Ultrasonic Deep Brain Stimulation During Anesthetic Sedation

Phase 2

Completed

Conditions: Mental Function

Registration Number: NCT05495945

Lead Sponsor: University of Michigan

Brief Summary: The purpose of this study is to see if mental functions take place during different levels of anesthesia. The researchers expect to gain a deeper understanding of mental function during different levels of anesthesia, and to evaluate if the use of ultrasonic brain stimulation accelerates return to consciousness.

Detailed Description: The decision was made in 2023 to focus on the Central Thalmus arm only for this trial. Participants were only randomized to this arm.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 13

Inclusion Criteria

The participants will be right-handed adults
Body mass index (BMI) less than 30.
All subjects will be English speakers.

Exclusion Criteria

Participants will be excluded if they have any medical contraindication to MRI scanning
Unable to undergo MRI scanning because of possible pregnancy or currently breastfeeding,
BMI>30
Metallic substances in the body, claustrophobia, anxiety, or cardiopulmonary disease;
Intracranial structural abnormality on T1-weighted MRI scans.
Potential subjects will be excluded if they have a history of allergy to propofol, eggs or egg products, soybean or soybean products,
Neurological, cardiovascular, or pulmonary illness;
Head injury with loss of consciousness;
Learning disability or other developmental disorder; sleep apnea or any severe snoring history;
Gastroesophageal reflux disease (GERD) or heartburn;
Pancreatitis or a history of pancreatitis, or sensory/motor loss sufficient to interfere with performance of the study. Participants with tattoos in the head or neck region will be excluded from study; other tattoos are subject to determination by investigators based on their assessment regarding participant safety. To eliminate aspiration risk subjects will also be excluded if they have had recent food or liquid intake (within 8 hours). Subjects will be excluded if they have a history of drug use, have a positive drug screen, are unwilling to abstain from alcohol for 24 hours prior to dosing, or have a current history of nicotine use. Women will be required to take a pregnancy test prior to participation to ensure a negative result. The pre-scan drug screen and pregnancy test will be paid for by the study.

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Blood Oxygen Level Dependent (BOLD) Response to Visual Stimuli	Up to 90 minutes	BOLD signal was measured by Magnetic Resonance Imaging (MRI) scanning of the brain in response to a visual stimuli. This method reflected changes in oxygenation of blood in the brain during a scene-processing task.

Secondary Outcome Measures

Name	Time	Method
Perceptual Criterion Derived From the Signal Detection Theory (SDT)	Up to 90 minutes	SDT was a means of measuring participants' ability to differentiate between information-bearing patterns and random patterns that distract from the information. Perceptual criterion measured a participant's tendency to say "yes" or "no" when the participant was unsure if a signal was present. Perceptual criterion was measured on a scale from -1.0 to 1.0, with a score of 0 indicating no bias towards "yes" or "no". Negative scores meant a bias towards "yes" (more likely to say a signal was present), while positive scores meant a bias towards "no" (more likely to say a signal was absent).
Grip Force	Up to 90 minutes	Participants' grip force of hand squeezing on a rubber ball in response to instructions was measured.
Sensitivity Derived From the Signal Detection Theory (SDT)	Up to 90 minutes	SDT was a means of measuring participants' ability to differentiate between information-bearing patterns and random patterns that distract from the information. Sensitivity measured a participant's ability to differentiate between real and scrambled images on a scale from 0.0 to 1.0, with higher scores indicating better accuracy in detecting a signal when it was present and lower scores indicating more missed signals. A score of 1.0 was perfect sensitivity (i.e., never missing a real signal).