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Normalization enhances brain network features that predict individual intelligence in children with epilepsy.

Thu, 03/07/2019 - 03:39
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Normalization enhances brain network features that predict individual intelligence in children with epilepsy.

PLoS One. 2019;14(3):e0212901

Authors: Paldino MJ, Golriz F, Zhang W, Chu ZD

Abstract
BACKGROUND AND PURPOSE: Architecture of the cerebral network has been shown to associate with IQ in children with epilepsy. However, subject-level prediction on this basis, a crucial step toward harnessing network analyses for the benefit of children with epilepsy, has yet to be achieved. We compared two network normalization strategies in terms of their ability to optimize subject-level inferences on the relationship between brain network architecture and brain function.
MATERIALS AND METHODS: Patients with epilepsy and resting state fMRI were retrospectively identified. Brain network nodes were defined by anatomic parcellation, first in patient space (nodes defined for each patient) and again in template space (same nodes for all patients). Whole-brain weighted graphs were constructed according to pair-wise correlation of BOLD-signal time courses between nodes. The following metrics were then calculated: clustering coefficient, transitivity, modularity, path length, and global efficiency. Metrics computed on graphs in patient space were normalized to the same metric computed on a random network of identical size. A machine learning algorithm was used to predict patient IQ given access to only the network metrics.
RESULTS: Twenty-seven patients (8-18 years) comprised the final study group. All brain networks demonstrated expected small world properties. Accounting for intrinsic population heterogeneity had a significant effect on prediction accuracy. Specifically, transformation of all patients into a common standard space as well as normalization of metrics to those computed on a random network both substantially outperformed the use of non-normalized metrics.
CONCLUSION: Normalization contributed significantly to accurate subject-level prediction of cognitive function in children with epilepsy. These findings support the potential for quantitative network approaches to contribute clinically meaningful information in children with neurological disorders.

PMID: 30835738 [PubMed - in process]

Altered limbic and autonomic processing supports brain-heart axis in Takotsubo syndrome.

Tue, 03/05/2019 - 21:37
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Altered limbic and autonomic processing supports brain-heart axis in Takotsubo syndrome.

Eur Heart J. 2019 Mar 05;:

Authors: Templin C, Hänggi J, Klein C, Topka MS, Hiestand T, Levinson RA, Jurisic S, Lüscher TF, Ghadri JR, Jäncke L

Abstract
AIMS: Takotsubo syndrome (TTS) is characterized by acute left ventricular dysfunction often triggered by emotional or physical stress. Severe activation of the sympathetic nervous system with catecholamine release caused by a dysfunctional limbic system has been proposed as a potential mechanism. We hypothesize that brain regions responsible for autonomic integration and/or limbic processing might be involved in the development of TTS. Here, we investigated alterations in resting state functional connectivity in TTS patients compared with healthy controls.
METHODS AND RESULTS: Using brain functional magnetic resonance imaging (fMRI), resting state functional connectivity has been assessed in 15 subjects with TTS and 39 healthy controls. Network-based statistical analyses were conducted to identify subnetworks with altered resting state functional connectivity. Sympathetic and parasympathetic networks have been constructed in addition to the default mode network and whole-brain network. We found parasympathetic- and sympathetic-associated subnetworks both showing reduced resting state functional connectivity in TTS patients compared with controls. Important brain regions constituting parasympathetic- and sympathetic-associated subnetworks included the amygdala, hippocampus, and insula as well as cingulate, parietal, temporal, and cerebellar regions. Additionally, the default mode network as well as limbic regions in the whole-brain analysis demonstrated reduced resting state functional connectivity in TTS, including the hippocampus, parahippocampal, and medial prefrontal regions.
CONCLUSION: For the first time, we demonstrate hypoconnectivity of central brain regions associated with autonomic functions and regulation of the limbic system in patients with TTS. These findings suggest that autonomic-limbic integration might play an important role in the pathophysiology and contribute to the understanding of TTS.

PMID: 30831580 [PubMed - as supplied by publisher]

Overlapping Brain Community Detection Using Bayesian Tensor Decomposition.

