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Dissociating tinnitus patients from healthy controls using resting-state cyclicity analysis and clustering.

Sun, 02/24/2019 - 00:26
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Dissociating tinnitus patients from healthy controls using resting-state cyclicity analysis and clustering.

Netw Neurosci. 2019;3(1):67-89

Authors: Zimmerman BJ, Abraham I, Schmidt SA, Baryshnikov Y, Husain FT

Abstract
Chronic tinnitus is a common and sometimes debilitating condition that lacks scientific consensus on physiological models of how the condition arises as well as any known cure. In this study, we applied a novel cyclicity analysis, which studies patterns of leader-follower relationships between two signals, to resting-state functional magnetic resonance imaging (rs-fMRI) data of brain regions acquired from subjects with and without tinnitus. Using the output from the cyclicity analysis, we were able to differentiate between these two groups with 58-67% accuracy by using a partial least squares discriminant analysis. Stability testing yielded a 70% classification accuracy for identifying individual subjects' data across sessions 1 week apart. Additional analysis revealed that the pairs of brain regions that contributed most to the dissociation between tinnitus and controls were those connected to the amygdala. In the controls, there were consistent temporal patterns across frontal, parietal, and limbic regions and amygdalar activity, whereas in tinnitus subjects, this pattern was much more variable. Our findings demonstrate a proof-of-principle for the use of cyclicity analysis of rs-fMRI data to better understand functional brain connectivity and to use it as a tool for the differentiation of patients and controls who may differ on specific traits.

PMID: 30793074 [PubMed]

Regional Homogeneity Abnormalities in Early-Onset and Adolescent-Onset Conduct Disorder in Boys: A Resting-State fMRI Study.

Sun, 02/24/2019 - 00:26
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Regional Homogeneity Abnormalities in Early-Onset and Adolescent-Onset Conduct Disorder in Boys: A Resting-State fMRI Study.

Front Hum Neurosci. 2019;13:26

Authors: Cao W, Li C, Zhang J, Dong D, Sun X, Yao S, Huang B, Liu J

Abstract
Purpose: Developmental taxonomic theory posits that formation of early-onset conduct disorder (EO-CD), is considered to have a neurodevelopmental etiology and have more severe psychosocial and neuropsychological dysfunction than adolescent-onset CD (AO-CD), which is thought to stem largely from social mimicry of deviant peers. The purpose of the current study was to investigate whether regional homogeneity (ReHo), denoting the spontaneous brain activity, supports developmental taxonomic theory in a resting state (rs). Materials and Methods: Rs-functional magnetic resonance imaging (fMRI) examinations were administered to 36 EO-CD patients, 32 AO-CD patients, and 30 healthy controls (HCs). All participants were male adolescents, aged between 12 and 17 years old. A one-way analysis of covariance (ANCOVA), with age and IQ as covariates, was performed to identify regions with significant group differences in ReHo values, followed by a post hoc analyses. Results: Compared with the AO-CD groups, EO-CD had higher ReHo values in the right middle/inferior frontal gyrus. Compared with the HCs, the EO-CD group exhibited lower ReHo values in the left precuneus, left middle occipital gyrus, left cerebellum posterior lobe and the right inferior parietal lobule, as well as higher ReHo values in the right middle frontal gyrus, left insula/inferior frontal gyrus, right postcentral gyrus, and the left anterior cingulate gyrus. Compared with the HCs, the AO-CD group showed lower ReHo values in the bilateral precuneus, left cerebellum posterior lobe, and the right inferior parietal lobule. Conclusion: Significant differences in ReHo were observed between the EO-CD and AO-CD groups, implying distinct neuropathological mechanisms of the two CD subtypes, consistent with developmental taxonomic theory. CD-associated abnormalities in ReHo may be related to high-order cognitive and low-level perceptual system impairments in CD.

PMID: 30792633 [PubMed]

Beyond binary parcellation of the vestibular cortex - A dataset.

Sun, 02/24/2019 - 00:26
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Beyond binary parcellation of the vestibular cortex - A dataset.

Data Brief. 2019 Apr;23:103666

Authors: Kirsch V, Boegle R, Keeser D, Kierig E, Ertl-Wagner B, Brandt T, Dieterich M

Abstract
The data-set presented in this data article is supplementary to the original publication, doi:10.1016/j.neuroimage.2018.05.018 (Kirsch et al., 2018). Named article describes handedness-dependent organizational patterns of functional subunits within the human vestibular cortical network that were revealed by functional magnetic resonance imaging (fMRI) connectivity parcellation. 60 healthy volunteers (30 left-handed and 30 right-handed) were examined on a 3T MR scanner using resting state fMRI. The multisensory (non-binary) nature of the human (vestibular) cortex was addressed by using masked binary and non-binary variations of independent component analysis (ICA). The data have been made publicly available via github (https://github.com/RainerBoegle/BeyondBinaryParcellationData).

