"> <a class="named-anchor" id="d2552204e198"> <!-- named anchor --> </a> <h5 class="section-title" id="d2552204e199">Study Objectives:</h5> <p id="d2552204e201">To assess the validity of sleep architecture and sleep continuity biomarkers obtained from a portable, multichannel forehead electroencephalography (EEG) recorder. </p> </div><div class="section"> <a class="named-anchor" id="d2552204e203"> <!-- named anchor --> </a> <h5 class="section-title" id="d2552204e204">Methods:</h5> <p id="d2552204e206">Forty-seven subjects simultaneously underwent polysomnography (PSG) while wearing a multichannel frontopolar EEG recording device (Sleep Profiler). The PSG recordings independently staged by 5 registered polysomnographic technologists were compared for agreement with the autoscored sleep EEG before and after expert review. To assess the night-to-night variability and first night bias, 2 nights of self-applied, in-home EEG recordings obtained from a clinical cohort of 63 patients were used (41% with a diagnosis of insomnia/depression, 35% with insomnia/obstructive sleep apnea, and 17.5% with all three). The between-night stability of abnormal sleep biomarkers was determined by comparing each night's data to normative reference values. </p> </div><div class="section"> <a class="named-anchor" id="d2552204e208"> <!-- named anchor --> </a> <h5 class="section-title" id="d2552204e209">Results:</h5> <p id="d2552204e211">The mean overall interscorer agreements between the 5 technologists were 75.9%, and the mean kappa score was 0.70. After visual review, the mean kappa score between the autostaging and five raters was 0.67, and staging agreed with a majority of scorers in at least 80% of the epochs for all stages except stage N1. Sleep spindles, autonomic activation, and stage N3 exhibited the least between-night variability ( <i>P</i> &lt; .0001) and strongest between-night stability. Antihypertensive medications were found to have a significant effect on sleep quality biomarkers ( <i>P</i> &lt; .02). </p> </div><div class="section"> <a class="named-anchor" id="d2552204e219"> <!-- named anchor --> </a> <h5 class="section-title" id="d2552204e220">Conclusions:</h5> <p id="d2552204e222">A strong agreement was observed between the automated sleep staging and human-scored PSG. One night's recording appeared sufficient to characterize abnormal slow wave sleep, sleep spindle activity, and heart rate variability in patients, but a 2-night average improved the assessment of all other sleep biomarkers. </p> </div><div class="section"> <a class="named-anchor" id="d2552204e224"> <!-- named anchor --> </a> <h5 class="section-title" id="d2552204e225">Commentary:</h5> <p id="d2552204e227">Two commentaries on this article appear in this issue on pages 771 and 773.</p> </div><div class="section"> <a class="named-anchor" id="d2552204e229"> <!-- named anchor --> </a> <h5 class="section-title" id="d2552204e230">Citation:</h5> <p id="d2552204e232">Levendowski DJ, Ferini-Strambi L, Gamaldo C, Cetel M, Rosenberg R, Westbrook PR. The accuracy, night-to-night variability, and stability of frontopolar sleep electroencephalography biomarkers. <i>J Clin Sleep Med.</i> 2017;13(6):791–803. </p> </div>