Auditory deep sleep stimulation in older adults at home: a randomized crossover trial

Abstract

Background Auditory stimulation has emerged as a promising tool to enhance non-invasively sleep slow waves, deep sleep brain oscillations that are tightly linked to sleep restoration and are diminished with age. While auditory stimulation showed a beneficial effect in lab-based studies, it remains unclear whether this stimulation approach could translate to real-life settings. Methods We present a fully remote, randomized, cross-over trial in healthy adults aged 62–78 years (clinicaltrials.gov: NCT03420677). We assessed slow wave activity as the primary outcome and sleep architecture and daily functions, e.g., vigilance and mood as secondary outcomes, after a two-week mobile auditory slow wave stimulation period and a two-week Sham period, interleaved with a two-week washout period. Participants were randomized in terms of which intervention condition will take place first using a blocked design to guarantee balance. Participants and experimenters performing the assessments were blinded to the condition. Results Out of 33 enrolled and screened participants, we report data of 16 participants that received identical intervention. We demonstrate a robust and significant enhancement of slow wave activity on the group-level based on two different auditory stimulation approaches with minor effects on sleep architecture and daily functions. We further highlight the existence of pronounced inter- and intra-individual differences in the slow wave response to auditory stimulation and establish predictions thereof. Conclusions While slow wave enhancement in healthy older adults is possible in fully remote settings, pronounced inter-individual differences in the response to auditory stimulation exist. Novel personalization solutions are needed to address these differences and our findings will guide future designs to effectively deliver auditory sleep stimulations using wearable technology.

Bidirectional associations between physical activity and sleep in older adults: a multilevel analysis using polysomnography

“…1 ). Compared to American, Swiss, and Brazilian older adults, the Japanese participants showed short total time in bed; however, a similar sleep structure has been reported in older adults from other countries 19 , 35 , 36 . Overall, compared with the National Sleep Foundation’s sleep quality recommendations 37 , the participants seemed to be relatively healthy in terms of sleep composition.…”

Benchmarking Real-Time Algorithms for In-Phase Auditory Stimulation of Low Amplitude Slow Waves With Wearable EEG Devices During Sleep

“…To test the generalization of our approach with independent data, we built a second, larger elderly test set composed of 319 recordings of sleep EEG without stimulation from 24 healthy adults older than 62 y (68 ± 4.7 years old, 10 females), who used the MHSL-SBv2 during 14 consecutive nights as part of a larger clinical trial (NCT03420677) [28]. For the analysis of the elderly test set, sleep was automatically scored postrecording into slow-wave NREM (N2 and N3 sleep stages) and non-NREM sleep (N1, REM and awake) for 20-s long epochs by a validated deep-learning algorithm (unpublished).…”

Closed-loop auditory stimulation of sleep slow oscillations: basic principles and best practices

“…It is thus unlikely, though conceivable, that subjects are aware of stimulation at some point of an experiment. The blinding of the experimenter still remains unaddressed by most manipulation studies using CLAS -so far, only a few studies such as Henin et al (2019) and Lustenberger et al (2022) followed rigorously double-blinded CLAS replication experiments to reinvestigate its influence on declarative memory consolidation. Counter to initial findings to enhance this kind of memory in smaller population groups, but in line with similar manipulation experiments in larger groups, no effects for enhancing memory consolidation could be replicated (also see Table 1).…”

“…The current literature lacks enough studies to transfer CLAS to home and to the best of our knowledge, only a single longitudinal study on CLAS has been done in real-life settings. In a randomized, cross-over, double-blind study in healthy adults aged between 62-78 years old, researchers evaluated the effect of CLAS on the SWA as the primary and sleep architecture and daily functions as the secondary outcomes (Lustenberger et al, 2022). The total duration of the study was six weeks, comprising two weeks of sham, and two weeks of stimulation, separated by two weeks as a washout period in between.…”