The Effect of Thalamic Stimulation on Sleep Oscillations

Not Applicable

• Conditions: Sleep; Neuromodulation

• Registration Number: NCT07217080
• Lead Sponsor: Massachusetts General Hospital

Brief Summary

The thalamus plays a key role in supporting sleep and is also a target of therapeutic stimulation. This project investigates when, where, and how electrical stimulation delivered to the thalamus in humans elicits or disrupts sleep oscillations. This research is a first step to better understand how current neuromodulation therapies affect sleep and may help advance toward new therapies to improve sleep for a wide range of neurological and neuropsychological disorders.

Detailed Description

The thalamus plays a key role in supporting sleep. The thalamus is also increasingly used as a stimulation therapeutic target, but the effect of thalamic stimulation on sleep has not been investigated.

We hypothesize that electrical stimulation delivered to the thalamus in humans could both elicit and disrupt sleep oscillations, such as spindles, depending on the timing and location of stimulation. We propose a study to obtain direct evidence in humans of how thalamic stimulation affects sleep.

We will test the hypothesis that stimulation during a thalamic sleep spindle disrupts it, while stimulation outside evokes a response resembling a k-complex followed by a spindle. Participants will be patients with refractory epilepsy who have semi-chronically implanted depth electrodes in the thalamus and other brain regions (\~100) as part of the pre-surgical clinical work-up. We will detect spindles and stimulate during or outside oscillations using a real-time closed-loop system that we developed. Simultaneously recording across the brain will comprehensively map the effect and extent of thalamic stimulation on sleep oscillations.

This will be the first step to unravel the effect of thalamic stimulation on sleep oscillations and maintenance. This will increase our understanding of the thalamus as a relay of sleep oscillations and could have profound implications to ensure good sleep quality for the increasing number of people implanted with therapeutic stimulation.

Study Timeline

• Study Start: 2025-01-06
• Status Verified: 2025-10
• Study First Submitted: 2025-10-10
• Study First Submitted QC: 2025-10-14
• Last Update Submitted: 2025-10-14
• Study First Posted: 2025-10-15
• Last Update Posted: 2025-10-15
• Primary Completion: 2029-11-30
• Study Completion: 2029-11-30

Recruitment & Eligibility

• Status: ENROLLING_BY_INVITATION
• Sex: All
• Target Recruitment: 50

Inclusion Criteria

• Patients getting intracranial recordings for clinical purposes who, as part of that plan, will receive thalamic electrodes.

Exclusion Criteria

• previous extensive resection or large atrophy

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Primary Outcome Measures

Name	Time	Method
Change from pre-stimulation baseline of sleep spindle rate	10 to 3000 milliseconds following stimulation	An increase in spindle rate is achieved if at least 50% of trials evoke a spindle as measured on intracranial EEG following stimulation. A spindle is evoked when the power in the 10-16Hz band is larger than pre-stimulation baseline power by at least 2 standard deviations.

Secondary Outcome Measures

Name	Time	Method
Number of channels with responses to stimulation	10 to 3000 milliseconds following stimulation	A channel responds to stimulation if the broadband power is larger than baseline by at least 2 standard deviations, as measured from the intracranial EEG.

Trial Locations

Locations (2)

Brigham and Women's Hospital; 🇺🇸 Boston, Massachusetts, United States

Massachusetts General Hospital; 🇺🇸 Boston, Massachusetts, United States