Classification of cognitive impairment in older adults based on brain functional state measurement data via hierarchical clustering analysis

Yangxiaoxue Liu; Na Wang; Xinling Su; Tianshu Zhao; Jiali Zhang; Yuhan Geng; Ning Wang; Ming Zhou; Gongzi Zhang; Liping Huang

doi:10.3389/fnagi.2023.1198481

Classification of cognitive impairment in older adults based on brain functional state measurement data via hierarchical clustering analysis

Front Aging Neurosci. 2023 Dec 15:15:1198481. doi: 10.3389/fnagi.2023.1198481. eCollection 2023.

Authors

Yangxiaoxue Liu^#^{1

2

3}, Na Wang^#², Xinling Su^#², Tianshu Zhao^{1

2

3}, Jiali Zhang^{1

2

3}, Yuhan Geng^{1

2}, Ning Wang², Ming Zhou^{1

2}, Gongzi Zhang², Liping Huang²

Affiliations

¹ Medical School of Chinese PLA, Beijing, China.
² Department of Rehabilitation Medicine, The First Medical Center, Chinese PLA General Hospital, Beijing, China.
³ School of Sport Medicine and Rehabilitation, Beijing Sport University, Beijing, China.

^# Contributed equally.

Abstract

Introduction: Cognitive impairment (CI) is a common degenerative condition in the older population. However, the current methods for assessing CI are not based on brain functional state, which leads to delayed diagnosis, limiting the initiatives towards achieving early interventions.

Methods: A total of one hundred and forty-nine community-dwelling older adults were recruited. Montreal Cognitive Assessment (MoCA) and Mini-Mental State Exam (MMSE) were used to screen for CI, while brain functional was assessed by brain functional state measurement (BFSM) based on electroencephalogram. Bain functional state indicators associated with CI were selected by lasso and logistic regression models (LRM). We then classified the CI participants based on the selected variables using hierarchical clustering analysis.

Results: Eighty-one participants with CI detected by MoCA were divided into five groups. Cluster 1 had relatively lower brain functional states. Cluster 2 had highest mental task-switching index (MTSi, 13.7 ± 3.4), Cluster 3 had the highest sensory threshold index (STi, 29.9 ± 7.7), Cluster 4 had high mental fatigue index (MFi) and cluster 5 had the highest mental refractory period index (MRPi), and external apprehension index (EAi) (21.6 ± 4.4, 35.4 ± 17.7, respectively). Thirty-three participants with CI detected by MMSE were divided into 3 categories. Cluster 1 had the highest introspective intensity index (IIi, 63.4 ± 20.0), anxiety tendency index (ATi, 67.2 ± 13.6), emotional resistance index (ERi, 50.2 ± 11.9), and hypoxia index (Hi, 41.8 ± 8.3). Cluster 2 had the highest implicit cognitive threshold index (ICTi, 87.2 ± 12.7), and cognitive efficiency index (CEi, 213.8 ± 72.0). Cluster 3 had higher STi. The classifications both showed well intra-group consistency and inter-group variability.

Conclusion: In our study, BFSM-based classification can be used to identify clinically and brain-functionally relevant CI subtypes, by which clinicians can perform personalized early rehabilitation.

Keywords: aging; brain functional state measurement; cognitive impairment; electroencephalogram; hierarchical clustering analysis.

Grants and funding

This study was supported by the National Key Research and Development Program of China (No. 2019YFB1311400) and the Project of Medical Engineering Laboratory of Chinese PLA General Hospital (No. 2022SYSZZKY14).