Functional connectivity and mild behavioral impairment in dementia‐free elderly

Bibliographic Details
Title: Functional connectivity and mild behavioral impairment in dementia‐free elderly
Authors: Maryam Ghahremani, Santhosh Nathan, Eric E. Smith, Alexander McGirr, Bradley Goodyear, Zahinoor Ismail
Source: Alzheimer’s & Dementia: Translational Research & Clinical Interventions, Vol 9, Iss 1, Pp n/a-n/a (2023)
Publisher Information: Wiley, 2023.
Publication Year: 2023
Collection: LCC:Neurology. Diseases of the nervous system
LCC:Geriatrics
Subject Terms: Alzheimer's disease, mild behavioral impairment, mild cognitive impairment, neuropsychiatric symptoms, resting‐state functional magnetic resonance imaging, Neurology. Diseases of the nervous system, RC346-429, Geriatrics, RC952-954.6
More Details: Abstract Background Mild behavioral impairment (MBI) is a syndrome that uses later‐life emergent and persistent neuropsychiatric symptoms (NPS) to identify a group at high risk for incident dementia. MBI is associated with neurodegenerative disease markers in advance of syndromic dementia. Functional connectivity (FC) correlates of MBI are understudied and could provide further insights into mechanisms early in the disease course. We used resting‐state functional magnetic resonance imaging (rs‐fMRI) to test the hypothesis that FC within the default mode network (DMN) and salience network (SN) of persons with MBI (MBI+) is reduced, relative to those without (MBI–). Methods From two harmonized dementia‐free cohort studies, using a score of ≥6 on the MBI Checklist to define MBI status, 32 MBI+ and 63 MBI– individuals were identified (mean age: 71.7 years; 54.7% female). Seed‐based connectivity analysis was implemented in each MBI group using the CONN fMRI toolbox (v20.b), with the posterior cingulate cortex (PCC) as the seed region within the DMN and anterior cingulate cortex (ACC) as the seed within the SN. The average time series from the PCC and ACC were used to determine FC with other regions within the DMN (medial prefrontal cortex, lateral inferior parietal cortex) and SN (anterior insula, supramarginal gyrus, rostral prefrontal cortex), respectively. Age, sex, years of education, and Montreal Cognitive Assessment scores were included as model covariates. The false discovery rate approach was used to correct for multiple comparisons, with a p‐value of .05 considered significant. Results For the DMN, MBI+ individuals exhibited reduced FC between the PCC and the medial prefrontal cortex, compared to MBI–. For the SN, MBI+ individuals exhibited reduced FC between the ACC and left anterior insula. Conclusion MBI in dementia‐free older adults is associated with reduced FC in networks known to be disrupted in dementia. Our results complement the evidence linking MBI with Alzheimer's disease biomarkers. Highlights Resting‐state functional magnetic resonance imaging was completed in 95 dementia‐free persons from FAVR and COMPASS‐ND studies. Participants were stratified by informant‐rated Mild Behavioral Impairment Checklist (MBI‐C) score, ≥6 for MBI+. MBI+ participants showed reduced functional connectivity (FC) within the default mode network and salience network. These FC changes are consistent with those seen in early‐stage Alzheimer's disease. MBI may help identify persons with early‐stage neurodegenerative disease.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 2352-8737
Relation: https://doaj.org/toc/2352-8737
DOI: 10.1002/trc2.12371
Access URL: https://doaj.org/article/2eb5ca08c5824ce8966a23fbb2d30361
Accession Number: edsdoj.2eb5ca08c5824ce8966a23fbb2d30361
Database: Directory of Open Access Journals
More Details
ISSN:23528737
DOI:10.1002/trc2.12371
Published in:Alzheimer’s & Dementia: Translational Research & Clinical Interventions
Language:English