PMID: 30788394 [PubMed]

Modular Functional-Metabolic Coupling Alterations of Frontoparietal Network in Schizophrenia Patients.

Sun, 02/24/2019 - 00:26
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Modular Functional-Metabolic Coupling Alterations of Frontoparietal Network in Schizophrenia Patients.

Front Neurosci. 2019;13:40

Authors: Xiang Q, Xu J, Wang Y, Chen T, Wang J, Zhuo K, Guo X, Zeljic K, Li W, Sun Y, Wang Z, Li Y, Liu D

Abstract
Background: Brain functional dysconnectivity, as well as altered network organization, have been demonstrated to occur in schizophrenia. Brain networks are increasingly understood to exhibit modular community structures, which provides advantages in robustness and functional adaptivity. The frontoparietal network (FPN) serves as an important functional module, and metabolic and functional alterations in the FPN are associated with the pathophysiology of schizophrenia. However, how intra-modular biochemical disruptions lead to inter-modular dysfunction of the FPN, remains unclear. In this study, we aim to investigate alterations in the modular functional-metabolic coupling of the FPN, in patients with schizophrenia. Methods: We combined resting-state functional magnetic resonance imaging (rs-fMRI) and magnetic resonance spectroscopy (MRS) technology and acquired multimodal neuroimaging data in 20 patients with schizophrenia and 26 healthy controls. For the MRS, the dorsolateral prefrontal cortex (DLPFC) region within the FPN was explored. Metabolites including gamma aminobutyric acid (GABA), N-aspart-acetyl (NAA) and glutamate + glutamine (Glx) were quantified, using LCModel software. A graph theoretical approach was applied for functional modular parcellation. The relationship between inter/intra-modular connectivity and metabolic concentration was examined using the Pearson correlation analysis. Moreover, correlations with schizophrenia symptomatology were investigated by the Spearman correlation analysis. Results: The functional topological network consisted of six modules in both subject groups, namely, the default mode, frontoparietal, central, hippocampus, occipital, and subcortical modules. Inter-modular connectivity between the frontoparietal and central modules, and the frontoparietal and the hippocampus modules was decreased in the patient group compared to the healthy controls, while the connectivity within the frontoparietal modular increased in the patient group. Moreover, a positive correlation between the frontoparietal and central module functional connectivity and the NAA in the DLPFC was found in the healthy control group (r = 0.614, p = 0.001), but not in the patient group. Significant functional dysconnectivity between the frontoparietal and limbic modules was correlated with the clinical symptoms of patients. Conclusions: This study examined the links between functional connectivity and the neuronal metabolic level in the DLPFC of SCZ. Impaired functional connectivity of the frontoparietal areas in SCZ, may be partially explained by a neurochemical-functional connectivity decoupling effect. This disconnection pattern can further provide useful insights in the cognitive and perceptual impairments of schizophrenia in future studies.

PMID: 30787862 [PubMed]

Resting state functional connectivity in neurosurgical patients under propofol anesthesia: detectability and variability between patients and between sessions.

Thu, 02/21/2019 - 00:23
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Resting state functional connectivity in neurosurgical patients under propofol anesthesia: detectability and variability between patients and between sessions.

World Neurosurg. 2019 Feb 16;:

Authors: Metwali H, Raemaekers M, Kniese K, Samii A

Abstract
BACKGROUND: Intraoperative assessment of the functional connectivity (FC) provides a new possibility of mapping the eloquent brain region before, during, and after tumor resection. a systematic analysis of the detectability of FC and its variation between subjects and session.
METHODS: the FC was analyzed in 10 pituitary adenoma patients under propofol anesthesia before and after tumor resection. The FC of each session (totally 20 sessions) was correlated to a reference matrix of a group of healthy subjects to evaluate the variations of the overall, interhemispheric and intrahemispheric FC between sessions.
RESULTS: The resting state patterns could be detected during anesthesia (F(1,9)= 112.14; p<0.001)There was a significant effect of session (F(1,9)= 19,401; p=0.002), which included a reduction in resting state from first to the second session. There was no effect of connection type (F(2,8)=1,498; p=0.280), nor was there an interaction between connection type and session (F(2,8),=0.187; p=0.833). The correlation between the observed reduction in resting state activity between the sessions, and the time span between sessions was not significant (r=0.25;p=0.29). The FC of the first session showed a significant correlation to the initial dose of anesthesia (r= 0.7, P= 0.007). However, there was no significant correlation between the total dose of propofol and the FC of the second session (r=1.7; p=0.6).
CONCLUSION: Significant FC could be detected under anesthesia but showed a significant decrease in the second session. To implement the FC intraoperative brain mapping, further studies are required to optimize the depth sedation in order to obtain stable FC between sessions.