Tue, 03/05/2019 - 21:37
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Overlapping Brain Community Detection Using Bayesian Tensor Decomposition.

J Neurosci Methods. 2019 Mar 01;:

Authors: Mirzaei S, Soltanian-Zadeh H

Abstract
It has been found that specific regions in the brain are dedicated to specific functions. Detection and analysis of the constituent functional networks of the brain is of great importance for understanding the brain functionality and diagnosing some neuropsychiatric illnesses. In this paper, we introduce Non-negative Tensor Factorization (NTF) methods to identify the overlapping communities in brain networks using resting-state functional Magnetic Resonance Imaging (rs-fMRI) data. Instead of taking average over a group of subjects, we use individual subject connectivity matrices to build the tensor data. Decomposed factors indicate the community membership probabilities and inter-subject variability indices modeling the community strengths over subjects. In contrast to the methods based on Non-negative Matrix Factorization (NMF) which are generally applied to the average connectivity matrices, using tensor factorization modeling preserves the information conveyed by the individual subjects. The experiments are carried out on simulated data as well as real Human Connectome Project (HCP) rs-fMRI datasets. To evaluate the effectiveness of the proposed framework, we have computed reproducibility over time and groups of subjects. Test-retest reliability is also examined through computing the intra-class correlation coefficient (ICC) index. The results show that the proposed NTF-based frameworks lead to stable and accurate results.

PMID: 30831137 [PubMed - as supplied by publisher]

Resting-state fMRI effective connectivity between the bed nucleus of the stria terminalis and amygdala nuclei.

Tue, 03/05/2019 - 21:37
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Resting-state fMRI effective connectivity between the bed nucleus of the stria terminalis and amygdala nuclei.

Hum Brain Mapp. 2019 Mar 04;:

Authors: Hofmann D, Straube T

Abstract
The bed nucleus of the stria terminalis (BNST) and the laterobasal nucleus (LB), centromedial nucleus (CM), and superficial nucleus (SF) of the amygdala form an interconnected dynamical system, whose combined activity mediates a variety of behavioral and autonomic responses in reaction to homeostatic challenges. Although previous research provided deeper insight into the structural and functional connections between these nuclei, studies investigating their resting-state functional magnetic resonance imaging (fMRI) connectivity were solely based on undirected connectivity measures. Here, we used high-quality data of 391 subjects from the Human Connectome Project to estimate the effective connectivity (EC) between the BNST, the LB, CM, and SF through spectral dynamic causal modeling, the relation of the EC estimates with age and sex as well as their stability over time. Our results reveal a time-stable asymmetric EC structure with positive EC between all amygdala nuclei, which strongly inhibited the BNST while the BNST exerted positive influence onto all amygdala nuclei. Simulation of the impulse response of the estimated system showed that this EC structure shapes partially antagonistic (out of phase) activity flow between the BNST and amygdala nuclei. Moreover, the BNST-LB and BNST-CM EC parameters were less negative in males. In conclusion, our data points toward partially separated information processing between BNST and amygdala nuclei in the resting-state.

PMID: 30829454 [PubMed - as supplied by publisher]

A review of hippocampal activation in post-traumatic stress disorder.

Tue, 03/05/2019 - 21:37
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A review of hippocampal activation in post-traumatic stress disorder.

Psychophysiology. 2019 Mar 04;:e13357

Authors: Joshi SA, Duval ER, Kubat B, Liberzon I

Abstract
Post-traumatic stress disorder (PTSD) is often characterized by deficits in memory encoding and retrieval and aberrant fear and extinction learning. The hippocampus plays a critical role in memory and contextual processing and has been implicated in intrinsic functional connectivity networks involved in self-referential thought and memory-related processes. This review focuses on hippocampal activation findings during memory and fear and extinction learning tasks, as well as resting state hippocampal connectivity in individuals with PTSD. A preponderance of functional neuroimaging studies to date, using memory, fear learning, and extinction tasks, report decreased or "controls comparable" hippocampal activation in individuals with PTSD, which is usually associated with poorer performance on the task imaged. Existing evidence thus raises the possibility that greater hippocampal recruitment in PTSD participants may be required for similar performance levels. Studies of resting state functional connectivity in PTSD predominantly report reduced within-network connectivity in the default mode network (DMN), as well as greater coupling between the DMN and salience network (SN) via the hippocampus. Together, these findings suggest that deficient hippocampal activation in PTSD may be associated with poorer performance during memory, extinction recall, and fear renewal tasks. Furthermore, studies of resting state connectivity implicate the hippocampus in decreased within-network DMN connectivity and greater coupling with SN regions characteristic of PTSD.

