共查询到20条相似文献，搜索用时 15 毫秒
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Xue‐Zhen Xiao Yu‐Hei Shum Troby K.‐Y. Lui Yang Wang Alexandra T.‐C. Cheung Winnie C. W. Chu Sebastiaan F. W. Neggers Sandra S.‐M. Chan Chun‐Yu Tse 《Human brain mapping》2020,41(11):2883-2897
Current theories of automatic or preattentive change detection suggest a regularity or prediction violation mechanism involving functional connectivity between the inferior frontal cortex (IFC) and the superior temporal cortex (STC). By disrupting the IFC function with transcranial magnetic stimulation (TMS) and recording the later STC mismatch response with event‐related optical signal (EROS), previous study demonstrated a causal IFC‐to‐STC functional connection in detecting a pitch or physical change. However, physical change detection can be achieved by memory comparison of the physical features and may not necessarily involve regularity/rule extraction and prediction. The current study investigated the IFC–STC functional connectivity in detecting rule violation (i.e., an abstract change). Frequent standard tone pairs with a constant relative pitch difference, but varying pitches, were presented to establish a pitch interval rule. This abstract rule was violated by deviants with reduced relative pitch intervals. The EROS STC mismatch response to the deviants was abolished by the TMS applied at the IFC 80 ms after deviance onset, but preserved in the spatial (TMS on vertex), auditory (TMS sound), and temporal (200 ms after deviance onset) control conditions. These results demonstrate the IFC–STC connection in preattentive abstract change detection and support the regularity or prediction violation account. 相似文献
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《Brain stimulation》2020,13(5):1467-1475
BackgroundPrefrontal abnormalities in schizophrenia have consistently emerged from resting state and cognitive neuroimaging studies. However, these correlative findings require causal verification via combined imaging/stimulation approaches. To date, no interleaved transcranial magnetic stimulation and functional magnetic resonance imaging study (TMS fMRI) has probed putative prefrontal cortex abnormalities in schizophrenia.Objective/Hypothesis: We hypothesized that subjects with schizophrenia would show significant hyperexcitability at the site of stimulation (BA9) and decreased interhemispheric functional connectivity.MethodsWe enrolled 19 unmedicated subjects with schizophrenia and 22 controls. All subjects underwent brain imaging using a 3T MRI scanner with a SENSE coil. They also underwent a single TMS fMRI session involving motor threshold (rMT) determination, structural imaging, and a parametric TMS fMRI protocol with 10 Hz triplet pulses at 0, 80, 100 and 120% rMT. Scanning involved a surface MR coil optimized for bilateral prefrontal cortex image acquisition.ResultsOf the original 41 enrolled subjects, 8 subjects with schizophrenia and 11 controls met full criteria for final data analyses. At equal TMS intensity, subjects with schizophrenia showed hyperexcitability in left BA9 (p = 0.0157; max z-score = 4.7) and neighboring BA46 (p = 0.019; max z-score = 4.47). Controls showed more contralateral functional connectivity between left BA9 and right BA9 through increased activation in right BA9 (p = 0.02; max z-score = 3.4). GM density in subjects with schizophrenia positively correlated with normalized prefrontal to motor cortex ratio of the corresponding distance from skull to cortex ratio (S-BA9/S-MC) (r = 0.83, p = 0.004).ConclusionsSubjects with schizophrenia showed hyperexcitability in left BA9 and impaired interhemispheric functional connectivity compared to controls. Interleaved TMS fMRI is a promising tool to investigate prefrontal dysfunction in schizophrenia. 相似文献
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O'Shea J Taylor PC Rushworth MF 《Cortex; a journal devoted to the study of the nervous system and behavior》2008,44(5):598-608
We review three ways in which transcranial magnetic stimulation (TMS) has been used to investigate causal interactions between different brain areas: (1) combined with functional imaging; (2) combined with EEG; and (3) applied successively over two brain areas. We discuss the theoretical advantages of each technique, illustrated by examples from the literature, and highlight the potential of these approaches to provide novel insights into the neural bases of action control. 相似文献
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《Brain stimulation》2022,15(1):63-72
BackgroundThe efficacy of repetitive transcranial magnetic stimulation (rTMS) for depression may vary depending on the subregion stimulated within the dorsolateral prefrontal cortex (DLPFC). Clinical TMS typically uses scalp-based landmarks for DLPFC targeting, rather than individualized MRI guidance.ObjectiveIn rTMS patients, determine the brain systems targeted by multiple DLPFC stimulation rules by computing several surrogate measures: underlying brain targets labeled with connectivity-based atlases, subgenual cingulate anticorrelation strength, and functionally connected networks.MethodsForty-nine patients in a randomized controlled trial of rTMS therapy for treatment resistant major depression underwent structural and functional MRI. DLPFC rules were applied virtually using MR-image guidance. Underlying cortical regions were labeled, and connectivity with the subgenual cingulate and whole-brain computed.ResultsScalp-targeting rules applied post hoc to these MRIs that adjusted for head size, including Beam F3, were comparably precise, successful in directly targeting classical DLPFC and frontal networks, and anticorrelated with the subgenual cingulate. In contrast, all rules involving fixed distances introduced variability in regions and networks targeted. The 5 cm rule targeted a transitional DLPFC region with a different connectivity profile from the adjusted rules. Seed-based connectivity analyses identified multiple regions, such as posterior cingulate and inferior parietal lobe, that warrant further study in order to understand their potential contribution to clinical response.ConclusionEEG-based rules consistently targeted DLPFC brain regions with resting-state fMRI features known to be associated with depression response. These results provide a bridge from lab to clinic by enabling clinicians to relate scalp-targeting rules to functionally connected brain systems. 相似文献
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《Brain stimulation》2020,13(3):765-773
BackgroundIn healthy subjects (HS), transcranial magnetic stimulation (TMS) demonstrated an increase in motor-evoked potential (MEP) amplitudes during specific linguistic tasks. This finding indicates functional connections between speech-related cortical areas and the dominant primary motor cortex (M1).ObjectiveTo investigate M1 function with TMS and the speech-related cortical network with neuroimaging measures in frontotemporal dementia (FTD), including the non-fluent variant of primary progressive aphasia (nfv-PPA) and the behavioral variant of FTD (bv-FTD).MethodsM1 excitability changes during specific linguistc tasks were examined using TMS in 24 patients (15 with nfv-PPA and 9 with bv-FTD) and in 18 age-matched HS. In the same patients neuroimaging was used to assess changes in specific white matter (WM) bundles and grey matter (GM) regions involved in language processing, with diffusion tensor imaging (DTI) and voxel-based morphometry (VBM).ResultsDuring the linguistic task, M1 excitability increased in HS, whereas in FTD patients it did not. M1 excitability changes were comparable in nfv-PPA and bv-FTD. DTI revealed decreased fractional anisotropy in the superior and inferior longitudinal and uncinate fasciculi. Moreover, VBM disclosed GM volume loss in the left frontal operculum though not in the parietal operculum or precentral gyrus. Furthermore, WM and GM changes were comparable in nfv-PPA and bv-FTD. There was no correlation between neurophysiological and neuroimaging changes in FTD. Atrophy in the left frontal operculum correlated with linguistic dysfunction, assessed by semantic and phonemic fluency tests.ConclusionWe provide converging neurophysiological and neuroimaging evidence of abnormal speech-related cortical network activation in FTD. 相似文献
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Cognitive control, the ability to use goal-directed information to guide behaviour, is impaired in schizophrenia, and mainly related to dysfunctions within the fronto-posterior brain network. However, cognitive control is a broad cognitive function encompassing distinct sub-processes that, until now, studies have failed to separate and relate to specific brain regions. The goal of this preliminary fMRI study is to investigate the functional specialization of posterior brain regions, and their functional interaction with lateral prefrontal cortex (LPFC) regions, in schizophrenia. Fourteen healthy participants and 15 matched schizophrenic patients participated in this fMRI study. We used a task paradigm that differentiates two cognitive control sub-processes according to the temporal framing of information, namely the control of immediate context (present cues) vs. temporal episode (past instructions). We found that areas activated during contextual and episodic controls were in dorsal posterior regions and that activations did not significantly differ between schizophrenic patients and healthy participants. However, while processing contextual signals, patients with schizophrenia failed to show decreased connectivity between caudal LPFC and areas located in ventral posterior regions. The absence of group difference in the functional specialization of posterior regions is difficult to interpret due to our small sample size. One interpretation for our connectivity results is that patients present an inefficient extinction of posterior regions involved in attention shifting by prefrontal areas involved in the top-down control of contextual signals. Further studies with larger sample sizes will be needed to ascertain those observations. 相似文献