PMID: 30780041 [PubMed - as supplied by publisher]

Overlap between hippocampal pre-encoding and encoding patterns supports episodic memory.

Thu, 02/21/2019 - 00:23
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Overlap between hippocampal pre-encoding and encoding patterns supports episodic memory.

Hippocampus. 2019 Feb 19;:

Authors: Sadeh T, Chen J, Goshen-Gottstein Y, Moscovitch M

Abstract
It is well-established that whether the information will be remembered or not depends on the extent to which the learning context is reinstated during post-encoding rest and/or at retrieval. It has yet to be determined, however, if the fundamental importance of contextual reinstatement to memory extends to periods of spontaneous neurocognitive activity prior to learning. We thus asked whether memory performance can be predicted by the extent to which spontaneous pre-encoding neural patterns resemble patterns elicited during encoding. Individuals studied and retrieved lists of words while undergoing fMRI-scanning. Multivoxel hippocampal patterns during resting periods prior to encoding resembled hippocampal patterns at encoding most strongly for items that were subsequently remembered. Furthermore, across subjects, the magnitude of similarity correlated with a behavioral measure of episodic recall. The results indicate that the neural context before learning is an important determinant of memory.

PMID: 30779457 [PubMed - as supplied by publisher]

Changes in Functional Connectivity Following Treatment With Emotion Regulation Therapy.

Thu, 02/21/2019 - 00:23
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Changes in Functional Connectivity Following Treatment With Emotion Regulation Therapy.

Front Behav Neurosci. 2019;13:10

Authors: Scult MA, Fresco DM, Gunning FM, Liston C, Seeley SH, García E, Mennin DS

Abstract
Emotion regulation therapy (ERT) is an efficacious treatment for distress disorders (i.e., depression and anxiety), predicated on a conceptual model wherein difficult to treat distress arises from intense emotionality (e.g., neuroticism, dispositional negativity) and is prolonged by negative self-referentiality (e.g., worry, rumination). Individuals with distress disorders exhibit disruptions in two corresponding brain networks including the salience network (SN) reflecting emotion/motivation and the default mode network (DMN) reflecting self-referentiality. Using resting-state functional connectivity (rsFC) analyses, seeded with primary regions in each of these networks, we investigated whether ERT was associated with theoretically consistent changes across nodes of these networks and whether these changes related to improvements in clinical outcomes. This study examined 21 generalized anxiety disorder (GAD) patients [with and without major depressive disorder (MDD)] drawn from a larger intervention trial (Renna et al., 2018a), who completed resting state fMRI scans before and after receiving 16 sessions of ERT. We utilized seed-based connectivity analysis with seeds in the posterior cingulate cortex (PCC), right anterior insula, and right posterior insula, to investigate whether ERT was associated with changes in connectivity of nodes of the DMN and SN networks to regions across the brain. Findings revealed statistically significant treatment linked changes in both the DMN and SN network nodes, and these changes were associated with clinical improvement corresponding to medium effect sizes. The results are discussed in light of a nuanced understanding of the role of connectivity changes in GAD and MDD, and begin to provide neural network support for the hypothesized treatment model predicated by ERT.

PMID: 30778290 [PubMed]

The Feasibility of Integrating Resting-State fMRI Networks into Radiotherapy Treatment Planning.

Thu, 02/21/2019 - 00:23
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The Feasibility of Integrating Resting-State fMRI Networks into Radiotherapy Treatment Planning.

J Med Imaging Radiat Sci. 2019 Mar;50(1):119-128

Authors: Sours Rhodes C, Zhang H, Patel K, Mistry N, Kwok Y, D'Souza WD, Regine WF, Gullapalli RP

Abstract
BACKGROUND: Functional magnetic resonance imaging (fMRI) presents the ability to selectively protect functionally significant regions of the brain when primary brain tumors are treated with radiation therapy. Previous research has focused on task-based fMRI of language and sensory networks; however, there has been limited investigation on the inclusion of resting-state fMRI into the design of radiation treatment plans.
METHODS AND MATERIALS: In this pilot study of 9 patients with primary brain tumors, functional data from the default mode network (DMN), a network supporting cognitive functioning, was obtained from resting-state fMRI and retrospectively incorporated into the design of radiation treatment plans. We compared the dosimetry of these fMRI DMN avoidance treatment plans with standard of care treatment plans to demonstrate feasibility. In addition, we used normal tissue complication probability models to estimate the relative benefit of fMRI DMN avoidance treatment plans over standard of care treatment plans in potentially reducing memory loss, a surrogate for cognitive function.
RESULTS: On average, we achieved 20% (P = 0.002) and 12% (P = 0.002) reductions in the mean and maximum doses, respectively, to the DMN without compromising the dose coverage to the planning tumor volume or the dose-volume constraints to organs at risk. Normal tissue complication probability models revealed that when the fMRI DMN was considered during radiation treatment planning, the probability of developing memory loss was lowered by more than 20%.
CONCLUSION: In this pilot study, we demonstrated the feasibility of including rs-MRI data into the design of radiation treatment plans to spare cognitively relevant brain regions during radiation therapy. These results lay the groundwork for future clinical trials that incorporate such treatment planning methods to investigate the long-term behavioral impact of this reduction in dose to the cognitive areas and their neural networks that support cognitive performance.