PMID: 30829407 [PubMed - as supplied by publisher]

Altered organization of the dorsal attention network is associated with freezing of gait in Parkinson's disease.

Tue, 03/05/2019 - 21:37
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Altered organization of the dorsal attention network is associated with freezing of gait in Parkinson's disease.

Parkinsonism Relat Disord. 2019 Feb 23;:

Authors: Maidan I, Jacob Y, Giladi N, Hausdorff JM, Mirelman A

Abstract
INTRODUCTION: Deficits in executive function and attention have been associated with freezing of gait (FOG) in patients with Parkinson's disease (PD). However, the exact changes in the ventral and dorsal attentional networks that may contribute to FOG are unknown. Our aim was to examine the changes in connectivity of the attentional networks in patients with PD and their role in FOG.
METHODS: Resting-state fMRI was obtained in 20 healthy controls (age: 69.7 ± 1.3yrs), 11 patients without FOG (age: 74.1 ± 1.2yrs), and 26 patients with FOG (age: 72.3 ± 1.3yrs). Graph theory analysis was used to examine differences in previously defined attention networks between groups.
RESULTS: We found differences between the groups in the dorsal attentional network (Global Efficiency: p = 0.007, Local Efficiency: p = 0.017, Between Centrality: p = 0.010). Global efficiency was lower in patients with FOG compared to healthy controls (p = 0.003) and patients without FOG (p = 0.025). Local efficiency was higher in patients with FOG compared to healthy controls (p = 0.014) but not compared to patients without FOG (p = 0.109). In contrast, no differences were found in the ventral attentional network between the groups (Global Efficiency: p = 0.258, Local Efficiency: p = 0.114, Between Centrality: p = 0.130).
CONCLUSIONS: Altered organization of the dorsal attention network in patients with FOG may explain the higher risk for FOG during complex walking situations. In contrast, the lack of changes in the ventral attention network may partially explain the effectiveness of external cues on gait in patients with PD. Our findings support the idea that attentional networks play an important role in FOG.

PMID: 30827838 [PubMed - as supplied by publisher]

Baseline effective connectivity predicts response to repetitive transcranial magnetic stimulation in patients with treatment-resistant depression.

Tue, 03/05/2019 - 21:37
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Baseline effective connectivity predicts response to repetitive transcranial magnetic stimulation in patients with treatment-resistant depression.

Eur Neuropsychopharmacol. 2019 Feb 28;:

Authors: Iwabuchi SJ, Auer DP, Lankappa ST, Palaniyappan L

Abstract
Repetitive transcranial magnetic stimulation (rTMS) has become a popular treatment option for treatment-resistant depression (TRD). However, suboptimal response rates highlight the need for improved efficacy through optimisation of treatment protocol and patient selection. We investigate whether the limbic salience network and its connectivity with prefrontal stimulation sites predict immediate and longer-term responsiveness to rTMS. Twenty-seven patients with TRD were randomly allocated to receive 16 sessions of either conventional rTMS or intermittent theta-burst (iTBS) over 4 weeks; delivered using connectivity profiling and neuronavigation to target person-specific dorsolateral prefrontal cortex (DLPFC). At baseline and 3-month follow-up, patients underwent clinical assessment and scanning session, and 1-month clinical follow-up. Resting-state fMRI data were entered into seed-based functional and effective connectivity analyses between right anterior insula (rAI) and DLPFC target, and independent components analysis to extract resting-state networks. Cerebral blood flow (CBF) was also assessed in the rAI. All brain measures were compared between baseline and follow-up, and related to treatment response at 1- and 3-months. Baseline fronto-insular effective connectivity and salience network connectivity were significantly positively correlated, while baseline rAI CBF was negatively correlated, with early (1-month) response to rTMS treatment but not sustained response (3-months), suggesting persistence of therapeutic response is not associated with baseline features. Connectivity or CBF measures did not change between the two time points. We demonstrate that fronto-insular and salience-network interactions can predict early response to rTMS in TRD, suggesting that these network nodes may be key regions toward developing rTMS response biomarkers.

