New resting-state fMRI related studies at PubMed

Amplitude of Low-Frequency Fluctuations and Resting-State Functional Connectivity in Trait Positive Empathy: A Resting-State fMRI Study

Mon, 03/08/2021 - 11:00

Front Psychiatry. 2021 Feb 18;12:604106. doi: 10.3389/fpsyt.2021.604106. eCollection 2021.

ABSTRACT

Positive empathy is the ability to share and understand the positive emotions of others. In recent years, although positive empathy has received more and more attention, trait positive empathy (TPE)-related spontaneous brain activity during the resting state has not been extensively explored. We used the amplitude of low-frequency fluctuations (ALFFs) and resting-state functional connectivity (RSFC) of the resting-state functional magnetic resonance imaging signal to explore TPE-associated brain regions. We found that higher TPE was associated with higher ALFFs in the right insula and lower ALFFs in the right subgenual cingulate (SGC), right dorsomedial prefrontal cortex (dmPFC), and right precuneus. RSFC analyses showed that higher functional connectivity between the right insula and left parahippocampal gyrus, left inferior parietal lobule and left middle temporal gyrus were related to higher TPE. Moreover, the connection between the right dmPFC and the left medial orbitofrontal cortex, left middle occipital gyrus and left posterior cingulate cortex were positively related to TPE. Meanwhile, the strength of functional connectivity between the right SGC and left supplementary motor area was positively associated with TPE. These findings may indicate that TPE is linked to emotional (especially the experience of more positive emotions and better negative emotion regulation) and self-referential processing.

PMID:33679474 | PMC:PMC7930913 | DOI:10.3389/fpsyt.2021.604106

Ongoing Oscillatory Electrophysiological Alterations in Frail Older Adults: A MEG Study

Mon, 03/08/2021 - 11:00

Front Aging Neurosci. 2021 Feb 18;13:609043. doi: 10.3389/fnagi.2021.609043. eCollection 2021.

ABSTRACT

Objective: The role of the central nervous system in the pathophysiology of frailty is controversial. We used magnetoencephalography (MEG) to search for abnormalities in the ongoing oscillatory neural activity of frail individuals without global cognitive impairment. Methods: Fifty four older (≥70 years) and cognitively healthy (Mini-Mental State Examination ≥24) participants were classified as robust (0 criterion, n = 34) or frail (≥ 3 criteria, n = 20) following Fried's phenotype. Memory, language, attention, and executive function were assessed through well-validated neuropsychological tests. Every participant underwent a resting-state MEG and a T1-weighted magnetic resonance imaging scan. We performed MEG power spectral analyses to compare the electrophysiological profiles of frail and robust individuals. We used an ensemble learner to investigate the ability of MEG spectral power to discriminate frail from robust participants. Results: We identified increased relative power in the frail group in the mu (p < 0.05) and sensorimotor (p < 0.05) frequencies across right sensorimotor, posterior parietal, and frontal regions. The ensemble learner discriminated frail from robust participants [area under the curve = 0.73 (95% CI = 0.49-0.98)]. Frail individuals performed significantly worse in the Trail Making Test, Digit Span Test (forward), Rey-Osterrieth Complex Figure, and Semantic Fluency Test. Interpretation: Frail individuals without global cognitive impairment showed ongoing oscillatory alterations within brain regions associated with aspects of motor control, jointly to failures in executive function. Our results suggest that some physical manifestations of frailty might partly arise from failures in central structures relevant to sensorimotor and executive processing.

PMID:33679373 | PMC:PMC7935553 | DOI:10.3389/fnagi.2021.609043

Healthy Aging Alters the Functional Connectivity of Creative Cognition in the Default Mode Network and Cerebellar Network

Mon, 03/08/2021 - 11:00

Front Aging Neurosci. 2021 Feb 18;13:607988. doi: 10.3389/fnagi.2021.607988. eCollection 2021.

