Loading search results
Conclusion of funding
Subcortical-cortical Network Dynamics of Anesthesia and Consciousness
Sponsor study identifier
observational
57
1 country
1
Study Start
October 15, 2020
Actual (reported)Primary Completion
November 14, 2024
Actual (reported)Study Completion
December 31, 2025
Actual (reported)General anesthesia (GA) is a medically induced state of unresponsiveness and unconsciousness, which millions of people experience every year. Despite its ubiquity, a clear and consistent picture of the brain circuits mediating consciousness and responsiveness has not emerged. Studies to date are limited by lack of direct recordings in human brain during medically induced anesthesia. Our overall hypothesis is that the current model of consciousness, originally proposed to model disorders and recovery of consciousness after brain injury, can be generalized to understand mechanisms of consciousness more broadly. This will be studied through three specific aims. The first is to evaluate the difference in anesthesia sensitivity in patients with and without underlying basal ganglia pathology. Second is to correlate changes in brain circuitry with induction and emergence from anesthesia. The third aim is to evaluate the effects of targeted deep brain stimulation on anesthesia induced loss and recovery of consciousness. This study focuses on experimentally studying these related brain circuits by taking advantage of pathological differences in movement disorder patient populations undergoing deep brain stimulation (DBS) surgery. DBS is a neurosurgical procedure that is used as treatment for movement disorders, such as Parkinson's disease and essential tremor, and provides a mechanism to acquire brain activity recordings in subcortical structures. This study will provide important insight by using human data to shed light on the generalizability of the current model of consciousness. The subject's surgery for DBS will be prolonged by up to 40 minutes in order to record the participant's brain activity and their responses to verbal and auditory stimuli.
Registry-reported information. Elapsed time and enrollment totals alone do not measure study progress or recruitment pace.
December 31, 2025
Actual (reported)Click on a node to explore related trials.
Some registry-reported names shown below are not yet linked in this graph.
Dates and qualifiers reported by the registry. Estimated dates do not confirm that a milestone has occurred.
July 30, 2020
Actual (reported)August 6, 2020
Actual (reported)October 15, 2020
Actual (reported)November 14, 2024
Actual (reported)December 31, 2025
Actual (reported)June 8, 2026
Actual (reported)Propofol Dose Response Curve
Average targeted serum dose of propofol at which 50% of patients had loss of behavioral responses
Baseline visit
Behavioral Assessment of Propofol Induced Loss / Recovery of Consciousness and Responsiveness
Number of participants with loss of at least 50% of behavioral responses at a targeted serum concentration of 1.5 ug/mL using the following three behavioral responses will be evaluated: (1) loss/recovery of spontaneous movement (i.e., loss and recovery of responsiveness) (2) loss/recovery of movement in response to stimuli (separately to clicks \[non-salient\] and verbal stimuli \[salient\]), and (3) loss/recovery of movement to command (verbal command with patient name with instruction to open their eyes, as proxy of loss/recovery of consciousness).
baseline
This cohort will serve as as the observed group, displaying basal ganglia pathology. A syringe pump controlled by Stanpump implementing the Eleveld Pharmacokinetics-Pharmacodynamics (PK-PD) model for propofol will be used as a targeted controlled infusion (TCI) system to achieve plasma target propofol concentrations. Target effect-site concentration of propofol will be started at 1.4 μg/mL and will be increased by 0.3 μg/mL with reassessment until endpoints are achieved. Experiments will be completed with DBS off.
This cohort will serve as a control group (no basal ganglia pathology). A syringe pump controlled by Stanpump implementing the Eleveld Pharmacokinetics-Pharmacodynamics (PK-PD) model for propofol will be used as a TCI system to achieve plasma target propofol concentrations. Target effect-site concentration of propofol will be started at 1.4 μg/mL and will be increased by 0.3 μg/mL with reassessment until endpoints are achieved. Experiments will be completed with DBS off.
This cohort will serve as as the observed group, displaying basal ganglia pathology. A syringe pump controlled by Stanpump implementing the Eleveld Pharmacokinetics-Pharmacodynamics (PK-PD) model for propofol will be used as a targeted controlled infusion (TCI) system to achieve plasma target propofol concentrations. Target effect-site concentration of propofol will be started at 1.4 μg/mL and will be increased by 0.3 μg/mL with reassessment until endpoints are achieved. Participants will be stimulated at the Gpi via DBS leads during propofol induced loss of consciousness.
