Most recent paper

Causality Analysis to the Abnormal Subcortical-Cortical Connections in Idiopathic-Generalized Epilepsy

Mon, 07/18/2022 - 18:00

Front Neurosci. 2022 Jun 30;16:925968. doi: 10.3389/fnins.2022.925968. eCollection 2022.

ABSTRACT

Idiopathic generalized epilepsy (IGE) was characterized by 3-6 Hz generalized spike-wave discharges (GSWDs), and extensive altered interactions in subcortical-cortical circuit. However, the dynamics and the causal relationship among these interactions were less studied. Using resting-state functional magnetic resonance imaging (fMRI) data, the abnormal connections in the subcortical-cortical pathway in IGE were examined. Then, we proposed a novel method of granger causal analysis based on the dynamic functional connectivity, and the predictive effects among these abnormal connections were calculated. The results showed that the thalamus, and precuneus were key regions representing abnormal functional network connectivity (FNC) in the subcortical-cortical circuit. Moreover, the connectivity between precuneus and adjacent regions had a causal effect on the widespread dysfunction of the thalamocortical circuit. In addition, the connection between the striatum and thalamus indicated the modulation role on the cortical connection in epilepsy. These results described the causality of the widespread abnormality of the subcortical-cortical circuit in IGE in terms of the dynamics of functional connections, which provided additional evidence for understanding the potential modulation pattern of the abnormal epileptic pathway.

PMID:35844218 | PMC:PMC9280354 | DOI:10.3389/fnins.2022.925968

Abnormal Voxel-Based Degree Centrality in Patients With Postpartum Depression: A Resting-State Functional Magnetic Resonance Imaging Study

Mon, 07/18/2022 - 18:00

Front Neurosci. 2022 Jun 30;16:914894. doi: 10.3389/fnins.2022.914894. eCollection 2022.

ABSTRACT

Postpartum depression (PPD) is a major public health concern with significant consequences for mothers, their children, and their families. However, less is known about its underlying neuropathological mechanisms. The voxel-based degree centrality (DC) analysis approach provides a new perspective for exploring the intrinsic dysconnectivity pattern of whole-brain functional networks of PPD. Twenty-nine patients with PPD and thirty healthy postpartum women were enrolled and received resting-state functional magnetic resonance imaging (fMRI) scans in the fourth week after delivery. DC image, clinical symptom correlation, and seed-based functional connectivity (FC) analyses were performed to reveal the abnormalities of the whole-brain functional network in PPD. Compared with healthy controls (HCs), patients with PPD exhibited significantly increased DC in the right hippocampus (HIP.R) and left inferior frontal orbital gyrus (ORBinf.L). The receiver operating characteristic (ROC) curve analysis showed that the area under the curve (AUC) of the above two brain regions is all over 0.7. In the seed-based FC analyses, the PPD showed significantly decreased FC between the HIP.R and right middle frontal gyrus (MFG.R), between the HIP.R and left median cingulate and paracingulate gyri (DCG.L), and between the ORBinf.L and the left fusiform (FFG.L) compared with HCs. The PPD showed significantly increased FC between the ORBinf.L and the right superior frontal gyrus, medial (SFGmed.R) compared with HCs. Mean FC between the HIP.R and DCG.L positively correlated with EDPS scores in the PPD group. This study provided evidence of aberrant DC and FC within brain regions in patients with PPD, which was associated with the default mode network (DMN) and limbic system (LIN). Identification of these above-altered brain areas may help physicians to better understand neural circuitry dysfunction in PPD.

PMID:35844214 | PMC:PMC9280356 | DOI:10.3389/fnins.2022.914894

Interindividual Variability in Functional Connectivity Discovers Differential Development of Cognition and Transdiagnostic Dimensions of Psychopathology in Youth

Sat, 07/16/2022 - 18:00

Neuroimage. 2022 Jul 13:119482. doi: 10.1016/j.neuroimage.2022.119482. Online ahead of print.

ABSTRACT

Cognitive and psychological development during adolescence is different from one another, which is rooted in individual differences in maturational changes in the adolescent brain. This study employed multi-modal MRI data and characterized interindividual variability in functional connectivity (IVFC) and its associations with cognition and psychopathology using the Philadelphia Neurodevelopmental Cohort (PNC) of 755 youth. We employed resting state functional MRI (rs-fMRI) and diffusion weighted images (DWIs) to estimate brain structural and functional networks. We computed the IVFC of individuals and examined its relation with structural and functional organizations. We further employed sparse partial least squares (sparse-PLS) and meta-analysis to examine the developmental associations of the IVFC with cognition and transdiagnostic dimensions of psychopathology in early, middle, and late adolescence. Our results revealed that the IVFC spatial topography reflects the brain functional integration and structure-function decoupling. Age effects on the IVFC of association networks were mediated by the FC among the triple networks, including frontoparietal, salience, and default mode networks (DMN), while those of primary and cerebellar networks were mediated by the cerebello-cortical FC. The IVFC of the triple and cerebellar networks explained the variance of executive functions and externalizing behaviors in early adolescence and then the variance of emotion and internalizing and psychosis in middle and late adolescence. We further evaluated this finding via meta-analysis on task-based studies on cognition and psychopathology. These findings implicate the emerging importance of the IVFC of the triple and cerebellar networks in cognitive, emotional, and psychopathological development during adolescence.

