New resting-state fMRI related studies at PubMed

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Cognitive performance change of pediatric patients after conducting frontal transcortical approach to treat lateral ventricular tumor.

Sun, 09/24/2017 - 14:20

Cognitive performance change of pediatric patients after conducting frontal transcortical approach to treat lateral ventricular tumor.

Childs Nerv Syst. 2017 Sep 22;:

Authors: Zhu W, He J, Li X, Wang L, Lu Z, Li C, Gong J

Abstract
OBJECTIVE: Applying frontal transcortical approach to treat lateral ventricular tumor is one of the most common neurosurgical manipulations. The frontal transcortical approach generally passes through the middle frontal gyrus in which there is no major function involved in the traditional sense. However, current researches have suggested that the prefrontal cortex (PFC) plays a central role in the whole network of the brain cognitive frame. In addition, cognitive function is crucial in growing and developmental stages and essential for the educational achievement, especially for children. Based on this, the authors in this study analyzed cognitive performance change of pediatric patients who had accepted frontal transcortical operation in 1-year follow-up and discussed the possibility of higher cognitive functions of the damaged region.
PATIENTS AND METHODS: In this single-center study, 15 pediatric patients (median age at surgery, 9.21 years old; range, 6.42-14.17 years old) who had been treated with frontal transcortical approach for lateral ventricular tumors were selected as research objects. The cognitive function assessment was conducting by adopting the revised Wechsler Intelligence Scale for Children-fourth edition (WISC-IV). In addition, the resting-state functional magnetic resonance imaging (resting-state fMRI) and diffusion tensor imaging (DTI) were carried out to measure the level of co-activation and to explore the functional connectivity between the brain regions at the preoperative period and 1-year follow-up after surgery.
RESULTS: GTR was achieved in all patients, and all patients were in good condition after surgery. Compared to the preoperative indices of WISC-IV, patients generally had a lower level of indices of the WISC-IV after surgery, for example, the total IQ was declined to M = 83.60, SD = 9.500 from M = 95.33, SD = 13.844 within 1 year convalescence. The data of perceptual reasoning (t = - 2.392, p = 0.016), processing speed (t = - 2.121, p = 0.033), and total IQ (t = -2.638, p = 0.008) before and after surgery showed statistically significance. Furthermore, decreased functional connectivity and disconnected neural fasciculus were revealed by the size of activation regions in the resting-state fMRI and the reconstruction of three-dimensional images of white matter tracts in the DTI pre- and post-operative.
CONCLUSION: The PFC was not regarded as a major functional area in the past, but the researches at present have shown that the interactions between PFC and other posterior brain regions serve as the basis of the higher cognitive functions. According to imaging manifestations and WISC-IV tasks in this paper, we found that the PFC injury caused by the frontal transcortical approach led to damaged brain structure and impaired the performance of cognitive function. On this basis, we detected that the perceptual reasoning and processing speed maybe have more extensive connections with the middle frontal gyrus.

PMID: 28939939 [PubMed - as supplied by publisher]

Characterizing dynamic amplitude of low-frequency fluctuation and its relationship with dynamic functional connectivity: An application to schizophrenia.

Sun, 09/24/2017 - 14:20

Characterizing dynamic amplitude of low-frequency fluctuation and its relationship with dynamic functional connectivity: An application to schizophrenia.

Neuroimage. 2017 Sep 19;:

Authors: Fu Z, Tu Y, Di X, Du Y, Pearlson GD, Turner JA, Biswal BB, Zhang Z, Calhoun VD

Abstract
The human brain is a highly dynamic system with non-stationary neural activity and rapidly-changing neural interaction. Resting-state dynamic functional connectivity (dFC) has been widely studied during recent years, and the emerging aberrant dFC patterns have been identified as important features of many mental disorders such as schizophrenia (SZ). However, only focusing on the time-varying patterns in FC is not enough, since the local neural activity itself (in contrast to the inter-connectivity) is also found to be highly fluctuating from research using high-temporal-resolution imaging techniques. Exploring the time-varying patterns in brain activity and their relationships with time-varying brain connectivity is important for advancing our understanding of the co-evolutionary property of brain network and the underlying mechanism of brain dynamics. In this study, we introduced a framework for characterizing time-varying brain activity and exploring its associations with time-varying brain connectivity, and applied this framework to a resting-state fMRI dataset including 151 SZ patients and 163 age- and gender matched healthy controls (HCs). In this framework, 48 brain regions were first identified as intrinsic connectivity networks (ICNs) using group independent component analysis (GICA). A sliding window approach was then adopted for the estimation of dynamic amplitude of low-frequency fluctuation (dALFF) and dFC, which were used to measure time-varying brain activity and time-varying brain connectivity respectively. The dALFF was further clustered into six reoccurring states by the k-means clustering method and the group difference in occurrences of dALFF states was explored. Lastly, correlation coefficients between dALFF and dFC were calculated and the group difference in these dALFF-dFC correlations was explored. Our results suggested that 1) ALFF of brain regions was highly fluctuating during the resting-state and such dynamic patterns are altered in SZ, 2) dALFF and dFC were correlated in time and their correlations are altered in SZ. The overall results support and expand prior work on abnormalities of brain activity, static FC (sFC) and dFC in SZ, and provide new evidence on aberrant time-varying brain activity and its associations with brain connectivity in SZ, which might underscore the disrupted brain cognitive functions in this mental disorder.