ABSTRACT

Creativity is a higher-order neurocognitive process that produces unusual and unique thoughts. Behavioral and neuroimaging studies of younger adults have revealed that creative performance is the product of dynamic and spontaneous processes involving multiple cognitive functions and interactions between large-scale brain networks, including the default mode network (DMN), fronto-parietal executive control network (ECN), and salience network (SN). In this resting-state functional magnetic resonance imaging (rs-fMRI) study, group independent component analysis (group-ICA) and resting state functional connectivity (RSFC) measures were applied to examine whether and how various functional connected networks of the creative brain, particularly the default-executive and cerebro-cerebellar networks, are altered with advancing age. The group-ICA approach identified 11 major brain networks across age groups that reflected age-invariant resting-state networks. Compared with older adults, younger adults exhibited more specific and widespread dorsal network and sensorimotor network connectivity within and between the DMN, fronto-parietal ECN, and visual, auditory, and cerebellar networks associated with creativity. This outcome suggests age-specific changes in the functional connected network, particularly in the default-executive and cerebro-cerebellar networks. Our connectivity data further elucidate the critical roles of the cerebellum and cerebro-cerebellar connectivity in creativity in older adults. Furthermore, our findings provide evidence supporting the default-executive coupling hypothesis of aging and novel insights into the interactions of cerebro-cerebellar networks with creative cognition in older adults, which suggest alterations in the cognitive processes of the creative aging brain.

PMID:33679372 | PMC:PMC7929978 | DOI:10.3389/fnagi.2021.607988

Constructing Brain Connectivity Model Using Causal Network Reconstruction Approach

Mon, 03/08/2021 - 11:00

Front Neuroinform. 2021 Feb 18;15:619557. doi: 10.3389/fninf.2021.619557. eCollection 2021.

ABSTRACT

Studying brain function is a challenging task. In the past, we could only study brain anatomical structures post-mortem, or infer brain functions from clinical data of patients with a brain injury. Nowadays technology, such as functional magnetic resonance imaging (fMRI), enable non-invasive brain activity observation. Several approaches have been proposed to interpret brain activity data. The brain connectivity model is a graphical tool that represents the interaction between brain regions, during certain states. It depicts how a brain region cause changes to other parts of the brain, which can be implied as information flow. This model can be used to help interpret how the brain works. There are several mathematical frameworks that can be used to infer the connectivity model from brain activity signals. Granger causality is one such approach and is one of the first that has been applied to brain activity data. However, due to the concept of the framework, such as the use of pairwise correlation, combined with the limitation of brain activity data such as low temporal resolution in case of fMRI signal, makes the interpretation of the connectivity difficult. We therefore propose the application of the Tigramite causal discovery framework on fMRI data. The Tigramite framework uses measures such as causal effect to analyze causal relations in the system. This enables the framework to identify both direct and indirect pathways or connectivities. In this paper, we applied the framework to the Human Connectome Project motor task-fMRI dataset. We then present the results and discuss how the framework improves interpretability of the connectivity model. We hope that this framework will help us understand more complex brain functions such as memory, consciousness, or the resting-state of the brain, in the future.

PMID:33679363 | PMC:PMC7930222 | DOI:10.3389/fninf.2021.619557

Morphometric and Functional Brain Connectivity Differentiates Chess Masters From Amateur Players

Mon, 03/08/2021 - 11:00

Front Neurosci. 2021 Feb 19;15:629478. doi: 10.3389/fnins.2021.629478. eCollection 2021.

ABSTRACT

A common task in brain image analysis includes diagnosis of a certain medical condition wherein groups of healthy controls and diseased subjects are analyzed and compared. On the other hand, for two groups of healthy participants with different proficiency in a certain skill, a distinctive analysis of the brain function remains a challenging problem. In this study, we develop new computational tools to explore the functional and anatomical differences that could exist between the brain of healthy individuals identified on the basis of different levels of task experience/proficiency. Toward this end, we look at a dataset of amateur and professional chess players, where we utilize resting-state functional magnetic resonance images to generate functional connectivity (FC) information. In addition, we utilize T1-weighted magnetic resonance imaging to estimate morphometric connectivity (MC) information. We combine functional and anatomical features into a new connectivity matrix, which we term as the functional morphometric similarity connectome (FMSC). Since, both the FC and MC information is susceptible to redundancy, the size of this information is reduced using statistical feature selection. We employ off-the-shelf machine learning classifier, support vector machine, for both single- and multi-modality classifications. From our experiments, we establish that the saliency and ventral attention network of the brain is functionally and anatomically different between two groups of healthy subjects (chess players). We argue that, since chess involves many aspects of higher order cognition such as systematic thinking and spatial reasoning and the identified network is task-positive to cognition tasks requiring a response, our results are valid and supporting the feasibility of the proposed computational pipeline. Moreover, we quantitatively validate an existing neuroscience hypothesis that learning a certain skill could cause a change in the brain (functional connectivity and anatomy) and this can be tested via our novel FMSC algorithm.