PMID: 30777232 [PubMed - in process]

Segregation of salience network predicts treatment response of depression to repetitive transcranial magnetic stimulation.

Wed, 02/20/2019 - 00:22
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Segregation of salience network predicts treatment response of depression to repetitive transcranial magnetic stimulation.

Neuroimage Clin. 2019 Feb 13;22:101719

Authors: Fan J, Tso IF, Maixner DF, Abagis T, Hernandez-Garcia L, Taylor SF

Abstract
BACKGROUND: The present study tested the hypothesis that network segregation, a graph theoretic measure of functional organization of the brain, is correlated with treatment response in patients with major depressive disorder (MDD) undergoing repetitive transcranial magnetic stimulation (rTMS).
METHODS: Network segregation, calculated from resting state functional magnetic resonance imaging scans, was measured in 32 patients with MDD who entered a sham-controlled, double-blinded, randomized trial of rTMS to the left dorsolateral prefrontal cortex, and a cohort of 20 healthy controls (HCs). Half of the MDD patients received sham treatment in the blinded phase, followed by active rTMS in the open-label phase. The analyses focused on segregation of the following networks: default mode (DMN), salience (SN), fronto-parietal (FPN), cingulo-opercular (CON), and memory retrieval (MRN).
RESULTS: There was no differential change in network segregation comparing sham to active treatment. However, in the combined group of patients who completed active rTMS treatment (in the blinded plus open-label phases), higher baseline segregation of SN significantly predicted more symptom improvement after rTMS. Compared to HCs at baseline, MDD patients showed decreased segregation in DMN, and trend-level decreases in SN and MRN.
CONCLUSION: The results highlight the importance of network segregation in MDD, particularly in the SN, where more normal baseline segregation of SN may predict better treatment response to rTMS in depression.

PMID: 30776777 [PubMed - as supplied by publisher]

Investigation of Resting-State BOLD Networks in the Human Brainstem and Spinal Cord.

Wed, 02/20/2019 - 00:22
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Investigation of Resting-State BOLD Networks in the Human Brainstem and Spinal Cord.

Neuroscience. 2019 Feb 15;:

Authors: Harita S, Ioachim G, Powers J, Stroman PW

Abstract
Resting-state functional magnetic resonance imaging (rs-fMRI) has been used to investigate networks within the cortex and has also provided some insight into the networks present in the brainstem (BS) and spinal cord (SC). The purpose of this study was to investigate resting-state blood oxygenation-level dependent (BOLD) fluctuations in the BS/SC and to identify resting-state networks (RSNs) across these regions. Resting-state BOLD fMRI data were obtained from the entire BS and cervical SC in 16 healthy participants, at 3 T, with T2-weighted single-shot fast spin-echo imaging. Data were spatially normalized and processed to remove physiological noise. Cluster-cluster functional connectivity was investigated across the entire 3D region by means of temporal correlations, and structural equation modeling (SEM) was used to investigate RSNs. Extensive connectivity was observed within and across BS and SC regions, with connections spanning up to 120 mm, although shorter connections were more prevalent. SEM results revealed extensive brainstem-cord connectivity that included specific anatomical regions within the brainstem. The results indicate the presence of a complex resting-state network which is highly interconnected in the spinal cord. Known anatomical connections between cortical and BS regions support the conclusion that the observed resting-state BOLD fluctuations in the BS/SC may be related to autonomic regulation. Future studies are required to further investigate these resting-state BOLD networks.

PMID: 30776404 [PubMed - as supplied by publisher]

Atypical Flexibility in Dynamic Functional Connectivity Quantifies the Severity in Autism Spectrum Disorder.

Wed, 02/20/2019 - 00:22
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Atypical Flexibility in Dynamic Functional Connectivity Quantifies the Severity in Autism Spectrum Disorder.

