Table_9_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（Stroke）是认知障碍的重要诱因。富人俱乐部组织结构（rich club organization）是一类高度互连的大脑核心网络结构，与认知功能密切相关。本研究假设脑卒中后认知障碍（post-stroke cognitive impairment, PSCI）患者存在该网络结构的紊乱。
方法：本研究收集了21名健康对照（healthy controls, HC）、16名出血性脑卒中后认知障碍患者（hemorrhagic stroke PSCI, hPSCI）以及21名缺血性脑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软件提取脑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：在低度节点度k水平下，hPSCI组与iPSCI组的标准化富人俱乐部系数均高于HC组（iPSCI组k=1~8，hPSCI组k=2~8）。与HC组相比，PSCI患者的馈通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。组间存在显著差异的馈通连接与局部连接与MMSE及MoCA评分呈正相关：在hPSCI组中主要分布于感觉运动网络（sensorimotor network, SMN）与视觉网络（visual network, VN），在iPSCI组中主要分布于SN与DMN。此外，局部连接降低与低度节点度下的标准化富人俱乐部系数（ϕnorm(k)）与脑卒中病灶的三维形态特征及一阶统计量存在相关性。
结论：本研究揭示了PSCI患者存在低度节点度水平下的富人俱乐部组织结构紊乱，而其功能性核心网络则相对保留。认知相关网络（DMN、SN、CN与ORB）中馈通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PSCI患者的病理机制提供新视角。脑卒中病灶的形态与信号特征，或可为探究功能连接与全脑网络损伤提供重要线索。