Time‐of‐day variations in different measures of sleepiness (MSLT, pupillography, and SSS) and their interrelations

Abstract

The aim of the present study is to analyze how well physiological measures of sleepiness derived from pupillography and the Multiple Sleep Latency Test correlate with a subjective measure, the Stanford Sleepiness Scale (SSS) score. The results are based on data from 12 healthy participants, who underwent these tests every 2 hr from 7:00 a.m. until 11:00 p.m. Sleep latencies were correlated with four different variables derived from pupillography and the SSS score. The results indicate that the physiologically based variables correspond very well. This is reflected by similar patterns of time-of-day variations, a good agreement at the group level, and correlations at the individual level, whereas the SSS shows a quite different pattern of variation. The two physiological measures of sleepiness seem to reflect the same aspect of the level of tonic central nervous activation, which is not correlated with the subjective feeling of sleepiness.

Association between pupillometric sleepiness measures and sleep latency derived by MSLT in clinically sleepy patients

“…However when RPUI, which is a default output of the portable electronic pupillometer F2D, is used, it is advisable to adjust RPUI by PD in the inter-individual comparisons. PD correlated neither with SL nor ESS, indicating that this pupillometric parameter is not suitable for detecting inter-individual differences in sleepiness, while in intraindividual circadian variations [16], it correlated well with MSLT-derived sleepiness, which seems to reflect the same aspect of the level of tonic central nervous activation. Morrell [23] indicated that both SL and ESS reduced with age in patients with moderate-to-severe sleep disordered breathing, and Eggert [24] found PUI and PD to decrease with increasing age in healthy subjects.…”

“…Therefore, the association between pupillometry and MSLT could not be adjusted for the time-of-day effects [13,16] in this study.…”

“…These studies proved that PU is a valid and objective indicator of reduced arousal and showed pupillometry to be a useful tool for the screening and measurement of alertness whenever this outcome is of interest and for the monitoring of treatment for sleep disorders or in clinical trials. However, although the association between sleepiness measured by pupillography and MSLT has been addressed in many studies, the results to date have been inconclusive [12,13,16,17] for many reasons, such as small sample size [13].…”

Nur valide oder auch akkurat?

“…Erste Hinweise auf die zu erwartenden Größenordnungen des Risikos, im Zuge einer einzelnen Risikoexposition (z. [5,15,22,23,26,33,35,39]) und F subjektive Schläfrigkeitsskalen [19,28,38,39,40]. …”

“…Die Validität des PST wurde durch eine Reihe von Validierungskriterien bestätigt: F Medikation mit (De-)Aktivierungsinduktion [10,11,30], F mit Schläfrigkeit assoziierte, klinische Störungsbilder [43], F zirkadiane Verläufe [28,39,42], F physiologische Parameter (z. B. Elektroenzephalographie, EEG; [24]), F Multipler Schlaflatenz-Test (MSLT; [5,15,22,23,26,33,35,39]) und F subjektive Schläfrigkeitsskalen [19,28,38,39,40]. …”