PMID:33679310 | PMC:PMC7933502 | DOI:10.3389/fnins.2021.629478

Electrophysiological signatures of resting state networks predict cognitive deficits in stroke

Sun, 03/07/2021 - 11:00

Cortex. 2021 Feb 12;138:59-71. doi: 10.1016/j.cortex.2021.01.019. Online ahead of print.

ABSTRACT

Localized damage to different brain regions can cause specific cognitive deficits. However, stroke lesions can also induce modifications in the functional connectivity of intrinsic brain networks, which could be responsible for the behavioral impairment. Though resting state networks (RSNs) are typically mapped using fMRI, it has been recently shown that they can also be detected from high-density EEG. We build on a state-of-the-art approach to extract RSNs from 64-channels EEG activity in a group of right stroke patients and to identify neural predictors of their cognitive performance. Fourteen RSNs previously found in fMRI and high-density EEG studies on healthy participants were successfully reconstructed from our patients' EEG recordings. We then correlated EEG-RSNs functional connectivity with neuropsychological scores, first considering a wide frequency band (1-80 Hz) and then specific frequency ranges in order to examine the association between each EEG rhythm and the behavioral impairment. We found that visuo-spatial and motor impairments were primarily associated with the dorsal attention network, with contribution dependent on the specific EEG band. These findings are in line with the hypothesis that there is a core system of brain networks involved in specific cognitive domains. Moreover, our results pave the way for low-cost EEG-based monitoring of intrinsic brain networks' functioning in neurological patients to complement clinical-behavioral measures.

PMID:33677328 | DOI:10.1016/j.cortex.2021.01.019

Neuropsychiatric disease classification using functional connectomics - results of the connectomics in neuroimaging transfer learning challenge

Sun, 03/07/2021 - 11:00

Med Image Anal. 2021 Jan 28;70:101972. doi: 10.1016/j.media.2021.101972. Online ahead of print.

ABSTRACT

Large, open-source datasets, such as the Human Connectome Project and the Autism Brain Imaging Data Exchange, have spurred the development of new and increasingly powerful machine learning approaches for brain connectomics. However, one key question remains: are we capturing biologically relevant and generalizable information about the brain, or are we simply overfitting to the data? To answer this, we organized a scientific challenge, the Connectomics in NeuroImaging Transfer Learning Challenge (CNI-TLC), held in conjunction with MICCAI 2019. CNI-TLC included two classification tasks: (1) diagnosis of Attention-Deficit/Hyperactivity Disorder (ADHD) within a pre-adolescent cohort; and (2) transference of the ADHD model to a related cohort of Autism Spectrum Disorder (ASD) patients with an ADHD comorbidity. In total, 240 resting-state fMRI (rsfMRI) time series averaged according to three standard parcellation atlases, along with clinical diagnosis, were released for training and validation (120 neurotypical controls and 120 ADHD). We also provided Challenge participants with demographic information of age, sex, IQ, and handedness. The second set of 100 subjects (50 neurotypical controls, 25 ADHD, and 25 ASD with ADHD comorbidity) was used for testing. Classification methodologies were submitted in a standardized format as containerized Docker images through ChRIS, an open-source image analysis platform. Utilizing an inclusive approach, we ranked the methods based on 16 metrics: accuracy, area under the curve, F1-score, false discovery rate, false negative rate, false omission rate, false positive rate, geometric mean, informedness, markedness, Matthew's correlation coefficient, negative predictive value, optimized precision, precision, sensitivity, and specificity. The final rank was calculated using the rank product for each participant across all measures. Furthermore, we assessed the calibration curves of each methodology. Five participants submitted their method for evaluation, with one outperforming all other methods in both ADHD and ASD classification. However, further improvements are still needed to reach the clinical translation of functional connectomics. We have kept the CNI-TLC open as a publicly available resource for developing and validating new classification methodologies in the field of connectomics.

