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

NCT00001845 | Completed

• 2 other identifiers: 99016499-CC-0164
• Study Type: observational
• Target: 30
• Locations: 1 country
• Sites: 1

Brief 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.

Conditions

Healthy; Hypercapnia

Keywords

MRI; Cerebral Blood Flow; CO2 Inhalation; Acetazolamide; Perfusion; Healthy Volunteer

Eligibility Criteria

• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Any normal volunteer above the age of 18 years old who is capable of giving informed consent.

You may not qualify if:

• 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.

Sponsors & Collaborators

• National Institutes of Health Clinical Center (CC): lead

Study Sites (1)

Warren G. Magnuson Clinical Center (CC)

Bethesda, Maryland, 20892, United States

Location

Related Publications (3)

• Brian JE Jr. Carbon dioxide and the cerebral circulation. Anesthesiology. 1998 May;88(5):1365-86. doi: 10.1097/00000542-199805000-00029. No abstract available.

  PMID: 9605698 BACKGROUND

• Olesen J, Paulson OB, Lassen NA. Regional cerebral blood flow in man determined by the initial slope of the clearance of intra-arterially injected 133Xe. Stroke. 1971 Nov-Dec;2(6):519-40. doi: 10.1161/01.str.2.6.519. No abstract available.

  PMID: 5164581 BACKGROUND

• Hauge A, Thoresen M, Walloe L. Changes in cerebral blood flow during hyperventilation and CO2-breathing measured transcutaneously in humans by a bidirectional, pulsed, ultrasound Doppler blood velocitymeter. Acta Physiol Scand. 1980 Oct;110(2):167-73. doi: 10.1111/j.1748-1716.1980.tb06647.x.

  PMID: 6782831 BACKGROUND

MeSH Terms

Conditions

Hypercapnia

Condition Hierarchy (Ancestors)

Signs and Symptoms, Respiratory; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Design

• Study Type: observational
• Sponsor Type: NIH

Study Record Dates

• First Submitted: November 3, 1999
• First Posted: November 4, 1999
• Study Start: September 1, 1999
• Study Completion: August 1, 2004
• Last Updated: March 4, 2008

Record last verified: 2004-08

Locations

US (1)