PMID: 28939432 [PubMed - as supplied by publisher]

EEG Resting-State Networks: microstates' source localization.

Sun, 09/24/2017 - 14:20

EEG Resting-State Networks: microstates' source localization.

Brain Connect. 2017 Sep 22;:

Authors: Custo A, van der Ville D, Wells WM, Tomescu IM, Michel C

Abstract
Using EEG to elucidate the spontaneous activation of brain resting state networks is non trivial as the signal of interest is of low amplitude and it is difficult to distinguish the underlying neural sources. Using the principles of electric field topographical analysis, it is possible to estimate the meta-stable states of the brain (i.e., the resting state topographies, so-called microstates). We estimated seven resting state topographies explaining the EEG dataset with k-means clustering (N=164, 256 electrodes). Using a method specifically designed to localize the sources of broadband EEG scalp topographies by matching sensor and source space temporal patterns, we demonstrated that we can estimate the EEG resting state networks reliably by measuring the reproducibility of our findings. After subtracting their mean from the seven EEG resting state networks, we identified seven state-specific networks. The mean map includes regions known to be densely anatomically and functionally connected (superior frontal, superior parietal, insula, and anterior cingulate cortices). While the mean map can be interpreted as a "router", cross-linking multiple functional networks, the seven state-specific resting state networks partly resemble and extend previous fMRI-based networks estimated as the hemodynamic correlates of four canonical EEG microstates.

PMID: 28938855 [PubMed - as supplied by publisher]

Inter-hemispherical asymmetry in default-mode functional connectivity and BAIAP2 gene are associated with anger expression in ADHD adults.

Sat, 09/23/2017 - 13:20

Inter-hemispherical asymmetry in default-mode functional connectivity and BAIAP2 gene are associated with anger expression in ADHD adults.

Psychiatry Res. 2017 Sep 12;269:54-61

Authors: Hasler R, Preti MG, Meskaldji DE, Prados J, Adouan W, Rodriguez C, Toma S, Hiller N, Ismaili T, Hofmeister J, Sinanaj I, Baud P, Haller S, Giannakopoulos P, Schwartz S, Perroud N, Van De Ville D

Abstract
Attention deficit hyperactivity disorder (ADHD) is accompanied by resting-state alterations, including abnormal activity, connectivity and asymmetry of the default-mode network (DMN). Concurrently, recent studies suggested a link between ADHD and the presence of polymorphisms within the gene BAIAP2 (i.e., brain-specific angiogenesis inhibitor 1-associated protein 2), known to be differentially expressed in brain hemispheres. The clinical and neuroimaging correlates of this polymorphism are still unknown. We investigated the association between BAIAP2 polymorphisms and DMN functional connectivity (FC) asymmetry as well as behavioral measures in ADHD adults. Resting-state fMRI was acquired from 30 ADHD and 15 healthy adults. For each subject, rs7210438 and rs8079626 within the gene BAIAP2 were genotyped. ADHD severity, impulsiveness and anger were assessed for the ADHD group. Using multivariate analysis of variance, we found that genetic features do have an impact on DMN FC asymmetry. In particular, polymorphism rs8079626 affects medial frontal gyrus and inferior parietal lobule connectivity asymmetry, lower for AA than AG/GG carriers. Further, when combining FC asymmetry and the presence of the rs8079626 variant, we successfully predicted increased externalization of anger in ADHD. In conclusion, a complex interplay between genetic vulnerability and inter-hemispherical DMN FC asymmetry plays a role in emotion regulation in adult ADHD.

PMID: 28938222 [PubMed - as supplied by publisher]

Ensemble Hierarchical High-Order Functional Connectivity Networks for MCI Classification.

Sat, 09/23/2017 - 13:20
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Ensemble Hierarchical High-Order Functional Connectivity Networks for MCI Classification.