PMID: 30827757 [PubMed - as supplied by publisher]

Phase fMRI informs whole-brain function connectivity balance across lifespan with connection-specific aging effects during the resting state.

Tue, 03/05/2019 - 00:36
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Phase fMRI informs whole-brain function connectivity balance across lifespan with connection-specific aging effects during the resting state.

Brain Struct Funct. 2019 Mar 02;:

Authors: Chen Z, Zhou Q, Calhoun V

Abstract
A functional magnetic resonance imaging (fMRI) experiment produces complex-valued images consisting of pairwise magnitude and phase images. As different perspective on the same magnetic source, fMRI magnitude and phase data are complementary for brain function analysis. We collected 600-subject fMRI data during rest, decomposed via group-level independent component analysis (ICA) (mICA and pICA for magnitude and phase respectively), and calculated brain functional network connectivity matrices (mFC and pFC). The pFC matrix shows a fewer of significant connections balanced across positive and negative relationships. In comparison, the mFC matrix contains a positively-biased pattern with more significant connections. Our experiment data analyses also show that human brain maintains a whole-brain connection balance in resting state across an age span from 10 to 76 years, however, phase and magnitude data analyses reveal different connection-specific age effects on significant positive and negative subnetwork couplings.

PMID: 30826929 [PubMed - as supplied by publisher]

Exploring Brain Mechanisms Underlying Gulf War Illness with Group ICA based Analysis of fMRI Resting State Networks.

Sun, 03/03/2019 - 21:35
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Exploring Brain Mechanisms Underlying Gulf War Illness with Group ICA based Analysis of fMRI Resting State Networks.

Neurosci Lett. 2019 Feb 27;:

Authors: Gopinath KS, Sakoglu U, Crosson BA, Haley RW

Abstract
Around 200,000 veterans (up to 32% of those deployed) of the 1991 Gulf War (GW) suffer from GW illness (GWI), which is characterized by multiple deficits in cognitive, affective, sensory and nociception domains. In this study we employed resting state fMRI (rsfMRI) to map impairments in brain function in GWI with advanced network analysis. RsfMRI data was obtained from 60 GWI veterans and 30 age-matched military controls. Group independent component analysis (GICA) was conducted to probe the functional connectivity networks in all 90 subjects. GICA revealed impaired functional connectivity (FC) in GWI veterans between a number of brain function networks consistent with their self-reported symptoms. GWI veterans exhibited impaired FC between language networks, and sensory input networks of all modalities as well as motor output networks. GWI veterans also exhibited impaired FC between different sensory perception and motor networks, and between different networks in the sensorimotor domain. These FC impairments provide putative mechanism of central nervous system dysfunction in GWI.

PMID: 30825590 [PubMed - as supplied by publisher]

The Intrinsic Neural Architecture of Inhibitory Control: The Role of Development and Emotional Experience.

Sun, 03/03/2019 - 00:32
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The Intrinsic Neural Architecture of Inhibitory Control: The Role of Development and Emotional Experience.

Neuropsychologia. 2019 Feb 26;:

