Cerebral blood flow changes during aging process and in cognitive disorders: A review.

Naghmeh Mokhber,Aidin Shariatzadeh,Golnaz Shojaeian Babaei,Hamidreza Saber,M Reza Azarpazhooh,Abolfazl Avan,Gary Chaimowitz

doi:10.1177/19714009211002778

Abstract

We aimed to summarize the available evidence on cerebral blood flow (CBF) changes in normal aging and common cognitive disorders. We searched PubMed for studies on CBF changes in normal aging and cognitive disorders up to 1 January 2019. We summarized the milestones in the history of CBF assessment and reviewed the current evidence on the association between CBF and cognitive changes in normal aging, vascular cognitive impairment (VCI) and Alzheimer’s disease (AD). There is promising evidence regarding the utility of CBF studies in cognition research. Age-related CBF changes could be related to a progressive neuronal loss or diminished activity and synaptic density of neurons in the brain. While a similar cause or outcome theory applies to VCI and AD, it is possible that CBF reduction might precede cognitive decline. Despite the diversity of CBF research findings, its measurement could help early detection of cognitive disorders and also understanding their underlying etiology.

Highlights

Normal neuronal cell activity and brain function need a simultaneous increase in cerebral blood flow (CBF) in response to an increased energy demand
Previous reviews of CBF studies and dementia focused on CBF regulation and neurovascular dysfunction,[1] cardiovascular determinants of CBF in normal aging[2] and regional changes in dementia subtypes, and discussed specific CBF assessment techniques.[3,4,5]
In 1990, Seiji Ogawa showed the difference in magnetic properties of oxygenated and deoxygenated hemoglobin.[16]. This was a revolution in modern functional magnetic resonance imaging (MRI) and led to a technique known as blood oxygenation level-dependent or (BOLD) contrast

Summary

Introduction

Normal neuronal cell activity and brain function need a simultaneous increase in cerebral blood flow (CBF) in response to an increased energy demand. There is controversial evidence regarding the association between age-related CBF changes and the development and progression of cognitive impairment and dementia. Previous reviews of CBF studies and dementia focused on CBF regulation and neurovascular dysfunction,[1] cardiovascular determinants of CBF in normal aging[2] and regional changes in dementia subtypes, and discussed specific CBF assessment techniques.[3,4,5] The main goal of this review is to provide a summary of age-related CBF changes compared with neurocognitive diseases

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