Target effect-site concentration of propofol will be started at 1.4 μg/mL and will be increased by 0.3 μg/mL with reassessment until endpoints are achieved.
Registry-reported names are shown in full. Names without a link have not yet been matched to a Syfrah profile.
Study participants are Parkinson's disease and essential tremor patients undergoing revision/replacement of an implantable pulse generator for DBS, or initial DBS implantation.
Nader Pouratian
Dallas, Texas, 75235, United States
Nader Pouratian, MD, PhD
University of Texas Southwestern Medical Center
57 participants (actual enrollment reported by the registry).
First Submitted
July 30, 2020
First Posted
August 6, 2020
Study Start
October 15, 2020
Actual (reported)Electrocorticogram (ECoG) and Pallidal Local Field Potential (LFP) Recordings
Oscillatory frequency at which maximal power changes occur with inducing loss of consciousness, as measured using ECoG and Globus Pallidus internus / Globus Pallidus externus (GPi/GPe) LFP recordings during DBS implantation surgery with target-controlled infusion of propofol. This is not an average frequency but a single peak value based on population spectra at which maximal changes are noted. The number reported is not an average of peaks across patients, but the peak identified after integrating data across the population studied. There is no corresponding measure of dispersion or prevision based on the way the value is identified. Rather, it is a single peak value.
Baseline
This cohort will serve as as the observed group, displaying basal ganglia pathology. A syringe pump controlled by Stanpump implementing the Eleveld Pharmacokinetics-Pharmacodynamics (PK-PD) model for propofol will be used as a targeted controlled infusion (TCI) system to achieve plasma target propofol concentrations. Target effect-site concentration of propofol will be started at 1.4 μg/mL and will be increased by 0.3 μg/mL with reassessment until endpoints are achieved. Participants will be stimulated at the Gpe via DBS leads during propofol induced loss of consciousness.
A syringe pump controlled by Stanpump implementing the Eleveld Pharmacokinetics-Pharmacodynamics (PK-PD) model for propofol will be used as a targeted controlled infusion (TCI) system to achieve plasma target propofol concentrations. Target effect-site concentration of propofol will be started at 1.4 μg/mL and will be increased by 0.3 μg/mL with reassessment until endpoints are achieved. Participants will be stimulated at the Gpe via DBS leads, and cortical activity will be recorded via ECoG during propofol induced loss of consciousness.
A syringe pump controlled by Stanpump implementing the Eleveld Pharmacokinetics-Pharmacodynamics (PK-PD) model for propofol will be used as a targeted controlled infusion (TCI) system to achieve plasma target propofol concentrations. Target effect-site concentration of propofol will be started at 1.4 μg/mL and will be increased by 0.3 μg/mL with reassessment until endpoints are achieved. Participants will be stimulated at the Gpi via DBS leads, and cortical activity will be recorded via ECoG during propofol induced loss of consciousness.
A syringe pump controlled by Stanpump implementing the Eleveld Pharmacokinetics-Pharmacodynamics (PK-PD) model for propofol will be used as a targeted controlled infusion (TCI) system to achieve plasma target propofol concentrations. Target effect-site concentration of propofol will be started at 1.4 μg/mL and will be increased by 0.3 μg/mL with reassessment until endpoints are achieved. Participants will not receive any stimulation via DBS leads, and cortical activity will be recorded via ECoG during propofol induced loss of consciousness.
Contact the study team to confirm eligibility.
Primary Completion
November 14, 2024
Actual (reported)Study Completion
December 31, 2025
Actual (reported)Last Updated
June 8, 2026
Results First Posted
June 8, 2026
Record last verified: 2026-06
Download the complete ClinicalTrials.gov record imported by Syfrah, including fields not shown in this page. The registry may contain a newer revision.
Source: ClinicalTrials.gov.
JSON downloads include source attribution and retrieval details alongside the unchanged original record or the separately normalized values.
Source retrieved: