Neurochemical Mechanisms of the Awake vs. Anesthetized Brain

Healthy Clinical Trial

Official title:

Characterizing the Neuropharmacology of Dexmedetomidine Through Trimodal Imaging

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05435560
• Other study ID #: 2021P003426
• Status: Recruiting
• Phase: Early Phase 1
• Start date: April 12, 2022
• Est. completion date: April 2023

Study information

• Verified date: June 2022
• Source: Massachusetts General Hospital
• Contact: Irena Bass, BA
• Phone: 617-726-9034
• Email: ibass[@]mgh.harvard.edu
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The investigators will be studying the sedative drug dexmedetomidine using hybrid PET/fMRI/EEG imaging to better understand the neuropharmacology of anesthesia/artificially induced sleep.

Description:

A group of healthy volunteers will undergo simultaneous PET/fMRI/EEG imaging under two different conditions: while being administered a sedative (dexmedetomidine), and while being administered a normal saline infusion, as a control. The order of these two scans will be randomized, and the study design is open label (ie subjects and investigators know which session will be the control scan and which one will be the sedative scan). Investigators hope that by comparing the results of the sedative and control scans, the different neuromodulatory states involved in the transition from wakefulness to medically induced vs naturally occurring sleep can be better understood.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 30
• Est. completion date: April 2023
• Est. primary completion date: April 2023
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 45 Years

Eligibility

Inclusion Criteria:

• Adults aged 18-45.
• No contraindications to MRI or PET scanning.

Exclusion Criteria:

• Contraindications to fMRI scanning and PET scanning (including presence of a cardiac pacemaker or pacemaker wires, metallic particles in the body, vascular clips in the head or previous neurosurgery, prosthetic heart valves, claustrophobia);
• Pregnancy or breast feeding;
• Current or past history of major medical, neurological, or psychiatric condition;
• History of major head trauma;
• Any cardiovascular disorders, including heart disorders or high blood pressure [>155/95];
• Breathing problems such as severe asthma;
• Bleeding disorder, or use of anticoagulants;
• Bladder obstruction, urinary problems, or history of impaired elimination;
• Known kidney or liver problems;
• Intestinal blockage;
• Raynaud syndrome
• Peripheral nerve injury;
• Diabetes;
• Glaucoma;
• Sleep disorder, such as sleep apnea, insomnia, or narcolepsy
• Current use of any drugs that affect sleep
• Current or recent use of medications (neurological or psychiatric) affecting brain function
• Current or past history of chronic pain (assessed at discretion of PI);
• History of allergic reactions
• History of chronic obstructive pulmonary diseases
• Ulcerative skin conditions or other dermatologic conditions which could interfere with blood pressure cuff placement
• Body mass index above 30
• Current smoker
• Lack of current health insurance coverage
• Employed under the direct supervision of the investigators conducting the research
• Hair in dreadlocks, twists, or braids that cannot be removed
• Eczema on the scalp or face

Related Conditions & MeSH terms

• Anesthesia
• Healthy

Intervention

Drug:
• Dexmedetomidine
During the imaging scan subjects will receive an initial bolus of dexmedetomidine over 10 minutes. After the bolus has been administered, a constant infusion of dexmedetomidine will be maintained for the remainder of the scan (about 60 minutes).
• Saline
During the imaging scan subjects will receive an initial bolus of saline over 10 minutes. After the bolus has been administered, a constant infusion of saline will be maintained for the remainder of the scan (about 60 minutes).

Locations

Country	Name	City	State
United States	Athinoula A. Martinos Center for Biomedical Imaging	Charlestown	Massachusetts

Sponsors (2)

Lead Sponsor	Collaborator
Massachusetts General Hospital	Boston University

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Brain positron emission tomography (PET) imaging signals.	Changes in dopamine receptor availability will be quantified from brain PET images.	2 hours
Primary	Functional magnetic resonance imaging (fMRI) signals.	fMRI measures of hemodynamic responses.	2 hours
Primary	Differences in electroencephalography (EEG) measures between arousal and anesthesia.	Arousal states will be characterized from changes in the EEG power spectrum.	2 hours
Secondary	Heart rate	Heart rate variability.	2 hours
Secondary	Pulse oximetry	Amplitude of pulse oximetry signal.	2 hours
Secondary	Respiratory physiology	Breathing rate (breaths per minute).	2 hours