Neuroimaging of mild behavioral impairment: A systematic review

Abstract

There are many neuroimaging studies of mild behavioral impairment (MBI), but the results have been somewhat inconsistent. Moreover, it remains unclear whether MBI is a risk factor or prodromal symptom of dementia. Therefore, a systematic review was conducted to summarize the results of neuroimaging studies of MBI and consider whether MBI is a prodromal symptom of dementia in terms of its neural correlates.A systematic review supported by a JSPS Grant-in-Aid for Scientific Research (C) was conducted using MBI neuroimaging studies identified using PubMed, PsycINFO, CINAHL, and Google Scholar on November 1, 2022. The inclusion criteria were (i) neuroimaging study; (ii) research on human subjects; (iii) papers written in English; and (iv) not a case study, review, book, comments, or abstract only. Joanna Briggs Institute critical appraisal checklists were used to assess the quality of selected studies, and 23 structural and functional imaging studies were ultimately included in the systematic review. The structural studies suggested an association of MBI with atrophy in the hippocampus, parahippocampal gyrus, entorhinal cortex, and temporal lobe, whereas the functional studies indicated involvement of an altered default mode network, frontoparietal control network, and salience network in MBI. A limitation in many studies was the use of region-of-interest analysis. The brain areas detected as neural correlates of MBI are considered to be alterations in the early stage of each dementia. Therefore, MBI may emerge against a background of pathological changes in dementia.

Patterns of a structural covariance network associated with Mild Behavioural Impairment in biologically defined Alzheimer’s Disease

“…Of note, while widespread alterations in fronto-parietal regions were found in previous studies investigating connectivity changes related to MBI correlates (12,13,25,90), we found that the MBI subscores of affectivity, impulse dyscontrol and social inappropriateness were associated with local network properties of speci c brain regions such as the IFG and PCC. This difference could be partially attributed to the methodological differences between our graph analysis approach and the seed-based connectivity analyses performed in these studies (12,13).…”

Optimizing detection of Alzheimer’s disease in mild cognitive impairment: a 4-year biomarker study of mild behavioral impairment in ADNI and MEMENTO

“…Findings also align with the bulk of the MBI literature comprising epidemiological or cohort studies with MBI as exposure, and outcomes of cognition, function, or risk marker. Consistently, whether in CN, MCI, or mixed dementia-free samples, or whether in clinical, community, or even online cohort studies, the data have consistently shown that selecting NPS in accordance with MBI criteria identifies a group with greater baseline risk [ 37 , 46 – 52 ], and/or greater risk for incident MCI and dementia [ 12 – 20 , 41 , 53 , 54 ] than the comparator groups.…”

Tau-PET in early cortical Alzheimer brain regions in relation to mild behavioral impairment in older adults with either normal cognition or mild cognitive impairment

“…Much of the MBI biomarker literature has focused on fluid biomarkers and structural (Matsuoka et al, 2023) and functional (Ghahremani, M. et al, 2023) imaging. Relatively little data have explored ligand-based PET imaging.…”