New resting-state fMRI related studies at PubMed

Individual brain regulation as learned via neurofeedback is related to affective changes in adolescents with autism spectrum disorder

Thu, 01/12/2023 - 11:00

Child Adolesc Psychiatry Ment Health. 2023 Jan 12;17(1):6. doi: 10.1186/s13034-022-00549-9.


BACKGROUND: Emotions often play a role in neurofeedback (NF) regulation strategies. However, investigations of the relationship between the induced neuronal changes and improvements in affective domains are scarce in electroencephalography-based studies. Thus, we extended the findings of the first study on slow cortical potential (SCP) NF in autism spectrum disorder (ASD) by linking affective changes to whole-brain activity during rest and regulation.

METHODS: Forty-one male adolescents with ASD were scanned twice at rest using functional magnetic resonance imaging. Between scans, half underwent NF training, whereas the other half received treatment as usual. Furthermore, parents reported on their child's affective characteristics at each measurement. The NF group had to alternatingly produce negative and positive SCP shifts during training and was additionally scanned using functional magnetic resonance imaging while applying their developed regulation strategies.

RESULTS: No significant treatment group-by-time interactions in affective or resting-state measures were found. However, we found increases of resting activity in the anterior cingulate cortex and right inferior temporal gyrus as well as improvements in affective characteristics over both groups. Activation corresponding to SCP differentiation in these regions correlated with the affective improvements. A further correlation was found for Rolandic operculum activation corresponding to positive SCP shifts. There were no significant correlations with the respective achieved SCP regulation during NF training.

CONCLUSION: SCP NF in ASD did not lead to superior improvements in neuronal or affective functioning compared to treatment as usual. However, the affective changes might be related to the individual strategies and their corresponding activation patterns as indicated by significant correlations on the whole-brain level. Trial registration This clinical trial was registered at (DRKS00012339) on 20th April, 2017.

PMID:36635760 | DOI:10.1186/s13034-022-00549-9

Predicting executive functioning from functional brain connectivity: network specificity and age effects

Thu, 01/12/2023 - 11:00

Cereb Cortex. 2023 Jan 12:bhac520. doi: 10.1093/cercor/bhac520. Online ahead of print.


Healthy aging is associated with altered executive functioning (EF). Earlier studies found age-related differences in EF performance to be partially accounted for by changes in resting-state functional connectivity (RSFC) within brain networks associated with EF. However, it remains unclear which role RSFC in EF-associated networks plays as a marker for individual differences in EF performance. Here, we investigated to what degree individual abilities across 3 different EF tasks can be predicted from RSFC within EF-related, perceptuo-motor, whole-brain, and random networks separately in young and old adults. Specifically, we were interested if (i) young and old adults differ in predictability depending on network or EF demand level (high vs. low), (ii) an EF-related network outperforms EF-unspecific networks when predicting EF abilities, and (iii) this pattern changes with demand level. Both our uni- and multivariate analysis frameworks analyzing interactions between age × demand level × networks revealed overall low prediction accuracies and a general lack of specificity regarding neurobiological networks for predicting EF abilities. This questions the idea of finding markers for individual EF performance in RSFC patterns and calls for future research replicating the current approach in different task states, brain modalities, different, larger samples, and with more comprehensive behavioral measures.

PMID:36635227 | DOI:10.1093/cercor/bhac520

Functional connectivity between dorsal attention and default mode networks mediates subjective sleep duration and depression in young females

Thu, 01/12/2023 - 11:00

J Affect Disord. 2023 Jan 9:S0165-0327(23)00033-2. doi: 10.1016/j.jad.2023.01.023. Online ahead of print.


BACKGROUND: Depression prevails throughout the world. Young females are more likely to suffer from depression because of lack of sleep.

METHODS: We recruited 405 young female participants to assess their subjective sleep duration and self-rating depression. The resting-state magnetic resonance imaging (rs-fMRI) data were collected to identify the brain regions related to sleep duration and depression, and a mediating model was established among sleep duration, depression and functional connectivity (FC) of rs-fMRI.

RESULTS: Correlation analysis indicated that subjective sleep duration was negatively associated with self-rating depression in young females (r = -0.22, p < .001). The network connectivity between dorsal attention network (DAN) and default mode network (DMN) positively correlated with self-rating depression (r = 0.13, p < .05), and negatively correlated with subjective sleep duration (r = -0.14, p < .01). Furthermore, the mediation analysis revealed that the FC of DAN-DMN significantly mediated the effect of sleep duration on depression.

LIMITATIONS: The study was a cross-section design and the sleep duration of the participants was subjectively reported. Future studies should consider to track the participants longitudinally and to measure the objective sleep duration by actigraph or polysomnography.

