Mild Behavioral Impairment Is Associated With Atrophy of Entorhinal Cortex and Hippocampus in a Memory Clinic Cohort

Veronika Matuskova; Zahinoor Ismail; Tomas Nikolai; Hana Markova; Katerina Cechova; Zuzana Nedelska; Jan Laczó; Meng Wang; Jakub Hort; Martin Vyhnalek

doi:10.3389/fnagi.2021.643271

Mild Behavioral Impairment Is Associated With Atrophy of Entorhinal Cortex and Hippocampus in a Memory Clinic Cohort

Front Aging Neurosci. 2021 May 24:13:643271. doi: 10.3389/fnagi.2021.643271. eCollection 2021.

Authors

Veronika Matuskova^{1

2}, Zahinoor Ismail^{3

4

5

6}, Tomas Nikolai^{1

2}, Hana Markova^{1

2}, Katerina Cechova^{1

2}, Zuzana Nedelska^{1

2}, Jan Laczó^{1

2}, Meng Wang^{4

5}, Jakub Hort^{1

2}, Martin Vyhnalek^{1

2}

Affiliations

¹ Memory Clinic, Department of Neurology, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czechia.
² International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia.
³ Department of Psychiatry, Cumming School of Medicine, Calgary, AB, Canada.
⁴ Department of Clinical Neurosciences, Cumming School of Medicine, Calgary, AB, Canada.
⁵ Department of Community Health Sciences, Cumming School of Medicine, Calgary, AB, Canada.
⁶ Hotchkiss Brain Institute and O'Brien Institute for Public Health, University of Calgary, Calgary, AB, Canada.

Abstract

Objectives: Mild behavioral impairment (MBI) is a syndrome describing late-onset persistent neuropsychiatric symptoms (NPS) in non-demented older adults. Few studies to date have investigated the associations of MBI with structural brain changes. Our aim was to explore structural correlates of NPS in a non-demented memory clinic sample using the Mild Behavioral Impairment Checklist (MBI-C) that has been developed to measure MBI.

Methods: One hundred sixteen non-demented older adults from the Czech Brain Aging Study with subjective cognitive concerns were classified as subjective cognitive decline (n = 37) or mild cognitive impairment (n = 79). Participants underwent neurological and neuropsychological examinations and brain magnetic resonance imaging (MRI) (1.5 T). The Czech version of the MBI-C was administered to participants' informants. Five a priori selected brain regions were measured, namely, thicknesses of the orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), posterior cingulate cortex (PCC), and entorhinal cortex (ERC) and volume of the hippocampus (HV), and correlated with MBI-C total and domain scores.

Results: Entorhinal cortex was associated with MBI-C total score (r_S = -0.368, p < 0.001) and with impulse dyscontrol score (r_S = -0.284, p = 0.002). HV was associated with decreased motivation (r_S = -0.248, p = 0.008) and impulse dyscontrol score (r_S = -0.240, p = 0.011).

Conclusion: Neuropsychiatric symptoms, particularly in the MBI impulse dyscontrol and motivation domains, are associated with medial temporal lobe atrophy in a clinical cohort of non-demented older adults. This study supports earlier involvement of temporal rather than frontal regions in NPS manifestation. Since these regions are typically affected early in the course of Alzheimer's disease (AD), the MBI-C may potentially help further identify individuals at-risk of developing AD dementia.

Keywords: entorhinal cortex; hippocampus; magnetic resonance imaging; mild behavioral impairment-checklist; mild cognitive impairment; neuropsychiatric symptoms; subjective cognitive decline.