Front Hum Neurosci. 2019;13:6

Authors: Harlalka V, Bapi RS, Vinod PK, Roy D

Abstract
Resting-state functional connectivity (FC) analyses have shown atypical connectivity in autism spectrum disorder (ASD) as compared to typically developing (TD). However, this view emerges from investigating static FC overlooking the whole brain transient connectivity patterns. In our study, we investigated how age and disease influence the dynamic changes in functional connectivity of TD and ASD. We used resting-state functional magnetic resonance imaging (rs-fMRI) data stratified into three cohorts: children (7-11 years), adolescents (12-17 years), and adults (18+ years) for the analysis. The dynamic variability in the connection strength and the modular organization in terms of measures such as flexiblity, cohesion strength, and disjointness were explored for each subject to characterize the differences between ASD and TD. In ASD, we observed significantly higher inter-subject dynamic variability in connection strength as compared to TD. This hyper-variability relates to the symptom severity in ASD. We also found that whole-brain flexibility correlates with static modularity only in TD. Further, we observed a core-periphery organization in the resting-state, with Sensorimotor and Visual regions in the rigid core; and DMN and attention areas in the flexible periphery. TD also develops a more cohesive organization of sensorimotor areas. However, in ASD we found a strong positive correlation of symptom severity with flexibility of rigid areas and with disjointness of sensorimotor areas. The regions of the brain showing high predictive power of symptom severity were distributed across the cortex, with stronger bearings in the frontal, motor, and occipital cortices. Our study demonstrates that the dynamic framework best characterizes the variability in ASD.

PMID: 30774589 [PubMed]

Low and high frequency rTMS effects on resting-state functional connectivity between the postcentral gyrus and the insula.

Wed, 02/20/2019 - 00:22
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Low and high frequency rTMS effects on resting-state functional connectivity between the postcentral gyrus and the insula.

Brain Connect. 2019 Feb 16;:

Authors: Addicott M, Luber B, Nguyen D, Palmer H, Lisanby S, Appelbaum L

Abstract
The insular cortex supports the conscious awareness of physical and emotional sensations, and the ability to modulate the insula could have important clinical applications in psychiatry. Repetitive transcranial magnetic stimulation (rTMS) uses transient magnetic fields to induce electrical currents in the superficial cortex. Given its deep location in the brain, the insula may not be directly stimulated by rTMS; however, rTMS may modulate the insula via its functional connections with superficial cortical regions. Furthermore, low versus high frequency rTMS are thought to have opposing effects on cortical excitability, and the present study investigated these effects on brain activity and functional connectivity with the insula. Separate groups of healthy participants (n = 14 per group) received low (1 Hz) or high (10 Hz) frequency rTMS in 5 daily sessions to the right postcentral gyrus, a superficial region known to be functionally connected to the insula. Resting-state functional connectivity (RSFC) was measured pre- and post-rTMS. Both 1 Hz and 10 Hz rTMS increased RSFC between the right postcentral gyrus and the left insula. These results suggest that low and high frequency rTMS have similar long-term effects on brain activity and RSFC. However, given the lack of difference, we cannot exclude the possibility that these effects are simply due to a non-specific effect. Given this limitation, these unexpected results underscore the need for acoustic- and stimulation-matched sham control conditions in rTMS research.

PMID: 30773890 [PubMed - as supplied by publisher]

[Brain regions responding to acupuncture stimulation of Zusanli (ST36) in healthy subjects analyzed on the basis of spontaneous brain activity].

Wed, 02/20/2019 - 00:22
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[Brain regions responding to acupuncture stimulation of Zusanli (ST36) in healthy subjects analyzed on the basis of spontaneous brain activity].

Zhen Ci Yan Jiu. 2019 Jan 25;44(1):66-70

Authors: Xiang AF, Liu H, Liu S, Shen XY

Abstract
OBJECTIVE: To determine the attributes of responses of the higher nerve center to acupuncture stimulation of Zusanli (ST36) on the basis of spontaneous brain activity, so as to explore the synchronization level of different brain rejoins after acupuncture.
METHODS: All studies using fMRI to investigate the effect of acupuncture stimulation of ST36 and/or other acupoints on the human brain (at least 10 healthy subjects or patients in one group) published in journals from January of 1995 to January of 2018 were searched from databases of CNKI and PubMed by using keywords of acupuncture, electroacupuncture, and resting-state functional magnetic resonance images (rs-fMRI) or regional homogeneity (ReHo). Brain functional image data of acupuncture stimulation of ST36 and/or other acupoints were collected and analyzed with anisotropic effect size-signed differential mapping (AES-SDM) software (Meta-analysis), and those of acupuncture of simple ST36 analyzed as a subgroup.
RESULTS: A total of 229 papers in Chinese and 109 in English were collected. According to our inclusive and exclusive standards, 11 papers containing 235 subjects were brought into analysis at last. Meta-analysis of brain image data of acupuncture at ST36 and/or other acupoints (comparison between pre- and post-acupuncture) revealed that the same brain regions (generality) which showed a significant increase in ReHo, are the right and left anterior cingulated gyrus, right caudate, left superior frontal gyrus, right middle frontal gyrus, and the right paracentral lobe, and those which showed a marked decrease of ReHo are the left mid-inferior occipital gyrus, left and right precentral and postcentral gyrus. The brain regions responding to acupuncture at ST36 only (specificity) are the right inferior parietal lobe, left middle inferior gyrus, right posterior lobe of cerebellum, and the left angular gyrus which displayed an increase of ReHo, and the right middle superior frontal gyrus which showed a decrease in ReHo.
CONCLUSION: After acupuncturing at ST36, the relative generality and specificity of the central response in healthy subjects reflected as the location of the affected brain regions and the difference in the synchronization level of the corresponding spontaneous brain activities.

