Diverse functional connectivity patterns of resting-state brain networks associated with good and poor hand outcomes following stroke

• Authors: Wenjun Hong, Medical School of Nanjing University; Qixiang Lin, Emory University; Zaixu Cui, University of Pennsylvania Perelman School of Medicine; Feiwen Liu, Chengdu Second People's Hospital; Rong Xu, Medical School of Nanjing University; Chozheng Tang, National Health Commission of the People's Republic of China
• Journal Title: NeuroImage: Clinical
• Volume: Volume 24
• Publisher: Elsevier | 2019-01-01, Pages 102065-102065
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1016/j.nicl.2019.102065
• Subjects: Health Sciences, Rehabilitation and Therapy; Health Sciences, Mental Health
• Keywords: Functional brain network; Functional connectivity; ICA; Independent component analysis; Resting-state functional magnetic resonance imaging; Stroke; Aged; Brain; Brain Mapping; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Nerve Net; Neural Pathways; Paralysis; Recovery of Function; Stroke

Abstract

Motor stroke has been characterized by disruptions in multiple large-scale functional brain networks. However, it remains unclear whether stroke patients with good hand outcomes show different connectivity profiles within and between networks from those with poor hand outcomes. In this cross-sectional study, we recruited 52 chronic subcortical stroke patients [illness duration (mean ± SD): 16 ± 16.2 months] and 52 healthy controls from the local hospital and community from June 2010 to August 2016. We first performed independent component analysis (ICA) on resting-state fMRI data to extract fifteen resting-state networks. Then, we compared the functional connectivity within and between networks across 52 healthy controls, 26 patients with a partially paralyzed hand (PPH), and 26 patients with a completely paralyzed hand (CPH). Compared to the patients with a PPH, the patients with a CPH showed increased connectivity in the contralesional sensorimotor cortex within the contralesional sensorimotor network; the increased connectivity was negatively correlated with the performance of the paretic hand. Moreover, the patients with a CPH, compared to those with a PPH, showed decreased strengths of connectivity between the ipsilesional sensorimotor network and both the dorsal sensorimotor network and ventral visual network; the decreased strengths of connectivity were positively correlated with the performance of the paretic hand. Collectively, our findings suggest that stroke patients with different hand outcomes show distinct functional reorganization patterns in large-scale brain networks. These findings shed light on the network-level neuromechanisms that help explain why stroke survivors in the chronic stage show different hand outcomes.