Electrical Synchronization of Slow Oscillations to Enhance Deep Sleep

Study Overview
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Brief Summary
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This study applied slowly oscillating (0.5 hz) transcranial electrical stimulation (TES; frontopolar and lateral frontal electrodes versus mastoid and occipital electrode returns) to synchronize the endogenous slow oscillations (SOs) of deep sleep (N3 or stage 3 Non-REM). A double-blind placebo control provided no stimulation. The primary endpoint was duration of N3 sleep during the night. Thirteen normal adults completed the study (before the study was terminated because of COVID-19), and usable data were obtained from ten. The synchronizing stimulation resulted in significantly longer N3 sleep compared to placebo.

Detailed Description
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Previous studies have demonstrated successful synchronization of SOs with slow TES pulses. However, the stimulation in those studies used electrodes in dorsolateral frontal areas (F3, F4 versus contralateral mastoids), consistent with the assumption that human SOs emanate from frontal neocortex. In the present study, we hypothesized that transcranial electrical stimulation (TES) could be applied to frontopolar and inferior frontal head sites in order to synchronize the limbic sources of SOs specifically and thereby enhance the duration of N3 sleep. Furthermore, based on our computational modeling with this more optimal targeting of the limbic sites, we hypothesized that we could use lower TES current levels (0.5 mA versus 1 or 2 mA in previous studies) that would be unlikely to disrupt sleep and that may still be successful in synchronizing SOs to enhance the adaptive neurophysiology of deep sleep.

Official Title
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Electrical Synchronization of Slow Oscillations to Enhance Deep Sleep

Conditions
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Sleep, Sleep Hygiene

Intervention / Treatment
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* Device: Transcranial Electrical Stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - Exclusion Criteria: history of seizures epilepsy brain trauma or injury insomnia sleep apnea medications that may affect the EEG.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Single Group Assignment
Interventional Model Description: First night adaptation sleep; second and third nights (one week apart) stimulation or placebo control (order randomized).
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Slow Oscillation Synchronization with TES<br>Transcranial Electrical Stimulation, 0.5 Hz sine wave, 0.5 mA, between frontal (frontopolar and inferior lateral frontal) and posterior (mastoid and occipital) electrodes. | Device: Transcranial Electrical Stimulation<br>* Oscillating electrical current<br>* Other names: Sleep WISP (Wireless Interface Sensor Pod);|
| Sham Comparator: Sham Control<br>No current delivered. | Device: Transcranial Electrical Stimulation<br>* Oscillating electrical current<br>* Other names: Sleep WISP (Wireless Interface Sensor Pod);|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| N3 Duration | Duration in minutes of N3 sleep | Measured during the night of sleep (typically 8 hours) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| N3 Percentage | Percentage of the night's sleep spent in N3 | Measured during the night of sleep (typically 8 hours) |