New resting-state fMRI related studies at PubMed

Subscribe to New resting-state fMRI related studies at PubMed feed New resting-state fMRI related studies at PubMed
NCBI: db=pubmed; Term=resting state fMRI
Updated: 36 min 6 sec ago

Spontaneous brain activity underlying auditory hallucinations in the hearing-impaired.

Sat, 01/16/2021 - 12:00
Related Articles

Spontaneous brain activity underlying auditory hallucinations in the hearing-impaired.

Cortex. 2021 Jan 05;136:1-13

Authors: Marschall TM, Ćurčić-Blake B, Brederoo SG, Renken RJ, Linszen MMJ, Koops S, Sommer IEC

Abstract
Auditory hallucinations, the perception of a sound without a corresponding source, are common in people with hearing impairment. Two forms can be distinguished: simple (i.e., tinnitus) and complex hallucinations (speech and music). Little is known about the precise mechanisms underlying these types of hallucinations. Here we tested the assumption that spontaneous activity in the auditory pathways, following deafferentation, underlies these hallucinations and is related to their phenomenology. By extracting (fractional) Amplitude of Low Frequency Fluctuation [(f)ALFF] scores from resting state fMRI of 18 hearing impaired patients with complex hallucinations (voices or music), 18 hearing impaired patients with simple hallucinations (tinnitus or murmuring), and 20 controls with normal hearing, we investigated differences in spontaneous brain activity between these groups. Spontaneous activity in the anterior and posterior cingulate cortex of hearing-impaired groups was significantly higher than in the controls. The group with complex hallucinations showed elevated activity in the bilateral temporal cortex including Wernicke's area, while spontaneous activity of the group with simple hallucinations was mainly located in the cerebellum. These results suggest a decrease in error monitoring in both hearing-impaired groups. Spontaneous activity of language-related areas only in complex hallucinations suggests that the manifestation of the spontaneous activity represents the phenomenology of the hallucination. The link between cerebellar activity and simple hallucinations, such as tinnitus, is new and may have consequences for treatment.

PMID: 33450598 [PubMed - as supplied by publisher]

Determining the impact of age and sex on the psychophysical and neurophysiological response to thermal pain across the adult lifespan.

Sat, 01/16/2021 - 12:00
Related Articles

Determining the impact of age and sex on the psychophysical and neurophysiological response to thermal pain across the adult lifespan.

J Adv Nurs. 2021 Jan 15;:

Authors: Atalla SW, Cowan RL, Anderson AR, Dietrich MS, Iversen L, Beth Kalvas L, Moss KO, Wright K, Monroe TB

Abstract
AIMS: Determine sex- and age-associated psychophysical and neurophysiological differences in the processing of pain across the adult lifespan.
DESIGN: Preliminary, exploratory, cross-sectional study.
METHODS: Using psychophysics (to measure intensity and unpleasantness) and functional magnetic resonance imaging blood oxygenation level dependent methods (to measure stimulus-evoked brain activation), we will examine sex- and age-associated differences in thermal pain processing and their underlying neurophysiology in a broad range of healthy adults (ages 30-89). We will acquire resting state functional connectivity data for secondary analyses exploring whether resting state connectivity predicts psychophysical and neurophysiological responses to thermal pain. To examine the effects of altered blood flow, we will acquire resting-state arterial spin labeling magnetic resonance imaging data to quantify resting cerebral blood flow. We will interpret findings in the context of a proposed neural model of pain, ageing, and sex. Study funding was received in June of 2014. Ethical approval was obtained from the Vanderbilt University IRB prior to study initiation.
CONCLUSION: Exploring the biological reasons for age- and sex-associated differences in pain processing will increase our understanding of pain in older adults. The paucity of neurobiological evidence to support best practice pain management in older adults places these individuals at risk for poor pain management.
IMPACT: Poorly treated pain in older adults is a critical public health problem associated with a poor quality of life and increased healthcare costs. Understanding how age and sex have an impact on central processing of pain across the lifespan is a critical step toward improving personalized pain medicine.

PMID: 33450111 [PubMed - as supplied by publisher]

Disrupted connectivity within visual, attentional and salience networks in the visual snow syndrome.

Sat, 01/16/2021 - 12:00
Related Articles

Disrupted connectivity within visual, attentional and salience networks in the visual snow syndrome.