PMID: 30773866 [PubMed - in process]

Altered dynamic global signal topography in antipsychotic-naive adolescents with early-onset schizophrenia.

Tue, 02/19/2019 - 12:22

Altered dynamic global signal topography in antipsychotic-naive adolescents with early-onset schizophrenia.

Schizophr Res. 2019 Feb 14;:

Authors: Wang X, Liao W, Han S, Li J, Zhang Y, Zhao J, Chen H

Abstract
Schizophrenia (SCZ) is a severe neuropsychiatric disease associated with dysfunction of brain regions and networks. Recent, functional magnetic resonance imaging (fMRI) studies have determined that the global signal (GS) is an important source of the local neuronal activity. However, the dynamics of this effect in SCZ remains unknown. To address this issue, 39 drug-naive patients with early-onset schizophrenia (EOS) and 31 age-, gender- and education-matched healthy controls underwent resting-state fMRI scans. Dynamic functional connectivity (DFC) was employed to assess the dynamic patterns of the GS in EOS. Dynamic analysis demonstrated that the topography of the GS in EOS can be divided into five different states. In the state1, the GS mainly affected the sensory regions. In the state2, the GS mainly affected the default mode network (DMN). In the state3, the GS mainly affected the frontoparietal network and the cingulate-opercular network. In the state4, the GS mainly affected the sensory and subcortical regions. In the state5, the GS mainly affected the sensory regions and DMN. In particular, the changes in the cerebellum, putamen and supramarginal gyrus was inversely proportional to the clinical symptoms. Our findings demonstrate that the influence of the GS on brain networks is dynamic and changes of this relationship may associate with clinical behavior in SCZ.

PMID: 30772067 [PubMed - as supplied by publisher]

Impaired prefrontal cortex-thalamus pathway in intractable temporal lobe epilepsy with aberrant executive control function: MRI evidence.

Mon, 02/18/2019 - 00:20
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Impaired prefrontal cortex-thalamus pathway in intractable temporal lobe epilepsy with aberrant executive control function: MRI evidence.

Clin Neurophysiol. 2019 Jan 18;130(4):484-490

Authors: Zhang C, Zhang H, Xu K, Yang H, Liu C, Yu T, Chen N, Li K

Abstract
OBJECTIVES: This study aimed to assess structural and functional connectivity alterations of the prefrontal cortex (PFC)-thalamus axis in individuals with unilateral intractable temporal lobe epilepsy (TLE) showing executive control function (ECF) impairment and to explore the potential mechanism.
METHODS: Thirty-eight individuals with intractable left TLE and twenty-nine healthy controls (HCs) were recruited for diffusion tensor imaging (DTI) and resting-state fMRI (rs-fMRI) scanning. According to the ECF state, patients were assigned to normal and impaired ECF groups. Functional connectivity (FC) and probabilistic diffusion tractography of the PFC- thalamus pathway were assessed. The general linear model (GLM) was employed for comparing fiber number (FN) and FC between groups. Pearson correlation analysis of FC, FN and ECF test scores was performed.
RESULTS: FC and FN of left DLPFC-thalamus pathway were significantly increased in the impaired ECF group compared with the normal ECF and HC groups. However, FC and FN were not correlated with ECF score.
CONCLUSIONS: These findings indicated increased connectivity between DLPFC and the ipsilateral thalamus might reflect nonfunctional nerve remodeling along the seizure pathway.
SIGNIFICANCE: The present findings suggest that the DLPFC-thalamus pathway may be an important structure for exploring the mechanisms of TLE with ECF dysfunction.

PMID: 30771725 [PubMed - as supplied by publisher]

Effects of Motor Imagery and Visual Neurofeedback on Activation in the Swallowing Network: A Real-Time fMRI Study.

Mon, 02/18/2019 - 00:20
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Effects of Motor Imagery and Visual Neurofeedback on Activation in the Swallowing Network: A Real-Time fMRI Study.