CONCLUSIONS: The participants with less sleep duration are more prone to develop depression feelings. The FC of DAN-DMN mediated the effect of sleep duration on depression. Thus, the FC of DAN-DMN could be consider as a neural target to relieve depression by increasing sleep duration in young females.

PMID:36634855 | DOI:10.1016/j.jad.2023.01.023

Brain network study of attentional cognitive impairment in children with bronchial asthma

Thu, 01/12/2023 - 11:00

Int J Dev Neurosci. 2023 Jan 12. doi: 10.1002/jdn.10250. Online ahead of print.


Bronchial asthma often causes cognitive impairment, especially attentional deficit, which has a serious impact on children's learning. This study aims to provide objective indicators for the evaluation of attention in asthma children. Thirty-one asthmatic and typically developing children (TDC) were tested by resting-state functional magnetic resonance imaging (rs-fMRI). Brain network-based methods of degree centricity and voxel-mirrored homotopic connectivity (VMHC) methods were used in the study. Compared with the TDC group, asthmatic children had lower DC values in the right superior frontal gyrus (after FDR correction, P<0.05). Meanwhile, VMHC values of bilateral superior frontal gyrus and bilateral superior parietal lobule in asthmatic children were lower than those in TDC group (after FDR correction, P<0.05). There was significant correlation between the correct percentage of CPT and DC value in right superior frontal gyrus, VMHC value in right superior frontal gyrus and right superior parietal lobule. In this study, impaired superior frontal gyrus and parietal lobe function are associated with attentional deficit in asthmatic children, and these brain regions are key brain regions in attention-related networks.

PMID:36633998 | DOI:10.1002/jdn.10250

BrainTGL: A dynamic graph representation learning model for brain network analysis

Wed, 01/11/2023 - 11:00

Comput Biol Med. 2023 Jan 6;153:106521. doi: 10.1016/j.compbiomed.2022.106521. Online ahead of print.


Modeling the dynamics characteristics in functional brain networks (FBNs) is important for understanding the functional mechanism of the human brain. However, the current works do not fully consider the potential complex spatial and temporal correlations in human brain. To solve this problem, we propose a temporal graph representation learning framework for brain networks (BrainTGL). The framework involves a temporal graph pooling for eliminating the noisy edges as well as data inconsistency, and a dual temporal graph learning for capturing the spatio-temporal features of the temporal graphs. The proposed method has been evaluated in both tasks of brain disease (ASD, MDD and BD) diagnosis/gender classification (classification task) and subtype identification (clustering task) on the four datasets: Human Connectome Project (HCP), Autism Brain Imaging Data Exchange (ABIDE), NMU-MDD and NMU-BD. A large improvement is achieved for the ASD diagnosis. Specifically, our model outperforms the GroupINN and ST-GCN by an average increase of 4.2% and 8.6% on accuracy, respectively, demonstrating its advantages in comparison to the state-of-the-art methods based on functional connectivity features or learned spatio-temporal features. The results demonstrate that learning the spatial-temporal brain network representation for modeling dynamics characteristics in FBNs can improve the model's performance on both disease diagnosis and subtype identification tasks for multiple disorders. Apart from performance, the improvements of computational efficiency and convergence speed reduce training costs.

PMID:36630830 | DOI:10.1016/j.compbiomed.2022.106521

Developmental and aging resting functional magnetic resonance imaging brain state adaptations in adolescents and adults: A large N (&gt;47K) study

Wed, 01/11/2023 - 11:00

Hum Brain Mapp. 2023 Jan 11. doi: 10.1002/hbm.26200. Online ahead of print.


The brain's functional architecture and organization undergo continual development and modification throughout adolescence. While it is well known that multiple factors govern brain maturation, the constantly evolving patterns of time-resolved functional connectivity are still unclear and understudied. We systematically evaluated over 47,000 youth and adult brains to bridge this gap, highlighting replicable time-resolved developmental and aging functional brain patterns. The largest difference between the two life stages was captured in a brain state that indicated coherent strengthening and modularization of functional coupling within the auditory, visual, and motor subdomains, supplemented by anticorrelation with other subdomains in adults. This distinctive pattern, which we replicated in independent data, was consistently less modular or absent in children and presented a negative association with age in adults, thus indicating an overall inverted U-shaped trajectory. This indicates greater synchrony, strengthening, modularization, and integration of the brain's functional connections beyond adolescence, and gradual decline of this pattern during the healthy aging process. We also found evidence that the developmental changes may also bring along a departure from the canonical static functional connectivity pattern in favor of more efficient and modularized utilization of the vast brain interconnections. State-based statistical summary measures presented robust and significant group differences that also showed significant age-related associations. The findings reported in this article support the idea of gradual developmental and aging brain state adaptation processes in different phases of life and warrant future research via lifespan studies to further authenticate the projected time-resolved brain state trajectories.

PMID:36629328 | DOI:10.1002/hbm.26200

Dissociable salience and default mode network modulation in generalized anxiety disorder: a connectome-wide association study

Tue, 01/10/2023 - 11:00

Cereb Cortex. 2023 Jan 10:bhac509. doi: 10.1093/cercor/bhac509. Online ahead of print.


Generalized anxiety disorder (GAD) is a common anxiety disorder experiencing psychological and somatic symptoms. Here, we explored the link between the individual variation in functional connectome and anxiety symptoms, especially psychological and somatic dimensions, which remains unknown. In a sample of 118 GAD patients and matched 85 healthy controls (HCs), we used multivariate distance-based matrix regression to examine the relationship between resting-state functional connectivity (FC) and the severity of anxiety. We identified multiple hub regions belonging to salience network (SN) and default mode network (DMN) where dysconnectivity associated with anxiety symptoms (P < 0.05, false discovery rate [FDR]-corrected). Follow-up analyses revealed that patient's psychological anxiety was dominated by the hyper-connectivity within DMN, whereas the somatic anxiety could be modulated by hyper-connectivity within SN and DMN. Moreover, hypo-connectivity between SN and DMN were related to both anxiety dimensions. Furthermore, GAD patients showed significant network-level FC changes compared with HCs (P < 0.01, FDR-corrected). Finally, we found the connectivity of DMN could predict the individual psychological symptom in an independent GAD sample. Together, our work emphasizes the potential dissociable roles of SN and DMN in the pathophysiology of GAD's anxiety symptoms, which may be crucial in providing a promising neuroimaging biomarker for novel personalized treatment strategies.

PMID:36627243 | DOI:10.1093/cercor/bhac509

True grit and brain: Trait grit mediates the connection of DLPFC functional connectivity density to posttraumatic growth following COVID-19

Tue, 01/10/2023 - 11:00

J Affect Disord. 2023 Jan 7:S0165-0327(23)00030-7. doi: 10.1016/j.jad.2023.01.022. Online ahead of print.


BACKGROUND: There is increasing interest in identifying factors to predict posttraumatic growth (PTG), a positive psychological response following traumatic events (e.g., the COVID-19 pandemic). Grit, a psychological trait of perseverance and passion to pursue long-term goals, has emerged as a promising predictor for PTG. This study aimed to examine the functional connectivity markers of grit and the potential brain-grit mechanism in predicting PTG.

METHODS: Baseline brain imaging scans and grit scale and other controlling measures were administered in 100 normal young adults before the COVID-19 pandemic, and follow-up PTG measurement was obtained during the period of community-level outbreak. Whole-brain correlation analysis and prediction analysis were used to identify the brain regions whose functional connectivity density (FCD) related to individuals' grit scores. Mediation analyses were performed to explore the mediation relation between FCD, grit and PTG.

RESULTS: Grit was positively related to FCD in the right dorsolateral prefrontal cortex (DLPFC), a core hub implicated in self-regulation and reward-motivation processes. Furthermore, grit mediated the effect of right DLPFC FCD on COVID-related PTG. These results survived controlling for self-control and family socioeconomic status.

LIMITATIONS: Our study is limited by only one-session neuroimaging data and self-reported behavioral measures in a sample of normal adults.

CONCLUSIONS: This study indicates grit and right DLPFC FCD as neuropsychological contributors for the development of PTG. It deepens our understanding of the neural bases of grit, and may have clinical potential to develop targeted brain interventions aimed at improving grit to raise PTG and mental health during the pandemic.

PMID:36627056 | DOI:10.1016/j.jad.2023.01.022

Diagnostic identification of chronic insomnia using ALFF and FC features of resting-state functional MRI and logistic regression approach

Mon, 01/09/2023 - 11:00

Sci Rep. 2023 Jan 9;13(1):406. doi: 10.1038/s41598-022-24837-8.


This study investigated whether the amplitude of low-frequency fluctuation (ALFF) and functional connectivity (FC) features could be used as potentially neurological markers to identify chronic insomnia (CI) using resting-state functional MRI and machine learning method logistic regression (LR). This study included 49 CI patients and 47 healthy controls (HC). Voxel-wise features, including the amplitude of low-frequency fluctuations (ALFF) and functional connectivity (FC), were extracted from resting-state functional magnetic resonance brain images. Then, we divided the data into two independent cohorts for training (44 CI patients and 42 HC patients), and independent validation (5 CI patients and 5 HC patients) by using logistic regression. The model was evaluated using 20 rounds of fivefold cross‑validation for training. In particular, a two-sample t-test (GRF corrected, p-voxel < 0.001, p-cluster < 0.05) was used for feature selection during the model training. Finally, single‑shot testing of the final model was performed on the independent validation cohort. A correlation analysis (Bonferroni correction, p < 0.05/4) was also conducted to determine whether the features contributing to the prediction were correlated with clinical characteristics, including the Insomnia Severity Index (ISI), Pittsburgh sleep quality index (PSQI), self-rating anxiety scale (SAS), and self-rating depression scale (SDS). Results showed that resting-state features had a discrimination accuracy of 86.40%, with a sensitivity of 93.00% and specificity of 79.80%. The area under the curve (AUC) was 0.89 (all [Formula: see text]< 0.001). The ALFF and FC features showed significant differences between the CI patients and HC. The regions contributing to the prediction mainly included the anterior cingulate, prefrontal cortex, orbital part of the frontal lobe, angular gyrus, cingulate gyrus, praecuneus, parietal lobe, temporal gyrus, superior temporal gyrus, and middle temporal gyrus. Furthermore, some specific functional connectivity among related regions was positively correlated with the ISI, and also negatively related to the SDS in correlation analysis. Our current study suggested that ALFF and FC in the regions contributing to diagnostic identification might serve as potential neuromarkers for CI.

PMID:36624131 | DOI:10.1038/s41598-022-24837-8

Subthalamic stimulation modulates motor network in Parkinson's disease: recover, relieve and remodel

Mon, 01/09/2023 - 11:00

Brain. 2023 Jan 10:awad004. doi: 10.1093/brain/awad004. Online ahead of print.


Aberrant dynamic switches between internal brain states are believed to underlie motor dysfunction in Parkinson's disease. Deep brain stimulation of the subthalamic nucleus is a well-established treatment for the motor symptoms of Parkinson's disease, yet it remains poorly understood how subthalamic stimulation modulates the whole-brain intrinsic motor network state dynamics. To investigate this, we acquired resting-state functional magnetic resonance imaging time-series data from 27 medication-free patients with Parkinson's disease (mean age: 64.8 years, standard deviation: 7.6) who had deep brain stimulation electrodes implanted in the subthalamic nucleus, in both on and off stimulation states. Sixteen matched healthy individuals were included as a control group. We adopted a powerful data-driven modeling approach, known as a hidden Markov model, to disclose the emergence of recurring activation patterns of interacting motor regions (whole-brain intrinsic motor network states) via the blood oxygen-level dependent signal detected in the resting-state functional magnetic resonance imaging time-series data from all participants. The estimated hidden Markov model disclosed the dynamics of distinct whole-brain motor network states, including frequency of occurrence, state duration, fractional coverage, and their transition probabilities. Notably, the data-driven decoding of whole-brain intrinsic motor network states revealed that subthalamic stimulation reshaped functional network expression and stabilized state transitions. Moreover, subthalamic stimulation improved motor symptoms by modulating key trajectories of state transition within whole-brain intrinsic motor network states. This modulation mechanism of subthalamic stimulation was manifested in three significant effects: recovery, relieving, and remodeling effects. Significantly, recovery effects correlated with improvements in tremor and posture symptoms induced by subthalamic stimulation (P < 0.05). Furthermore, subthalamic stimulation was found to restore a relatively low level of fluctuation of functional connectivity in all motor regions to a level closer to that of healthy participants. Also, changes in the fluctuation of functional connectivity between motor regions were associated with improvements in tremor and gait symptoms (P < 0.05). These findings fill a gap in our knowledge of the role of subthalamic stimulation at the level of neural activity, revealing the regulatory effects of subthalamic stimulation on whole-brain inherent motor network states in Parkinson's disease. Our results provide mechanistic insight and explanation for how subthalamic stimulation modulates motor symptoms in Parkinson's disease.

PMID:36623929 | DOI:10.1093/brain/awad004

Effect of online tDCS to left somatomotor cortex on neuropsychiatric symptoms among older adults at risk for dementia

Mon, 01/09/2023 - 11:00

Cortex. 2022 Dec 17;159:131-141. doi: 10.1016/j.cortex.2022.10.015. Online ahead of print.


BACKGROUND: Neuropsychiatric symptoms (NPS) in mild cognitive impairment (MCI) cause distress to patients and caregivers, and accelerate progression to dementia. Transcranial direct current stimulation (tDCS) is a promising non-invasive treatment for NPS.

OBJECTIVE/HYPOTHESIS: This pilot study assessed behavioral and neural effects of a 4-week anodal tDCS intervention targeting left sensorimotor cortex (LSMC: left precentral/postcentral gyri) during visual attention (compared to online sham tDCS), in 40 older adults (24 females, mean age = 71) with MCI.

METHODS: A phase 0 double-blinded randomized control trial was conducted. NPS (patient-reported mood symptoms plus a caregiver-reported questionnaire) and fMRI were measured at baseline and immediately post-intervention.

RESULTS: Generalized Estimating Equations found no significant group by time interactions for either NPS measure. However, there was evidence of decreased patient-reported NPS (Wald's χ2 = 3.80, p = .051), decreased LSMC activation during visual attention (Wald's χ2 = 2.93, p = .087), and increased LSMC-amygdala resting-state functional connectivity (rsFC; Wald's χ2 = 3.13, p = .077) in intervention group from pre-to post-intervention. Decrease in LSMC activation (Wald's χ2 = 9.20, p = .002) and increase in LSMC-amygdala rsFC (Wald's χ2 = 4.72, p = .030) related to decreased patient-reported NPS. Increased positive valence across sessions was significantly associated with intervention-related NPS improvement (Wald's χ2 = 22.92, p < .001). There were no findings for caregiver-reported NPS. Effects were stronger for left postcentral compared to left precentral gyrus.

CONCLUSION: We found tentative evidence that tDCS applied to LSMC during visual attention in older adults with MCI improved NPS via changes in LSMC activation and LSMC-amygdala rsFC, suggesting improved emotion regulation. Patient-reported NPS was more sensitive to these changes than caregiver-reports, and effects were strongest for left postcentral gyrus. Follow-up studies should perform precise mechanistic investigation and efficacy testing.

PMID:36623419 | DOI:10.1016/j.cortex.2022.10.015

Correlations between Hippocampus and Cognitive Score in Patients with Carotid Artery Stenosis Based on Resting State Functional Magnetic Resonance Imaging

Mon, 01/09/2023 - 11:00

Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 2022 Dec;44(6):980-989. doi: 10.3881/j.issn.1000-503X.14737.


Objective To investigate the correlations among brain functional connectivity,hippocampal subregion volume and cognitive score in the patients with carotid artery stenosis(CAS)based on resting state functional magnetic resonance imaging.Methods Forty CAS patients treated in the Nanjing Drum Tower Hospital Affiliated to Medical School of Nanjing University from January to December in 2019 and 31 healthy volunteers were enrolled in this study.All the participants underwent cognitive assessment,structural MRI for the measurement of hippocampal volume,and resting state functional magnetic resonance imaging for the examination of brain functional connectivity(FC).We compared the cognitive function,hippocampal subregion volumes,and brain functional connectivity between the two groups and investigated the correlations between the three indicators.Results The CAS patients had lower mini-mental state examination(MMSE)(F=13.346,P=0.001)and Montreal cognitive assessment(MoCA)(F=52.005,P<0.001)scores than the healthy volunteers.Compared with healthy volunteers,CAS patients showed small whole hippocampus(right side:t=2.176,P=0.033;left side:t=2.881,P=0.005;especially on the left side),small hippocampal tail(right side:t=2.394,P=0.019;left side:t=3.158,P=0.002),small hippocampal body(right side:t=2.336,P=0.022;left side:t=3.165,P=0.002),small subiculum(right side:t=2.211,P=0.030;left side:t=2.430;P=0.018),and small molecular layer(right side:t=2.103,P=0.039;left side:t=2.702,P=0.009).The whole hippocampal volume was positively correlated with MoCA and MMSE scores(left MoCA:r=0.289,P=0.015;right MMSE:r=0.249,P=0.038;left MMSE:r=0.316,P=0.008).The volume changes in the subiculum,presubiculum,and left molecular layer were positively correlated with MoCA(right subiculum:r=0.290,P=0.015;left subiculum:r=0.382,P=0.001;right presubiculum:r=0.293,P=0.014;left presubiculum:r=0.440,P<0.001;left molecular layer:r=0.259,P=0.031)and MMSE scores(right subiculum:r=0.278,P=0.020;left subiculum:r=0.419,P<0.001;right presubiculum:r=0.296,P=0.013;left presubiculum:r=0.506,P<0.001;left molecular layer:r=0.298,P=0.012),while the volume changes in the remaining hippocampal subregions were not correlated with cognitive scores(all P>0.05).Compared with healthy volunteers,the CAS patients presented low FC values of the left hippocampus to the occipital lobe and frontal lobe and of right hippocampus to the occipital lobe,temporal lobe,prefrontal lobe,and middle frontal gyrus(Gaussian random field correction,voxel P<0.01,cluster P<0.05).The volume changes of the left whole hippocampus,hippocampal head,and cornu ammonis 1(CA1)were positively correlated with the FC value of right hippocampus to the temporal lobe(left whole hippocampus:r=0.358,P=0.025;right hippocampal head:r=0.325,P=0.044;left hippocampal head:r=0.360,P=0.024;right CA1:r=0.326,P=0.043;left CA1:r=0.341,P=0.034).MoCA and MMSE scores were positively correlated with the FC value of right hippocampus to the frontal lobe(MoCA middle frontal gyrus:r=0.389,P=0.014;MoCA prefrontal lobe:r=0.363,P=0.023;MMSE prefrontal lobe:r=0.321,P=0.046).Conclusions CAS patients have different levels of cognitive impairment.Hippocampal atrophy and a decline in the FC value of hippocampus to the occipital lobe may play a role in cognitive impairment in CAS patients.This discovery lays a foundation for the future research on the mechanism of cognitive dysfunction in CAS patients.

PMID:36621787 | DOI:10.3881/j.issn.1000-503X.14737

A systematic review of the neural correlates of well-being reveals no consistent associations

Mon, 01/09/2023 - 11:00

Neurosci Biobehav Rev. 2023 Jan 5:105036. doi: 10.1016/j.neubiorev.2023.105036. Online ahead of print.


Findings from behavioral and genetic studies indicate a potential role for the involvement of brain structures and brain functioning in well-being. We performed a systematic review on the association between brain structures or brain functioning and well-being, including 56 studies. The 11 electroencephalography (EEG) studies suggest a larger alpha asymmetry (more left than right brain activation) to be related to higher well-being. The 18 Magnetic Resonance Imaging (MRI) studies, 26 resting-state functional MRI studies and two functional near-infrared spectroscopy (fNIRS) studies identified a wide range of brain regions involved in well-being, but replication across studies was scarce, both in direction and strength of the associations. The inconsistency could result from small sample sizes of most studies and a possible wide-spread network of brain regions with small effects involved in well-being. Future directions include well-powered brain-wide association studies and innovative methods to more reliably measure brain activity in daily life.

PMID:36621584 | DOI:10.1016/j.neubiorev.2023.105036

Local structural-functional connectivity decoupling of caudate nucleus in infantile esotropia

Mon, 01/09/2023 - 11:00

Front Neurosci. 2022 Dec 22;16:1098735. doi: 10.3389/fnins.2022.1098735. eCollection 2022.


Abnormal brain structural and functional properties were demonstrated in patients with infantile esotropia (IE). However, few studies have investigated the interaction between structural and functional connectivity (SC-FC) in patients with IE. Structural network was generated with diffusion tensor imaging and functional network was constructed with resting-state functional magnetic resonance imaging for 18 patients with IE as well as 20 age- and gender- matched healthy subjects. The SC-FC coupling for global connectome, short connectome and long connectome were examined in IE patients and compared with those of healthy subjects. A linear mixed effects model was employed to examine the group-age interaction in terms of the coupling metrics. The Pearson correlation between coupling measures and strabismus degree was evaluated in IE patients, on which the regulatory effect of age was also investigated through hierarchical regression analysis. Significantly decreased SC-FC coupling score for short connections was observed in left caudate nucleus (CAU) in IE patients, whereas no brain regions exhibited altered coupling metrics for global connections or long connections. The group-age interaction was also evident in local coupling metrics of left CAU. The age-related regulatory effect on coupling-degree association was distinguishing between brain regions implicated in visual processing and cognition-related brain areas in IE patients. Local SC-FC decoupling in CAU was evident in patients with IE and was initiated in their early postnatal period, possibly interfering the visual cortico-striatal loop and subcortical optokinetic pathway subserving visual processing and nasalward optokinesis during neurodevelopment, which provides new insight into underlying neuropathological mechanism of IE.

PMID:36620443 | PMC:PMC9815444 | DOI:10.3389/fnins.2022.1098735

Preservation of EEG spectral power features during simultaneous EEG-fMRI

Mon, 01/09/2023 - 11:00

Front Neurosci. 2022 Dec 23;16:951321. doi: 10.3389/fnins.2022.951321. eCollection 2022.


INTRODUCTION: Electroencephalographic (EEG) data quality is severely compromised when recorded inside the magnetic resonance (MR) environment. Here we characterized the impact of the ballistocardiographic (BCG) artifact on resting-state EEG spectral properties and compared the effectiveness of seven common BCG correction methods to preserve EEG spectral features. We also assessed if these methods retained posterior alpha power reactivity to an eyes closure-opening (EC-EO) task and compared the results from EEG-informed fMRI analysis using different BCG correction approaches.

METHOD: Electroencephalographic data from 20 healthy young adults were recorded outside the MR environment and during simultaneous fMRI acquisition. The gradient artifact was effectively removed from EEG-fMRI acquisitions using Average Artifact Subtraction (AAS). The BCG artifact was corrected with seven methods: AAS, Optimal Basis Set (OBS), Independent Component Analysis (ICA), OBS followed by ICA, AAS followed by ICA, PROJIC-AAS and PROJIC-OBS. EEG signal preservation was assessed by comparing the spectral power of traditional frequency bands from the corrected rs-EEG-fMRI data with the data recorded outside the scanner. We then assessed the preservation of posterior alpha functional reactivity by computing the ratio between the EC and EO conditions during the EC-EO task. EEG-informed fMRI analysis of the EC-EO task was performed using alpha power-derived BOLD signal predictors obtained from the EEG signals corrected with different methods.

RESULTS: The BCG artifact caused significant distortions (increased absolute power, altered relative power) across all frequency bands. Artifact residuals/signal losses were present after applying all correction methods. The EEG reactivity to the EC-EO task was better preserved with ICA-based correction approaches, particularly when using ICA feature extraction to isolate alpha power fluctuations, which allowed to accurately predict hemodynamic signal fluctuations during the EEG-informed fMRI analysis.

DISCUSSION: Current software solutions for the BCG artifact problem offer limited efficiency to preserve the EEG spectral power properties using this particular EEG setup. The state-of-the-art approaches tested here can be further refined and should be combined with hardware implementations to better preserve EEG signal properties during simultaneous EEG-fMRI. Existing and novel BCG artifact correction methods should be validated by evaluating signal preservation of both ERPs and spontaneous EEG spectral power.

PMID:36620439 | PMC:PMC9816433 | DOI:10.3389/fnins.2022.951321

Responsiveness variability during anaesthesia relates to inherent differences in brain structure and function of the frontoparietal networks

Mon, 01/09/2023 - 11:00

Hum Brain Mapp. 2023 Jan 8. doi: 10.1002/hbm.26199. Online ahead of print.


Anaesthesia combined with functional neuroimaging provides a powerful approach for understanding the brain mechanisms of consciousness. Although propofol is used ubiquitously in clinical interventions that reversibly suppress consciousness, it shows large inter-individual variability, and the brain bases of this variability remain poorly understood. We asked whether three networks key to conscious cognition-the dorsal attention (DAN), executive control (ECN), and default mode (DMN)-underlie responsiveness variability under anaesthesia. Healthy participants (N = 17) were moderately anaesthetized during narrative understanding and resting-state conditions inside the Magnetic Resonance Imaging scanner. A target detection task measured behavioural responsiveness. An independent behavioural study (N = 25) qualified the attention demands of narrative understanding. Then, 30% of participants were unaffected in their response times, thus thwarting a key aim of anaesthesia-the suppression of behavioural responsiveness. Individuals with stronger functional connectivity within the DAN and ECN, between them, and to the DMN, and with larger grey matter volume in frontal regions were more resilient to anaesthesia. For the first time, we show that responsiveness variability during propofol anaesthesia relates to inherent differences in brain structure and function of the frontoparietal networks, which can be predicted prior to sedation. Results highlight novel markers for improving awareness monitoring during clinical anaesthesia.

PMID:36617994 | DOI:10.1002/hbm.26199

Influence of the Peripheral Nervous System on Murine Osteoporotic Fracture Healing and Fracture-Induced Hyperalgesia

Sun, 01/08/2023 - 11:00

Int J Mol Sci. 2022 Dec 28;24(1):510. doi: 10.3390/ijms24010510.


Osteoporotic fractures are often linked to persisting chronic pain and poor healing outcomes. Substance P (SP), α-calcitonin gene-related peptide (α-CGRP) and sympathetic neurotransmitters are involved in bone remodeling after trauma and nociceptive processes, e.g., fracture-induced hyperalgesia. We aimed to link sensory and sympathetic signaling to fracture healing and fracture-induced hyperalgesia under osteoporotic conditions. Externally stabilized femoral fractures were set 28 days after OVX in wild type (WT), α-CGRP- deficient (α-CGRP -/-), SP-deficient (Tac1-/-) and sympathectomized (SYX) mice. Functional MRI (fMRI) was performed two days before and five and 21 days post fracture, followed by µCT and biomechanical tests. Sympathectomy affected structural bone properties in the fracture callus whereas loss of sensory neurotransmitters affected trabecular structures in contralateral, non-fractured bones. Biomechanical properties were mostly similar in all groups. Both nociceptive and resting-state (RS) fMRI revealed significant baseline differences in functional connectivity (FC) between WT and neurotransmitter-deficient mice. The fracture-induced hyperalgesia modulated central nociception and had robust impact on RS FC in all groups. The changes demonstrated in RS FC in fMRI might potentially be used as a bone traumata-induced biomarker regarding fracture healing under pathophysiological musculoskeletal conditions. The findings are of clinical importance and relevance as they advance our understanding of pain during osteoporotic fracture healing and provide a potential imaging biomarker for fracture-related hyperalgesia and its temporal development. Overall, this may help to reduce the development of chronic pain after fracture thereby improving the treatment of osteoporotic fractures.