PMID:33677261 | DOI:10.1016/j.media.2021.101972

Altered cortico-striatal functional connectivity in people with high levels of schizotypy: A longitudinal resting-state study

Sat, 03/06/2021 - 11:00

Asian J Psychiatr. 2021 Feb 28;58:102621. doi: 10.1016/j.ajp.2021.102621. Online ahead of print.

ABSTRACT

PURPOSE OF THE RESEARCH: Cortico-striatal functional connectivity has been implicated in the neuropathology of schizophrenia. However, the longitudinal relationship between the cortico-striatal connectivity and schizotypy remains unknown. We examined the resting-state fMRI connectivity in 27 individuals with a high level of schizotypy and 20 individuals with a low level of schizotypy at baseline and 18 months later. Correlations between changes in cortico-striatal connectivity and changes in schizotypy scores over time were examined.

PRINCIPAL RESULTS: We found both increased and decreased cortico-striatal connectivity in individuals with a high level of schizotypy at baseline. Over time, these individuals showed improvement in both the negative and positive schizotypal domains. Changes in striatal-insula connectivity were positively correlated with changes in positive schizotypy from baseline to follow-up.

MAJOR CONCLUSIONS: Our results suggested impaired cortico-striatal connectivity in individuals with a high level of schizotypy. The dysconnectivity mainly involves the dorsal striatum. The connectivity between the dorsal striatum and the insula may be a putative marker for temporal changes in positive schizotypy.

PMID:33676189 | DOI:10.1016/j.ajp.2021.102621

Consistency of functional connectivity across different movies

Sat, 03/06/2021 - 11:00

Neuroimage. 2021 Mar 3:117926. doi: 10.1016/j.neuroimage.2021.117926. Online ahead of print.

ABSTRACT

Movie fMRI has emerged as a powerful tool for investigating human brain function, and functional connectivity (FC) plays a predominant role in fMRI-based studies. Accordingly, movie-watching FC may have great potential for future studies on human brain function. Before wide application of movie-watching FC, however, it is essential to evaluate how much it is influenced by differences in movies. The main aim of this study was to investigate the consistency of movie-watching FC across different movies. For this purpose, we performed three sets of analyses on the four movie fMRI runs (with different movie stimuli) included in the HCP dataset. The first set was performed to evaluate the agreement of movie-watching FC in exact values using intra-class correlation (ICC), and the ICC of movie-watching FC across different movies (0.37 on average) was found to be comparable to that of resting-state FC across repeated scans. The second set was performed to evaluate the agreement of movie-watching FC in connectivity patterns, and the results indicate that individuals could be identified with relatively high accuracies (94%-99%) across different movies based on their FC matrices. The final set was performed to test the generalizability of predictive models based on movie-watching FC, as this generalizability is highly dependent on the consistency of the FC. The results indicate that predictive models trained based on FC extracted from one movie fMRI run can make good predictions on FC extracted from runs with different movie stimuli. Taken together, our findings indicate that movie-watching FC is highly consistent across different movies, and conclusions drawn based on movie-watching FC are generalizable.

PMID:33675997 | DOI:10.1016/j.neuroimage.2021.117926

Differences in basic psychological needs-related resting-state functional connectivity between individuals with high and low life satisfaction

Sat, 03/06/2021 - 11:00

Neurosci Lett. 2021 Mar 3:135798. doi: 10.1016/j.neulet.2021.135798. Online ahead of print.

ABSTRACT

Basic psychological needs including autonomy, competence, and relatedness can be affected by the level of life satisfaction. The current research aimed to elucidate differences in the association of these needs and functional connectivity of reward processing and emotion regulation between individuals with high and low life satisfaction. A total of 83 young adults were divided into the high life satisfaction (HLS) and low life satisfaction (LLS) groups and were scanned for 5-min resting-state fMRI. A seed-to-voxel analysis was performed using the seeds of the nucleus accumbens (NAcc), medial orbitofrontal cortex, subgenual anterior cingulate cortex (sgACC), insula, and amygdala. Analysis of covariance was conducted to test differences in the association of basic psychological needs and functional connectivity between the two groups. Connectivity strengths between the NAcc and right ventromedial prefrontal cortex and between the sgACC and left ventromedial prefrontal cortex were higher in the HLS group as the autonomy and relatedness scores increased, respectively, whereas in the LLS group as they decreased. Connectivity strengths between the NAcc and right midcingulate cortex and between the sgACC and left fusiform gyrus were higher in the HLS group as the competence and relatedness scores decreased, respectively, but in the LLS group as they increased. These findings suggest that individuals' perceived life satisfaction affects the relationship between the neural mechanism for reward processing and emotion regulation and basic psychological needs support. Psychological need satisfactions seem to have an emotional impact by acting as a contradictory brain mechanism between individuals with high and low life satisfaction.

