CompletedNot Applicable

Study of Brain Blood Flow During Induced Hypercapnia (Excess Blood Carbon Dioxide)

United States30 participantsStarted 1999-09

Plain-language summary

This study will evaluate magnetic resonance imaging (MRI ) methods for measuring changes in the brain's blood flow during hypercapnia (a condition of excess carbon dioxide in the blood). MRI is a diagnostic tool that uses a large magnet and radio waves to produce images of the body without X-rays. Healthy normal volunteers in this study may have as many as six MRI scans over a 2-year period. For this procedure, the person lies on a stretcher placed in a strong magnetic field produced by the MRI machine. During the scan, the person's blood carbon dioxide (CO2 ) levels will be increased either by: 1) breathing air mixtures containing up to 5% CO2; or 2) receiving an intravenous (I.V.) injection of a drug called acetazolamide. Persons who breathe CO2 will have their heart rate, blood pressure and oxygen levels monitored throughout the procedure. Those receiving acetazolamide will have the drug injected intravenously (I.V.) into an arm vein. If the volunteer experiences any unpleasant side effects from the CO2 or acetazolamide, the study will be stopped. The information gained from this study will be used to develop better ways to study brain function, possibly leading to better diagnostic and treatment methods.

Who can participate

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

INCLUSION CRITERIA: Any normal volunteer above the age of 18 years old who is capable of giving informed consent. EXCLUSION CRITERIA: Subjects will be excluded if they have contraindications to MR scanning, such as the following: aneurism clip, implanted neural stimulator, implanted cardiac pacemaker or autodefibrillator, chochlear implant, ocular foreign body (e.g., metal shavings), or insulin pump. Also, subjects will be excluded if they have panic disorder or migrane (because of possible complications with CO2 inhilation), or if they have cirrhosis, are on high dose aspirin therapy, or have an allergy to acetazolamide injection). Subjects will be excluded if they have allergies to sulfonamide drugs or if they have a chronic respiratory illness.

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

Trial details

NCT IDNCT00001845

SponsorNational Institutes of Health Clinical Center (CC)

Sponsor typeNIH

Study typeOBSERVATIONAL

View on ClinicalTrials.gov More Healthy trials

Plain-language summary

Who can participate

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.