脑小血管病患者认知障碍早期功能网络连接性研究

目的 研究脑小血管病（cerebral small vessel disease,CSVD）患者认知障碍早期大尺度静息态网络
（resting-state network,RSN）之间连接模式的变化。
方法 2015年7月-2018年12月,从上海交通大学医学院附属仁济医院神经内科脑卒中门诊前瞻性
连续招募非痴呆CSVD患者,收集患者的基线人口社会学资料、血管危险因素,进行神经心理学评估
和多模态MRI检查,分为无认知障碍（no cognitive impairment,NCI）组和轻度认知障碍（mild cognitive
impairment,MCI）组。对两组患者的功能网络连接性（functional network connectivity,FNC）进行比较,
并与认知功能进行相关性分析。
结果 ①本研究共纳入CSVD患者185例,其中MCI组117例（63.2%）,NCI组68例（36.8%）,平均
年龄为64.6±7.2岁,男性86例（78.4%）。MCI组与NCI组相比,男性较少（P =0.035）,教育年限偏低
（P =0.003）,两组患者的年龄和血管危险因素无统计差异。②校正年龄、性别、教育年限后,在RSN
水平,MCI组比NCI组执行控制网络（executive control network,ECN）和右额顶网络（right frontoparietal
network,RFPN）之间的功能连接减弱（P＜0.05）;在独立成分（independent component,IC）水平,MCI组
比NCI组在涉及听觉网络（auditory network,AN）、默认模式网络（default mode network,DMN）、ECN及
RFPN的部分IC之间的功能连接减弱（均P＜0.05）,在涉及DMN、AN及视觉网络（visual network,VN）的
部分IC之间的功能连接增强（均P＜0.05）。③除AN-13与DMN-16、RFPN-26与ECN-19外,FNC与总体认知、
注意与执行和视空间功能均呈正相关（均P＜0.05）。
结论 CSVD患者认知障碍早期,ECN和RFPN之间的功能连接减弱,FNC在涉及AN、DMN、ECN、RFPN
的IC之间减弱,涉及DMN、AN、VN的IC之间代偿性增强,且FNC与认知功能相关。FNC可能成为CSVD认
知障碍新的神经网络标志物。     

未服药单相和双相抑郁障碍患者静息态核心脑网络效应连接分析

目的比较静息状态下单相抑郁障碍(unipolar depression, UD)、双相抑郁障碍(bipolar depression, BD)患者执行控制网络(executive control network, ECN)、突显网络(salience network, SN)和默认网络(default mode network, DMN)网络内及网络间效应连接的异同, 并分析UD与BD患者之间效应连接差异与临床症状的相关性。方法于2021年3月至2022年6月纳入18～35岁未服药的39例UD患者(UD组)、24例BD患者(BD组)和50例健康对照者(healthy control, HC;HC组), 采集所有受试者的静息态功能磁共振成像(functional magnetic resonance imaging, fMRI)和T1结构像数据。采用基于频谱的动态因果模型分析方法, 检测3组ECN、SN和DMN网络内及网络间效应连接的差异, 并进一步采用典型相关的分析方法检测2个患者组之间效应连接的差异与临床症状的相关性。结果与HC组相比, 2个患者组均表现出SN网络的网络内兴奋性效应降...     

轻度认知障碍和阿尔茨海默病静息态功能磁共振成像研究进展

随着功能磁共振研究的不断发展,大量的研究发现轻度认知障碍（MCI）和阿尔茨海默病（AD）患者的部分脑区自发活动发生改变.这种改变包括脑区相似性的改变和不同脑区之间功能连接的改变, 主要发生于大脑默认网络（DMN）的大部分区域中.本文将近年来在这方面的研究进展进行了综述.     