Authors: Petrican R, Grady CL

Abstract
Inhibitory control is a key determinant of goal-directed behavior. Its susceptibility to reward implies that its variations may not only reflect cognitive ability, but also sensitivity to goal-relevant information. Since cognitive ability and motivational sensitivity vary as a function of age and mood, we hypothesized that their relevance for predicting individual differences in inhibition would similarly vary. Here, we tested this prediction with respect to the brain's intrinsic functional architecture. Specifically, we reasoned that age and affective functioning would both moderate the relationship between inhibition and resting state expression of the dynamic neural organization patterns linked to engaging in cognitive effort versus those involved in manipulating motivationally salient information. First, we used task fMRI data from the Human Connectome Project (N=359 participants) to identify the brain organization patterns unique to effortful cognitive processing versus manipulation of motivationally relevant information. We then assessed the association between inhibitory control and relative expression of these two neural patterns in an independent resting state dataset from the Nathan Kline Institute-Rockland lifespan sample (N=247). As hypothesized, the relation between inhibition and intrinsic functional brain architecture varied as a function of age and affective functioning. Among those with superior affective functioning, better inhibitory control in adolescence and early adulthood was associated with stronger resting state expression of the brain pattern that typified processing of motivationally salient information. The opposite effect emerged beyond the age of 49. Among individuals with poorer affective functioning, a significant link between inhibition and brain architecture emerged only before the age of 28. In this group, superior inhibition was associated with stronger resting state expression of the neural pattern that typified effortful cognitive processing. Our results thus imply that motivational relevance makes a unique contribution to superior cognitive functioning during earlier life stages. However, its relevance to higher-order mentation decreases with aging and increased prevalence of mood-related problems, which raises the possibility that patterns of neurobehavioral responsiveness to motivational salience may constitute sensitive markers of successful lifespan development.

PMID: 30822448 [PubMed - as supplied by publisher]

Resting-state networks and neurometabolites in children with ADHD after 10 weeks of treatment with micronutrients: results of a randomised placebo-controlled trial.

Sun, 03/03/2019 - 00:32
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Resting-state networks and neurometabolites in children with ADHD after 10 weeks of treatment with micronutrients: results of a randomised placebo-controlled trial.

Nutr Neurosci. 2019 Mar 01;:1-11

Authors: Borlase N, Melzer TR, Eggleston MJF, Darling KA, Rucklidge JJ

Abstract
Children with attention-deficit/hyperactivity disorder (ADHD) show significant abnormalities on MR imaging in network communication and connectivity. The prefrontal-striatal-cerebella circuitry, involved in attention is particularly disrupted. Neurometabolites, the biochemical structures that support neurological structural integrity, particularly in the prefrontal cortex and striatum are associated with symptoms. This study aimed to explore changes in neurometabolite levels through treatment with vitamins and minerals (micronutrients), hypothesising that treatment would impact neural circuitry and correspond to a reduction in symptoms. Twenty-seven non-medicated children (M = 10.75 years) with DSM5 diagnosed ADHD were randomised to receive daily micronutrients or placebo for 10 weeks. Main outcome measures included the Clinical Global Impression-Improvement Scale and ADHD-RS-IV Clinician Ratings of ADHD symptoms. Magnetic resonance spectroscopy of the bilateral pre-frontal cortex and bilateral striatum, resting state fMRI and structural images were acquired 1 week pre-treatment, and in the last week of intervention. Results did not show any significant differences in the measured brain metrics and the levels of neurometabolites between treatment and placebo groups after ten weeks of treatment with micronutrients. In the treatment group there was a trend for: decreased choline in the striatum; decreased glutamate in the prefrontal cortex; increased grey matter in the anterior thalamus; increased white matter in the fornix and improved network integrity of the default mode network, dorsal attention network and frontal executive network. The small sample size of the current study limits results, future studies with higher power are warranted to explore any association between micronutrient treatment and neurological changes.

PMID: 30821654 [PubMed - as supplied by publisher]

Altered glutamatergic response and functional connectivity in treatment resistant schizophrenia: the effect of riluzole and therapeutic implications.

Sun, 03/03/2019 - 00:32
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Altered glutamatergic response and functional connectivity in treatment resistant schizophrenia: the effect of riluzole and therapeutic implications.