Med Image Comput Comput Assist Interv. 2016 Oct;9901:18-25

Authors: Chen X, Zhang H, Shen D

Abstract
Conventional functional connectivity (FC) and corresponding networks focus on characterizing the pairwise correlation between two brain regions, while the high-order FC (HOFC) and networks can model more complex relationship between two brain region "pairs" (i.e., four regions). It is eye-catching and promising for clinical applications by its irreplaceable function of providing unique and novel information for brain disease classification. Since the number of brain region pairs is very large, clustering is often used to reduce the scale of HOFC network. However, a single HOFC network, generated by a specific clustering parameter setting, may lose multifaceted, highly complementary information contained in other HOFC networks. To accurately and comprehensively characterize such complex HOFC towards better discriminability of brain diseases, in this paper, we propose a novel HOFC based disease diagnosis framework, which can hierarchically generate multiple HOFC networks and further ensemble them with a selective feature fusion method. Specifically, we create a multi-layer HOFC network construction strategy, where the networks in upper layers are formed by hierarchically clustering the nodes of the networks in lower layers. In such a way, information is passed from lower layers to upper layers by effectively removing the most redundant part of information and, at the same time, retaining the most unique part. Then, the retained information/features from all HOFC networks are fed into a selective feature fusion method, which combines sequential forward selection and sparse regression, to further select the most discriminative feature subset for classification. Experimental results confirm that our novel method outperforms all the single HOFC networks corresponding to any single parameter setting in diagnosis of mild cognitive impairment (MCI) subjects.

PMID: 28936492 [PubMed - in process]

Radiology Case of the Month: Persistent Lateral Foot Pain.

Sat, 09/23/2017 - 13:20
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Radiology Case of the Month: Persistent Lateral Foot Pain.

J La State Med Soc. 2016 Sep-Oct;168(5):182-183

Authors: Stark C, Gupta ND, Serou M, Neitzschman H

Abstract
A 33-year-old female presents with persistent lateral foot pain. Patient does not recall prior trauma that may have led to injury. Symptoms are significantly improved with rest and nonsteroidal anti-inflammatory medications.

PMID: 27797351 [PubMed - indexed for MEDLINE]

The spectrum of structural and functional network alterations in malformations of cortical development.

Fri, 09/22/2017 - 12:00
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The spectrum of structural and functional network alterations in malformations of cortical development.

Brain. 2017 Aug 01;140(8):2133-2143

Authors: Hong SJ, Bernhardt BC, Gill RS, Bernasconi N, Bernasconi A

Abstract
Neuroimaging studies of malformations of cortical development have mainly focused on the characterization of the primary lesional substrate, while whole-brain investigations remain scarce. Our purpose was to assess large-scale brain organization in prevalent cortical malformations. Based on experimental evidence suggesting that distributed effects of focal insults are modulated by stages of brain development, we postulated differential patterns of network anomalies across subtypes of malformations. We studied a cohort of patients with focal cortical dysplasia type II (n = 63), subcortical nodular heterotopia (n = 44), and polymicrogyria (n = 34), and compared them to 82 age- and sex-matched controls. Graph theoretical analysis of structural covariance networks indicated a consistent rearrangement towards a regularized architecture characterized by increased path length and clustering, as well as disrupted rich-club topology, overall suggestive of inefficient global and excessive local connectivity. Notably, we observed a gradual shift in network reconfigurations across subgroups, with only subtle changes in focal cortical dysplasia type II, moderate effects in heterotopia and maximal effects in polymicrogyria. Analysis of resting state functional connectivity also revealed gradual network changes, with most marked rearrangement in polymicrogyria; contrary to findings in the structural domain, however, functional architecture was characterized by decreases in both local and global parameters. Diverging results in the structural and functional domain were supported by formal structure-function coupling analysis. Our findings support the concept that time of insult during corticogenesis impacts the severity of topological network reconfiguration. Specifically, late-stage malformations, typified by polymicrogyria, may selectively disrupt the formation of large-scale cortico-cortical networks and thus lead to a more profound impact on whole-brain organization than early stage disturbances of predominantly radial migration patterns observed in cortical dysplasia type II, which likely affect a relatively confined cortical territory.

PMID: 28899007 [PubMed - indexed for MEDLINE]

A Single Session of rTMS Enhances Small-Worldness in Writer's Cramp: Evidence from Simultaneous EEG-fMRI Multi-Modal Brain Graph.

Thu, 09/21/2017 - 11:00
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A Single Session of rTMS Enhances Small-Worldness in Writer's Cramp: Evidence from Simultaneous EEG-fMRI Multi-Modal Brain Graph.