PMID:33675884 | DOI:10.1016/j.neulet.2021.135798

Resting state functional connectivity in adolescent synthetic cannabinoid users with and without attention-deficit/hyperactivity disorder

Sat, 03/06/2021 - 11:00

Hum Psychopharmacol. 2021 Mar 6. doi: 10.1002/hup.2781. Online ahead of print.

ABSTRACT

OBJECTIVE: Synthetic cannabinoids (SCs) have become increasingly popular in recent years, especially among adolescents. The first aim of the current study was to examine resting-state functional connectivity (rsFC) in SC users compared to controls. Our second aim was to examine the influence of comorbid attention-deficit/hyperactivity disorder (ADHD) symptomatology on rsFC changes in SC users compared to controls.

METHODS: Resting-state functional magnetic resonance imaging (fMRI) analysis included 25 SC users (14 without ADHD and 11 with ADHD combined type) and 12 control subjects.

RESULTS: We found (i) higher rsFC between the default mode network (DMN) and salience network, dorsal attention network and cingulo-opercular network, and (ii) lower rsFC within the DMN and between the DMN and visual network in SC users compared to controls. There were no significant differences between SC users with ADHD and controls, nor were there any significant differences between SC users with and without ADHD.

CONCLUSIONS: We found the first evidence of abnormalities within and between resting state networks in adolescent SC users without ADHD. In contrast, SC users with ADHD showed no differences compared to controls. These results suggest that comorbidity of ADHD and substance dependence may show different rsFC alterations than substance use alone.

PMID:33675677 | DOI:10.1002/hup.2781

Brain Function in Children with Obstructive Sleep Apnea: A Resting-State fMRI Study

Sat, 03/06/2021 - 11:00

Sleep. 2021 Mar 1:zsab047. doi: 10.1093/sleep/zsab047. Online ahead of print.

ABSTRACT

OBJECTIVE: To explore the neural difference between children with obstructive sleep apnea (OSA) and healthy controls, together with the relation between this difference and cognitive dysfunction of children with OSA.

METHODS: Twenty children with OSA (7.2 ± 3.1 years, apnea hypopnea index (AHI): 16.5 ± 16.6 events/h) and 29 healthy controls (7.7 ± 2.8 years, AHI: 1.7 ± 1.2 events/h) were recruited and matched with age, gender, and handedness. All children underwent resting-state fMRI (rs-fMRI) and T1-wighted imaging. Some children were sedated for MRI scanning. We compared amplitude of low frequency fluctuation (ALFF) and regional homogeneity (ReHo) of children with OSA with those of healthy controls. During resting-state, the former reflects the intensity of the spontaneous neural activities, whereas the latter reflects temporal similarity of the spontaneous neural activities within a local brain region. Pearson correlation analysis was performed between these features of rs-fMRI and cognitive scores among children with OSA.

RESULTS: Compared with controls, children with OSA showed decreased ALFF in the left angular gyrus but increased ALFF in the right insula, and decreased ReHo in the left medial superior frontal gyrus, right lingual gyrus and left precuneus. Additionally, among children with OSA, the ReHo value in the right lingual gyrus was negatively correlated with FIQ and VIQ, whereas that in the left medial superior frontal gyrus was positively correlated with VIQ.

CONCLUSIONS: Children with OSA presented abnormal neural activities in some brain regions and impaired cognitive functions with the former possibly being the neural mechanism of the latter.

PMID:33675225 | DOI:10.1093/sleep/zsab047

A neuroimaging investigation into the role of peripheral metabolic biomarkers in the anticipation of reward in alcohol use

Fri, 03/05/2021 - 11:00

Drug Alcohol Depend. 2021 Feb 16;221:108638. doi: 10.1016/j.drugalcdep.2021.108638. Online ahead of print.