Psychopharmacology (Berl). 2019 Feb 28;:

Authors: Pillinger T, Rogdaki M, McCutcheon RA, Hathway P, Egerton A, Howes OD

Abstract
RATIONALE: Anterior cingulate cortex (ACC) glutamatergic abnormalities are reported in treatment-resistant schizophrenia (TRS) and implicated in functional dysconnectivity and psychopathology. Preclinical evidence indicates riluzole reduces synaptic glutamate. However, it is unknown whether riluzole can modulate glutamate metabolite levels and associated functional connectivity in TRS.
OBJECTIVES: To examine the relationship between glutamatergic function and cortical connectivity and determine if riluzole can modulate glutamate metabolite levels and cortical functional connectivity in TRS.
METHODS: Nineteen TRS patients and 18 healthy volunteers (HV) underwent magnetic resonance imaging consisting of MR spectroscopy measuring ACC glutamate plus glutamine (Glx), fMRI measuring resting ACC-functional connectivity, and arterial spin labelling measuring regional cerebral blood flow (rCBF), and clinical measures. They then received 50 mg riluzole twice daily for 2 days when imaging was repeated.
RESULTS: Baseline (pre-riluzole) Glx levels were correlated directly with negative symptom severity (r = 0.49; p = 0.03) and inversely with verbal learning in TRS (r = - 0.63; p = 0.002), but not HV (r = - 0.24; p = 0.41). Connectivity between the ACC and anterior prefrontal cortex (aPFC) was correlated with verbal learning in TRS (r = 0.49; p = 0.04), but not HV (r = 0.28; p = 0.33). There was a significant group × time interaction effect on Glx levels (p < 0.05) and on ACC connectivity to the aPFC (p < 0.05, FWE-corrected). Riluzole decreased Glx and increased ACC-aPFC connectivity in TRS relative to HV. Change in Glx correlated inversely with change in ACC-aPFC connectivity in TRS (r = - 0.52; p = 0.02) but not HV (r = 0.01; p = 0.98). Riluzole did not alter rCBF (p > 0.05), indicating absence of a non-specific blood flow effect.
CONCLUSION: Results indicate glutamatergic function and cortical connectivity are linked to symptoms and cognitive measures and that it is possible to pharmacologically modulate them in TRS.

PMID: 30820633 [PubMed - as supplied by publisher]

Functional connectivity between prefrontal cortex and subgenual cingulate predicts antidepressant effects of ketamine.

Sun, 03/03/2019 - 00:32
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Functional connectivity between prefrontal cortex and subgenual cingulate predicts antidepressant effects of ketamine.

Eur Neuropsychopharmacol. 2019 Feb 25;:

Authors: Gärtner M, Aust S, Bajbouj M, Fan Y, Wingenfeld K, Otte C, Heuser-Collier I, Böker H, Hättenschwiler J, Seifritz E, Grimm S, Scheidegger M

Abstract
Converging evidence suggests that a single sub-anesthetic dose of ketamine can produce strong and rapid antidepressant effects in patients that do not respond to standard treatment. Despite a considerable amount of research investigating ketamine's mechanisms of action, the exact neuronal targets conveying the antidepressant effects have not been identified yet. Preclinical studies suggest that molecular changes induced by ketamine bring forward large-scale network reconfigurations that might relate to ketamine's antidepressant properties. In this prospective two-site study we measured resting state fMRI in 24 depressed patients prior to, and 24 h after a single sub-anesthetic dose of ketamine. We analyzed functional connectivity (FC) at baseline and after ketamine and focused our analysis on baseline FC and FC changes directly linked to symptom reduction in order to identify neuronal targets that predict individual clinical responses to ketamine. Our results show that FC increases after ketamine between right lateral prefrontal cortex (PFC) and subgenual anterior cingulate cortex (sgACC) are positively linked to treatment response. Furthermore, low baseline FC between these regions predicts treatment outcome. We conclude that PFC-sgACC connectivity may represent a promising biomarker with both predictive and explanatory power.

PMID: 30819549 [PubMed - as supplied by publisher]

When to collect resting-state data: The influence of odor on post-task resting-state connectivity.

Sat, 03/02/2019 - 00:31
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When to collect resting-state data: The influence of odor on post-task resting-state connectivity.