PMID:35842101 | DOI:10.1016/j.neuroimage.2022.119482

BOLD cofluctuation 'events' are predicted from static functional connectivity

Sat, 07/16/2022 - 18:00

Neuroimage. 2022 Jul 13:119476. doi: 10.1016/j.neuroimage.2022.119476. Online ahead of print.

ABSTRACT

Recent work identified single time points ("events") of high regional cofluctuation in functional Magnetic Resonance Imaging (fMRI) which contain more large-scale brain network information than other, low cofluctuation time points. This suggested that events might be a discrete, temporally sparse signal which drives functional connectivity (FC) over the timeseries. However, a different, not yet explored possibility is that network information differences between time points are driven by sampling variability on a constant, static, noisy signal. Using a combination of real and simulated data, we examined the relationship between cofluctuation and network structure and asked if this relationship was unique, or if it could arise from sampling variability alone. First, we show that events are not discrete - there is a gradually increasing relationship between network structure and cofluctuation; ∼50% of samples show very strong network structure. Second, using simulations we show that this relationship is predicted from sampling variability on static FC. Finally, we show that randomly selected points can capture network structure about as well as events, largely because of their temporal spacing. Together, these results suggest that, while events exhibit particularly strong representations of static FC, there is little evidence that events are unique timepoints that drive FC structure. Instead, a parsimonious explanation for the data is that events arise from a single static, but noisy, FC structure.

PMID:35842100 | DOI:10.1016/j.neuroimage.2022.119476

Shared and distinct structure-function substrates of heterogenous distractor suppression ability between high and low working memory capacity individuals

Sat, 07/16/2022 - 18:00

Neuroimage. 2022 Jul 13:119483. doi: 10.1016/j.neuroimage.2022.119483. Online ahead of print.

ABSTRACT

Salient stimuli can capture attention in a bottom-up manner; however, this attentional capture can be suppressed in a top-down manner. It has been shown that individuals with high working memory capacity (WMC) can suppress salient-but-irrelevant distractors better than those with low WMC; however, neural substrates underlying this difference remain unclear. To examine this, participants with high or low WMC (high-/low-WMC, n = 44/44) performed a visual search task wherein a color singleton item served as a salient distractor, and underwent structural and resting-state functional magnetic resonance imaging scans. Behaviorally, the color singleton distractor generally reduced the reaction time (RT). This RT benefit (ΔRT) was higher in the high-WMC group relative to the low-WMC group, indicating the superior distractor suppression ability of the high-WMC group. Moreover, leveraging voxel-based morphometry analysis, gray matter morphology (volume and deformation) in the ventral attention network (VAN) was found to show the same, positive associations with ΔRT in both WMC groups. However, correlations of the opposite sign were found between ΔRT and gray matter morphology in the frontoparietal (FPN)/default mode network (DMN) in the two WMC groups. Furthermore, resting-state functional connectivity analysis centering on regions with a structural-behavioral relationship found that connections between the left orbital and right superior frontal gyrus (hubs of DMN and VAN, respectively) was correlated with ΔRT in the high-WMC group (but not in the low-WMC group). Collectively, our work present shared and distinct neuroanatomical substrates of distractor suppression in high- and low-WMC individuals. Furthermore, intrinsic connectivity of the brain network hubs in high-WMC individuals may account for their superior ability in suppressing salient distractors.

PMID:35842098 | DOI:10.1016/j.neuroimage.2022.119483

Alterations in functional connectivity and interactions in resting-state networks in female patients with functional constipation

Fri, 07/15/2022 - 18:00

Neurol Sci. 2022 Jul 15. doi: 10.1007/s10072-022-06275-6. Online ahead of print.

ABSTRACT

BACKGROUND : Patients with functional constipation (FCon) have been reported with brain functional and structural abnormalities. However, no studies have been performed to investigate the differences in resting-state networks (RSNs) and changes in functional connectivity (FC) between RSNs in patients with FCon. Thus, the current study aimed to identify abnormal FC within and interaction between RSNs in patients with FCon to reveal the underlying neural mechanism.

METHODS: Functional MRI with independent component analysis was applied to investigate alterations in FC within and functional network connectivity (FNC) between RSNs including default mode- (DMN), basal ganglia- (BGN), salience- (SN), and left and right control executive-networks (LCEN/RCEN) in 39 female patients with FCon and 36 female healthy controls (HC). Patient Assessment of Constipation Quality of Life Scale (PAC-QOL) and Patient Assessment of Constipation Symptom Scale (PAC-SYM) were used to assess the constipation symptoms.