Front Hum Neurosci. 2017;11:443

Authors: Bharath RD, Panda R, Reddam VR, Bhaskar MV, Gohel S, Bhardwaj S, Prajapati A, Pal PK

Abstract
Background and Purpose: Repetitive transcranial magnetic stimulation (rTMS) induces widespread changes in brain connectivity. As the network topology differences induced by a single session of rTMS are less known we undertook this study to ascertain whether the network alterations had a small-world morphology using multi-modal graph theory analysis of simultaneous EEG-fMRI. Method: Simultaneous EEG-fMRI was acquired in duplicate before (R1) and after (R2) a single session of rTMS in 14 patients with Writer's Cramp (WC). Whole brain neuronal and hemodynamic network connectivity were explored using the graph theory measures and clustering coefficient, path length and small-world index were calculated for EEG and resting state fMRI (rsfMRI). Multi-modal graph theory analysis was used to evaluate the correlation of EEG and fMRI clustering coefficients. Result: A single session of rTMS was found to increase the clustering coefficient and small-worldness significantly in both EEG and fMRI (p < 0.05). Multi-modal graph theory analysis revealed significant modulations in the fronto-parietal regions immediately after rTMS. The rsfMRI revealed additional modulations in several deep brain regions including cerebellum, insula and medial frontal lobe. Conclusion: Multi-modal graph theory analysis of simultaneous EEG-fMRI can supplement motor physiology methods in understanding the neurobiology of rTMS in vivo. Coinciding evidence from EEG and rsfMRI reports small-world morphology for the acute phase network hyper-connectivity indicating changes ensuing low-frequency rTMS is probably not "noise".

PMID: 28928648 [PubMed]

Decreased structural connectivity and resting-state brain activity in the lateral occipital cortex is associated with social communication deficits in boys with autism spectrum disorder.

Thu, 09/21/2017 - 11:00
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Decreased structural connectivity and resting-state brain activity in the lateral occipital cortex is associated with social communication deficits in boys with autism spectrum disorder.

Neuroimage. 2017 Sep 16;:

Authors: Jung M, Tu Y, Lang CA, Ortiz A, Park J, Jorgenson K, Kong XJ, Kong J

Abstract
Autism spectrum disorder (ASD) is a prevalent neurodevelopmental disorder characterized by atypical social communication and repetitive behaviors. In this study, we applied a multimodal approach to investigate brain structural connectivity, resting state activity, and surface area and their associations with the core symptoms of ASD. Data from forty boys with ASD (mean age, 11.5 years; age range, 5.5-19.5) and forty boys with typical development (TD) (mean age, 12.3; age range, 5.8-19.7) were extracted from the Autism Brain Imaging Data Exchange II (ABIDE II) for data analysis. We found significantly decreased structural connectivity, resting state brain activity, and surface area at the occipital cortex in boys with ASD compared to boys with TD. In addition, we also found that resting state brain activity and surface area in the lateral occipital cortex was negatively correlated with communication scores in boys with ASD. Our results suggest that decreased structural connectivity and resting-state brain activity in the occipital cortex may impair the integration of verbal and non-verbal communication cues in boys with ASD, thereby impacting their social development.

PMID: 28927730 [PubMed - as supplied by publisher]

Genome-wide imaging association study implicates functional activity and glial homeostasis of the caudate in smoking addiction.

Thu, 09/21/2017 - 11:00
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Genome-wide imaging association study implicates functional activity and glial homeostasis of the caudate in smoking addiction.

BMC Genomics. 2017 Sep 19;18(1):740

Authors: Qian DC, Molfese DL, Jin JL, Titus AJ, He Y, Li Y, Vaissié M, Viswanath H, Baldwin PR, Krahe R, Salas R, Amos CI

Abstract
BACKGROUND: Nearly 6 million deaths and over a half trillion dollars in healthcare costs worldwide are attributed to tobacco smoking each year. Extensive research efforts have been pursued to elucidate the molecular underpinnings of smoking addiction and facilitate cessation. In this study, we genotyped and obtained both resting state and task-based functional magnetic resonance imaging from 64 non-smokers and 42 smokers. Smokers were imaged after having smoked normally ("sated") and after having not smoked for at least 12 h ("abstinent").
RESULTS: While abstinent smokers did not differ from non-smokers with respect to pairwise resting state functional connectivities (RSFCs) between 12 brain regions of interest, RSFCs involving the caudate and putamen of sated smokers significantly differed from those of non-smokers (P < 0.01). Further analyses of caudate and putamen activity during elicited experiences of reward and disappointment show that caudate activity during reward (CR) correlated with smoking status (P = 0.015). Moreover, abstinent smokers with lower CR experienced greater withdrawal symptoms (P = 0.024), which suggests CR may be related to smoking urges. Associations between genetic variants and CR, adjusted for smoking status, were identified by genome-wide association study (GWAS). Genes containing or exhibiting caudate-specific expression regulation by these variants were enriched within Gene Ontology terms that describe cytoskeleton functions, synaptic organization, and injury response (P < 0.001, FDR < 0.05).
CONCLUSIONS: By integrating genomic and imaging data, novel insights into potential mechanisms of caudate activation and homeostasis are revealed that may guide new directions of research toward improving our understanding of addiction pathology.

PMID: 28927378 [PubMed - in process]

Accounting for Non-Gaussian Sources of Spatial Correlation in Parametric fMRI Paradigms I: Revisiting Cluster-Based Inferences.