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BackgroundCervical dystonia (CD) is the most common form of focal dystonia with involuntary movements and postures of the head. The pathogenesis and neural mechanisms underlying CD have not been fully elucidated.MethodsTwenty-seven newly drug-naïve patients with CD and 21 healthy controls (HCs) were recruited with clinical assessment and resting-state functional magnetic resonance imaging (rs-fMRI) scanning. Severity of CD was measured by Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) and Tsui scores. Whole-brain voxel-wise intrinsic connectivity (IC) and seed-based functional connectivity (FC) analyses were performed for detection of changes in the CD group relative to HCs, controlling for age, gender, and global time series correlation, followed by correlation analyses of IC, seed-based FC and clinically relevant features, respectively.ResultsIn comparison with HCs, CD patients showed significantly increased IC measurement in the anterior part of the left supramarginal gyrus and extended to the inferior left postcentral gyrus (AL-SMG/IL-PCG). With this cluster as a seed, decreased FC was found in the right precentral and postcentral gyrus. Moreover, the regional IC value in the AL-SMG/IL-PCG was significantly positively correlated with TWSTRS-1 (severity) score, and significantly negatively correlated with the associated seed-based FC strength.ConclusionsOur results showed signs of both hyper- and hypo-connectivity in bilateral regions of the sensorimotor network related to CD. The imbalance of functional connectivity (both hyper- and hypo-) may hint both overloading and disrupted somatosensory or sensorimotor integration dysfunction within the sensorimotor network underlying the pathophysiology of CD, thus providing a network target for future therapies. 相似文献
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Yolande A.L. Pijnenburg Rob L.M. Strijers Yolande vd Made Wiesje M. van der Flier Philip Scheltens Cornelis J. Stam 《Clinical neurophysiology》2008,119(8):1732-1738
OBJECTIVE: To investigate the presence of EEG abnormalities in frontotemporal lobar degeneration (FTLD) in comparison with Alzheimer's disease (AD) and non-demented individuals with subjective memory complaints (SMC), using an elaborated visual EEG rating scale; furthermore, to investigate whether assessment of resting-state functional connectivity of the EEG is superior to visual evaluation in distinguishing between FTLD, AD and non-demented controls. METHODS: EEGs of 15 patients with FTLD, 20 with AD and 23 individuals with SMC were visually compared using the Grand Total EEG (GTE) score. The synchronization likelihood (SL) as a measure of functional connectivity between different EEG channels was calculated for the 0.5-4Hz, 4-8Hz, 8-10Hz, 10-13Hz, 13-30Hz and 30-45Hz frequency bands. Patients had mild to moderate dementia. RESULTS: In AD, as expected, the GTE revealed significant differences from FTLD and SMC, indicating more EEG slowing and loss of reactivity. Patients with FTLD, however, could not be discriminated from individuals with SMC by the GTE score. Analysis of resting-state functional connectivity showed decreased SL in AD compared to both FTLD and SMC in the lower and higher alpha frequency band and decreased SL in AD compared to SMC in the beta frequency band, whereas no differences between FTLD and AD or SMC were found. CONCLUSIONS: In patients with mild to moderate FTLD both the visually rated EEG and EEG measures of resting-state functional connectivity are normal. SIGNIFICANCE: Although widespread neuronal degeneration takes place in frontotemporal lobar degeneration, this is not reflected in the EEG during the mild to moderate stages of the disease. An abnormal EEG in a mildly demented subject favours a diagnosis of AD. 相似文献