RESULTS: FCon patients had changed regional FC between different networks contributing to the abnormal FNC among RSNs compared with HC. Patients with greater stool syndromes had increased FNC of BGN-SN and DMN-LCEN, and patients with greater worries/concerns and PAC-QOL total score had reduced FNC of SN-RCEN. The greater strength changes in FC in prefrontal and parietal cortices were associated with higher negative emotion scores and greater rectal symptoms, respectively.

CONCLUSION: The findings suggested that FCon patients had altered FC within and interactions between RSNs and the brain FC changes were associated with constipation symptoms and altered emotions.

PMID:35840872 | DOI:10.1007/s10072-022-06275-6

Age-related changes of whole-brain dynamics in spontaneous neuronal coactivations

Fri, 07/15/2022 - 18:00

Sci Rep. 2022 Jul 15;12(1):12140. doi: 10.1038/s41598-022-16125-2.

ABSTRACT

Human brains experience whole-brain anatomic and functional changes throughout the lifespan. Age-related whole-brain network changes have been studied with functional magnetic resonance imaging (fMRI) to determine their low-frequency spatial and temporal characteristics. However, little is known about age-related changes in whole-brain fast dynamics at the scale of neuronal events. The present study investigated age-related whole-brain dynamics in resting-state electroencephalography (EEG) signals from 73 healthy participants from 6 to 65 years old via characterizing transient neuronal coactivations at a resolution of tens of milliseconds. These uncovered transient patterns suggest fluctuating brain states at different energy levels of global activations. Our results indicate that with increasing age, shorter lifetimes and more occurrences were observed in the brain states that show the global high activations and more consecutive visits to the global highest-activation brain state. There were also reduced transitional steps during consecutive visits to the global lowest-activation brain state. These age-related effects suggest reduced stability and increased fluctuations when visiting high-energy brain states and with a bias toward staying low-energy brain states. These age-related whole-brain dynamics changes are further supported by changes observed in classic alpha and beta power, suggesting its promising applications in examining the effect of normal healthy brain aging, brain development, and brain disease.

PMID:35840643 | DOI:10.1038/s41598-022-16125-2

The Open-Access European Prevention of Alzheimer's Dementia (EPAD) MRI dataset and processing workflow

Fri, 07/15/2022 - 18:00

Neuroimage Clin. 2022 Jul 7;35:103106. doi: 10.1016/j.nicl.2022.103106. Online ahead of print.

ABSTRACT

The European Prevention of Alzheimer Dementia (EPAD) is a multi-center study that aims to characterize the preclinical and prodromal stages of Alzheimer's Disease. The EPAD imaging dataset includes core (3D T1w, 3D FLAIR) and advanced (ASL, diffusion MRI, and resting-state fMRI) MRI sequences. Here, we give an overview of the semi-automatic multimodal and multisite pipeline that we developed to curate, preprocess, quality control (QC), and compute image-derived phenotypes (IDPs) from the EPAD MRI dataset. This pipeline harmonizes DICOM data structure across sites and performs standardized MRI preprocessing steps. A semi-automated MRI QC procedure was implemented to visualize and flag MRI images next to site-specific distributions of QC features - i.e. metrics that represent image quality. The value of each of these QC features was evaluated through comparison with visual assessment and step-wise parameter selection based on logistic regression. IDPs were computed from 5 different MRI modalities and their sanity and potential clinical relevance were ascertained by assessing their relationship with biological markers of aging and dementia. The EPAD v1500.0 data release encompassed core structural scans from 1356 participants 842 fMRI, 831 dMRI, and 858 ASL scans. From 1356 3D T1w images, we identified 17 images with poor quality and 61 with moderate quality. Five QC features - Signal to Noise Ratio (SNR), Contrast to Noise Ratio (CNR), Coefficient of Joint Variation (CJV), Foreground-Background energy Ratio (FBER), and Image Quality Rate (IQR) - were selected as the most informative on image quality by comparison with visual assessment. The multimodal IDPs showed greater impairment in associations with age and dementia biomarkers, demonstrating the potential of the dataset for future clinical analyses.

PMID:35839659 | DOI:10.1016/j.nicl.2022.103106

Parietal-hippocampal rTMS improves cognitive function in Alzheimer's disease and increases dynamic functional connectivity of default mode network

Fri, 07/15/2022 - 18:00

Psychiatry Res. 2022 Jul 8;315:114721. doi: 10.1016/j.psychres.2022.114721. Online ahead of print.

ABSTRACT

Parietal-hippocampal repetitive transcranial magnetic stimulation (rTMS) improves cognitive function in Alzheimer's disease (AD), however, the underlying therapeutic mechanism has not been elucidated. A double-blind, randomized, sham-controlled parietal-hippocampal rTMS trial (five sessions/week for a total of 10 sessions) of mild-to-moderate AD patients was conducted in the study. High-frequency rTMS was applied to a subject-specific left lateral parietal region with the highest functional connectivity with the hippocampus based on resting-state fMRI. A multimodal MRI scan and a complete neuropsychological battery of tests were conducted at baseline, immediately after the intervention and 12-week follow-up after the rTMS treatment. Compared to sham treatment (n = 27), patients undergoing active rTMS treatment (n = 29) showed higher Mini Mental State Examination (MMSE) score and dynamic functional connectivity (dFC) magnitude of the default mode network (DMN) after two weeks of rTMS treatment, but not at 12-week follow-up. A significant positive correlation was observed between changes in MMSE and changes in the dFC magnitude of DMN in patients who underwent active-rTMS treatment, but not in those who received sham-rTMS treatment. The findings of the current study indicate that fMRI-guided rTMS treatment improves cognitive function of AD patients in the short term, and DMN functional connectivity contributes to therapeutic effectiveness of rTMS.

PMID:35839637 | DOI:10.1016/j.psychres.2022.114721

A resting state fMRI study of major depressive disorder with and without anxiety

Fri, 07/15/2022 - 18:00

Psychiatry Res. 2022 Jul 1;315:114697. doi: 10.1016/j.psychres.2022.114697. Online ahead of print.

ABSTRACT

BACKGROUND: The neurobiology of the Major depressive disorder (MDD) with anxiety is still unclear. The present study aimed to explore the brain correlates of MDD with and without anxiety in men and women during resting-state fMRI.

METHODS: Two hundred and fifty-four patients with MDD (MDD with anxiety, N = 152) and MDD without anxiety, N = 102) and 228 healthy controls (HCs) participated in this study. We compared the fALFF(fractional amplitude of low-frequency fluctuations) and ReHo(regional homogeneity) of ACC(anterior cingulate cortex) and insula among these three groups. We also compared gender difference between MDD with anxiety and MDD without anxiety.

RESULTS: We found that the fALFF values within the ACC and insula were significantly lower in MDD with anxiety compared to without anxiety and HCs. However, we did not find differences in ReHo values among the three groups. In women, we found significant differences in fALFF values between MDD with and without anxiety. These differences were not observed in men.

CONCLUSIONS: It is possible that MDD with anxiety show less spontaneous BOLD-fMRI signal intensity within the ACC and insula compared to MDD without anxiety, especially in women. The fALFF within the ACC and insula can be a potential biomarker for severe MDD phenotype.

PMID:35839636 | DOI:10.1016/j.psychres.2022.114697

Functional brain changes in Parkinson's disease: a whole brain ALE study

Fri, 07/15/2022 - 18:00

Neurol Sci. 2022 Jul 15. doi: 10.1007/s10072-022-06272-9. Online ahead of print.

ABSTRACT

BACKGROUND: Resting-state functional magnetic resonance imaging (rs-fMRI) was widely used as an effective tool in the diagnosis of neurodegenerative diseases. However, prior rs-fMRI studies reported inconsistent results for comparison between Parkinson's disease (PD) and healthy controls (HC).

METHODS: We searched studies published before December 2021 in databases (PubMed, Web of Science, and Google Scholar). An activation likelihood estimation (ALE) meta-analysis was made for functional changes in PD.

RESULTS: The study finally included 25 studies (including 973 PD patients and 766 HC). PD patients showed reduced amplitude of low frequency fluctuations (ALFF) in the left superior temporal gyrus (STG), the left superior frontal gyrus (SFG), the left medial frontal gyrus (MFG), the left precuneus (PCUN), and the right lentiform nucleus, compared to HC. PD patients showed increased ALFF in the right SFG, the left superior parietal lobule (SPL), the left STG, the right fusiform gyrus, the left inferior temporal gyrus (ITG), and the right parahippocampal gyrus (PHG), compared to HC. PD patients showed reduced regional homogeneity (ReHo) in the right declive, the right MFG, the left culmen, and the left thalamus, compared to HC. PD patients showed increased ReHo in the right SFG, compared to HC. Additionally, PD patients showed reduced functional connectivity (FC) in the right posterior cingulate (PCG), compared to HC.

CONCLUSIONS: The present ALE analysis has confirmed functional deficits in motor-, emotion-, and cognition-related regions in PD. Deficits in these regions in rs-fMRI studies could play a role in early diagnosis of PD.

PMID:35838849 | DOI:10.1007/s10072-022-06272-9

The Degree Centrality and Functional Connectivity in Patients With Temporal Lobe Epilepsy Presenting as Ictal Panic: A Resting State fMRI Study

Fri, 07/15/2022 - 18:00

Front Neurol. 2022 Jun 28;13:822253. doi: 10.3389/fneur.2022.822253. eCollection 2022.

ABSTRACT

OBJECTIVES: Ictal panic (IP) can be observed occasionally in patients with temporal lobe epilepsy (TLE). Such descriptions can be found in previous studies, but the mechanism is still not clear and often confused with panic attacks in patients with panic disorder (PD). We try to use imaging methods (resting-state functional magnetic resonance imaging, rs-fMRI) to study the mechanism of this psychiatric comorbidity in patients with TLE.

METHODS: Forty right-onset TLE patients were observed, including 28 patients with TLE but without IP and 12 patients with TLEIP along with 30 gender-age matched healthy controls were included. We collected clinical/physiological/neuropsychological and rs-fMRI data. Degree centrality (DC) and functional connectivity (FC) were calculated. For the DC and FC values, analysis of covariance (ANCOVA) was used to find different areas and t-tests were used to compare differences between the TLEIP, TLE without IP, and healthy control(HC)groups. The relationship between brain abnormalities and patient characteristics was explored by correlation analyses.

RESULTS: No significant differences in gender and age were found among the three groups, and no significant differences in education level, Montreal Cognitive Assessment (MOCA), Hamilton Depressive Scale (HAMD), Hamilton Anxiety Scale (HAMA), and epilepsy duration (years) between the TLEIP and TLE without IP groups. In addition to fear, other symptoms were observed, including nausea, palpitations, rising epigastric sensation, and dyspnea. There was no correlation between the duration of IP and HAMA. Moreover, all IP durations were <2 min. Compared to the HCs and TLE without IP group, the DC value of the TLEIP group in the left middle temporal gyrus (LMTG) was significantly increased. Compared to the HCs, FC could be found between the LMTG and left inferior temporal gyrus (LITG) in the TLEIP group. In addition, there was FC between the LMTG and cerebellum in the TLEIP group. The difference in the magnitude of FC between the TLEIP vs. HC group was greater than the difference between the TLE vs. HC group.

CONCLUSIONS: This study describes brain abnormalities in patients with TLEIP. These results will help to preliminarily understand the mechanism of ictal panic and abnormal functional connection in patients with TLE, and further explore the neuroimaging mechanism of ictal panic in patients with TLE.

PMID:35837228 | PMC:PMC9274169 | DOI:10.3389/fneur.2022.822253

Disruption of Cerebellar-Cerebral Functional Connectivity in Temporal Lobe Epilepsy and the Connection to Language and Cognitive Functions

Fri, 07/15/2022 - 18:00

Front Neurosci. 2022 Jun 28;16:871128. doi: 10.3389/fnins.2022.871128. eCollection 2022.

ABSTRACT

OBJECTIVE: To investigate the changes in the cerebellar-cerebral language network in temporal lobe epilepsy (TLE) patients from the cerebellar perspective, the research analyzes the changes of language and cognitive network in terms of functional connectivity (FC), as well as their efficiency of the reorganization were evaluated basing on relationship between the network metrics and neuropsychological scale scores.

METHODS: 30 TLE patients and 30 healthy controls were recruited. Brain activity was evaluated by voxel-mirrored homotopic connectivity analysis (VMHC). Two groups were analyzed and compared in terms of language FC using the following methods: Seed-to-Voxel analysis, pairwise correlations [region of interest(ROI)-to-ROI] and graph theory. Correlation analysis was performed between network properties and neuropsychological score.

RESULTS: Compared with healthy participants, VMHC values in the Cerebellum Anterior Lobe, Frontal Lobe, Frontal_Sup_R/L, Cingulum_Ant_R/L, and Cingulum_Mid_R/L were decreased in TLE patients. Decreased FC was observed from the Cerebelum_10_R to the left inferior frontal gyrus, from the Cerebelum_6_R to the left Lingual Gyrus, from the Cerebelum_4_5_R to left Lingual Gyrus, left Cuneal Cortex and Precuneous Cortex, from the Cerebelum_3_R to Brain-Stem, and from the Cerebelum_Crus1_L to Cerebelum_6_R in TLE patients. The FC was enhanced between bilateral Cingulum_Mid and angular gyrus and frontoparietal insular cranium, between Frontal_Sup_Med L and left/right superior temporal gyrus (pSTG l/r), while it was decreased between left middle temporal gyrus and pSTG l/r. Compared with controls, the Betweenness Centrality (BC) of the right superior marginal gyrus (SMG), Temporal_Pole_Mid_R and Temporal_Mid_L as well as the Degree Centrality (DC) and Nodal Efficiency (NE) of the right SMG were lower in TLE patients. Further analysis showed that decreased VMHC in bilateral Cerebellum Anterior Lobe was positively correlated with the Boston Naming Test score in TLE patients, but it was negatively correlated with the Verbal Fluency Test score. The NE and DC of SMG_R were both negatively correlated with visual perception score in Montreal Cognitive Assessment.

CONCLUSION: Our results suggest that presence of abnormalities in the static functional connectivity and the language and cognitive network of TLE patients. Cerebellum potentially represents an intervention target for delaying or improving language and cognitive deficits in patients with TLE.

PMID:35837122 | PMC:PMC9273908 | DOI:10.3389/fnins.2022.871128

RS-FetMRI: a MATLAB-SPM Based Tool for Pre-processing Fetal Resting-State fMRI Data

Thu, 07/14/2022 - 18:00

Neuroinformatics. 2022 Jul 14. doi: 10.1007/s12021-022-09592-5. Online ahead of print.

ABSTRACT

Resting-state functional magnetic resonance imaging (rs-fMRI) most recently has proved to open a measureless window on functional neurodevelopment in utero. Fetal brain activation and connectivity maps can be heavily influenced by 1) fetal-specific motion effects on the time-series and 2) the accuracy of time-series spatial normalization to a standardized gestational-week (GW) specific fetal template space.Due to the absence of a standardized and generalizable image processing protocol, the objective of the present work was to implement a validated fetal rs-fMRI preprocessing pipeline (RS-FetMRI) divided into 6 inter-dependent preprocessing modules (i.e., M1 to M6) and designed to work entirely as an extension for Statistical Parametric Mapping (SPM).RS-FetMRI pipeline output analyses on rs-fMRI time-series sampled from a cohort of fetuses acquired on both 1.5 T and 3 T MRI scanning systems showed increased efficacy of estimation of the degree of movement coupled with an efficient motion censoring procedure, resulting in increased number of motion-uncorrupted volumes and temporal continuity in fetal rs-fMRI time-series data. Moreover, a "structural-free" SPM-based spatial normalization procedure granted a high degree of spatial overlap with high reproducibility and a significant improvement in whole-brain and parcellation-specific Temporal Signal-to-Noise Ratio (TSNR) mirrored by functional connectivity analysis.To our knowledge, the RS-FetMRI pipeline is the first semi-automatic and easy-to-use standardized fetal rs-fMRI preprocessing pipeline completely integrated in MATLAB-SPM able to remove entry barriers for new research groups into the field of fetal rs-fMRI, for both research or clinical purposes, and ultimately to make future fetal brain connectivity investigations more suitable for comparison and cross-validation.

PMID:35834105 | DOI:10.1007/s12021-022-09592-5

Enhanced Visual Cortex Activation in People With Narcolepsy Type 1 During Active Sleep Resistance: An fMRI-EEG Study

Thu, 07/14/2022 - 18:00

Front Neurosci. 2022 Jun 27;16:904820. doi: 10.3389/fnins.2022.904820. eCollection 2022.

ABSTRACT

The brain activation patterns related to sleep resistance remain to be discovered in health and disease. The maintenance of wakefulness test (MWT) is an objective neuropsychological assessment often used to assess an individual's ability to resist sleep. It is frequently used in narcolepsy type 1, a disorder characterized by impaired sleep-wake control and the inability to resist daytime sleep. We investigated the neural correlates of active sleep resistance in 12 drug-free people with narcolepsy type 1 and 12 healthy controls. Simultaneous fMRI-EEG measurements were recorded during five cycles of two alternating conditions of active sleep resistance and waking rest. Cleaned EEG signals were used to verify wakefulness and task adherence. Pooling both subject groups, significantly higher fMRI activation when actively resisting sleep was seen in the brainstem, superior cerebellum, bilateral thalamus and visual cortices. In controls the activation clusters were generally smaller compared to patients and no significant activation was seen in the brainstem. Formal comparison between groups only found a significantly higher left primary visual cortex activation in patients during active sleep resistance. The active sleep resistance paradigm is a feasible fMRI task to study sleep resistance and induces evident arousal- and visual-related activity. Significantly higher left primary visual cortical activation in patients could be caused by an enhanced need of visual focus to resist sleep, or reflecting a more rapid descent in their level of alertness when resting.

PMID:35833089 | PMC:PMC9271668 | DOI:10.3389/fnins.2022.904820

Identification of Alzheimer's Disease Progression Stages Using Topological Measures of Resting-State Functional Connectivity Networks: A Comparative Study

Thu, 07/14/2022 - 18:00

Behav Neurol. 2022 Jul 4;2022:9958525. doi: 10.1155/2022/9958525. eCollection 2022.