Thu, 09/21/2017 - 11:00
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Accounting for Non-Gaussian Sources of Spatial Correlation in Parametric fMRI Paradigms I: Revisiting Cluster-Based Inferences.

Brain Connect. 2017 Sep 19;

Authors: Gopinath K, Krishnamurthy V, Sathian K

Abstract
In a recent study Eklund et al. (Eklund et al., 2016) employing resting state functional magnetic resonance imaging (rsfMRI) data as a surrogate for null fMRI datasets posited that cluster-wise family-wise error (FWE) rate corrected inferences made using parametric statistical methods in fMRI studies over the past two decades may have been invalid, particularly for cluster defining thresholds (CDTs) less stringent than p < 0.001; principally because the spatial autocorrelation functions (sACF) of fMRI data had been modeled incorrectly to follow a Gaussian form, whereas empirical data suggested otherwise (Eklund et al., 2016). Here we show that accounting for non-Gaussian signal components like those arising from resting state neural activity as well as physiological responses and motion artifacts in the null fMRI datasets yields first and second-level GLM analysis residuals with nearly uniform and Gaussian sACF. Further comparison with non-parametric permutation tests indicates that cluster-based FWE corrected inferences made with Gaussian spatial noise approximations are valid.

PMID: 28927289 [PubMed - as supplied by publisher]

Alterations in regional homogeneity of resting-state cerebral activity in patients with chronic prostatitis/chronic pelvic pain syndrome.

Wed, 09/20/2017 - 16:20
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Alterations in regional homogeneity of resting-state cerebral activity in patients with chronic prostatitis/chronic pelvic pain syndrome.

PLoS One. 2017;12(9):e0184896

Authors: Lin Y, Bai Y, Liu P, Yang X, Qin W, Gu J, Ding D, Tian J, Wang M

Abstract
The purpose of this study was to explore the neural mechanism in Chronic prostatitis/Chronic pelvic pain syndrome (CP/CPPS) using resting-state functional magnetic resonance imaging. The functional magnetic resonance imaging was performed on 31 male CP/CPPS-patients and 31 age and education matched male healthy controls on a 3-T magnetic resonance imaging unit. A two-sample t-test was adopted to reveal the regional homogeneity between the patients and healthy controls. The mean regional homogeneity values in the alerted brain regions of patients were correlated with the clinical measurements by using Pearson's correlation analyses. The CP/CPPS-patients had significantly decreased regional homogeneity in the bilateral anterior cingulate cortices, insular cortices and right medial prefrontal cortex, while significantly increased regional homogeneity in the brainstem and right thalamus compared with the healthy controls. In the CP/CPPS-patients, the mean regional homogeneity value in the left anterior cingulate cortex, bilateral insular cortices and brainstem were respectively correlated with the National Institutes of Health Chronic Prostatitis Symptom Index total score and pain subscale. These brain regions are important in the pain modulation process. Therefore, an impaired pain modulatory system, either by decreased descending pain inhibition or enhanced pain facilitation, may explain the pain symptoms in CP/CPPS.

PMID: 28926645 [PubMed - in process]

Brain functional connectome abnormalities in ALS are associated with disability and cortical hyperexcitability.

Wed, 09/20/2017 - 16:20
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Brain functional connectome abnormalities in ALS are associated with disability and cortical hyperexcitability.

Eur J Neurol. 2017 Sep 19;:

Authors: Geevasinga N, Korgaonkar MS, Menon P, Van den Bos M, Gomes L, Foster S, Kiernan MC, Vucic S

Abstract
OBJECTIVE: The present study utilized a multimodality approach encompassing connectome network combined with brain volume analysis, and assessment of cortical excitability to provide novel insights into amyotrophic lateral sclerosis (ALS) pathogenesis.
METHODS: Magnetic resonance images (MRI) were acquired using a 3.0 Tesla GE Signa HDx scanner, using an 8-channel head coil. MR images for the resting state scan were acquired using echo planar imaging MR sequence, acquiring 40 contiguous axial/oblique slices. Structural MRI 3D T1-weighted images were acquired in the sagittal plane using a 3D spoiled gradient echo sequences. For structural imaging, a T1 weighted high resolution (3T) MRI scan was used. Cortical excitability was assessed by using the threshold tracking transcranial magnetic stimulation paradigm. Network based statistics (NBS) and whole brain functional topology (using graph theoretical approaches) assessed functional connectivity.
RESULTS: Using a global NBS analysis approach, functional connectivity was increased in 12 network edges connecting 14 nodes (P<0.05) within the frontal, temporal, parietal and subcortical regions. Analysis of local connectedness disclosed dichotomous effects with reduced connectivity in the frontal and increased connectivity in occipital regions in ALS. Cortical hyperexcitability was evident in ALS patients and negatively correlated with functional connectivity changes in the precentral gyrus (P<0.01). Connectivity changes in the frontal regions were negatively associated with functional disability (P<0.05).
CONCLUSION: Multimodal assessment of cortical function in ALS patients has identified deficits in functional connectivity associated with cortical hyperexcitability that correlated with patient disability. Novel integration of functional brain assessment further contributes to understanding disease pathogenesis in ALS. This article is protected by copyright. All rights reserved.