卒中后抑郁患者静息态局部脑活动与默认网络功能连接改变的磁共振成像研究

采用静息态fMRI并基于局部一致性（regional homogeneity,ReHo）和独立成分分析（independent component analysis,ICA）方法研究卒中后抑郁患者（post-stroke depression,PSD）局部自发脑活动和默 认网络（default mode network,DMN）功能连接变化模式。 方法 纳入自2017年1月-2019年1月期间新乡医学院第一附属医院收治的20例PSD患者（PSD组）,以 及年龄、性别和受教育程度等均匹配的单纯缺血性卒中未抑郁患者19例（对照组）。分别采用MMSE、 汉密尔顿抑郁量表17项（Hamilton depression scale-17,HAMD-17）测试受试者的认知功能和抑郁情绪; 然后采集静息态fMRI数据,图像预处理后计算ReHo值并提取两组DMN成分。比较组间ReHo值和DMN功 能连接差异,并提取差异脑区的ReHo值和功能连接值与PSD组患者HAMD-17评分进行相关性分析。 结果 与对照组相比,PSD组右侧海马旁回和左侧小脑脚2区ReHo值升高（P <0.001,体素值>20 mm3, 未校正）,并且在DMN中左侧楔前叶功能连接增强[P =0.011,校正错误发现率（false discovery rate, FDR）]、右侧楔叶功能连接减弱（P =0.006,校正FDR）。右侧海马旁回的ReHo值与HAMD-17评分呈正 相关（r =0.556,P =0.011）;右侧楔叶功能连接值与HAMD-17评分呈负相关（r =-0.574,P =0.008）。 结论 PSD患者存在局部自发脑活动以及DMN功能连接异常并与患者的抑郁情绪相关。     

轻型缺血性卒中后认知障碍与脑动态功能连接状态改变的功能磁共振成像研究

目的 探索轻型缺血性卒中后有认知障碍（cognitive impairment,CI）患者和无认知障碍（no cognitive impairment,NCI）患者脑动态功能连接（functional connectivity,FC）状态的变化。 方法 选择2014年12月1日-2016年5月31日首都医科大学附属北京天坛医院神经病学中心就诊的 轻型急性缺血性卒中患者为研究对象,对所有患者进行神经心理学评估和多模态MRI检查,分为CI 组（15例）和NCI组（11例）,同时招募年龄、性别均匹配的志愿者作为健康对照（healthy control,HC）组 （29例）。基于静息态功能头颅MRI影像,利用动态功能网络连接方法构建一系列随时间变化的FC网络, 然后通过聚类方法划分为多个具有代表性的动态FC状态（分别为模块化连接状态、强连接状态、局 部连接状态和稀疏连接状态）,比较HC组、CI组与NCI组的FC动态特征（各状态的时间比例、驻留时间 及各状态间的转换次数）差异,并在两个时间点（基线和3个月随访期）探索CI组与NCI组动态FC状态 的变化。 结果 HC组、CI组和NCI组在基线和随访期各连接状态的时间比例差异均无统计学意义。基线CI组 和NCI组在稀疏连接状态的驻留时间比HC组更低,三组差异有统计学意义（P =0.035）,但两两比较 的结果均未通过Bonferroni校正;而在随访期,各连接状态的驻留时间差异均无统计学意义。纵向比 较中,与基线相比,CI组随访期在模块化连接状态的时间比例明显下降（P =0.035）,在稀疏连接状 态的时间比例明显上升（P =0.025）,在模块化连接状态的驻留时间明显降低（P =0.012）;而NCI 组 在两个时间点各连接状态的时间比例和驻留时间差异均无统计学意义。对于转换次数,所有组间的 差异均无统计学意义。 结论 轻型缺血性卒中患者急性期较对照人群有局部连接状态增多而稀疏连接状态减少的趋势, 但差异未达统计学意义;对于有认知障碍的轻型缺血性卒中患者,发病3个月时模块化连接状态和 稀疏连接状态均较急性期显著恢复;动态功能网络能够客观反映大脑功能的变化。     