ABSTRACT

Resting-state functional magnetic resonance imaging (rs-fMRI) has been widely employed to examine brain functional connectivity (FC) alterations in various neurological disorders. At present, various computational methods have been proposed to estimate connectivity strength between different brain regions, as the edge weight of FC networks. However, little is known about which model is more sensitive to Alzheimer's disease (AD) progression. This study comparatively characterized topological properties of rs-FC networks constructed with Pearson correlation (PC), dynamic time warping (DTW), and group information guided independent component analysis (GIG-ICA), aimed at investigating the sensitivity and effectivity of these methods in differentiating AD stages. A total of 54 subjects from Alzheimer's Disease Neuroimaging Initiative (ANDI) database, divided into healthy control (HC), mild cognition impairment (MCI), and AD groups, were included in this study. Network-level (global efficiency and characteristic path length) and nodal (clustering coefficient) metrics were used to capture groupwise difference across HC, MCI, and AD groups. The results showed that almost no significant differences were found according to global efficiency and characteristic path length. However, in terms of clustering coefficient, 52 brain parcels sensitive to AD progression were identified in rs-FC networks built with GIG-ICA, much more than PC (6 parcels) and DTW (3 parcels). This indicates that GIG-ICA is more sensitive to AD progression than PC and DTW. The findings also confirmed that the AD-linked FC alterations mostly appeared in temporal, cingulate, and angular areas, which might contribute to clinical diagnosis of AD. Overall, this study provides insights into the topological properties of rs-FC networks over AD progression, suggesting that FC strength estimation of FC networks cannot be neglected in AD-related graph analysis.

PMID:35832401 | PMC:PMC9273422 | DOI:10.1155/2022/9958525

Effects of Acupuncture at Neiguan in Neural Activity of Related Brain Regions: A Resting-State fMRI Study in Anxiety

Thu, 07/14/2022 - 18:00

Neuropsychiatr Dis Treat. 2022 Jul 6;18:1375-1384. doi: 10.2147/NDT.S368227. eCollection 2022.

ABSTRACT

BACKGROUND: Acupuncture of PC6 points has the effects of calming, tranquilizing, regulating qi, and relieving pain and has been clinically found to alleviate anxiety disorders. To explore the mechanism of improvement at the Neiguan point acupuncture in anxiety patients, we used fMRI to observe the changes in brain function in patients with immediate anxiety before and after acupuncture at the Neiguan point.

SUBJECTS AND METHODS: The experiment followed the principle of randomized, single-blind design. Twenty-four anxiety volunteers (14 males and 10 females, 20-35 years old) were divided randomly into two groups: a group of acupuncture at Neiguan and a group of acupuncture at non-acupoint. Functional magnetic resonance imaging (fMRI) was applied to measure brain activity pre- and post-acupuncture. The amplitude of low-frequency fluctuations (ALFF) and seed-based functional connectivity (FC) was used to analyze the activity and network of brain regions. Statistical analysis was done using SPSS 21.0 and REST 1.8 software.

RESULTS: ALFF results revealed that post-acupuncture at Neiguan increased the activity of the left parahippocampal gyrus, fusiform gyrus, and right superior temporal gyrus and decreased the activity of the right middle frontal gyrus, right precuneus, and cuneus. Post-acupuncture at non-acupoint led to a significant ALFF increase in the thalamus and middle frontal gyrus. The ALFF in the left middle frontal gyrus was decreased. Functional connectivity in several anterior default mode network (DMN) regions and vermis cerebelli at left parahippocampal/fusiform gyri was increased, and connectivity in bilateral superior temporal gyri was decreased. FC with posterior DMN regions decreased at the right middle frontal gyrus, right precuneus, and cuneus.

CONCLUSION: Our study elucidates that acupuncture at Neiguan modulates anxiety by activating or deactivating these brain anxiety-related regions and provides potential explanations for the application of PC6 acupuncture in mental diseases.

PMID:35832324 | PMC:PMC9271906 | DOI:10.2147/NDT.S368227

Affective Enhancement of Episodic Memory Is Associated With Widespread Patterns of Intrinsic Functional Connectivity in the Brain Across the Adult Lifespan

Thu, 07/14/2022 - 18:00

Front Behav Neurosci. 2022 Jun 27;16:910180. doi: 10.3389/fnbeh.2022.910180. eCollection 2022.

ABSTRACT

Subjectively arousing experiences tend to be better remembered than neutral ones. While numerous task-related neuroimaging studies have revealed the neural mechanisms associated with this phenomenon, it remains unclear how variability in the extent to which individuals show superior memory for subjectively arousing stimuli is associated with the intrinsic functional organization of their brains. Here, we addressed this issue using functional magnetic resonance imaging data collected at rest from a sample drawn from the Cambridge Centre for Ageing and Neuroscience cohort (N = 269, 18-86 years). Specifically, we performed multi-voxel pattern analysis of intrinsic functional connectivity, an unbiased, data-driven approach to examine whole-brain voxel-wise connectivity patterns. This technique allowed us to reveal the most important features from the high-dimensional, whole-brain connectivity structure without a priori hypotheses about the topography and direction of functional connectivity differences. Behaviorally, both item and associative memory accuracy were enhanced for trials with affectively arousing (positive or negative) stimuli than those with neutral ones. Whole-brain multi-voxel pattern analysis of functional connectivity revealed that the affective enhancement of memory was associated with intrinsic connectivity patterns of spatially distributed brain regions belonging to several functional networks in the cerebral cortex. Post hoc seed-based brain-behavior regression analysis and principal component analysis of the resulting correlation maps showed that these connectivity patterns were in turn primarily characterized by the involvement of heteromodal association and paralimbic (dorsal attention, salience, and default mode) networks of the cerebral cortex as well as select subcortical structures (striatum, thalamus, and cerebellum). Collectively, these findings suggest that the affective enhancement of episodic memory may be characterized as a whole-brain phenomenon, possibly supported by intrinsic functional interactions across several networks and structures in the brain.