Neuroimage. 2019 Feb 25;:

Authors: Cecchetto C, Fischmeister FP, Reichert JL, Bagga D, Schöpf V

Abstract
The human brain networks at rest represent spontaneous activity that is highly correlated between different brain regions. Previous studies have shown that these resting-state networks are flexible and dynamic, and they can be affected by performance of different types of tasks. Moreover, it has been suggested that the re-activation of a task-related brain network during rest promotes learning and improves the expertise on that task. However, it is still unclear whether the presence of different sensory information in the on-task state affects functional connectivity in subsequent resting-state fMRI even though the perception of the sensory information did not induce significant behavioral effects. To clarify this issue, we compared pre- and post-task resting-state fMRI of two groups of participants performing the same task either with an odor context (ODOR group) or without an odor context (AIR group). Seed-based functional connectivity analyses were performed with orbitofrontal cortex, piriform cortex and working-memory core network as seeds. The results showed that an odor context presented during an encoding task induced significant changes in the functional connectivity only within the olfactory network of the post-task resting-state compared to the same post-task situation without previous odor context. No significant difference in functional connectivity were found for the working-memory core network. This evidence emphasizes how the sensory context, in which a task is performed, is relevant for understanding the observed changes of functional connectivity during rest.

PMID: 30818023 [PubMed - as supplied by publisher]

Cognitive function assessment and comparison on lateral ventricular tumors resection by the frontal transcortical approach and anterior transcallosal approach respectively in children.

Sat, 03/02/2019 - 00:31
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Cognitive function assessment and comparison on lateral ventricular tumors resection by the frontal transcortical approach and anterior transcallosal approach respectively in children.

Neurosurg Rev. 2019 Feb 27;:

Authors: He J, Li Z, Yu Y, Lu Z, Li Z, Gong J

Abstract
Currently, there are few studies on cognitive impairment caused by neurosurgery, and there have been no studies on cognitive impairment after resection of lateral ventricular tumors in children. Previously, our research team has reported that the frontal transcortical approach can impair cognitive function. In this study, we explored which functions would be damaged by the transcallosal approach and compared the cognitive function changes caused by the two surgical approaches, so as to provide a theoretical basis for the selection of pre-operative surgical approaches. The authors prospectively collected pediatric patients with lateral ventricular tumors who had undergone surgical resection through the frontal transcortical approach and anterior transcallosal approach in Beijing Tiantan Hospital from November 2012 to May 2017. The inclusion criteria according to the Children Wechsler Scale requirements and clinical performance were formulated. Wechsler Intelligence Scale for Children®-fourth edition: Chinese version (WISC-IV) was adopted for general intelligence and cognitive function assessment in the study. 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 pre-operative period and 6-month follow-up in post-operation. A total of 30 patients were enrolled. Gross total resection was achieved in all patients, and no severe post-operative complications were observed. The frontal transcortical approach was applied in 19 patients, and the transcallosal approach was conducted for 11 patients. Compared with the pre-operative indices of WISC-IV, patients generally had a lower level of indices of the WISC-IV in post-operation. In patients accepting lateral ventricular tumors resection through the anterior transcallosal approach, the total IQ was declined to M = 84.82, SD = 8.072 from M = 93.27, SD = 6.635 within the 6-month convalescence. The data of working memory (t = - 2.990, p = 0.002) and total IQ (t = - 2.205, p = 0.028) pre- and post-operative showed statistical significance. But in the comparison of two surgical approaches, it was found that IQ had no statistical difference in WISC-IV tasks data. Previous studies suggest that the frontal transcortical approach impair perceptual reasoning, processing speed, and IQ, while this study indicates that the anterior transcallosal approach impairs patients' working memory and IQ. Both approaches make equal damage to IQ. Through comparing the two surgical approaches, it can be known that the anterior transcallosal approach cannot replace the frontal transcortical approach. The protection of cognitive function should be considered as one of the bases for neurosurgeons to select the operative approach before the operation. However, in an actual situation, the specific approach should be carefully selected by comprehensive consideration.

PMID: 30815764 [PubMed - as supplied by publisher]

Association between Thalamocortical Functional Connectivity Abnormalities and Cognitive Deficits in Schizophrenia.

Sat, 03/02/2019 - 00:31
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Association between Thalamocortical Functional Connectivity Abnormalities and Cognitive Deficits in Schizophrenia.