PMID: 28926154 [PubMed - as supplied by publisher]

An altered scaffold for information processing: Cognitive control development in adolescents with autism.

Wed, 09/20/2017 - 16:20
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An altered scaffold for information processing: Cognitive control development in adolescents with autism.

Biol Psychiatry Cogn Neurosci Neuroimaging. 2017 Sep;2(6):464-475

Authors: Solomon M, Hogeveen J, Libero L, Nordahl C

Abstract
We investigated how cognitive neuroscientific studies during the last decade have advanced understanding of cognitive control from adolescence to young adulthood in individuals with autism spectrum disorder (ASD). To do so, we conducted a selective review of the larger structural, resting state, and diffusion imaging studies of brain regions and networks related to cognitive control that have been conducted since 2007 in individuals with ASD and typical development (TYP) ages 10 to 30 years that examined how these regions and networks support behavioral and task-based fMRI performance on tasks assessing cognitive control during this period. Longitudinal structural studies reveal overgrowth of the anterior cingulate (ACC) and slower white matter development in the parietal cortex in adolescents with ASD versus TYP. Cross-sectional studies of the salience, executive control and default mode resting state functional connectivity networks, which mediate cognitive control, demonstrate patterns of connectivity that differ from TYP through adolescence. Finally, white matter tracts underlying these control-related brain regions continue to show reduced diffusion properties compared to TYP. It is thus not surprising that cognitive control tasks performance improves less during adolescence in ASD versus TYP. This review illustrates that a cognitive neuroscientific approach produces insights about the mechanisms of persistent cognitive control deficits in individuals with ASD from adolescence into young adulthood not apparent with neuropsychological methods alone, and draws attention to the great need for longitudinal studies of this period in those with ASD. Further investigation of ACC and fronto-parietal neural circuits may help specify pathophysiology and treatment options.

PMID: 28924621 [PubMed]

Common and dissociable regional cerebral blood flow differences associate with dimensions of psychopathology across categorical diagnoses.

Wed, 09/20/2017 - 16:20
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Common and dissociable regional cerebral blood flow differences associate with dimensions of psychopathology across categorical diagnoses.

Mol Psychiatry. 2017 Sep 19;:

Authors: Kaczkurkin AN, Moore TM, Calkins ME, Ciric R, Detre JA, Elliott MA, Foa EB, Garcia de la Garza A, Roalf DR, Rosen A, Ruparel K, Shinohara RT, Xia CH, Wolf DH, Gur RE, Gur RC, Satterthwaite TD

Abstract
The high comorbidity among neuropsychiatric disorders suggests a possible common neurobiological phenotype. Resting-state regional cerebral blood flow (CBF) can be measured noninvasively with magnetic resonance imaging (MRI) and abnormalities in regional CBF are present in many neuropsychiatric disorders. Regional CBF may also provide a useful biological marker across different types of psychopathology. To investigate CBF changes common across psychiatric disorders, we capitalized upon a sample of 1042 youths (ages 11-23 years) who completed cross-sectional imaging as part of the Philadelphia Neurodevelopmental Cohort. CBF at rest was quantified on a voxelwise basis using arterial spin labeled perfusion MRI at 3T. A dimensional measure of psychopathology was constructed using a bifactor model of item-level data from a psychiatric screening interview, which delineated four factors (fear, anxious-misery, psychosis and behavioral symptoms) plus a general factor: overall psychopathology. Overall psychopathology was associated with elevated perfusion in several regions including the right dorsal anterior cingulate cortex (ACC) and left rostral ACC. Furthermore, several clusters were associated with specific dimensions of psychopathology. Psychosis symptoms were related to reduced perfusion in the left frontal operculum and insula, whereas fear symptoms were associated with less perfusion in the right occipital/fusiform gyrus and left subgenual ACC. Follow-up functional connectivity analyses using resting-state functional MRI collected in the same participants revealed that overall psychopathology was associated with decreased connectivity between the dorsal ACC and bilateral caudate. Together, the results of this study demonstrate common and dissociable CBF abnormalities across neuropsychiatric disorders in youth.Molecular Psychiatry advance online publication, 19 September 2017; doi:10.1038/mp.2017.174.

PMID: 28924181 [PubMed - as supplied by publisher]

Altered functional connectivity in mesial temporal lobe epilepsy.

Wed, 09/20/2017 - 16:20
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Altered functional connectivity in mesial temporal lobe epilepsy.