Dysphagia. 2019 Feb 15;:

Authors: Kober SE, Grössinger D, Wood G

Abstract
Motor imagery of movements is used as mental strategy in neurofeedback applications to gain voluntary control over activity in motor areas of the brain. In the present functional magnetic resonance imaging (fMRI) study, we first addressed the question whether motor imagery and execution of swallowing activate comparable brain areas, which has been already proven for hand and foot movements. Prior near-infrared spectroscopy (NIRS) studies provide evidence that this is the case in the outer layer of the cortex. With the present fMRI study, we want to expand these prior NIRS findings to the whole brain. Second, we used motor imagery of swallowing as mental strategy during visual neurofeedback to investigate whether one can learn to modulate voluntarily activity in brain regions, which are associated with active swallowing, using real-time fMRI. Eleven healthy adults performed one offline session, in which they executed swallowing movements and imagined swallowing on command during fMRI scanning. Based on this functional localizer task, we identified brain areas active during both tasks and defined individually regions for feedback. During the second session, participants performed two real-time fMRI neurofeedback runs (each run comprised 10 motor imagery trials), in which they should increase voluntarily the activity in the left precentral gyrus by means of motor imagery of swallowing while receiving visual feedback (the visual feedback depicted one's own fMRI signal changes in real-time). Motor execution and imagery of swallowing activated a comparable network of brain areas including the bilateral pre- and postcentral gyrus, inferior frontal gyrus, basal ganglia, insula, SMA, and the cerebellum compared to a resting condition. During neurofeedback training, participants were able to increase the activity in the feedback region (left lateral precentral gyrus) but also in other brain regions, which are generally active during swallowing, compared to the motor imagery offline task. Our results indicate that motor imagery of swallowing is an adequate mental strategy to activate the swallowing network of the whole brain, which might be useful for future treatments of swallowing disorders.

PMID: 30771088 [PubMed - as supplied by publisher]

Ultra-high field MRI reveals mood-related circuit disturbances in depression: a comparison between 3-Tesla and 7-Tesla.

Mon, 02/18/2019 - 00:20
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Ultra-high field MRI reveals mood-related circuit disturbances in depression: a comparison between 3-Tesla and 7-Tesla.

Transl Psychiatry. 2019 Feb 15;9(1):94

Authors: Morris LS, Kundu P, Costi S, Collins A, Schneider M, Verma G, Balchandani P, Murrough JW

Abstract
Ultra-high field 7-Tesla (7 T) MRI has the potential to advance our understanding of neuropsychiatric disorders, including major depressive disorder (MDD). To date, few studies have quantified the advantage of resting state functional MRI (fMRI) at 7 T compared to 3-Tesla (3 T). We conducted a series of experiments that demonstrate the improvement in temporal signal-to-noise ratio (TSNR) of a multi-echo multi-band fMRI protocol with ultra-high field 7 T MRI, compared to a similar protocol using 3 T MRI in healthy controls (HC). We also directly tested the enhancement in ultra-high field 7 T fMRI signal power by examining the ventral tegmental area (VTA), a small midbrain structure that is critical to the expected neuropathology of MDD but difficult to discern with standard 3 T MRI. We demonstrate up to 300% improvement in TSNR and resting state functional connectivity coefficients provided by ultra-high field 7 T fMRI compared to 3 T, indicating enhanced power for detection of functional neural architecture. A multi-echo based acquisition protocol and signal denoising pipeline afforded greater gain in signal power compared to classic acquisition and denoising pipelines. Furthermore, ultra-high field fMRI revealed mood-related neurocircuit disturbances in patients with MDD compared to HC, which were not detectable with 3 T fMRI. Ultra-high field 7 T fMRI may provide an effective tool for studying functional neural architecture relevant to MDD and other neuropsychiatric disorders.

PMID: 30770788 [PubMed - in process]

Integration and segregation of functional segmented anterior and posterior hippocampal networks in memory performance.

Sun, 02/17/2019 - 00:19
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Integration and segregation of functional segmented anterior and posterior hippocampal networks in memory performance.

Behav Brain Res. 2019 Feb 12;:

Authors: Xu J, Zhang M

Abstract
PURPOSE: To determine the association between functional connectivity (FC) of functional-segmented anterior and posterior portions of the hippocampus and performance on verbal and visual memory tests in a young, healthy population.
METHODS: We recruited 100 healthy participants in the age of 19-29. Resting state fMRI data were acquired and voxel-wise correlation analysis was performed to functionally divide the hippocampus. We investigated the inter-hemispheric hippocampal-cortical functional connectivity after the participants took the assessment of episodic memory using verbal (California Verbal Learning Test II, CVLT-II) and visual subtests (Rey-Osterrieth Complex Figure, ROCF). The partial correlations were used to identify the association between the intra-hemispheric hippocampal-cortical mean resting correlation and memory performance.
RESULTS: The results showed that the anterior and posterior hippocampal networks involved differently in verbal and visual memory. Intra-hemispheric FC between left posterior hippocampus and posterior parahippocampal gyrus (PPHG) was positively correlated with CVLT-II Trail 2 Immediate Free Recall (r = 0.223, p = 0.029). Intra-hemispheric FC between left posterior hippocampus and posterior cingulate (PCC) was negatively correlated with ROCF Immediate Recall (r=-0.217 p = 0.034). Intra-hemispheric FC between left anterior hippocampus and temporal pole (TP) negatively correlated with ROCF Delayed Recall (r=-0.228, p = 0.025). Split half resampling procedure results showed some repeatability in our subjects.
CONCLUSION: The present results demonstrated that, the anterior hippocampus was specifically involved in the visual memory processing, whereas the posterior hippocampus contributed to both the verbal and visual memories, which may have implications for a functionally synergetic and dissociable role of the hippocampus in different kinds of memory.

