Brain network characteristics between subacute and chronic stroke survivors in active, imagery, passive movement task: a pilot study

Yifang Lin; Zewu Jiang; Gege Zhan; Haolong Su; XiaoYang Kang; Jie Jia

doi:10.3389/fneur.2023.1143955

Brain network characteristics between subacute and chronic stroke survivors in active, imagery, passive movement task: a pilot study

Front Neurol. 2023 Jul 19:14:1143955. doi: 10.3389/fneur.2023.1143955. eCollection 2023.

Authors

Yifang Lin^{1

2}, Zewu Jiang¹, Gege Zhan³, Haolong Su³, XiaoYang Kang³, Jie Jia^{1

2

4

5}

Affiliations

¹ Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China.
² Department of Rehabilitation Medicine, Shanghai Jing'an District Central Hospital, Shanghai, China.
³ Academy for Engineering and Technology, Fudan University, Shanghai, China.
⁴ National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China.
⁵ National Center for Neurological Disorders, Shanghai, China.

Abstract

Background: The activation patterns and functional network characteristics between stroke survivors and healthy individuals based on resting-or task-state neuroimaging and neurophysiological techniques have been extensively explored. However, the discrepancy between stroke patients at different recovery stages remains unclear.

Objective: To investigate the changes in brain connectivity and network topology between subacute and chronic patients, and hope to provide a basis for rehabilitation strategies at different stages after stroke.

Methods: Fifteen stroke survivors were assigned to the subacute group (SG, N = 9) and chronic group (CG, N = 6). They were asked to perform hand grasping under active, passive, and MI conditions when recording EEG. The Fugl-Meyer Assessment Upper Extremity subscale (FMA_UE), modified Ashworth Scale (MAS), Manual Muscle Test (MMT), grip and pinch strength, modified Barthel Index (MBI), and Berg Balance Scale (BBS) were measured.

Results: Functional connectivity analyses showed significant interactions on frontal, parietal and occipital lobes connections in each frequency band, particularly in the delta band. The coupling strength of premotor cortex, M1, S1 and several connections linked to frontal, parietal, and occipital lobes in subacute subjects were lower than in chronic subjects in low alpha, high alpha, low beta, and high beta bands. Nodal clustering coefficient (CC) analyses revealed that the CC in chronic subjects was higher than in subacute subjects in the ipsilesional S1 and occipital area, contralesional dorsolateral prefrontal cortex and parietal area. Characteristic path length (CPL) analyses showed that CPL in subacute subjects was lower than in chronic subjects in low beta, high beta, and gamma bands. There were no significant differences between subacute and chronic subjects for small-world property.

Conclusion: Subacute stroke survivors were characterized by higher transfer efficiency of the entire brain network and weak local nodal effects. Transfer efficiency was reduced, the local nodal role was strengthened, and more neural resources needed to be mobilized to perform motor tasks for chronic survivors. Overall, these results may help to understand the remodeling pattern of the brain network for different post-stroke stages on task conditions and the mechanism of spontaneous recovery.

Keywords: brain network topology; electroencephalography; stroke stage; task-related coherence; upper limb.