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The gut microbiome appears to play an important role in human health and disease. However, only little is known about how variability in the gut microbiome contributes to individual differences during early and sensitive stages of brain and behavioral development. The current study examined the link between gut microbiome, brain, and behavior in newborn infants (N = 63; M [age] = 25 days). Infant gut microbiome diversity was measured from stool samples using metagenomic sequencing, infant functional brain network connectivity was assessed using a resting state functional near infrared spectroscopy (rs-fNIRS) procedure, and infant behavioral temperament was assessed using parental report. Our results show that gut microbiota composition is linked to individual variability in brain network connectivity, which in turn mediated individual differences in behavioral temperament, specifically negative emotionality, among infants. Furthermore, virulence factors, possibly indexing pathogenic activity, were associated with differences in brain network connectivity linked to negative emotionality. These findings provide novel insights into the early developmental origins of the gut microbiome-brain axis and its association with variability in important behavioral traits. This suggests that the gut microbiome is an important biological factor to consider when studying human development and health. 相似文献
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Previous studies with intracranial recordings suggested that a more random spatial structure of functional brain networks could be related to seizure generation. Here, we studied whether similar network changes in weighted and unweighted networks can be found in generalized absence seizures recorded with surface EEG. We retrospectively selected EEG recordings of eleven children with absence seizures. The functional neural networks were characterized by calculating both coherence and synchronization likelihood (SL) between 21 EEG signals that were either broad band filtered (1-48 Hz) or filtered in different frequency bands. From both weighted and unweighted networks the clustering coefficient (C) and path length (L) were computed and compared to 500 random networks. We compared the ictal with the pre-ictal network structure. During absence seizures there was an increase of synchronization in all frequency bands, seen most clearly in the SL-based networks, and the functional network topology changed towards a more ordered pattern, with an increase of C/C-s and L/L-s. This study supports the hypothesis of functional neural network changes during absence seizures. The network became more regularized in weighted and unweighted analyses, when compared to the more randomized pre-ictal network configuration. 相似文献
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Mitsouko van Assche Elisabeth Dirren Alexia Bourgeois Andreas Kleinschmidt Jonas Richiardi Emmanuel Carrera 《Journal of cerebral blood flow and metabolism》2021,41(9):2174
After stroke restricted to the primary motor cortex (M1), it is uncertain whether network reorganization associated with recovery involves the periinfarct or more remote regions. We studied 16 patients with focal M1 stroke and hand paresis. Motor function and resting-state MRI functional connectivity (FC) were assessed at three time points: acute (<10 days), early subacute (3 weeks), and late subacute (3 months). FC correlates of recovery were investigated at three spatial scales, (i) ipsilesional non-infarcted M1, (ii) core motor network (M1, premotor cortex (PMC), supplementary motor area (SMA), and primary somatosensory cortex), and (iii) extended motor network including all regions structurally connected to the upper limb representation of M1. Hand dexterity was impaired only in the acute phase (P = 0.036). At a small spatial scale, clinical recovery was more frequently associated with connections involving ipsilesional non-infarcted M1 (Odds Ratio = 6.29; P = 0.036). At a larger scale, recovery correlated with increased FC strength in the core network compared to the extended motor network (rho = 0.71;P = 0.006). These results suggest that FC changes associated with motor improvement involve the perilesional M1 and do not extend beyond the core motor network. Core motor regions, and more specifically ipsilesional non-infarcted M1, could hence become primary targets for restorative therapies. 相似文献
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Simon W. Davis Bruce Luber David L.K. Murphy Sarah H. Lisanby Roberto Cabeza 《Human brain mapping》2017,38(12):5987-6004