PMID:36613952 | DOI:10.3390/ijms24010510

Central Nervous System Involvement in Primary Sjögren's Syndrome: Narrative Review of MRI Findings

Sun, 01/08/2023 - 11:00

Diagnostics (Basel). 2022 Dec 21;13(1):14. doi: 10.3390/diagnostics13010014.


Central nervous system (CNS) involvement is one of the numerous extraglandular manifestations of primary Sjögren's syndrome (pSS). Moreover, neurological complaints precede the sicca symptoms in 25-60% of the cases. We review the magnetic resonance imaging (MRI) lesions typical for pSS, involving the conventional examination, volumetric and morphometric studies, diffusion tensor imaging (DTI) and resting-state fMRI. The most common radiological lesions in pSS are white matter hyperintensities (WMH), scattered alterations hyperlucent on T2 and FLAIR sequences, typically located periventricularly and subcortically. Cortical atrophy and ventricular dilatation can also occur in pSS. Whilst these conditions are thought to be more common in pSS than healthy controls, DTI and resting-state fMRI alterations demonstrate evident microstructural changes in pSS. As pSS is often accompanied by cognitive symptoms, these MRI alterations are expectedly related to them. This relationship is not clearly delineated in conventional MRI studies, but DTI and resting-state fMRI examinations show more convincing correlations. In conclusion, the CNS manifestations of pSS do not follow a certain pattern. As the link between the MRI lesions and clinical manifestations is not well established, more studies involving larger populations should be performed to elucidate the correlations.

PMID:36611306 | DOI:10.3390/diagnostics13010014

Neurochemical and functional reorganization of the cognitive-ear link underlies cognitive impairment in presbycusis

Sat, 01/07/2023 - 11:00

Neuroimage. 2023 Jan 4:119861. doi: 10.1016/j.neuroimage.2023.119861. Online ahead of print.


Recent studies suggest that the interaction between presbycusis and cognitive impairment may be partially explained by the cognitive-ear link. However, the underlying neurophysiological mechanisms remain largely unknown. In this study, we combined magnetic resonance spectroscopy (MRS) and resting-state functional magnetic resonance imaging (fMRI) to investigate auditory gamma-aminobutyric acid (GABA) and glutamate (Glu) levels, intra- and inter-network functional connectivity, and their relationships with auditory and cognitive function in 51 presbycusis patients and 51 well-matched healthy controls. Our results confirmed reorganization of the cognitive-ear link in presbycusis, including decreased auditory GABA and Glu levels and aberrant functional connectivity involving auditory networks (AN) and cognitive-related networks, which were associated with reduced speech perception or cognitive impairment. Moreover, mediation analyses revealed that decreased auditory GABA levels and dysconnectivity between the AN and default mode network (DMN) mediated the association between hearing loss and impaired information processing speed in presbycusis. These findings highlight the importance of AN-DMN dysconnectivity in cognitive-ear link reorganization leading to cognitive impairment, and hearing loss may drive reorganization via decreased auditory GABA levels. Modulation of GABA neurotransmission may lead to new treatment strategies for cognitive impairment in presbycusis patients.

PMID:36610677 | DOI:10.1016/j.neuroimage.2023.119861

Higher betweenness and degree centrality in the frontal and cerebellum cortex of Meige's syndrome patients than hemifacial spasm patients

Fri, 01/06/2023 - 11:00

Neuroreport. 2023 Feb 1;34(2):102-107. doi: 10.1097/WNR.0000000000001865. Epub 2022 Dec 17.


Meige's syndrome and hemifacial spasm (HFS) are two different forms of dystonic movement disorder, but their difference in terms of resting state functional connectivity (rsFC) remains unclear. The present study applied resting state fMRI on the patients and quantified their functional connectivity with graph theoretical measures, including the degree centrality and the betweenness centrality. Fifteen Meige's syndrome patients and 19 HFS patients matched in age and gender were recruited and their MRI data were collected. To analyze the rsFC, we adopted the Anatomical Automatic Labeling (AAL) template, a brain atlas system including 90 regions of interest (ROIs) covering all the brain regions of cerebral cortex. For each participant, the time-course of each ROI was extracted, and the corresponding degree centrality and betweenness centrality of each ROI were computed. These measures were then compared between the Meige's syndrome patients and the HFS patients. Meige's syndrome patients showed higher betweenness centrality and degree centrality of bilateral superior medial frontal cortex, the left cerebellum cortex, etc. than the HFS patients. Our results suggest that the rsFC pattern in Meige's syndrome patients might become more centralized toward the prefrontal and vestibular cerebellar systems, indicating less flexibility in their functional connections. These results preliminarily revealed the characteristic abnormality in the functional connection of Meige's patients and may help to explore better treatment.

PMID:36608166 | DOI:10.1097/WNR.0000000000001865