隐匿性脑梗死轻度认知功能障碍的影响因素分析

目的 分析影响隐匿性脑梗死(SCI)患者认知功能障碍的因素.方法 82例SCI患者应用简易精神状态检查量表(MMSE)及中文版蒙特利尔认知评估量表(MoCA)的检测,并比较两种量表对轻度认知障碍(MCI)的检出率.依据测查结果分为轻度认知功能障碍(MCI)组及认知功能正常(NCI)组,所有患者均进行一般情况评定和实验室检查、抑郁量表评估、影像学检测病灶的部位和侧别、颈动脉彩色多普勒测定颈动脉粥样硬化程度.结果 MoCA量表测查MCI的敏感性较MMSE明显增高(MoCA 41.46%,MMSE12.20%,P＜0.01).MCI组合并抑郁者较NCI组多(P＜0.01),MCI组病灶多位于额颞叶皮质及皮质下以及丘脑与NCI组相比有不同,NCI组病灶多位于基底节区、脑干及小脑.颈动脉管腔内径、内膜中层厚度(IMT)及不稳定斑块两组比较有差异(P＜0.01),颈动脉稳定斑块两组比较无差异.结论 在SCI合并MCI的检测中,MoCA量表的敏感性高于MMSE,MoCA对筛选SCI患者是否合并MCI有临床指导意义.SCI中MCI的发生与病灶部位及侧别、颈动脉管腔内径、IMT、斑块的稳定性及是否合并抑郁等多种因素有关.     

血尿酸与脑小血管病患者血管性轻度认知障碍的相关性研究

目的 探讨血尿酸（uric acid,UA）与脑小血管病（cerebral small vessel disease,CSVD）患者血管性轻度 认知障碍（vascular mild cognitive impairment,VaMCI）的相关性。 方法 选择2015年10月-2017年6月于潍坊医学院附属医院就诊的87例CSVD患者和44例体检者,根据 蒙特利尔评估表（montreal cognitive assessment,MoCA）将CSVD患者分为VaMCI组47例和认知正常组40 例,用Logistic回归分析及Pearson相关分析来分析尿酸与脑小血管病患者轻度认知障碍的相关性。 结果 CSVD认知正常组及轻度认知障碍组血UA水平（[ 315.15±56.76）μmol/L,（363.32±42.58） μmol/L]高于对照组（[ 269.66±40.21）μmol/L]（均P<0.001）,且CSVD轻度认知障碍组血尿酸水平 高于认知正常组（P <0.001）。轻度认知损害组UA水平与其MoCA总分、视空间与执行能力、记忆、语 言呈负相关（r =-0.351,P =0.015;r =-0.456,P =0.001;r =-0.408,P =0.004;r =-0.329,P =0.024）。 Logistic回归分析结果显示,血UA水平[比值比（odds ratio,OR）1.020,95%可信区间（confidence interval, CI）1.009～1.032,P =0.01]是CSVD患者轻度认知障碍的独立危险因素。 结论 CSVD血管性轻度认知障碍患者血UA升高,且血UA是CSVD患者轻度认知障碍的危险因素。UA 水平与CSVD血管性轻度认知障碍患者蒙特利尔评估总分、视空间与执行能力、记忆、语言呈负相关。     

血清GFAP、Hcy与Fazekas评分对脑小血管病患者认知障碍的预测价值

目的 探讨血清胶质纤维酸性蛋白(GFAP)、同型半胱氨酸(Hcy)与Fazekas评分对脑小血管病(CSVD)患者认知障碍的预测价值.方法 选取海南医学院第二附属医院2019年1月至2020年6月收治的129例CSVD患者,根据蒙特利尔认知量表(MoCA)分为认知障碍组和认知正常组.收集患者性别、年龄、基础病史、血脂、血清GFAP、Hcy及Fazekas评分等资料,分析血清GFAP、Hcy水平、Fazekas评分与MoCA评分相关性及其对CSVD患者认知障碍的预测价值.结果 129例CSVD患者院后半年内出现认知功能障碍56例,发生率为43.41％;其中轻度障碍16例,中度障碍33例,重度障碍7例.认知障碍组患者血清GFAP、Hcy水平、Fazekas评分均明显高于认知正常组(P＜0.05).随着认知障碍病情的加重,CSVD患者血清GFAP、Hcy水平呈明显增高趋势(P＜0.05);重度认知障碍患者Fazekas评分高于轻度认知障碍患者(P＜0.05).血清GFAP、Hcy水平、Fazekas评分与MoCA评分呈显著负相关(P＜0.05).血清GFAP、Hcy水平、Fazekas评分预测CSVD患者认知障碍的ROC曲线下面积为0.888、0.886、0.883,最佳临界值分别为6.26μg·mL-1、15.30μ mol·L-1、2.5分.结论 血清GFAP、Hcy水平及Fazekas评分与CSVD患者认知状况密切相关,可作为早期预测认知障碍的参考指标.     

