Acoustic Stimulation to Study and Modulate Sleepwalking and Related Arousal Disorders (DoA-CLAS)

Closed-Loop and Open-Loop Acoustic Stimulation During Sleep to Investigate and Modulate Disorders of Arousal in Children and Adults

Disorders of Arousal (DoA)-such as sleepwalking, sleep terrors, and confusional arousals-are common sleep problems that happen during deep, non-dreaming sleep. Researchers do not fully understand what triggers these episodes or how to influence them.

This study tests whether playing soft sounds during sleep can help researchers learn more about, and possibly induce or modulate, these episodes under safe, supervised conditions. Participants with DoA will spend two nights in the sleep laboratory, with painless sensors placed on the scalp and body (similar to a regular sleep study). On one night, no sound is played. On the other night, soft sounds are played during deep sleep. The order of the two nights is decided randomly for each participant.

A small group of healthy volunteers without DoA will also take part, undergoing a single night with sound stimulation, to help researchers understand whether the sounds affect everyone the same way or specifically trigger episodes in people with DoA.

A subgroup of participants with DoA will also take part in a later, exploratory step in which the sound is triggered automatically, in real time, based on brain activity patterns.

The sounds used are very quiet, similar in volume to normal conversation, and stimulation is stopped right away if a participant shows any discomfort. The goal of this research is to better understand what triggers Disorders of Arousal, and to test whether sound-based stimulation could one day help study or manage this condition.

Study Overview

• Status: Not yet recruiting
• Conditions: Sleepwalking; NREM Parasomnias; Sleep Terrors; Confusional Arousals
• Intervention / Treatment: Device: Closed-Loop/Open-Loop Acoustic Stimulation (CLAS)

Detailed Description

Disorders of Arousal (DoA)-including sleepwalking, sleep terrors, and confusional arousals-are NREM parasomnias whose underlying neurophysiological triggers remain poorly understood. A growing body of evidence suggests that DoA episodes do not emerge randomly from sleep but arise from identifiable pre-episode EEG states characterized by increased slow-wave activity and reduced cortical activation, consistent with a transient state of arousal instability. Closed-loop acoustic stimulation (CLAS) is an established, non-invasive method for probing and modulating NREM sleep physiology, but has not previously been applied in the specific context of NREM parasomnias.

This study investigates whether controlled acoustic stimulation, initially delivered with randomized timing and subsequently in a real-time, EEG-triggered closed-loop fashion, can reliably elicit or modulate DoA episodes under supervised laboratory conditions. A small group of healthy volunteers undergoes a single stimulation night to estimate the specificity of stimulation-elicited motor responses, helping distinguish genuine DoA vulnerability from a non-specific arousal response to sound.

The within-subject, randomized-order design in DoA participants allows each to serve as their own control, isolating the effect of acoustic stimulation from other sources of night-to-night variability. The exploratory closed-loop sub-study tests the technical feasibility of triggering stimulation based on real-time EEG markers of vulnerability, representing a first step toward future predictive or modulation-based approaches for this condition.

This study is part of a broader research programme on the neurobiological characterization of Disorders of Arousal; related observational components (including neuroimaging, neuropsychological assessment, and home monitoring) are registered separately.

• Study Type: Interventional
• Enrollment (Estimated): 50
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Anna Castelnovo, MD, PhD; Phone Number: 0041 918116117; Email: anna.castelnovo@eoc.ch
• Study Contact Backup: Name: Mauro Manconi, MD, PhD; Phone Number: 0041918116869; Email: mauro.manconi@eoc.ch

Study Locations

• Switzerland
  • Canton Ticino
    • Lugano, Canton Ticino, Switzerland, 6962
      • Ospedale Italiano di Lugano
      • Contact: Anna Castelnovo, MD, PhD; Phone Number: +41 91 811 6117; Email: anna.castelnovo@eoc.ch

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

For participants with Disorders of Arousal (DoA):

• Diagnosis of a Disorder of Arousal (sleepwalking, sleep terror, or confusional arousal) per ICSD-3 criteria, confirmed by video-polysomnography or by clinical diagnosis plus a positive Arousal Disorders Questionnaire (ADQ) and compatible history
• Age 6-17 years (paediatric) or 18-60 years (adult) at enrollment
• At least one documented episode in the 4 weeks (paediatric) or 6 months (adult) prior to enrollment
• Ability to understand and complete study materials in Italian
• Written informed consent (and age-appropriate assent for minors, per Swiss Human Research Act Art. 22-23)

For healthy volunteers:

• No documented sleep disorder, confirmed by clinical interview, questionnaires, or prior instrumental examination
• Age- and sex-matched to the paediatric DoA group
• No clinically significant psychiatric or neurological history
• Written informed consent and age-appropriate assent

Exclusion Criteria (all participants):

• Epilepsy or other major neurological disorder
• Comorbid REM sleep behavior disorder or other REM parasomnia
• Current psychopharmacological or psychotropic medication (except melatonin ≤2 mg)
• Neurodevelopmental disorder precluding protocol collaboration (paediatric participants)
• Clinically relevant sleep-disordered breathing (Apnea-Hypopnea Index >5 events/hour)
• Clinically significant hearing deficit
• Significant sleep deprivation in the 48 hours prior to laboratory recording
• Pregnancy (adult participants)
• Inadequate EEG recording quality (>40% artifact channels or epochs) - applied at the session level

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: DoA - No-Stimulation Night (Baseline); Participants with DoA (N=55) undergo overnight high-density EEG and video-polysomnography with no acoustic stimulation. Within-subject baseline condition; order relative to Arm 2 is randomized per participant.
Experimental: DoA - Acoustic Stimulation Night; The same DoA participants (N=55) undergo overnight high-density EEG and video-polysomnography with low-intensity open-loop acoustic stimulation delivered during slow-wave sleep; order relative to Arm 1 is randomized per participant. A subset of 10 participants additionally undergoes a later, exploratory real-time closed-loop stimulation sub-phase.	Device: Closed-Loop/Open-Loop Acoustic Stimulation (CLAS); Brief, low-intensity auditory stimuli (pure tones or noise bursts, 50-70 dB SPL, approximately 1 second in duration) delivered via a standard speaker during confirmed slow-wave sleep (SWS). In the initial open-loop phase, stimuli are presented with randomized timing. In a later closed-loop sub-study, stimuli are triggered automatically in real time based on predefined EEG features, within randomized vulnerability versus refractory stimulation windows. Stimulation is immediately interrupted in the event of distress, full awakening, or any adverse reaction.
Experimental: Healthy Control - Single Stimulation Night; A separate group of healthy participants (N=5) undergoes a single overnight high-density EEG and video-polysomnography recording including open-loop acoustic stimulation during slow-wave sleep, to estimate the specificity of stimulation-elicited motor responses relative to the DoA group.	Device: Closed-Loop/Open-Loop Acoustic Stimulation (CLAS); Brief, low-intensity auditory stimuli (pure tones or noise bursts, 50-70 dB SPL, approximately 1 second in duration) delivered via a standard speaker during confirmed slow-wave sleep (SWS). In the initial open-loop phase, stimuli are presented with randomized timing. In a later closed-loop sub-study, stimuli are triggered automatically in real time based on predefined EEG features, within randomized vulnerability versus refractory stimulation windows. Stimulation is immediately interrupted in the event of distress, full awakening, or any adverse reaction.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of DoA Episodes During the Stimulation Night Compared With the No-Stimulation Night	Number of video-polysomnographically confirmed Disorders of Arousal (DoA) episodes (sleepwalking, sleep terror, or confusional arousal), compared within-subject between the stimulation night and the no-stimulation (baseline) night.	Assessed during the two laboratory overnight recordings (no-stimulation night and stimulation night), at least 48 hours apart, up to 6 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Duration of DoA Episodes (Seconds): Stimulation Night vs. No-Stimulation Night	Mean duration (seconds) of video-polysomnographically confirmed DoA episodes, compared within-subject between the stimulation night and the no-stimulation (baseline) night.	Assessed during the two laboratory overnight recordings (no-stimulation night and stimulation night), at least 48 hours apart, up to 6 weeks.
Proportion of Slow-Wave Sleep Epochs With Successful Stimulation Trigger (Percentage)	Percentage of detected slow-wave sleep epochs in which acoustic stimulation was successfully triggered within the predefined target window, during the stimulation night.	Assessed during the stimulation-night overnight recording, up to 6 weeks.
Visual Analogue Scale (VAS) Rating of Perceived Discomfort Related to Acoustic Stimulation	Participant-rated discomfort attributable to acoustic stimulation, using a 0-10 visual analogue scale (0 = no discomfort, 10 = worst imaginable discomfort)	Assessed the morning following the stimulation night, up to 6 weeks.
Arousal Index (EEG Arousals per Hour of Sleep): Stimulation Night vs. No-Stimulation Night	Arousal index (number of EEG-defined arousals per hour of total sleep time, scored per AASM criteria), compared between the stimulation night and the no-stimulation night.	Assessed during both laboratory overnight recordings (no-stimulation night and stimulation night), up to 6 weeks.
Sleep Efficiency (Percentage): Stimulation Night vs. No-Stimulation Night	Sleep efficiency (percentage of time in bed spent asleep), derived from polysomnographic sleep staging, compared between the stimulation night and the no-stimulation night.	Assessed during both laboratory overnight recordings (no-stimulation night and stimulation night), up to 6 weeks.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of DoA Episodes With Reported Conscious Experience: Spontaneous vs. Stimulation-Elicited Episodes	Percentage of DoA episodes associated with a reported conscious experience (recalled or unrecalled mental content, assessed via immediate post-episode interview), compared between spontaneous episodes (no-stimulation night) and stimulation-elicited episodes (stimulation night).	Assessed immediately after each DoA episode during both laboratory overnight recordings (no-stimulation night and stimulation night), up to 6 weeks.
Source-Level EEG Spectral Power (Delta 0.5-4 Hz and Beta 18-30 Hz Bands): Spontaneous vs. Stimulation-Elicited DoA Episodes	Power spectral density in the delta and beta bands, source-localized, compared between spontaneous DoA episodes (no-stimulation night) and stimulation-elicited DoA episodes (stimulation night).	Derived from continuous high-density EEG recorded during both laboratory overnight recordings (no-stimulation night and stimulation night), up to 6 weeks.
Odds Ratio of DoA Episode Occurrence During EEG-Defined Fragility vs. Refractory Stimulation Windows (Closed-Loop Feasibility)	Odds ratio of DoA episode occurrence when stimulation is delivered during EEG-defined fragility windows versus randomly selected refractory windows, in the exploratory closed-loop pilot sub-study.	Assessed during the closed-loop pilot phase (Phase 3b), within a subset of participants, up to 6 weeks.