ABSTRACT

BACKGROUND: The relationship between alcohol use and metabolism has focused on the effects of alcohol use on metabolic factors. Metabolic factors, such as triglycerides, cholesterol, and glucose, have been shown to be associated with increased risk for heavy alcohol consumption and alcohol use disorder (AUD). It's been suggested that changes in metabolic factors may play a role in reward seeking behaviors and pathways. Studies on feeding behavior and obesity revealed the role of triglycerides in neural response to food cues in neurocircuitry regulating reward and feeding behaviors. This study aimed to explore the relationship of peripheral metabolism, alcohol use, and reward processing in individuals that use alcohol.

METHODS: Ninety participants from a previously collected dataset were included in the analysis. Participants were treatment seeking, detoxified individuals with AUD and healthy individuals without AUD, with the following metabolic biomarkers: triglyceride, glucose, high- and low-density cholesterol, and HbA1c levels. Participants completed a neuroimaging version of the Monetary Incentive Delay task (MID).

RESULTS: Correlations on peripheral metabolic biomarkers, alcohol use, and neural activity during reward anticipation and outcome during the MID task were not significant. Mediation models revealed triglycerides and high-density cholesterol had significant effects on left anterior insula during anticipation of potential monetary loss and this effect was not mediated by alcohol use.

CONCLUSION: Limbic recruitment by anticipation of monetary rewards revealed an independent relationship with peripheral metabolism and was not affected by individual differences in alcohol use, despite the effects of alcohol use on metabolic markers and reward processing neural circuitry.

PMID:33667782 | DOI:10.1016/j.drugalcdep.2021.108638

A Structure-Function Substrate of Memory for Spatial Configurations in Medial and Lateral Temporal Cortices

Fri, 03/05/2021 - 11:00

Cereb Cortex. 2021 Feb 27:bhab001. doi: 10.1093/cercor/bhab001. Online ahead of print.

ABSTRACT

Prior research has shown a role of the medial temporal lobe, particularly the hippocampal-parahippocampal complex, in spatial cognition. Here, we developed a new paradigm, the conformational shift spatial task (CSST), which examines the ability to encode and retrieve spatial relations between unrelated items. This task is short, uses symbolic cues, incorporates two difficulty levels, and can be administered inside the scanner. A cohort of 48 healthy young adults underwent the CSST, together with a set of behavioral measures and multimodal magnetic resonance imaging (MRI). Inter-individual differences in CSST performance correlated with scores on an established spatial memory paradigm, but neither with episodic memory nor mnemonic discrimination, supporting specificity. Analyzing high-resolution structural MRI data, individuals with better spatial memory showed thicker medial and lateral temporal cortices. Functional relevance of these findings was supported by task-based functional MRI analysis in the same participants and ad hoc meta-analysis. Exploratory resting-state functional MRI analyses centered on clusters of morphological effects revealed additional modulation of intrinsic network integration, particularly between lateral and medial temporal structures. Our work presents a novel spatial memory paradigm and supports an integrated structure-function substrate in the human temporal lobe. Task paradigms are programmed in python and made open access.

PMID:33667310 | DOI:10.1093/cercor/bhab001

A comprehensive data-driven analysis framework for detecting impairments in brain function networks with resting state fMRI in HIV-infected individuals on cART

Fri, 03/05/2021 - 11:00

J Neurovirol. 2021 Mar 5. doi: 10.1007/s13365-021-00943-7. Online ahead of print.

ABSTRACT

Central nervous system (CNS) sequelae continue to be common in HIV-infected individuals despite combination antiretroviral therapy (cART). These sequelae include HIV-associated neurocognitive disorder (HAND) and virologic persistence in the CNS. Resting state functional magnetic resonance imaging (rsfMRI) is a widely used tool to examine the integrity of brain function and pathology. In this study, we examined 16 HIV-positive (HIV+) subjects and 12 age, sex, and race matched HIV seronegative controls (HIV-) whole-brain high-resolution rsfMRI along with a battery of neurocognitive tests. A comprehensive data-driven analysis of rsfMRI revealed impaired functional connectivity, with very large effect sizes in executive function, language, and multisensory processing networks in HIV+ subjects. These results indicate the potential of high-resolution rsfMRI in combination with advanced data analysis techniques to yield biomarkers of neural impairment in HIV.

PMID:33666883 | DOI:10.1007/s13365-021-00943-7

Myocardial Deformation Assessed by MR Feature Tracking in Groups of Patients With Ischemic Heart Disease

Fri, 03/05/2021 - 11:00

J Magn Reson Imaging. 2021 Mar 4. doi: 10.1002/jmri.27588. Online ahead of print.