Hum Brain Mapp. 2021 Jan 15;:

Authors: Puledda F, O'Daly O, Schankin C, Ffytche D, Williams SC, Goadsby PJ

Abstract
Here we investigate brain functional connectivity in patients with visual snow syndrome (VSS). Our main objective was to understand more about the underlying pathophysiology of this neurological syndrome. Twenty-four patients with VSS and an equal number of gender and age-matched healthy volunteers attended MRI sessions in which whole-brain maps of functional connectivity were acquired under two conditions: at rest while watching a blank screen and during a visual paradigm consisting of a visual-snow like stimulus. Eight unilateral seed regions were selected a priori based on previous observations and hypotheses; four seeds were placed in key anatomical areas of the visual pathways and the remaining were derived from a pre-existing functional analysis. The between-group analysis showed that patients with VSS had hyper and hypoconnectivity between key visual areas and the rest of the brain, both in the resting state and during a visual stimulation, compared with controls. We found altered connectivity internally within the visual network; between the thalamus/basal ganglia and the lingual gyrus; between the visual motion network and both the default mode and attentional networks. Further, patients with VSS presented decreased connectivity during external sensory input within the salience network, and between V5 and precuneus. Our results suggest that VSS is characterised by a widespread disturbance in the functional connectivity of several brain systems. This dysfunction involves the pre-cortical and cortical visual pathways, the visual motion network, the attentional networks and finally the salience network; further, it represents evidence of ongoing alterations both at rest and during visual stimulus processing.

PMID: 33448525 [PubMed - as supplied by publisher]

Boost in Test-Retest Reliability in Resting State fMRI with Predictive Modeling.

Sat, 01/16/2021 - 12:00
Related Articles

Boost in Test-Retest Reliability in Resting State fMRI with Predictive Modeling.

Cereb Cortex. 2021 Jan 14;:

Authors: Taxali A, Angstadt M, Rutherford S, Sripada C

Abstract
Recent studies found low test-retest reliability in functional magnetic resonance imaging (fMRI), raising serious concerns among researchers, but these studies mostly focused on the reliability of individual fMRI features (e.g., individual connections in resting state connectivity maps). Meanwhile, neuroimaging researchers increasingly employ multivariate predictive models that aggregate information across a large number of features to predict outcomes of interest, but the test-retest reliability of predicted outcomes of these models has not previously been systematically studied. Here we apply 10 predictive modeling methods to resting state connectivity maps from the Human Connectome Project dataset to predict 61 outcome variables. Compared with mean reliability of individual resting state connections, we find mean reliability of the predicted outcomes of predictive models is substantially higher for all 10 modeling methods assessed. Moreover, improvement was consistently observed across all scanning and processing choices (i.e., scan lengths, censoring thresholds, volume- vs. surface-based processing). For the most reliable methods, the reliability of predicted outcomes was mostly, though not exclusively, in the "good" range (above 0.60). Finally, we identified three mechanisms that help to explain why predicted outcomes of predictive models have higher reliability than individual imaging features. We conclude that researchers can potentially achieve higher test-retest reliability by making greater use of predictive models.

PMID: 33447841 [PubMed - as supplied by publisher]

Network-based functional connectivity predicts response to exposure therapy in unmedicated adults with obsessive-compulsive disorder.

Sat, 01/16/2021 - 12:00
Related Articles

Network-based functional connectivity predicts response to exposure therapy in unmedicated adults with obsessive-compulsive disorder.

Neuropsychopharmacology. 2021 Jan 14;:

Authors: Shi TC, Pagliaccio D, Cyr M, Simpson HB, Marsh R

Abstract
Obsessive-compulsive disorder (OCD) is associated with alterations in cortico-striato-thalamo-cortical brain networks, but some resting-state functional magnetic resonance imaging studies report more diffuse alterations in brain connectivity. Few studies have assessed functional connectivity within or between networks across the whole brain in unmedicated OCD patients or how patterns of connectivity predict response to exposure and ritual prevention (EX/RP) therapy, a first-line treatment for OCD. Herein, multiband resting-state functional MRI scans were collected from unmedicated, adult patients with OCD (n = 41) and healthy participants (n = 36); OCD patients were then offered twice weekly EX/RP (17 sessions). A whole-brain-network-based statistic approach was used to identify group differences in resting-state connectivity. We detected altered pre-treatment functional connectivity between task-positive regions in the temporal gyri (middle and superior) and regions of the cingulo-opercular and default networks in individuals with OCD. Signal extraction was performed using a reconstruction independent components analysis and isolated two independent subcomponents (IC1 and IC2) within this altered connectivity. In the OCD group, linear mixed-effects models tested whether IC1 or IC2 values predicted the slope of change in Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) scores across EX/RP treatment. Lower (more different from controls) IC2 score significantly predicted greater symptom reduction with EX/RP (Bonferroni-corrected p = 0.002). Collectively, these findings suggest that an altered balance between task-positive and task-negative regions centered around temporal gyri may contribute to difficulty controlling intrusive thoughts or urges to perform ritualistic behaviors.

PMID: 33446895 [PubMed - as supplied by publisher]

Individual-fMRI-approaches reveal cerebellum and visual communities to be functionally connected in obsessive compulsive disorder.

Sat, 01/16/2021 - 12:00
Related Articles

Individual-fMRI-approaches reveal cerebellum and visual communities to be functionally connected in obsessive compulsive disorder.