Epilepsy Res. 2017 Sep 08;137:45-52

Authors: Burianová H, Faizo NL, Gray M, Hocking J, Galloway G, Reutens D

Abstract
Growing evidence of altered functional connectivity suggests that mesial temporal lobe epilepsy (mTLE) alters not only hippocampal networks, but also a number of resting state networks. These highly coherent, yet functionally distinct brain circuits interact dynamically with each other in order to mediate consciousness, memory, and attention. However, little is currently known about the modulation of these networks by epileptiform activity, such as interictal spikes and seizures. The objective of the study was to use simultaneous EEG-fMRI to investigate functional connectivity in three resting state networks: default mode network (DMN), salience network (SN), and dorsal attentional network (DAN) in patients with mTLE compared to a healthy cohort, and in relation to the onset of interictal spikes and the period immediately prior to the spikes. Compared to the healthy participants, mTLE patients showed significant alterations in functional connectivity of all three resting state networks, generally characterized by a lack of functional connectivity to prefrontal areas and increased connectivity to subcortical and posterior areas. Critically, prior to the onset of interictal spikes, compared to resting state, mTLE patients showed a lack of functional connectivity to the DMN and decreased synchronization within the SN and DAN, demonstrating alterations in functional coherence that may be responsible for the generation of epileptiform activity. Our findings demonstrate mTLE-related alterations of connectivity during the resting state as well as in relation to the onset of interictal spikes. These functional changes may underlie epilepsy-related cognitive abnormalities, because higher cognitive functions, such as memory or attention, rely heavily on the coordinated activity of all three resting state networks.

PMID: 28923408 [PubMed - as supplied by publisher]

Rapid whole-brain resting-state fMRI at 3 Tesla: Efficiency-optimized three-dimensional EPI versus repetition time-matched simultaneous-multi-slice EPI.

Wed, 09/20/2017 - 16:20
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Rapid whole-brain resting-state fMRI at 3 Tesla: Efficiency-optimized three-dimensional EPI versus repetition time-matched simultaneous-multi-slice EPI.

Neuroimage. 2017 Sep 15;:

Authors: Stirnberg R, Huijbers W, Brenner D, Poser BA, Breteler M, Stöcker T

Abstract
State-of-the-art simultaneous-multi-slice (SMS-)EPI and 3D-EPI share several properties that benefit functional MRI acquisition. Both sequences employ equivalent parallel imaging undersampling with controlled aliasing to achieve high temporal sampling rates. As a volumetric imaging sequence, 3D-EPI offers additional means of acceleration complementary to 2D-CAIPIRINHA sampling, such as fast water excitation and elliptical sampling. We performed an application-oriented comparison between a tailored, six-fold CAIPIRINHA-accelerated 3D-EPI protocol at 530 ms temporal and 2.4 mm isotropic spatial resolution and an SMS-EPI protocol with identical spatial and temporal resolution for whole-brain resting-state fMRI at 3 T. The latter required eight-fold slice acceleration to compensate for the lack of elliptical sampling and fast water excitation. Both sequences used vendor-supplied on-line image reconstruction. We acquired test/retest resting-state fMRI scans in ten volunteers, with simultaneous acquisition of cardiac and respiration data, subsequently used for optional physiological noise removal (nuisance regression). We found that the 3D-EPI protocol has significantly increased temporal signal-to-noise ratio throughout the brain as compared to the SMS-EPI protocol, especially when employing motion and nuisance regression. Both sequence types reliably identified known functional networks with stronger functional connectivity values for the 3D-EPI protocol. We conclude that the more time-efficient 3D-EPI primarily benefits from reduced parallel imaging noise due to a higher, actual k-space sampling density compared to SMS-EPI. The resultant BOLD sensitivity increase makes 3D-EPI a valuable alternative to SMS-EPI for whole-brain fMRI at 3 T, with voxel sizes well below 3 mm isotropic and sampling rates high enough to separate dominant cardiac signals from BOLD signals in the frequency domain.

PMID: 28923276 [PubMed - as supplied by publisher]

The Knockout of Synapsin II in Mice Impairs Social Behavior and Functional Connectivity Generating an ASD-like Phenotype.

Wed, 09/20/2017 - 16:20
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The Knockout of Synapsin II in Mice Impairs Social Behavior and Functional Connectivity Generating an ASD-like Phenotype.