卒中后认知功能障碍变化与静息态功能 核磁的相关研究

目的 研究缺血性卒中患者认知功能障碍发病3个月认知功能动态变化特点及其与静息 态功能核磁功能连接的关系。方法 收集 2016 年 9 月至 2017 年 2 月就诊于首都医科大学附属北京天 坛医院神经内科脑血管病房的基底节区急性缺血性卒中伴认知障碍患者 23 例,基底节区急性缺血性 卒中不伴认知障碍患者 17 例,在卒中后 2 周及 3 个月时对患者进行认知功能评价及采集静息态功能核 磁（fMRI）影像,另选取 30 名年龄、性别、文化程度匹配的健康自愿者为对照组。进行认知评估和静息 态 fMRI 影像采集。比较基线及 3 个月认知功能变化及功能连接强度变化情况,采用多重线性回归分析 卒中后认知功能障碍与功能连接强度变化的关系。结果 在卒中发病 2 周时,与对照组比较,卒中伴 认知障碍组的听觉词语学习测验（AVLT）总分、Rey-Osterrieth 复杂图形测验（RCFT）- 延迟回忆、波士顿 命名（BNT）、词语流畅性（VFT）、符号数字转换测验（SDMT）得分明显下降,连线测验（TMT）-A、TMT-B 耗 时和 Stroop 色词测验（CWT）耗时明显延长（P＜ 0.05）。与卒中不伴认知障碍组相比,卒中伴认知障碍组 RCFT- 延迟回忆得分显著下降,TMT-A 耗时明显延长。卒中伴认知障碍组在卒中发病 2 周时额叶功能 连接强度较对照组显著增强（GRF 校正后,体素P＜ 0.05,簇P＜ 0.05）。在 3 个月时,卒中伴认知障碍组 RCFT- 延迟回忆得分较基线（发病 2 周）时显著改善（P＜ 0.05）;卒中伴认知障碍组额叶功能连接强度较 基线（发病2周）显著降低（GRF校正后,体素P＜0.05,簇P＜0.05）;且额叶功能连接强度下降值与视觉延 迟回忆改善值呈正相关（GRF校正后,体素P＜0.05,簇P＜0.05）。结论 基底节区急性缺血性卒中后认 知障碍患者在急性期额叶功能连接强度明显增强,发病 3 个月较 2 周时视觉延迟回忆得分明显改善,额 叶功能连接强度逐渐下降,与视觉延迟回忆改善有关。     

脑小血管病患者 MR 弥散张量成像的改变及与认知功能障碍的关系

目的：探讨脑小血管病患者MR弥散张量成像的改变以及与认知功能障碍间的关系。方法选取我院接受检查的小脑血管疾病患者70例,根据有无认知障碍分为非痴呆认知功能障碍（VCIND）组39例和认知功能正常（NCI）组31例。对患者进行蒙特利尔认知评估（MoCA）及MRI检查,并对弥散张力成像（DTI）进行处理,显示表观弥散系数图（ADC）以及各向异性分数图（FA）,分析MoCA与DTI的相关性。结果 VCIND组MoCA量表评分（17.54±4.31）分,NCI组为（24.01±2.02）分;VCIND组双侧半卵圆中心、双侧额叶、双侧丘脑以及左侧尾状核 FA 值明显低于 NCI组,VCIND 组左侧尾状核ADC值明显高于NCI组,差异有统计学意义（P＜0.05）。双侧半卵圆中心、双侧额叶以及左侧尾状核FA值与MoCA呈正相关（P＜0.05）。结论脑小血管疾病患者认知功能障碍与DTI的FA值呈正相关。     