Sci Rep. 2021 Jan 14;11(1):1354

Authors: Kashyap R, Eng GK, Bhattacharjee S, Gupta B, Ho R, Ho CSH, Zhang M, Mahendran R, Sim K, Chen SHA

Abstract
There is significant interest in understanding the pathophysiology of Obsessive-Compulsive Disorder (OCD) using resting-state fMRI (rsfMRI). Previous studies acknowledge abnormalities within and beyond the fronto-striato-limbic circuit in OCD that require further clarifications. However, limited information could be inferred from the conventional way of investigating the functional connectivity differences between OCD and healthy controls. Here, we identified altered brain organization in patients with OCD by applying individual-based approaches to maximize the identification of underlying network-based features specific to the OCD group. rsfMRI of 20 patients with OCD and 22 controls were preprocessed, and individual-fMRI-subspace was derived for each subject within each group. We evaluated group differences in functional connectivity using individual-fMRI-subspace and established its advantage over conventional-fMRI methodology. We applied prediction-based approaches to highlight the group differences by evaluating the differences in functional connections that predicted the clinical scores (namely, the Obsessive-Compulsive Inventory-Revised (OCI-R) and Hamilton Anxiety Rating Scale). Then, we explored the brain network organization of both groups by estimating the subject-specific communities within each group. Lastly, we evaluated associations between the inter-individual variation of nodes in the communities to clinical measures using linear regression. Functional connectivity analysis using individual-fMRI-subspace detected 83 connections that were different between OCD and control groups, compared to none found using conventional-fMRI methodology. Connectome-based prediction analysis did not show significant overlap between the two groups in the functional connections that predicted the clinical scores. This suggests that the functional architecture in patients with OCD may be different compared to controls. Seven communities were found in both groups. Interestingly, within the OCD group but not controls, we observed functional connectivity between cerebellar and visual regions, and lack of connectivity between striato-limbic and frontal areas. Inter-individual variations in the community-size of these two communities were also associated with the OCI-R score (p < .005). Due to our small sample size, we further validated our results by (i) accounting for head motion, (ii) applying global signal regression (GSR) in data processing, and (iii) using an alternate atlas for parcellation. While the main results were consistently observed with accounting for head motion and using another atlas, the key findings were not reproduced with GSR application. The study demonstrated the existence of disconnectedness in fronto-striato-limbic community and connectedness between cerebellar and visual areas in OCD patients, which was also related to the clinical symptomatology of OCD.

PMID: 33446780 [PubMed - in process]

Vasoactive intestinal polypeptide plasma levels associated with affective symptoms and brain structure and function in healthy females.

Sat, 01/16/2021 - 12:00
Related Articles

Vasoactive intestinal polypeptide plasma levels associated with affective symptoms and brain structure and function in healthy females.

Sci Rep. 2021 Jan 14;11(1):1406

Authors: Simon RA, Barazanji N, Jones MP, Bednarska O, Icenhour A, Engström M, Hamilton JP, Keita ÅV, Walter S

Abstract
Vasoactive intestinal polypeptide (VIP) is a neuroendocrine peptide distributed throughout the human body, including the CNS, where it is particularly abundant in brain regions associated with anxiety and depression. Based on earlier studies indicating that peripheral VIP may cross through the blood-brain barrier, we hypothesized plasma VIP levels to be associated with symptoms of anxiety and depression, as well as brain volume and resting-state functional connectivity in the amygdala, hippocampus, parahippocampus, and orbitofrontal cortex. Plasma VIP concentrations and anxiety/depression symptoms were measured in 37 healthy females. Functional and structural magnetic resonance imaging were used to evaluate functional connectivity and brain volume respectively, and their associations with VIP concentrations within brain regions associated with anxiety and depression. Negative correlations were found between VIP levels and symptoms of anxiety (r = - 0.44, p = 0.002) and depression (r = - 0.50, p = 0.001). Functional connectivity demonstrated significant VIP-dependent positive associations between the amygdala seed region with both the right parahippocampus (t(33) = 3.1, pFDR = 0.02) and right lateral orbitofrontal cortex (OFC; t(33) = 2.9, pFDR = 0.02). Moreover, VIP concentrations were significantly, positively correlated with brain volume in the left amygdala (r = 0.28, p = 0.007) and left lateral OFC (r = 0.29, p = 0.004). The present findings highlight a potential role for VIP in the neurobiology of affective symptoms.

PMID: 33446759 [PubMed - in process]

Test-retest reliability of laser evoked pain perception and fMRI BOLD responses.

Sat, 01/16/2021 - 12:00
Related Articles

Test-retest reliability of laser evoked pain perception and fMRI BOLD responses.

Sci Rep. 2021 Jan 14;11(1):1322

Authors: Bi Y, Hou X, Zhong J, Hu L

Abstract
Pain perception is a subjective experience and highly variable across time. Brain responses evoked by nociceptive stimuli are highly associated with pain perception and also showed considerable variability. To date, the test-retest reliability of laser-evoked pain perception and its associated brain responses across sessions remain unclear. Here, an experiment with a within-subject repeated-measures design was performed in 22 healthy volunteers. Radiant-heat laser stimuli were delivered on subjects' left-hand dorsum in two sessions separated by 1-5 days. We observed that laser-evoked pain perception was significantly declined across sessions, coupled with decreased brain responses in the bilateral primary somatosensory cortex (S1), right primary motor cortex, supplementary motor area, and middle cingulate cortex. Intraclass correlation coefficients between the two sessions showed "fair" to "moderate" test-retest reliability for pain perception and brain responses. Additionally, we observed lower resting-state brain activity in the right S1 and lower resting-state functional connectivity between right S1 and dorsolateral prefrontal cortex in the second session than the first session. Altogether, being possibly influenced by changes of baseline mental state, laser-evoked pain perception and brain responses showed considerable across-session variability. This phenomenon should be considered when designing experiments for laboratory studies and evaluating pain abnormalities in clinical practice.

PMID: 33446726 [PubMed - in process]

A proof of concept machine learning analysis using multimodal neuroimaging and neurocognitive measures as predictive biomarker in bipolar disorder.

Sat, 01/16/2021 - 12:00
Related Articles

A proof of concept machine learning analysis using multimodal neuroimaging and neurocognitive measures as predictive biomarker in bipolar disorder.

Asian J Psychiatr. 2020 Apr;50:101984

Authors: Achalia R, Sinha A, Jacob A, Achalia G, Kaginalkar V, Venkatasubramanian G, Rao NP

Abstract
BACKGROUND: Concomitant use of complementary, multimodal imaging measures and neurocognitive measures is reported to have higher accuracy as a biomarker in Alzheimer's dementia. However, such an approach has not been examined to differentiate healthy individuals from Bipolar disorder. In this study, we examined the utility of support vector machine (SVM) technique to differentiate bipolar disorder patients and healthy using structural, functional and diffusion tensor images of brain and neurocognitive measures.
METHODS: 30 patients with Bipolar disorder-I and 30 age, sex matched individuals participated in the study. Structural MRI, resting state functional MRI and diffusion tensor images were obtained using a 1.5 T scanner. All participants were administered neuropsychological tests to measure executive functions. SVM, a supervised machine learning technique was applied to differentiate patients and healthy individuals with k-fold cross validation over 10 trials.
RESULTS: The composite marker consisting of both neuroimaging and neuropsychological measures, had an accuracy of 87.60 %, sensitivity of 82.3 % and specificity of 92.7 %. The performance of composite marker was better compared to that of individual markers on classificatory.
CONCLUSIONS: We were able to achieve a high accuracy for machine learning technique in distinguishing BD from HV using a combination of multimodal neuroimaging and neurocognitive measures. Findings of this proof of concept study, if replicated in larger samples, could have potential clinical applications.

PMID: 32143176 [PubMed - indexed for MEDLINE]

Differential response to SSRI versus Placebo and distinct neural signatures among data-driven subgroups of patients with major depressive disorder.

Fri, 01/15/2021 - 17:00
Related Articles

Differential response to SSRI versus Placebo and distinct neural signatures among data-driven subgroups of patients with major depressive disorder.

J Affect Disord. 2020 Dec 28;282:602-610

Authors: Chin Fatt CR, Cooper CM, Jha MK, Minhajuddin A, Rush AJ, Trombello JM, Fava M, McInnis M, Weissman M, Trivedi MH

Abstract
OBJECTIVE: To identify data-driven subgroups in Major Depressive Disorder (MDD) in order to elucidate underlying neural correlates and determine if these subgroups have utility in predicting response to antidepressant versus placebo.
METHODS: Using 27 clinical measures at baseline of Establishing Moderators and Biosignatures of Antidepressant Response for Clinical Care for Depression (EMBARC) study, participants with MDD (n=244) were sub grouped using principal component (PC) analysis. Baseline-to-week-8 changes in depression severity with sertraline versus placebo were compared in these subgroups. Resting-state functional connectivity of these subgroups were compared to those of healthy controls (n=38).
RESULTS: Eight subgroups were identified from four PCs: (PC1) severity of depression-associated symptoms, (PC2) sub-threshold mania and anhedonia, (PC3) childhood trauma, medical comorbidities, and sexual dysfunction, and (PC4) personality traits of openness and agreeableness. Participants with high childhood trauma experienced greater improvement with sertraline (Cohen's d=0.87), whereas those with either higher levels of subthreshold hypomanic symptoms (Cohen's d=0.67) or with lower levels of agreeableness and openness experienced greater improvement with placebo (Cohen's d=0.71). Participants with high childhood trauma had greater connectivity between salience and dorsal attention networks, whereas those with higher levels of subthreshold hypomanic symptoms and lower levels of agreeableness and openness had greater connectivity within limbic network and that of visual network with hippocampus and dorsal attention network.
CONCLUSION: Assessing history of childhood trauma, presence of subthreshold hypomanic symptoms and personality traits may help to identify subgroups of patients with MDD who respond differentially to sertraline or placebo and have distinct neural signatures.

PMID: 33445082 [PubMed - as supplied by publisher]

Altered brain intrinsic functional hubs and connectivity associated with relapse risk in heroin dependents undergoing methadone maintenance treatment: A resting-state fMRI study.

Fri, 01/15/2021 - 17:00
Related Articles

Altered brain intrinsic functional hubs and connectivity associated with relapse risk in heroin dependents undergoing methadone maintenance treatment: A resting-state fMRI study.

Drug Alcohol Depend. 2021 Jan 02;219:108503

Authors: Wang L, Hu F, Wang W, Li Q, Li Y, Zhu J, Qin Y, Shi H, Li W, Wang Y

Abstract
BACKGROUND: The neural substrates underlying the relapse behavior of heroin dependents (HD) who received long-term methadone maintenance treatment (MMT) have yet to be thoroughly expounded. This study investigated the relapse-related intrinsic functional hubs of HD and their functional integration feature at whole brain network level.
METHODS: 57 male HD receiving MMT and 49 matched healthy controls (HC) were enrolled. All of the subjects received resting-state functional magnetic resonance imaging scan. And the 57 patients were assigned a 26-month follow-up for collecting illegal drug use information. Of them, 11 were non-relapsers and 46 relapsers. We analyzed the voxel-based degree centrality (DC) to reveal the differences in nodule centrality between HD and HC, conducted Pearson partial-correlation analysis to confirm the relationship between relapse frequency and DC value of the nodes with significant intergroup differences, and finally compared the functional connectivity (FC) of the relapse-related hubs between non-relapsers and relapsers.
RESULTS: We found the DC values of right insula and left nucleus accumbens (NAc) were negatively correlated with relapse frequency. Compared with the non-relapsers, the relapsers had a significant decreased FC between left NAc and inhibitory control circuitry, including left dorsolateral prefrontal cortex, left inferior frontal gyrus and motor regions.
CONCLUSIONS: These findings suggest that the neural substrates of relapse vulnerability in HD undergoing MMT are the intrinsic functional hubs of introceptive and reward systems and the latter modulates relapse behavior via interaction with inhibitory control circuit.

PMID: 33444899 [PubMed - as supplied by publisher]

Brain functional networks associated with social bonding in monogamous voles.

Fri, 01/15/2021 - 17:00
Related Articles

Brain functional networks associated with social bonding in monogamous voles.

Elife. 2021 Jan 14;10:

Authors: López-Gutiérrez MF, Gracia-Tabuenca Z, Ortiz JJ, Camacho FJ, Young LJ, Paredes RG, Diaz NF, Portillo W, Alcauter S

Abstract
Previous studies have related pair bonding in Microtus ochrogaster, the prairie vole, with plastic changes in several brain regions. However, the interactions between these socially-relevant regions have yet to be described. In this study, we used resting state magnetic resonance imaging to explore bonding behaviors and functional connectivity of brain regions previously associated with pair bonding. Thirty-two male and female prairie voles were scanned at baseline, 24h and 2 weeks after the onset of cohabitation By using network based statistics, we identified that the functional connectivity of a cortico-striatal network predicted the onset of affiliative behavior, while another predicted the amount of social interaction during a partner preference test. Furthermore, a network with significant changes in time was revealed, also showing associations with the level of partner preference. Overall, our findings revealed the association between network-level functional connectivity changes and social bonding.

PMID: 33443015 [PubMed - as supplied by publisher]

A novel fully immersive virtual reality environment for upper extremity rehabilitation in patients with stroke.

Fri, 01/15/2021 - 17:00
Related Articles

A novel fully immersive virtual reality environment for upper extremity rehabilitation in patients with stroke.

Ann N Y Acad Sci. 2021 Jan 14;:

Authors: Mekbib DB, Debeli DK, Zhang L, Fang S, Shao Y, Yang W, Han J, Jiang H, Zhu J, Zhao Z, Cheng R, Ye X, Zhang J, Xu D

Abstract
Given the rising incidence of stroke, several technology-driven methods for rehabilitation have recently been developed. Virtual reality (VR) is a promising therapeutic technology among them. We recently developed a neuroscientifically grounded VR system to aid recovery of motor function poststroke. The developed system provides unilateral and bilateral upper extremity (UE) training in a fully immersive virtual environment that may stimulate and activate mirror neurons (MNs) in the brain necessary for UE rehabilitation. Twenty-three participants were randomized to a VR group (n = 12) to receive VR intervention (8 h within 2 weeks) plus 8-h occupational therapy (OT) or a control group (n = 11) to receive time-matched OT alone. Treatment effects on motor recovery and cortical reorganization were investigated using the Barthel Index (BI), Fugl-Meyer Upper Extremity (FM-UE), and resting-state fMRI. Both groups significantly improved BI (P < 0.05), reflecting the recovery of UE motor function. The VR group revealed significant improvements on FM-UE scores (P < 0.05) than the control group. Neural activity increased after the intervention, particularly in the brain areas implicating MNs, such as in the primary motor cortex. Overall, results suggested that using a neuroscientifically grounded VR system might offer additional benefits for UE rehabilitation in patients receiving OT.

PMID: 33442915 [PubMed - as supplied by publisher]

Resting-state functional connectivity predicts recovery from visually induced motion sickness.

Fri, 01/15/2021 - 17:00
Related Articles

Resting-state functional connectivity predicts recovery from visually induced motion sickness.

Exp Brain Res. 2021 Jan 13;:

Authors: Miyazaki J, Yamamoto H, Ichimura Y, Yamashiro H, Murase T, Yamamoto T, Umeda M, Higuchi T

Abstract
Movies depicting certain types of motion often provoke uncomfortable symptoms similar to motion sickness, termed visually induced motion sickness (VIMS). VIMS generally evolves slowly during the viewing of a motion stimulus and, when the stimulus is removed, the recovery proceeds over time. Recent human neuroimaging studies have provided new insights into the neural bases of the evolution of VIMS. In contrast, no study has investigated the neural correlates of the recovery from VIMS. Study of the recovery process is critical for the development of a way to promote recovery and could provide further clues for understanding the mechanisms of VIMS. We thus investigated brain activity during the recovery from VIMS with functional connectivity magnetic resonance imaging. We found enhanced recovery-related functional connectivity patterns involving brain areas such as the insular, cingulate and visual cortical regions, which have been suggested to play important roles in the emergence of VIMS. These regions also constituted large interactive networks. Furthermore, the increase in functional connectivity was correlated with the subjective awareness of recovery for the following five pairs of brain regions: insula-superior temporal gyrus, claustrum-left and right inferior parietal lobules, claustrum-superior temporal gyrus and superior frontal gyrus-lentiform nucleus. Considering the previous findings on the functions of these regions and the present results, it is suggested that the increase in FC may reflect brain processes such as enhanced interoceptive awareness to one's own bodily state, a neuroplastic change in visual-processing circuits and/or the maintenance of visual spatial memory.

PMID: 33442756 [PubMed - as supplied by publisher]

Role of the Nucleus Basalis as a Key Network Node in Temporal Lobe Epilepsy.

Fri, 01/15/2021 - 17:00
Related Articles

Role of the Nucleus Basalis as a Key Network Node in Temporal Lobe Epilepsy.

Neurology. 2021 Jan 13;:

Authors: González HFJ, Narasimhan S, Johnson GW, Wills KE, Haas KF, Konrad PE, Chang C, Morgan VL, Rubinov M, Englot DJ

Abstract
OBJECTIVE: To determine if nucleus basalis of Meynert (NBM) may be a key network structure of altered functional connectivity in temporal lobe epilepsy (TLE), we examined fMRI with network based analyses.
METHODS: We acquired resting-state fMRI in 40 adults with TLE and 40 matched healthy control participants. We calculated functional connectivity of NBM and used multiple complementary network based analyses to explore the importance of NBM in TLE networks without biasing our results by our approach. We compared patients to controls and examined associations of network properties with disease metrics and neurocognitive testing.
RESULTS: We observed marked decreases in connectivity between NBM and the rest of the brain in patients with TLE(0.91±0.88, mean±SD) versus controls(1.96±1.13,p<0.001 t-test). Larger decreases in connectivity between NBM and fronto-parietal-insular regions were associated with higher frequency of consciousness-impairing seizures(r=-0.41, p=0.008, Pearson). A core network of altered nodes in TLE included NBM ipsilateral to the epileptogenic side and bilateral limbic structures. Further, normal community affiliation of ipsilateral NBM was lost in patients, and this structure displayed the most altered clustering coefficient of any node examined(3.46±1.17 controls versus 2.23±0.93 patients). Abnormal connectivity between NBM and subcortical arousal community was associated with modest neurocognitive deficits. Finally, a logistic regression model incorporating connectivity properties of ipsilateral NBM successfully distinguished patients versus control datasets with moderately high accuracy(78%).
CONCLUSIONS: These results suggest that while NBM is rarely studied in epilepsy, it may be one of the most perturbed network nodes in TLE, contributing to widespread neural effects in this disabling disorder.

PMID: 33441453 [PubMed - as supplied by publisher]

Brain functional changes in perimenopausal women: an amplitude of low-frequency fluctuation study.

Thu, 01/14/2021 - 16:00
Related Articles

Brain functional changes in perimenopausal women: an amplitude of low-frequency fluctuation study.

Menopause. 2021 Jan 11;Publish Ahead of Print:

Authors: Liu N, Zhang Y, Liu S, Zhang X, Liu H

Abstract
OBJECTIVE: To evaluate the effects of sex hormones on amplitude of low-frequency fluctuation (ALFF) in brain regions related to cognition in perimenopausal women.
METHODS: This cross-sectional study involved 25 perimenopausal women and 25 premenopausal women who underwent behavioral evaluations, sex hormone level measurements, and functional magnetic resonance imaging (fMRI). All data and ALFF analyses were preprocessed using the Data Processing Assistant for Resting-State fMRI. Statistical analyses were performed using the Resting-State fMRI Data Analysis Toolkit to explore the differences in ALFF between perimenopausal and premenopausal women. The gray matter volume (GMV) values extracted from brain regions (regions of interest) with significantly different ALFF values between the perimenopausal and premenopausal groups were compared. We analyzed the correlations of the ALFF and GMV values of these regions of interest with the results of behavioral evaluations and sex hormone levels in the two groups.
RESULTS: Compared with the premenopausal group, the perimenopausal group showed significant ALFF increase in the left gyrus rectus. Regions with decreased ALFF in the perimenopausal group included the left superior temporal gyrus, left inferior frontal gyrus, and left insula. The GMV values of the left gyrus rectus and left superior temporal gyrus were reduced in perimenopausal women. Furthermore, the estradiol level was negatively correlated with the ALFF value of the left gyrus rectus in perimenopausal women.
CONCLUSIONS: The ALFF and GMV values of certain brain regions related to cognitive function were changed in perimenopausal women. Such functional brain alterations may provide more information regarding the mechanism of cognitive dysfunction in perimenopausal women.

PMID: 33438891 [PubMed - as supplied by publisher]

Contralesional functional network reorganization of the insular cortex in diffuse low-grade glioma patients.

Thu, 01/14/2021 - 16:00
Related Articles

Contralesional functional network reorganization of the insular cortex in diffuse low-grade glioma patients.

Sci Rep. 2021 Jan 12;11(1):623

Authors: Fang S, Zhou C, Wang Y, Jiang T

Abstract
Diffuse low-grade gliomas (DLGGs) growing on the insular lobe induce contralesional hemispheric insular lobe compensation of damaged functioning by increasing cortical volumes. However, it remains unclear how functional networks are altered in patients with insular lobe DLGGs during functional compensation. Thirty-five patients with insular DLGGs were classified into the left (insL, n = 16) and right groups (insR, n = 19), and 33 healthy subjects were included in the control group. Resting state functional magnetic resonance imaging was used to generate functional connectivity (FC), and network topological properties were evaluated using graph theoretical analysis based on FC matrices. Network-based statistics were applied to compare differences in the FC matrices. A false discovery rate was applied to correct the topological properties. There was no difference in the FC of edges between the control and insL groups; however, the nodal shortest path length of the right insular lobe was significantly increased in the insL group compared to the control group. Additionally, FC was increased in the functional edges originating from the left insular lobe in the insR group compared to the control group. Moreover, there were no differences in topological properties between the insR and control groups. The contralesional insular lobe is crucial for network alterations. The detailed patterns of network alterations were different depending on the affected hemisphere. The observed network alterations might be associated with functional network reorganization and functional compensation.

PMID: 33436741 [PubMed - in process]

Sensory over-responsivity is related to GABAergic inhibition in thalamocortical circuits.

Thu, 01/14/2021 - 16:00
Related Articles

Sensory over-responsivity is related to GABAergic inhibition in thalamocortical circuits.

Transl Psychiatry. 2021 Jan 12;11(1):39

Authors: Wood ET, Cummings KK, Jung J, Patterson G, Okada N, Guo J, O'Neill J, Dapretto M, Bookheimer SY, Green SA

Abstract
Sensory over-responsivity (SOR), extreme sensitivity to or avoidance of sensory stimuli (e.g., scratchy fabrics, loud sounds), is a highly prevalent and impairing feature of neurodevelopmental disorders such as autism spectrum disorders (ASD), anxiety, and ADHD. Previous studies have found overactive brain responses and reduced modulation of thalamocortical connectivity in response to mildly aversive sensory stimulation in ASD. These findings suggest altered thalamic sensory gating which could be associated with an excitatory/inhibitory neurochemical imbalance, but such thalamic neurochemistry has never been examined in relation to SOR. Here we utilized magnetic resonance spectroscopy and resting-state functional magnetic resonance imaging to examine the relationship between thalamic and somatosensory cortex inhibitory (gamma-aminobutyric acid, GABA) and excitatory (glutamate) neurochemicals with the intrinsic functional connectivity of those regions in 35 ASD and 35 typically developing pediatric subjects. Although there were no diagnostic group differences in neurochemical concentrations in either region, within the ASD group, SOR severity correlated negatively with thalamic GABA (r = -0.48, p < 0.05) and positively with somatosensory glutamate (r = 0.68, p < 0.01). Further, in the ASD group, thalamic GABA concentration predicted altered connectivity with regions previously implicated in SOR. These variations in GABA and associated network connectivity in the ASD group highlight the potential role of GABA as a mechanism underlying individual differences in SOR, a major source of phenotypic heterogeneity in ASD. In ASD, abnormalities of the thalamic neurochemical balance could interfere with the thalamic role in integrating, relaying, and inhibiting attention to sensory information. These results have implications for future research and GABA-modulating pharmacologic interventions.