PMID: 30768997 [PubMed - as supplied by publisher]

Sertraline Effects on Striatal Resting-State Functional Connectivity in Youth With OCD: A Pilot Study.

Sun, 02/17/2019 - 00:19
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Sertraline Effects on Striatal Resting-State Functional Connectivity in Youth With OCD: A Pilot Study.

J Am Acad Child Adolesc Psychiatry. 2018 Oct 30;:

Authors: Bernstein GA, Cullen KR, Harris EC, Conelea CA, Zagoloff AD, Carstedt PA, Lee SS, Mueller BA

Abstract
OBJECTIVE: Foundational knowledge on neural circuitry underlying pediatric obsessive-compulsive disorder (OCD) and how it changes during standard treatment is needed to provide the basis for conceptualization and development of novel, targeted treatments. This study explored the effects of sertraline, a selective serotonin reuptake inhibitor, on resting-state functional connectivity (RSFC) in cortico-striatal-thalamic-cortical circuits in pediatric OCD.
METHOD: Medication-free youths with OCD (n=14) and healthy controls (n=14) were examined at baseline and 12 weeks with resting-state fMRI. Between scan sessions, participants with OCD received 12 weeks of sertraline. For each scan, we conducted seed-based whole-brain RSFC analyses with 6 striatal seeds. Analysis of variance (ANOVA) examined the interaction between group and time on striatal connectivity, including cluster-based thresholding to correct for multiple tests. Connectivity changes within circuits identified in group analyses were correlated with clinical change.
RESULTS: Two significant group x time effects in the OCD group showed increased striatal connectivity from baseline to 12 weeks compared with controls. Circuits demonstrating this pattern included right putamen with left frontal cortex/insula and left putamen with left frontal cortex and pre- and post-central cortices. Increase in connectivity in left putamen circuit was significantly correlated with clinical improvement on Children's Yale-Brown Obsessive-Compulsive Scale (r = -0.58, p = .03).
CONCLUSION: Sertraline appears to affect specific striatal-based circuits in pediatric OCD, and in part, these changes may account for clinical improvement. Future work is needed to confirm these preliminary findings, which would facilitate identification of circuit-based targets for novel treatment development.

PMID: 30768407 [PubMed - as supplied by publisher]

Association Between Age and Familial Risk for Alcoholism on Functional Connectivity in Adolescence.

Sun, 02/17/2019 - 00:19
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Association Between Age and Familial Risk for Alcoholism on Functional Connectivity in Adolescence.

J Am Acad Child Adolesc Psychiatry. 2019 Feb 13;:

Authors: Vaidya JG, Elmore AL, Wallace A, Langbehn DR, Kramer JR, Kuperman S, O'Leary DS

Abstract
OBJECTIVE: Youth with a family history of alcohol use disorder (family history positive; FHP) are at increased risk for developing maladaptive substance use relative to family history negative (FHN) peers. Building on earlier studies demonstrating morphological differences and distinct patterns of neural activation in FHP, the purpose of the present study was to investigate differential intrinsic functional connectivity among brain networks indexing premorbid risk of developing alcohol use disorder (AUD).
METHOD: The current study examined intrinsic functional connectivity using resting state functional magnetic resonance imaging (fMRI) in 191 adolescents 13 to 18 years with and without family history of alcohol use disorder (AUD) via independent component analysis (ICA), a method enabling data-driven investigation of internetwork and intranetwork connectivity among brain regions at rest.
RESULTS: Analyses revealed significantly lower intranetwork connectivity in FHP compared to FHN participants between dorsal premotor cortex and other sensorimotor network regions. Reduced intranetwork connectivity in this region was further correlated with the number of biological family members with AUD and mood disorders. Robust differences were also evident in internetwork connectivity as a function of age. However, there was no evidence for family history by age interactions.
CONCLUSION: Intra- but not inter-network connectivity appears to differentiate FHP and FHN adolescents whereas age differences within adolescence are marked by differences in internetwork connectivity.

PMID: 30768382 [PubMed - as supplied by publisher]