Although cerebral blood flow (CBF) alterations are associated with Alzheimer's disease (AD), CBF patterns across prodromal stages of AD remain unclear. Therefore, we investigated patterns of regional CBF in 162 Alzheimer's Disease Neuroimaging Initiative participants characterized as cognitively unimpaired (CU; = 80), objectively-defined subtle cognitive decline (Obj-SCD; = 31), or mild cognitive impairment (MCI; = 51). Arterial spin labeling MRI quantified regional CBF in a priori regions of interest: hippocampus, inferior temporal gyrus, inferior parietal lobe, medial orbitofrontal cortex, and rostral middle frontal gyrus. Obj-SCD participants had increased hippocampal and inferior parietal CBF relative to CU and MCI participants and increased inferior temporal CBF relative to MCI participants. CU and MCI groups did not differ in hippocampal or inferior parietal CBF, but CU participants had increased inferior temporal CBF relative to MCI participants. There were no CBF group differences in the two frontal regions. Thus, we found an inverted-U pattern of CBF signal across prodromal AD stages in regions susceptible to early AD pathology. Hippocampal and inferior parietal hyperperfusion in Obj-SCD may reflect early neurovascular dysregulation, whereby higher CBF is needed to maintain cognitive functioning relative to MCI participants, yet is also reflective of early cognitive inefficiencies that distinguish Obj-SCD from CU participants.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8054731 | PMC |
http://dx.doi.org/10.1177/0271678X20935171 | DOI Listing |
J Neurophysiol
January 2025
The Neuroimaging Research Group, Brain Sciences Center, Department of Veterans Affairs Health Care System, Minneapolis, MN, 55417, USA.
Performance of a task involves the engagement of various brain areas, as evidenced by the effects of lesions of particular brain areas and the results of functional neuroimaging and neurophysiological studies. Here we tested the hypothesis that overall task performance would depend on the level of ongoing, resting-state change in synaptic activity of participating areas, such that the degree of success of the outcome would be higher, the higher the resting-state activation. For that purpose, we used 248-sensor magnetoencephalography (MEG) in healthy people to obtain estimates of resting-state synaptic activity in various areas and then correlated those estimates to the average performance score in three visuospatial tasks assessed outside the MEG session using the Montreal Cognitive Assessment (MoCA), namely the Trails, Cube, and Clock Drawing (TCCD) tasks.
View Article and Find Full Text PDFNat Sci Sleep
January 2025
Department of Radiology, The First Affiliated Hospital of Hunan Normal University (Hunan Provincial People's Hospital), Changsha, Hunan, People's Republic of China.
Background: COVID-19 has led to reports of fatigue and sleep problems. Brain function changes underlying sleep problems (SP) post-COVID-19 are unclear.
Purpose: This study investigated SP-related brain functional connectivity (FC) alterations.
Neurol Sci
January 2025
School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Background: Alzheimer's disease (AD) is a progressive neurodegenerative disorder ranging from mild cognitive impairment (MCI) to AD dementia. Abnormal cerebral perfusion alterations, influenced by amyloid-beta (Aβ) accumulations, have been implicated in cognitive decline along this spectrum.
Objective: This study investigates the relationship between cerebrospinal fluid (CSF) Aβ1-42 levels and regional cerebral blood flow (CBF) changes across the AD continuum using the Arterial Spin Labeling (ASL) technique.
Hum Brain Mapp
February 2025
Université libre de Bruxelles (ULB), UNI - ULB Neuroscience Institute, Laboratoire de Neuroanatomie et Neuroimagerie translationnelles (LN2T), Brussels, Belgium.
Language control processes allow for the flexible manipulation and access to context-appropriate verbal representations. Functional magnetic resonance imaging (fMRI) studies have localized the brain regions involved in language control processes usually by comparing high vs. low lexical-semantic control conditions during verbal tasks.
View Article and Find Full Text PDFNeuropsychologia
January 2025
Centre for Cognitive Neuroscience, Department of Psychology, University of Salzburg, Austria.
Neuroscience has examined the brain processes of recognizing and identifying a known person. But the process of integrating the representation of a temporarily unrecognised person with the representation of the familiar person is not yet known (e.g.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!