PMID: 33436538 [PubMed - in process]

Default mode and salience network alterations in suicidal and non-suicidal self-injurious thoughts and behaviors in adolescents with depression.

Thu, 01/14/2021 - 16:00
Related Articles

Default mode and salience network alterations in suicidal and non-suicidal self-injurious thoughts and behaviors in adolescents with depression.

Transl Psychiatry. 2021 Jan 12;11(1):38

Authors: Ho TC, Walker JC, Teresi GI, Kulla A, Kirshenbaum JS, Gifuni AJ, Singh MK, Gotlib IH

Abstract
Suicidal ideation (SI) and non-suicidal self-injury (NSSI) are two distinct yet often co-occurring risk factors for suicide deaths in adolescents. Elucidating the neurobiological patterns that specifically characterize SI and NSSI in adolescents is needed to inform the use of these markers in intervention studies and to develop brain-based treatment targets. Here, we clinically assessed 70 adolescents-49 adolescents with depression and 21 healthy controls-to determine SI and NSSI history. Twenty-eight of the depressed adolescents had a history of SI and 29 had a history of NSSI (20 overlapping). All participants underwent a resting-state fMRI scan. We compared groups in network coherence of subdivisions of the central executive network (CEN), default mode network (DMN), and salience network (SN). We also examined group differences in between-network connectivity and explored brain-behavior correlations. Depressed adolescents with SI and with NSSI had lower coherence in the ventral DMN compared to those without SI or NSSI, respectively, and healthy controls (all ps < 0.043, uncorrected). Depressed adolescents with NSSI had lower coherence in the anterior DMN and in insula-SN (all ps < 0.030, uncorrected), and higher CEN-DMN connectivity compared to those without NSSI and healthy controls (all ps < 0.030, uncorrected). Lower network coherence in all DMN subnetworks and insula-SN were associated with higher past-month SI and NSSI (all ps < 0.001, uncorrected). Thus, in our sample, both SI and NSSI are related to brain networks associated with difficulties in self-referential processing and future planning, while NSSI specifically is related to brain networks associated with disruptions in interoceptive awareness.

PMID: 33436537 [PubMed - in process]

Time-Varying Functional Connectivity Decreases as a Function of Acute Nicotine Abstinence.

Thu, 01/14/2021 - 16:00
Related Articles

Time-Varying Functional Connectivity Decreases as a Function of Acute Nicotine Abstinence.

Biol Psychiatry Cogn Neurosci Neuroimaging. 2020 Oct 19;:

Authors: Fedota JR, Ross TJ, Castillo J, McKenna MR, Matous AL, Salmeron BJ, Menon V, Stein EA

Abstract
BACKGROUND: The nicotine withdrawal syndrome (NWS) includes affective and cognitive disruptions whose incidence and severity vary across time during acute abstinence. However, most network-level neuroimaging uses static measures of resting-state functional connectivity and assumes time-invariance and is thus unable to capture dynamic brain-behavior relationships. Recent advances in resting-state functional connectivity signal processing allow characterization of time-varying functional connectivity (TVFC), which characterizes network communication between networks that reconfigure over the course of data collection. Therefore, TVFC may more fully describe network dysfunction related to the NWS.
METHODS: To isolate alterations in the frequency and diversity of communication across network boundaries during acute nicotine abstinence, we scanned 25 cigarette smokers in the nicotine-sated and abstinent states and applied a previously validated method to characterize TVFC at a network and a nodal level within the brain.
RESULTS: During abstinence, we found brain-wide decreases in the frequency of interactions between network nodes in different modular communities (i.e., temporal flexibility). In addition, within a subset of the networks examined, the variability of these interactions across community boundaries (i.e., spatiotemporal diversity) also decreased. Finally, within 2 of these networks, the decrease in spatiotemporal diversity was significantly related to NWS clinical symptoms.
CONCLUSIONS: Using multiple measures of TVFC in a within-subjects design, we characterized a novel set of changes in network communication and linked these changes to specific behavioral symptoms of the NWS. These reductions in TVFC provide a meso-scale network description of the relative inflexibility of specific large-scale brain networks during acute abstinence.

PMID: 33436331 [PubMed - as supplied by publisher]

Pages