ABSTRACT

BACKGROUND: Global myocardial strain assessments have been shown to provide useful measures of contractility in many diseases, but whether feature tracking (FT)-derived strain at rest can differentiate ischemic myocardium from infarcted and remote myocardium in patients with coronary artery disease (CAD) remains unclear.

PURPOSE: To evaluate the performance of magnetic resonance imaging FT-derived strain in the detection of regional myocardial deformation in ischemic, infarcted, and apparent normal myocardium in CAD.

STUDY TYPE: Retrospective POPULATION: A total of 109 patients with CAD.

FIELD STRENGTH/SEQUENCES: Steady-state free-precession rest cine, T1-weighted saturation-recovery fast gradient echo stress/rest perfusion, and two-dimensional phase-sensitive inversion recovery breath-hold late gadolinium enhancement (LGE) tests were performed at 3.0 T.

ASSESSMENT: Based on perfusion and LGE images, left ventricular (LV) myocardial segments of CAD patients were categorized into ischemic, infarcted, and negative groups. The FT longitudinal (LS) and circumferential strain (CS) of normal subjects and the three CAD groups were calculated. Z-scores of each segment of CAD patients were calculated.

STATISTIC TESTS: χ2 testing, analysis of variance (ANOVA), and Kruskal-Wallis tests. Z-scores were used to compare the strain between CAD groups.

RESULTS: There were significant differences in global LS (GLS) and CS (GCS) between healthy controls (GLS: -19.0% ± 1.4%, GCS, -20.9% ± 1.8%), ischemia (GLS: -17.4% ± 2.1%, GCS, -19.6% ± 1.9%), infarction (GLS: -16.4% ± 1.9%, GCS, -17.8% ± 1.9%), and negative patients (GLS: -17.7% ± 1.4%, GCS, -20.9% ± 2.4%) (all P < 0.05). There were significant differences in regional LS and CS between ischemic (LS, -16.1% ± 5.0%, CS, -18.7% ± 5.0%), infarcted (LS, -14.8% ± 5.2%, CS, -15.3% ± 4.8%), and negative segments (LS, -17.6% ± 5.2%, CS, -19.8% ± 4.8%) (all P < 0.05). The differences in the z-scores of regional LS and CS between the ischemic, infarcted, and negative segments were also significant (all P < 0.05).

DATA CONCLUSION: FT-derived rest strain indices of the LV myocardium of CAD patients were higher compared to healthy controls and varied between ischemic, infarcted, and negative segments.

LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY: Stage 5.

PMID:33665932 | DOI:10.1002/jmri.27588

Auditory Stimulation Modulates Resting-State Functional Connectivity in Unresponsive Wakefulness Syndrome Patients

Fri, 03/05/2021 - 11:00

Front Neurosci. 2021 Feb 16;15:554194. doi: 10.3389/fnins.2021.554194. eCollection 2021.

ABSTRACT

Passive listening to music is associated with several psychological and physical benefits in both, healthy and diseased populations. In this fMRI study, we examined whether preferred music has effects on the functional connectivity within resting-state networks related to consciousness. Thirteen patients in unresponsive wakefulness syndrome (UWS) and 18 healthy controls (HC) were enrolled. Both groups were exposed to different auditory stimulation (scanner noise, preferred music, and aversive auditory stimulation). Functional connectivity was analyzed using a seed-based approach. In HC, no differences were found between the three conditions, indicating that their networks are already working at high level. UWS patients showed impaired functional connectivity within all resting-state networks. In addition, functional connectivity of the auditory network was modulated by preferred music and aversive auditory stimulation. Hence, both conditions have the potential to modulate brain activity of UWS patients.

PMID:33664643 | PMC:PMC7921457 | DOI:10.3389/fnins.2021.554194

Understanding Vulnerability and Adaptation in Early Brain Development using Network Neuroscience

Fri, 03/05/2021 - 11:00

Trends Neurosci. 2021 Mar 1:S0166-2236(21)00021-7. doi: 10.1016/j.tins.2021.01.008. Online ahead of print.