PMID:35832290 | PMC:PMC9271876 | DOI:10.3389/fnbeh.2022.910180

Functional Connectivity in Compulsive Sexual Behavior Disorder - Systematic Review of Literature and Study on Heterosexual Males

Wed, 07/13/2022 - 18:00

J Sex Med. 2022 Jul 10:S1743-6095(22)01463-1. doi: 10.1016/j.jsxm.2022.05.146. Online ahead of print.

ABSTRACT

BACKGROUND: Compulsive Sexual Behavior Disorder (CSBD) was recently included in ICD-11 as a new impulse control disorder. While this certainly improved the diagnosis of CSBD, the underlying brain mechanisms of the disorder are still poorly understood. Better description of brain functional deficits is required.

AIM: Here we investigate patterns of resting-state brain functional connectivity (fc) in a group of CSBD patients compared to a group of healthy controls (HC).

METHODS: A MATLAB toolbox named CONN functional connectivity toolbox was employed to study patterns of brain connectivity. Also correlation between fc and severity of CSBD symptoms and other psychological characteristics, assessed with questionnaires, were examined.

OUTCOMES: We collected resting-state functional magnetic resonance imaging data from 81 heterosexual males: 52 CSBD patients and 29 HC.

RESULTS: We found increased fc between left inferior frontal gyrus and right planum temporale and polare, right and left insula, right Supplementary Motor Cortex (SMA), right parietal operculum, and also between left supramarginal gyrus and right planum polare, and between left orbitofrontal cortex and left insula when compared CSBD and HC. The decreased fc was observed between left middle temporal gyrus and bilateral insula and right parietal operculum. No significant correlations between psychological questionnaires assessing CSBD symptoms and resting-state functional connectivity were observed.

CLINICAL IMPLICATIONS: Results from our study extend the knowledge of brain mechanisms differentiating CSBD from HC.

STRENGTHS & LIMITATIONS: The study was the first large sample study showing 5 distinct functional brain networks differentiating CSBD patients and HC. However, the sample was limited only to heterosexual men, in the future a greater diversity in studied sample and longitudinal studies are needed. Also, the present study examined functional connectivity at the level of regions of interest (ROIs). Future studies could verify these results by examining functional connectivity at the voxel level.

CONCLUSION: The identified functional brain networks differentiate CSBD from HC and provide some support for incentive sensitization as mechanism underlying CSBD symptoms. The correlation between psychological assessment (ie, severity of CSBD, depression and anxiety symptoms, level of impulsivity and compulsivity) and resting-state functional connectivity need further examination. Draps M, Adamus S, Wierzba M, et al. Functional Connectivity in Compulsive Sexual Behavior Disorder - Systematic Review of Literature and Study on Heterosexual Males. J Sex Med 2022;XX:XXX-XXX.

PMID:35831231 | DOI:10.1016/j.jsxm.2022.05.146

Different functional connectivity optimal frequency in autism compared with healthy controls and the relationship with social communication deficits: Evidence from gene expression and behavior symptom analyses

Wed, 07/13/2022 - 18:00

Hum Brain Mapp. 2022 Jul 13. doi: 10.1002/hbm.26011. Online ahead of print.

ABSTRACT

Studies have reported that different brain regions/connections possess distinct frequency properties, which are related to brain function. Previous studies have proposed altered brain activity frequency and frequency-specific functional connectivity (FC) patterns in autism spectrum disorder (ASD), implying the varied dominant frequency of FC in ASD. However, the difference of the dominant frequency of FC between ASD and healthy controls (HCs) remains unclear. In the present study, the dominant frequency of FC was measured by FC optimal frequency, which was defined as the intermediate of the frequency bin at which the FC strength could reach the maximum. A multivariate pattern analysis was conducted to determine whether the FC optimal frequency in ASD differs from that in HCs. Partial least squares regression (PLSR) and enrichment analyses were conducted to determine the relationship between the FC optimal frequency difference of ASD/HCs and cortical gene expression. PLSR analyses were also performed to explore the relationship between FC optimal frequency and the clinical symptoms of ASD. Results showed a significant difference of FC optimal frequency between ASD and HCs. Some genes whose cortical expression patterns are related to the FC optimal frequency difference of ASD/HCs were enriched for social communication problems. Meanwhile, the FC optimal frequency in ASD was significantly related to social communication symptoms. These results may help us understand the neuro-mechanism of the social communication deficits in ASD.

PMID:35822559 | DOI:10.1002/hbm.26011