A growing literature has focused on the brain's ability to augment processing in local regions by recruiting distant communities of neurons in response to neural decline or insult. In particular, both younger and older adult populations recruit bilateral prefrontal cortex (PFC) as a means of compensating for increasing neural effort to maintain successful cognitive function. However, it remains unclear how local changes in neural activity affect the recruitment of this adaptive mechanism. To address this problem, we combined graph theoretical measures from functional MRI with diffusion weighted imaging and repetitive transcranial magnetic stimulation (rTMS) to resolve a central hypothesis: how do aged brains flexibly adapt to local changes in cortical activity? Specifically, we applied neuromodulation to increase or decrease local activity in a cortical region supporting successful memory encoding (left dorsolateral PFC or DLPFC) using 5 or 1 Hz rTMS, respectively. We then assessed a region's local within‐module degree, or the distributed between‐module degree (BMD) between distant cortical communities. We predicted that (1) local stimulation‐related deficits may be counteracted by boosting BMD between bilateral PFC, and that this effect should be (2) positively correlated with structural connectivity. Both predictions were confirmed; 5 Hz rTMS increased local success‐related activity and local increases in PFC connectivity, while 1 Hz rTMS decreases local activity and triggered a more distributed pattern of bilateral PFC connectivity to compensate for this local inhibitory effect. These results provide an integrated, causal explanation for the network interactions associated with successful memory encoding in older adults. Hum Brain Mapp 38:5987–6004, 2017 . © 2017 Wiley Periodicals, Inc. 相似文献
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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 cognitiveimpairment,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 frontoparietalnetwork,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。 相似文献
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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 cognitiveimpairment,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 frontoparietalnetwork,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。 相似文献
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目的基于图论的分析方法了解难治性癫痫患者脑功能网络介数属性变化,探讨介数异常脑区间功能连接改变的意义。方法采集难治性癫痫患者及健康被试RS-f MRI数据后,通过Gretna中Network Analysis模块预处理并计算出各脑区的介数值,经统计检验找出介数值有差异脑区;运用REST软件将上述脑区作为ROI两两之间做功能连接,经统计检验后找出脑区间差异的连接。结果与对照组相比,癫痫组介数值升高的脑区有右侧额下回三角部、右侧嗅皮质;介数值下降的脑区有右侧额上回背外侧、左侧额上回眶部、左侧前扣带回、右侧颞上回、右侧颞下回;与健康被试相比,额下回三角部与颞上回之间的连接降低。结论难治性癫痫患者脑功能网络介数属性及异常脑区间的功能连接改变,引起脑区间信息交流的障碍,可能导致癫痫患者认知功能的损伤。 相似文献
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Language development and the capacity for communication in infants are predominantly supported by their mothers, beginning when infants are still in utero. Although a mother’s speech should thus have a significant impact on her neonate’s brain, neurocognitive evidence for this hypothesis remains elusive. The present study examined 37 neonates using near-infrared spectroscopy and observed the interactions between multiple cortical regions while neonates heard speech spoken by their mothers or by strangers. We analyzed the functional connectivity between regions whose response-activation patterns differed between the two types of speakers. We found that when hearing their mothers’ speech, functional connectivity was enhanced in both the neonatal left and right frontotemporal networks. On the left it was enhanced between the inferior/middle frontal gyrus and the temporal cortex, while on the right it was enhanced between the frontal pole and temporal cortex. In particular, the frontal pole was more strongly connected to the left supramarginal area when hearing speech from mothers. These enhanced frontotemporal networks connect areas that are associated with language (left) and voice processing (right) at later stages of development. We suggest that these roles are initially fostered by maternal speech. 相似文献
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Altered cerebellar‐cerebral functional connectivity in benign adult familial myoclonic epilepsy 
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下载免费PDF全文 Lili Long Ling‐Li Zeng Yanmin Song Hui Shen Peng Fang Linlin Zhang Lin Xu Jian Gong Yun‐Ci Zhang Yong Zhang Pinting Zhou Sha Huang Si Chen Yuanyuan Xie Dewen Hu Bo Xiao 《Epilepsia》2016,57(6):941-948
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As a study method of resting state network (RSN), resting state functional MRI (rfMRI) can be applied to detect low frequency fluctuate (LFF) in various cerebral areas based on resting state blood oxygen level dependence (BOLD) signals; and it is easier and more consistent than task-related fMRI. The development, features and methods of rfMRI as well as the application in epilepsy were reviewed in this article. 相似文献