ABSTRACT

Early adversity influences brain development and emerging behavioral phenotypes relevant for psychiatric disorders. Understanding the effects of adversity before and after conception on brain development has implications for contextualizing current public health crises and pervasive health inequities. The use of functional magnetic resonance imaging (fMRI) to study the brain at rest has shifted understanding of brain functioning and organization in the earliest periods of life. Here we review applications of this technique to examine effects of early life stress (ELS) on neurodevelopment in infancy, and highlight targets for future research. Building on the foundation of existing work in this area will require tackling significant challenges, including greater inclusion of often marginalized segments of society, and conducting larger, properly powered studies.

PMID:33663814 | DOI:10.1016/j.tins.2021.01.008

Anhedonia correlates with functional connectivity of the nucleus accumbens subregions in patients with major depressive disorder

Thu, 03/04/2021 - 11:00

Neuroimage Clin. 2021 Feb 23;30:102599. doi: 10.1016/j.nicl.2021.102599. Online ahead of print.

ABSTRACT

BACKGROUND: The nucleus accumbens (NAc) is an important region in reward circuit that has been linked with anhedonia, which is a characteristic symptom of major depressive disorder (MDD). However, the relationship between the functional connectivity of the NAc subregions and anhedonia in MDD patients remains unclear.

METHODS: We acquired resting-state functional magnetic resonance imaging (fMRI) scans from fifty-one subjects (23 MDD patients and 28 healthy controls). We assessed subjects' trait anhedonia with the Temporal Experience of Pleasure Scale (TEPS). Seed-based resting-state functional connectivity (rsFC) was conducted for each of the NAc subregions (bilateral core-like and shell-like subdivisions) separately to identify regions whose rsFCs with the NAc subregions were altered in the MDD patients and regions whose rsFCs with the NAc subregions showed different correlates with anhedonia between the MDD patients and the healthy controls.

RESULTS: Compared with the health controls, the MDD patients showed decreased rsFCs of the right NAc core-like subdivision with the left mid-anterior orbital prefrontal cortex and the right inferior parietal lobe as well as decreased rsFC of the left NAc core-like subdivision with the right middle frontal gyrus. Moreover, the severity of anhedonia by the group interaction was significant for the rsFC of the right NAc shell-like subdivision with the subgenual/pregenual anterior cingulate cortex and the rsFC of the right NAc core-like subdivision with the precuneus.

CONCLUSIONS: We found that the neural correlates of anhedonia indicated by the rsFCs of the NAc subregions were modulated by depression. The modulation effect was regionally-dependent. These findings enrich our understanding of the neural basis of anhedonia in MDD.

PMID:33662708 | DOI:10.1016/j.nicl.2021.102599

The neurobiology of prefrontal transcranial direct current stimulation (tDCS) in promoting brain plasticity: a systematic review and meta-analyses of human and rodent studies

Thu, 03/04/2021 - 11:00

Neurosci Biobehav Rev. 2021 Mar 1:S0149-7634(21)00095-6. doi: 10.1016/j.neubiorev.2021.02.035. Online ahead of print.

ABSTRACT

The neurobiological mechanisms underlying prefrontal transcranial direct current stimulation (tDCS) remain elusive. Randomized, sham-controlled trials in humans and rodents applying in vivo prefrontal tDCS were included to explore whether prefrontal tDCS modulates resting-state and event-related functional connectivity, neural oscillation and synaptic plasticity. Fifty studies were included in the systematic review and 32 in the meta-analyses. Neuroimaging meta-analysis indicated anodal prefrontal tDCS significantly enhanced bilateral median cingulate activity [familywise error (FWE)-corrected p < .005]; meta-regression revealed a positive relationship between changes in median cingulate activity after tDCS and current density (FWE-corrected p < .005) as well as electric current strength (FWE-corrected p < .05). Meta-analyses of electroencephalography and magnetoencephalography data revealed nonsignificant changes (ps >.1) in both resting-state and event-related oscillatory power across all frequency bands. Applying anodal tDCS over the rodent hippocampus/prefrontal cortex enhanced long-term potentiation and brain brain-derived neurotrophic factor expression in the stimulated brain regions (ps <.005). Evidence supporting prefrontal tDCS administration is preliminary; more methodologically consistent studies evaluating its effects on cognitive function that include brain activity measurements are needed.

PMID:33662444 | DOI:10.1016/j.neubiorev.2021.02.035

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