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.
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 Type
INTERVENTIONAL
Allocation
NA
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
50
Direct electrical stimulation of thalamic nuclei and cortical structures using clinically implanted depth electrodes will allow assessing the effect of stimulation on sleep oscillations.
Brigham and Women's Hospital
Boston, Massachusetts, United States
Massachusetts General Hospital
Boston, Massachusetts, United States
Change from pre-stimulation baseline of sleep spindle rate
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.
Time frame: 10 to 3000 milliseconds following stimulation
Number of channels with responses to 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.
Time frame: 10 to 3000 milliseconds following stimulation
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.