Collaborators and Investigators

• Sponsor: Anna Castelnovo
• Collaborators: University of Bologna; University of Wisconsin, Madison; Swiss National Science Foundation; University of Applied Sciences and Arts of Southern Switzerland; University of the Italian Switzerland
• Investigators: Principal Investigator: Anna Castelnovo, Neurocenter of Southern Switzerland

Study record dates

Study Major Dates

• Study Start (Estimated): October 1, 2026
• Primary Completion (Estimated): July 30, 2030
• Study Completion (Estimated): July 30, 2030

Study Registration Dates

• First Submitted: June 29, 2026
• First Submitted That Met QC Criteria: August 4, 2026
• First Posted (Actual): August 10, 2026

Study Record Updates

• Last Update Posted (Actual): August 10, 2026
• Last Update Submitted That Met QC Criteria: August 4, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: Consciousness; Parasomnia; High-density EEG; Sleep medicine; Slow-wave sleep; Disorders of arousal; Somnambulism; Closed-loop acoustic stimulation; Pediatric sleep disorders
• Additional Relevant MeSH Terms: Nervous System Diseases; Mental Disorders; Sleep Wake Disorders; Parasomnias; Somnambulism; Night Terrors; Sleep Arousal Disorders
• Other Study ID Numbers: AMBIZIONE-DoA-CLAS-2026; PZ00-3_233285 (Other Grant/Funding Number: Swiss National Science Foundation (SNSF), Ambizione Grant)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

IPD Plan Description

De-identified individual participant data underlying the primary and secondary outcome measures (high-density EEG recordings, episode classification, and questionnaire-derived measures) will be made available following publication of the primary results, in accordance with the SNSF Open Research Data policy and FAIR Data Principles ("as open as possible, as closed as necessary").

Derived and anonymized EEG datasets and analysis code will be deposited in FAIR-compliant, non-commercial repositories (e.g., OpenNeuro, Zenodo) with persistent identifiers, and released under a Creative Commons Attribution license (CC BY 4.0), unless stronger restrictions are required.

Raw high-density EEG with synchronized video cannot be made openly available, as full anonymization is not feasible; these data will be deposited only in repositories supporting controlled access (e.g., EBRAINS), with access granted upon reasoned request to a Data Access Committee, subject to a Data Use Agreement and complian

• IPD Sharing Time Frame: Beginning approximately 12 months after publication of the primary results, with no specified end date.
• IPD Sharing Access Criteria: Access to controlled raw data (EEG with video) is granted upon reasoned request to a Data Access Committee, subject to a Data Use Agreement reviewed by the EOC Data Protection Officer. Anonymized derived datasets and code are openly available without restriction.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; ICF; ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No