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Active, Not Recruiting

NCT Number: NCT05180981

Imaging Brain Fluids During Breathing

This study will perform magnetic resonance imaging (MRI) measurements of hemodynamics and cerebrospinal fluid flow across breathing tasks and during breath-locked neuromodulation.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Healthy

Age range

18 year–70 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Boston University - Charles River Campus, Boston, Massachusetts, United States

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About this study

Cerebrospinal fluid (CSF) flow is essential for brain health, as it clears waste products from the brain. This study will investigate how breathing affects the flow of CSF around the brain. The investigators will perform high resolution magnetic resonance imaging (MRI) scans in participants who are breathing in specific patterns or performing simple tasks and test the effects on CSF flow. Participants will complete an imaging study visit in which the investigators will image their brain activity while they perform simple tasks, including paced breathing tasks. The participants will be split into two arms: (1) paced breathing (25 participants low resolution, 15 participants high resolution), (2) transcutaneous vagal nerve stimulation (25 participants low resolution, 15 participants high resolution). The MRI scans will take place in the 7 Tesla MRI scanner at Massachusetts General Hospital.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adult age 18-70 years

Exclusion criteria

  • No ferrous metal implanted in head or body
  • No history of major head trauma
  • No neurological or psychiatric disorder
  • Not using medication that affects brain function
  • No implanted electronic devices (e.g. pacemaker)
  • No implant that poses an MR contraindication
  • Not pregnant, suspect they are pregnant, or seeking to become pregnant
  • Not claustrophobic
  • No piercings or jewelry that cannot be removed
  • Does not weigh more than 250 pounds
  • Normal or contact-corrected normal vision

Exclusion for transcutaneous vagus nerve stimulation (tVNS) arm:

  • Conditions of skin or anatomy that affect left auricle or forehead skin and could impact placement of electrodes for tVNS or forehead stimulation
  • Diagnosis of significant cardiovascular or cerebrovascular disease [e.g. congestive heart failure, stroke, cardiac conduction disorders (including: bundle branch block, heart block, long Q-T syndrome), history of asystole or non-sustained ventricular tachycardia.
  • Bradycardia (defined as resting heart rate <50 bpm)
  • Hypotension defined as blood pressure <90/60 mmHg

Treatment and study plan

transcutaneous vagal nerve stimulation

Device

Noninvasive stimulation vs sham stimulation will be delivered via an auricular device.

Breathing task

Behavioral

Participants will be asked to breathe in specific patterns.

Primary outcomes

  1. functional magnetic resonance imaging (fMRI) signals

    Time frame: During study (2 hours)

    fMRI measures of hemodynamic responses. Units: percent signal change

  2. Cerebrospinal fluid (CSF) signals

    Time frame: During study (2 hours)

    MR-based measures of CSF signals. Units: percent signal change

Secondary outcomes

  1. Heart rate

    Time frame: During study ( 2 hours)

    Heart rate variability will be calculated. Units: milliseconds (ms)

  2. Pulse oximetry

    Time frame: During study ( 2 hours)

    Amplitude of pulse oximetry signal. Units: arbitrary (no physical units are output by this system)

  3. Respiratory physiology timing

    Time frame: During study (2 hours)

    Breath timing. Units: Hertz (Hz)

  4. Respiratory physiology amplitude

    Time frame: During study (2 hours)

    Breath amplitude. Units: arbitrary (no physical units output by this sensor)

Sponsors and collaborators

Lead sponsor

Boston University Charles River Campus

Other

Collaborators

  • National Center for Complementary and Integrative Health (NCCIH)

Registry information

Official study title

Neuroimaging the Impact of Respiration and Respiratory-gated Neuromodulation on Human Glymphatic Physiology

Important dates

Study start
2022
Primary completion
2026
Study completion
2026
First posted
Jan 6, 2022
Registry last updated
Jul 27, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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