Impaired cerebral vascular and metabolic responses to parametric N-back tasks in subjective cognitive decline

Yaoyu Zhang; Wenying Du; Yayan Yin; Huanjie Li; Zhaowei Liu; Yang Yang; Ying Han; Jia-Hong Gao

doi:10.1177/0271678X211012153

Impaired cerebral vascular and metabolic responses to parametric N-back tasks in subjective cognitive decline

J Cereb Blood Flow Metab. 2021 Oct;41(10):2743-2755. doi: 10.1177/0271678X211012153. Epub 2021 May 5.

Authors

Yaoyu Zhang^{1

2}, Wenying Du³, Yayan Yin⁴, Huanjie Li⁵, Zhaowei Liu⁶, Yang Yang², Ying Han^{3

7

8

9}, Jia-Hong Gao^{2

10

11}

Affiliations

¹ Institute for Medical Imaging Technology, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
² Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.
³ Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China.
⁴ Department of Radiology, Xuanwu Hospital of Capital Medical University, Beijing, China.
⁵ School of Biomedical Engineering, Dalian University of Technology, Dalian, China.
⁶ Center for Excellence in Brain Science and Intelligence Technology (Institute of Neuroscience), Chinese Academy of Sciences, Shanghai, China.
⁷ Biomedical Engineering Institute, Hainan University, Haikou, China.
⁸ Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, Beijing, China.
⁹ National Clinical Research Center for Geriatric Disorders, Beijing, China.
¹⁰ Beijing City Key Lab for Medical Physics and Engineering, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing, China.
¹¹ McGovern Institute for Brain Research, Peking University, Beijing, China.

Abstract

Previous studies reported abnormally increased and/or decreased blood oxygen level-dependent (BOLD) activations during functional tasks in subjective cognitive decline (SCD). The neurophysiological basis underlying these functional aberrations remains debated. This study aims to investigate vascular and metabolic responses and their dependence on cognitive processing loads during functional tasks in SCD. Twenty-one SCD and 18 control subjects performed parametric N-back working-memory tasks during MRI scans. Task-evoked percentage changes (denoted as δ) in cerebral blood volume (δCBV), cerebral blood flow (δCBF), BOLD signal (δBOLD) and cerebral metabolic rate of oxygen (δCMRO₂) were evaluated. In the frontal lobe, trends of decreased δCBV, δCBF and δCMRO₂ and increased δBOLD were observed in SCD compared with control subjects under lower loads, and these trends increased to significant differences under the 3-back load. δCBF was significantly correlated with δCMRO₂ in controls, but not in SCD subjects. As N-back loads increased, the differences between SCD and control subjects in δCBF and δCMRO₂ tended to enlarge. In the parietal lobe, no significant between-group difference was observed. Our findings suggested that impaired vascular and metabolic responses to functional tasks occurred in the frontal lobe of SCD, which contributed to unusual BOLD hyperactivation and was modulated by cognitive processing loads.

Keywords: Subjective cognitive decline (SCD); blood oxygen level-dependent (BOLD); cerebral blood flow (CBF); cerebral blood volume (CBV); cerebral metabolic rate of oxygen (CMRO2).

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aged
Cerebrovascular Circulation / physiology*
Cognitive Dysfunction / physiopathology*
Humans
Middle Aged