Skip to content

Blood Vessel Anatomy and Blood Flow Regulation

The Impact of Cerebral Anatomical Variations on Cerebrovascular Reactivity

Status
Active, not recruiting
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT05396287
Enrollment
80
Registered
2022-05-31
Start date
2022-07-19
Completion date
2027-05-01
Last updated
2026-07-07

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Brain Blood Flow, Healthy

Keywords

MRI, Brain blood flow

Brief summary

Brain blood flow regulation will be measured in response to environmental changes using MRI.

Detailed description

Global brain blood flow decreases with advancing age; however, some adults have accelerated declines in brain blood flow, placing them at a greater risk of cognitive impairment. Similarly, brain reactivity to increased levels of carbon dioxide decreases with age, with a greater decline in adults with vascular risk factors and is impaired in early Alzheimer's disease. Preclinical models suggest that reduced brain blood flow, results in low levels of oxygen regionally. Currently, there are a lack of human studies that investigate the cause or consequence of altered blood flow regulation in the brain. The research aims are: 1. Determine the impact of vertebral artery hypoplasia (VAH) on brain reactivity to increased levels of carbon dioxide. 2. Determine the impact of VAH on the brain blood flow response to acute low levels of oxygen.

Interventions

DEVICEMRI

Participants will undergo an MRI scan while participating in two breathing tests (hypercapnia and hypoxia) to measure brain blood flow.

Sponsors

University of Wisconsin, Madison
Lead SponsorOTHER
National Institute of Neurological Disorders and Stroke (NINDS)
CollaboratorNIH

Study design

Observational model
CASE_CONTROL
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
55 Years to 69 Years

Inclusion criteria

* BMI ≤38.5 kg/m2 * Nonsmoker * Female subjects: postmenopausal * Currently enrolled in the Wisconsin Alzheimer's Disease Research Clinical Core

Exclusion criteria

* Diagnosis of mild cognitive impairment or Alzheimer's disease * Uncontrolled hypertension * History or evidence of hepatic disease, hematological disease, or peripheral vascular disease * Severe kidney injury requiring hemodialysis * Cardiovascular disease including: severe congestive heart failure, coronary artery disease, ischemic heart disease (stents, coronary artery bypass grafts) and tachycardia * History of clinically significant ischemic or hemorrhagic stroke, or significant cerebrovascular disease * History of HIV/AIDS * Severe untreated obstructive sleep apnea * History of diabetes with HbA1c greater than 9.5% * Major neurologic disorders other than dementia (e.g., multiple sclerosis, amyotrophic lateral sclerosis, brain surgery, etc.) * Current or recent (\<1 year) major psychiatric condition (Axis I) or addictive disorders * Contraindications to MRI

Design outcomes

Primary

MeasureTime frameDescription
Cerebral Vascular Reactivity to HypercapniaOne study visit, up to 120 minutes in the MRIThe change in brain blood flow using MRI will be measured in response to a hypercapnic breathing test. The participants cerebral vascular reactivity to hypercapnia will be compared between the controls (without VAH) and those with VAH.
Cerebral Blood Flow Response to HypoxiaOne study visit, up to 120 minutes in the MRIThe change in brain blood flow using MRI will be measured in response to a hypoxic breathing test. The participants cerebral blood flow response to hypoxia will be compared between the controls (without VAH) and those with VAH.

Countries

United States

Contacts

PRINCIPAL_INVESTIGATORJill N Barnes, PhD

University of Wisconsin, Madison

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jul 8, 2026