Global brain hypoperfusion and oxygenation in amnestic mild cognitive impairment

Authors

Jie Liu, Institute for Exercise and Environmental Medicine, University of Texas Southwestern Medical Center, Tangdu Hospital
Yong-Sheng Zhu, Institute for Exercise and Environmental Medicine, University of Texas Southwestern Medical Center
Muhammad Ayaz Khan, Institute for Exercise and Environmental Medicine, University of Texas Southwestern Medical Center
Estee Brunk, Institute for Exercise and Environmental Medicine
Kristin Martin-Cook, University of Texas Southwestern Medical Center
Myron F. Weiner, University of Texas Southwestern Medical Center
C. Munro Cullum, University of Texas Southwestern Medical Center
Hanzhang Lu, University of Texas Southwestern Medical Center
Benjamin D. Levine, Institute for Exercise and Environmental Medicine, University of Texas Southwestern Medical Center
Ramon Diaz-Arrastia, University of Texas Southwestern Medical Center at Dallas
Rong Zhang, Institute for Exercise and Environmental Medicine, University of Texas Southwestern Medical CenterFollow

Date of this Version

2014

Citation

Alzheimer’s & Dementia 10 (2014) 162–170

Comments

This article is a U.S. government work, and is not subject to copyright in the United States.

Abstract

Background: To determine if global brain hypoperfusion and oxygen hypometabolism occur in patients with amnestic mild cognitive impairment (aMCI). Methods: Thirty-two aMCI and 21 normal subjects participated. Total cerebral blood flow (TCBF), cerebral metabolic rate of oxygen (CMRO₂), and brain tissue volume were measured using colorcoded duplex ultrasonography (CDUS), near-infrared spectroscopy (NIRS), and MRI. TCBF was normalized by total brain tissue volume (TBV) for group comparisons (nTCBF). Cerebrovascular resistance (CVR) was calculated as mean arterial pressure divided by TCBF. Results: Reductions in nTCBF by 9%, CMRO₂ by 11%, and an increase in CVR by 13% were observed in aMCI relative to normal subjects. No group differences in TBV were observed. nTCBF was correlated with CMRO₂ in normal controls, but not in aMCI. Conclusions: Global brain hypoperfusion, oxygen hypometabolism, and neurovascular decoupling observed in aMCI suggest that changes in cerebral hemodynamics occur early at a prodromal stage of Alzheimer’s disease, which can be assessed using low-cost and bedside-available CDUS and NIRS technology.