title: Global brain hypoperfusion and oxygenation in amnestic mild cognitive impairment.
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 color-coded 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.
authors.affiliation: Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi'an, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.affiliation: Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Yong-Sheng
authors.initials: YS
authors.lastname: Zhu
authors.affiliation: Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Muhammad Ayaz
authors.initials: MA
authors.lastname: Khan
authors.affiliation: Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA.
authors.forename: Estee
authors.initials: E
authors.lastname: Brunk
authors.affiliation: Department of Neurology and Neurotherapeutics and the Alzheimer's Disease Center, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Kristin
authors.initials: K
authors.lastname: Martin-Cook
authors.affiliation: Department of Neurology and Neurotherapeutics and the Alzheimer's Disease Center, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Myron F
authors.initials: MF
authors.lastname: Weiner
authors.affiliation: Department of Neurology and Neurotherapeutics and the Alzheimer's Disease Center, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: C Munro
authors.initials: CM
authors.lastname: Cullum
authors.affiliation: Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Hanzhang
authors.initials: H
authors.lastname: Lu
authors.affiliation: Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Levine
authors.affiliation: Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA.
authors.forename: Ramon
authors.initials: R
authors.lastname: Diaz-Arrastia
authors.affiliation: Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Neurology and Neurotherapeutics and the Alzheimer's Disease Center, University of Texas Southwestern Medical Center, Dallas, TX, USA. Electronic address: RongZhang@texashealth.org.
authors.forename: Rong
authors.initials: R
authors.lastname: Zhang
mesh_terms: D000368:Aged; D001921:Brain / Q000098:blood supply* / Q000473:pathology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D060825:Cognitive Dysfunction / Q000097:blood* / Q000473:pathology*; D015150:Echocardiography, Doppler; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism*; D015203:Reproducibility of Results; D019265:Spectroscopy, Near-Infrared
chemical_list: D010100:Oxygen
keywords: Cerebral blood flow; Cerebral metabolic rate of oxygen; MRI; Mild cognitive impairment; Near-infrared spectroscopy; Ultrasonography