Cereb Cortex. 2017 Oct 01;27(10):5014-5023

Authors: Michetti C, Caruso A, Pagani M, Sabbioni M, Medrihan L, David G, Galbusera A, Morini M, Gozzi A, Benfenati F, Scattoni ML

Abstract
Autism spectrum disorders (ASD) and epilepsy are neurodevelopmental conditions that appear with high rate of co-occurrence, suggesting the possibility of a common genetic basis. Mutations in Synapsin (SYN) genes, particularly SYN1 and SYN2, have been recently associated with ASD and epilepsy in humans. Accordingly, mice lacking Syn1 or Syn2, but not Syn3, experience epileptic seizures and display autistic-like traits that precede the onset of seizures. Here, we analyzed social behavior and ultrasonic vocalizations emitted in 2 social contexts by SynI, SynII, or SynIII mutants and show that SynII mutants display the most severe ASD-like phenotype. We also show that the behavioral SynII phenotype correlates with a significant decrease in auditory and hippocampal functional connectivity as measured with resting state functional magnetic resonance imaging (rsfMRI). Taken together, our results reveal a permissive contribution of Syn2 to the expression of normal socio-communicative behavior, and suggest that Syn2-mediated synaptic dysfunction can lead to ASD-like behavior through dysregulation of cortical connectivity.

PMID: 28922833 [PubMed - in process]

Probabilistic Entity-Relationship Diagram: A correlation between functional connectivity and spontaneous brain activity during resting state in major depressive disorder.

Wed, 09/20/2017 - 16:20
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Probabilistic Entity-Relationship Diagram: A correlation between functional connectivity and spontaneous brain activity during resting state in major depressive disorder.

PLoS One. 2017;12(6):e0178386

Authors: Zhang L, Shi L, Zhang B, Zhao L, Dong Y, Liu J, Lian Z, Liang L, Chen W, Luo X, Pei S, Mo X, Huang W, Ouyang F, Guo B, Liang C, Zhang S

Abstract
BACKGROUND: Alterations of functional connectivity (FC) and spontaneous brain activity (SBA) during the resting state has been observed in subjects with major depressive disorder (MDD). Although there are many studies separately describing on the alterations of FC and SBA in major depressive disorder, their correlation are still have not been performed.
METHODS: A literature search based on Pubmed and Embase was conducted until 20 April 2016 to identify studies evaluating the correlation for the alterations between functional connectivity and spontaneous brain activity during resting-state in MDD. Meta-analyses were performed using the Probabilistic Entity-Relationship Diagram (PERD) approach to summarize the relationships among multiple factors in an intuitive manner.
RESULTS: A total of 30 studies (747 individuals with MDD and 757 healthy controls) met the inclusion criteria. In this study, we demonstrated that the functional connectivity and spontaneous brain activity, which was quantitatively measured by the primary analysis methods, was decreased in the parahippocampal gyrus, orbitofrontal cortex (OFC) and postcentral gyrus (PCG), and increased in insula and left dorsal medial prefrontal cortex (DMPFC) in MDD patients. Furthermore, we found that MDD patients presented negative correlation alterations both FC and SBA in the default mode network and the dorsal attention network, but positive correlation alterations both FC and SBA in the insular network, executive control network, the salience network and the other network.
CONCLUSIONS: Our results first suggested that there were correlation alterations between functional connectivity and spontaneous brain activity during resting-state in patients with MDD. Besides, we applied a recent meta-analysis approach (PERD) to summarize and integrate the inconsistence of the existing findings regarding the network dysfunction of MDD.

PMID: 28594841 [PubMed - indexed for MEDLINE]

Nicotinic modulation of salience network connectivity and centrality in schizophrenia.

Wed, 09/20/2017 - 16:20
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Nicotinic modulation of salience network connectivity and centrality in schizophrenia.

J Psychiatr Res. 2017 Jun;89:85-96

Authors: Smucny J, Wylie KP, Kronberg E, Legget KT, Tregellas JR

Abstract
Although functional abnormalities of the salience network are associated with schizophrenia, the acute effects of nicotine on its function and network dynamics during the resting state in patients are poorly understood. In this study, the effects of a 7 mg nicotine patch (vs. placebo) on salience network connectivity were examined in 17 patients with schizophrenia and 19 healthy subjects. We hypothesized abnormal connectivity between the salience network and other major networks (e.g. executive network) in patients under placebo administration and amelioration of this difference after nicotine. We also examined effects of nicotine on betweenness centrality (a measure of the influence of a region on information transfer throughout the brain) and local efficiency (a measure of local information transfer) of the network. A hybrid independent component analysis (ICA)/seed-based connectivity approach was implemented in which the salience network was extracted by ICA and cortical network peaks (anterior cingulate cortex (ACC), left and right insula) were used as seeds for whole-brain seed-to-voxel connectivity analysis. Significant drug X diagnosis interactions were observed between the ACC seed and superior parietal lobule and ventrolateral prefrontal cortex. A significant interaction effect was also observed between the left insula seed and middle cingulate cortex. During placebo conditions, abnormal connectivity predicted negative symptom severity and lower global functioning in patients. A significant drug X diagnosis interaction was also observed for betweenness centrality of the ACC. These results suggest that nicotine may target abnormalities in functional connectivity between salience and executive network areas in schizophrenia as well as affect the ability of the salience network to act as an integrator of global signaling in the disorder.

PMID: 28193583 [PubMed - indexed for MEDLINE]

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