Table_5_Decreased Functional Connectivities of Low-Degree Level Rich Club Organization and Caudate in Post-stroke Cognitive Impairment Based on Resting-State fMRI and Radiomics Features.XLSX

BackgroundStroke is an important cause of cognitive impairment. Rich club organization, a highly interconnected network brain core region, is closely related to cognition. We hypothesized that the disturbance of rich club organization exists in patients with post-stroke cognitive impairment (PSCI).
MethodsWe collected data on resting-state functional magnetic resonance imaging (rs-fMRI) with 21 healthy controls (HC), 16 hemorrhagic stroke (hPSCI), and 21 infarct stroke (iPSCI). 3D shape features and first-order statistics of stroke lesions were extracted using 3D slicer software. Additionally, we assessed cognitive function using the Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE).
ResultsNormalized rich club coefficients were higher in hPSCI and iPSCI than HC at low-degree k-levels (k = 1–8 in iPSCI, k = 2–8 in hPSCI). Feeder and local connections were significantly decreased in PSCI patients versus HC, mainly distributed in salience network (SN), default-mode network (DMN), cerebellum network (CN), and orbitofrontal cortex (ORB), especially involving the right and left caudate with changed nodal efficiency. The feeder and local connections of significantly between-group difference were positively related to MMSE and MoCA scores, primarily distributed in the sensorimotor network (SMN) and visual network (VN) in hPSCI, SN, and DMN in iPSCI. Additionally, decreased local connections and low-degree ϕnorm(k) were correlated to 3D shape features and first-order statistics of stroke lesions.
ConclusionThis study reveals the disrupted low-degree level rich club organization and relatively preserved functional core network in PSCI patients. Decreased feeder and local connections in cognition-related networks (DMN, SN, CN, and ORB), particularly involving the caudate nucleus, may offer insight into pathological mechanism of PSCI patients. The shape and signal features of stroke lesions may provide an essential clue for the damage of functional connectivity and the whole brain networks.

背景：脑卒中是认知障碍的重要致病因素。富集群组织（rich club organization）是指脑内由高度互联的核心区域构成的网络，其与认知功能密切相关。本研究假设卒中后认知障碍（post-stroke cognitive impairment, PSCI）患者存在富集群组织紊乱。
方法：本研究收集了21名健康对照者（healthy controls, HC）、16名出血性卒中后认知障碍患者（hemorrhagic stroke PSCI, hPSCI）以及21名缺血性卒中后认知障碍患者（infarct stroke PSCI, iPSCI）的静息态功能磁共振成像（resting-state functional magnetic resonance imaging, rs-fMRI）数据。使用3D Slicer软件提取卒中病灶的三维形态特征与一阶统计量。此外，采用蒙特利尔认知评估量表（Montreal Cognitive Assessment, MoCA）与简易精神状态检查表（Mini-Mental State Examination, MMSE）对受试者的认知功能进行评估。
结果：在低度数k水平下，出血性与缺血性卒中后认知障碍患者的标准化富集群系数均高于健康对照者：缺血性卒中后认知障碍组为k=1~8，出血性卒中后认知障碍组为k=2~8。与健康对照者相比，卒中后认知障碍患者的馈入连接与局部连接显著降低，这些连接主要分布于突显网络（salience network, SN）、默认模式网络（default-mode network, DMN）、小脑网络（cerebellum network, CN）以及眶额皮层（orbitofrontal cortex, ORB），尤其累及左右尾状核并伴随节点效率改变。存在组间显著差异的馈入连接与局部连接与MMSE及MoCA评分呈正相关：在出血性卒中后认知障碍患者中主要分布于感觉运动网络（sensorimotor network, SMN）与视觉网络（visual network, VN），在缺血性卒中后认知障碍患者中主要分布于突显网络与默认模式网络。此外，降低的局部连接与低度数标准化富集群系数ϕnorm(k)与卒中病灶的三维形态特征及一阶统计量显著相关。
结论：本研究揭示了卒中后认知障碍患者存在低度数水平富集群组织受损，而功能核心网络相对保留。认知相关网络（默认模式网络、突显网络、小脑网络及眶额皮层）中馈入连接与局部连接的降低，尤其是累及尾状核的改变，可为阐明卒中后认知障碍患者的病理机制提供新的视角。卒中病灶的形态与信号特征可为理解功能连接及全脑网络损伤提供重要线索。