Altered functional organization within and between resting-state networks in chronic subcortical infarction

This study aimed to investigate the changes in functional connectivity (FC) within each resting-state network (RSN) and between RSNs in subcortical stroke patients who were well recovered in global motor function. Eleven meaningful RSNs were identified via functional magnetic resonance imaging data from 25 subcortical stroke patients and 22 normal controls using independent component analysis. Compared with normal controls, stroke patients exhibited increased intranetwork FC in the sensorimotor (SMN), visual (VN), auditory (AN), dorsal attention (DAN), and default mode (DMN) networks; they also exhibited decreased intranetwork FC in the frontoparietal network (FPN) and anterior DMN. Stroke patients displayed a shift from no FC in controls to negative internetwork FC between the VN and AN as well as between the VN and SMN. Stroke patients also exhibited weakened positive (anterior and posterior DMN; posterior DMN and right FPN) or negative (AN and right FPN; posterior DMN and dorsal SMN) internetwork FC when compared with normal controls. We suggest that subcortical stroke may induce connectivity changes in multiple functional networks, affecting not only the intranetwork FC within RSNs but also the internetwork FC between these RSNs.     

Three subsystems of the inferior parietal cortex are differently affected in mild cognitive impairment

The Inferior parietal cortex (IPC), including the intraparietal sulcus (IPS), angular gyrus (AG), and supramarginal gyrus (SG), plays an important role in episodic memory, and is considered to be one of the specific neuroimaging markers in predicting the conversion of mild cognitive impairment (MCI) to Alzheimer's disease (AD). However, it is still unclear whether the connectivity of the IPC is impaired in MCI patients. In the present study, we used resting state fMRI to examine the functional connectivity of the three subdivisions of the IPC in MCI patients after controlling the impact of regional grey matter atrophy. It was found that, using IPS, AG, and SG as seeds of functional connectivity, three canonical functional networks could be correspondingly traced, i.e., executive control network (ECN), default mode network (DMN), and salience network (SN), and the three networks are differently altered in MCI patients. In contrast to the healthy controls, it was found that in MCI patients: 1) AG connectivity was significantly reduced within the DMN; 2) IPS showed decreased connectivity with the right inferior frontal gyrus while showing increased connectivity with the left frontal regions within the ECN; and 3) SG displayed decreased connectivity with a distribution of regions including the frontal and parietal regions, and increased connectivity with some sub-cortical areas within the SN. Moreover, the connectivity within the three networks was correlated with episodic memory and general cognitive impairment in MCI patients. These results extend well beyond the DMN, and further suggest that MCI is associated with alteration of large-scale functional brain networks.     

Cerebral small vessel disease affects white matter microstructure in mild cognitive impairment

Microstructural white matter deterioration is a frequent finding in mild cognitive impairment (MCI), potentially underlying default mode network (DMN) dysfunctioning. Thus far, microstructural damage in MCI has been attributed to Alzheimer's disease pathophysiology. A cerebrovascular role, in particular the role of cerebral small vessel disease (CSVD), received less interest. Here, we used diffusion tensor imaging (DTI) to examine the role of CSVD in microstructural deterioration within the normal appearing white matter (NAWM) in MCI. MCI patients were subdivided into those with (n = 20) and without (n = 31) macrostructural CSVD evidence on MRI. Using TBSS we performed microstructural integrity comparisons within the whole brain NAWM. Secondly, we segmented white matter tracts interconnecting DMN brain regions by means of automated tractography segmentation. We used NAWM DTI measures from these tracts as dependent variables in a stepwise‐linear regression analysis, with structural and demographical predictors. Our results indicated microstructural deterioration within the anterior corpus callosum, internal and external capsule and periventricular white matter in MCI patients with CSVD, while in MCI patients without CSVD, deterioration was restricted to the right perforant path, a tract along the hippocampus. Within the full cohort of MCI patients, microstructure within the NAWM of the DMN fiber tracts was affected by the presence of CSVD. Within the cingulum along the hippocampal cortex we found a relationship between microstructural integrity and ipsilateral hippocampal volume and the extent of white matter hyperintensity. In conclusion, we found evidence of CSVD‐related microstructural damage in fiber tracts subserving the DMN in MCI. Hum Brain Mapp 35:2836–2851, 2014. © 2013 Wiley Periodicals, Inc .     

