Blood Vessel Anatomy and Blood Flow Regulation

• Conditions: Brain Blood Flow; Healthy
• Interventions: Device: MRI

• Registration Number: NCT05396287
• Lead Sponsor: University of Wisconsin, Madison

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.

Study Timeline

• Study First Submitted: 2022-05-25
• Study First Submitted QC: 2022-05-25
• Study First Posted: 2022-05-31
• Study Start: 2022-07-19
• Status Verified: 2025-02
• Last Update Submitted: 2025-02-17
• Last Update Posted: 2025-02-19
• Primary Completion: 2025-06-30
• Study Completion: 2025-06-30

Recruitment & Eligibility

• Status: ENROLLING_BY_INVITATION
• Sex: All
• Target Recruitment: 80

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

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Controls	MRI	Healthy controls
Vertebral Artery Hypoplasia	MRI	Healthy individuals with vertebral artery hypoplasia

Primary Outcome Measures

Name	Time	Method
Cerebral Vascular Reactivity to Hypercapnia	One study visit, up to 120 minutes in the MRI	The 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 Hypoxia	One study visit, up to 120 minutes in the MRI	The 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.

Trial Locations

Locations (1)

University of Wisconsin-Madison; 🇺🇸 Madison, Wisconsin, United States