Altered intra‐ and inter‐network functional coupling of resting‐state networks associated with motor dysfunction in stroke

Motor functions are supported through functional integration across the extended motor system network. Individuals following stroke often show deficits on motor performance requiring coordination of multiple brain networks; however, the assessment of connectivity patterns after stroke was still unclear. This study aimed to investigate the changes in intra‐ and inter‐network functional connectivity (FC) of multiple networks following stroke and further correlate FC with motor performance. Thirty‐three left subcortical chronic stroke patients and 34 healthy controls underwent resting‐state functional magnetic resonance imaging. Eleven resting‐state networks were identified via independent component analysis (ICA). Compared with healthy controls, the stroke group showed abnormal FC within the motor network (MN), visual network (VN), dorsal attention network (DAN), and executive control network (ECN). Additionally, the FC values of the ipsilesional inferior parietal lobule (IPL) within the ECN were negatively correlated with the Fugl‐Meyer Assessment (FMA) scores (hand + wrist). With respect to inter‐network interactions, the ipsilesional frontoparietal network (FPN) decreased FC with the MN and DAN; the contralesional FPN decreased FC with the ECN, but it increased FC with the default mode network (DMN); and the posterior DMN decreased FC with the VN. In sum, this study demonstrated the coexistence of intra‐ and inter‐network alterations associated with motor‐visual attention and high‐order cognitive control function in chronic stroke, which might provide insights into brain network plasticity following stroke.     

The effect of white matter signal abnormalities on default mode network connectivity in mild cognitive impairment

Regions within the default mode network (DMN) are particularly vulnerable to Alzheimer's disease pathology and mechanisms of DMN disruption in mild cognitive impairment (MCI) are still unclear. White matter lesions are presumed to be mechanistically linked to vascular dysfunction whereas cortical atrophy may be related to neurodegeneration. We examined associations between DMN seed‐based connectivity, white matter lesion load, and cortical atrophy in MCI and cognitively healthy controls. MCI showed decreased functional connectivity (FC) between the precuneus‐seed and bilateral lateral temporal cortex (LTC), medial prefrontal cortex (mPFC), posterior cingulate cortex, and inferior parietal lobe compared to those with controls. When controlling for white matter lesion volume, DMN connectivity differences between groups were diminished within bilateral LTC, although were significantly increased in the mPFC explained by significant regional associations between white matter lesion volume and DMN connectivity only in the MCI group. When controlling for cortical thickness, DMN FC was similarly decreased across both groups. These findings suggest that white matter lesions and cortical atrophy are differentially associated with alterations in FC patterns in MCI. Associations between white matter lesions and DMN connectivity in MCI further support at least a partial but important vascular contribution to age‐associated neural and cognitive impairment.     

Cerebellar Neural Circuits Involving Executive Control Network Predict Response to Group Cognitive Behavior Therapy in Social Anxiety Disorder

Some intrinsic connectivity networks including the default mode network (DMN) and executive control network (ECN) may underlie social anxiety disorder (SAD). Although the cerebellum has been implicated in the pathophysiology of SAD and several networks relevant to higher-order cognition, it remains unknown whether cerebellar areas involved in DMN and ECN exhibit altered resting-state functional connectivity (rsFC) with cortical networks in SAD. Forty-six patients with SAD and 64 healthy controls (HC) were included and submitted to the baseline resting-state functional magnetic resonance imaging (fMRI). Seventeen SAD patients who completed post-treatment clinical assessments were included after group cognitive behavior therapy (CBT). RsFC of three cerebellar subregions in both groups was assessed respectively in a voxel-wise way, and these rsFC maps were compared by two-sample t tests between groups. Whole-brain voxel-wise regression was performed to examine whether cerebellar connectivity networks can predict response to CBT. Lower rsFC circuits of cerebellar subregions compared with HC at baseline (p < 0.05, corrected by false discovery rate) were revealed. The left Crus I rsFC with dorsal medial prefrontal cortex was negatively correlated with symptom severity. The clinical assessments in SAD patients were significantly decreased after CBT. Higher pretreatment cerebellar rsFC with angular gyrus and dorsal lateral frontal cortex corresponded with greater symptom improvement following CBT. Cerebellar rsFC circuits involving DMN and ECN are possible neuropathologic mechanisms of SAD. Stronger pretreatment cerebellar rsFC circuits involving ECN suggest potential neural markers to predict CBT response.     

Network-level dysconnectivity in patients with nasopharyngeal carcinoma (NPC) early post-radiotherapy: longitudinal resting state fMRI study

In this study, we seek to longitudinally investigate the network-level functional connectivity (FC) alternations and its association with irradiation dose and cognition changes in the early stage post radiotherapy (RT) in nasopharyngeal carcinoma (NPC) patients. We performed independent component analysis (ICA) of resting state blood oxygen level-dependent functional magnetic resonance imaging (BOLD-fMRI) from 39 newly diagnosed NPC patients before receiving treatment (baseline), and 3 months post-RT. the default mode network (DMN), salience network (SN), and executive control network (ECN) were extracted with well-validated software (GIFT). Inter-network connectivity was assessed using the functional network connectivity (FNC) toolbox. The inter- and intra-network FC was compared between time points, and the z value of FC alternation was correlated with the RT dose value and cognitive changes. Compared with baseline, the FC of the left anterior cingulate cortex (ACC) within the DMN, and the right insular within the SN, significantly reduced 3 months post-RT, with greater effects at higher doses in the right insular. Bilateral ECN FC was also significantly lower 3 months post-RT compared to the baseline. Chemotherapy was not associated with inter- and intra- network FC change. We found intra- and inter-network FC disruption in NPC patients 3 months post-RT, with the right insular showing a dose-dependent effect. Thus, this network-level FC may serve as a potential biomarker of the RT-induced brain functional impairments, and provide valuable targets for further functional recovery treatment.     

Disrupted topological organization of resting‐state functional brain networks in cerebral small vessel disease

We aimed to investigate alterations in functional brain networks and assess the relationship between functional impairment and topological network changes in cerebral small vessel disease (CSVD) patients with and without cerebral microbleeds (CMBs). We constructed individual whole‐brain, region of interest (ROI) level functional connectivity (FC) networks for 24 CSVD patients with CMBs (CSVD‐c), 42 CSVD patients without CMBs (CSVD‐n), and 36 healthy controls (HCs). Then, we used graph theory analysis to investigate the global and nodal topological disruptions between groups and relate network topological alterations to clinical parameters. We found that both the CSVD and control groups showed efficient small‐world organization in FC networks. However, compared to CSVD‐n patients and controls, CSVD‐c patients exhibited a significantly decreased clustering coefficient, global efficiency, and local efficiency and an increased shortest path length, indicating a disrupted balance between local specialization and global integration in FC networks. Although both the CSVD and control groups showed highly similar hub distributions, the CSVD‐c group exhibited significantly altered nodal betweenness centrality (BC), mainly distributed in the default mode network (DMN), attention, and visual functional areas. There were almost no global or regional alterations between CSVD‐n patients and controls. Furthermore, the altered nodal BC of the right anterior/posterior cingulate gyrus and left cuneus were significantly correlated with cognitive parameters in CSVD patients. These results suggest that CSVD patients with and without CMBs had segregated disruptions in the topological organization of the intrinsic functional brain network. This study advances our current understanding of the pathophysiological mechanisms underlying CSVD.