Sci Rep. 2019 Feb 27;9(1):2952

Authors: Chen P, Ye E, Jin X, Zhu Y, Wang L

Abstract
Cognitive deficits are considered a core component of schizophrenia and may predict functional outcome. However, the neural underpinnings of neuropsychological impairment remain to be fully elucidated. Data of 59 schizophrenia patients and 72 healthy controls from a public resting-state fMRI database was employed in our study. Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Battery was used to measure deficits of cognitive abilities in schizophrenia. Neural correlates of cognitive deficits in schizophrenia were examined by linear regression analysis of the thalamocortical network activity with scores of seven cognitive domains. We confirmed the combination of reduced prefrontal-thalamic connectivity and increased sensorimotor-thalamic connectivity in patients with schizophrenia. Correlation analysis with cognition revealed that in schizophrenia (1) the thalamic functional connectivity in the bilateral pre- and postcentral gyri was negatively correlated with attention/vigilance and speed of processing (Pearson's r ≤ -0.443, p ≤ 0.042, FWE corrected), and positively correlated with patients' negative symptoms (Pearson's r ≥ 0.375, p ≤ 0.003, FWE corrected); (2) the thalamic functional connectivity in the right cerebellum was positively correlated with speed of processing (Pearson's r = 0.388, p = 0.01, FWE corrected). Our study demonstrates that thalamic hyperconnectivity with sensorimotor areas is related to the severity of cognitive deficits and clinical symptoms, and extends our understanding of the neural underpinnings of "cognitive dysmetria" in schizophrenia.

PMID: 30814558 [PubMed - in process]

Patients with autism spectrum disorders display reproducible functional connectivity alterations.

Sat, 03/02/2019 - 00:31
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Patients with autism spectrum disorders display reproducible functional connectivity alterations.

Sci Transl Med. 2019 Feb 27;11(481):

Authors: Holiga Š, Hipp JF, Chatham CH, Garces P, Spooren W, D'Ardhuy XL, Bertolino A, Bouquet C, Buitelaar JK, Bours C, Rausch A, Oldehinkel M, Bouvard M, Amestoy A, Caralp M, Gueguen S, Ly-Le Moal M, Houenou J, Beckmann CF, Loth E, Murphy D, Charman T, Tillmann J, Laidi C, Delorme R, Beggiato A, Gaman A, Scheid I, Leboyer M, d'Albis MA, Sevigny J, Czech C, Bolognani F, Honey GD, Dukart J

Abstract
Despite the high clinical burden, little is known about pathophysiology underlying autism spectrum disorder (ASD). Recent resting-state functional magnetic resonance imaging (rs-fMRI) studies have found atypical synchronization of brain activity in ASD. However, no consensus has been reached on the nature and clinical relevance of these alterations. Here, we addressed these questions in four large ASD cohorts. Using rs-fMRI, we identified functional connectivity alterations associated with ASD. We tested for associations of these imaging phenotypes with clinical and demographic factors such as age, sex, medication status, and clinical symptom severity. Our results showed reproducible patterns of ASD-associated functional hyper- and hypoconnectivity. Hypoconnectivity was primarily restricted to sensory-motor regions, whereas hyperconnectivity hubs were predominately located in prefrontal and parietal cortices. Shifts in cortico-cortical between-network connectivity from outside to within the identified regions were shown to be a key driver of these abnormalities. This reproducible pathophysiological phenotype was partially associated with core ASD symptoms related to communication and daily living skills and was not affected by age, sex, or medication status. Although the large effect sizes in standardized cohorts are encouraging with respect to potential application as a treatment and for patient stratification, the moderate link to clinical symptoms and the large overlap with healthy controls currently limit the usability of identified alterations as diagnostic or efficacy readout.

PMID: 30814340 [PubMed - in process]

Functional dysconnectivity within the emotion-regulating system is associated with affective symptoms in major depressive disorder: A resting-state fMRI study.

Sat, 03/02/2019 - 00:31
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Functional dysconnectivity within the emotion-regulating system is associated with affective symptoms in major depressive disorder: A resting-state fMRI study.

Aust N Z J Psychiatry. 2019 Feb 28;:4867419832106

Authors: He Z, Lu F, Sheng W, Han S, Long Z, Chen Y, Luo W, Yu Y, Nan X, Ouyang A, Cui Q, Chen H

Abstract
OBJECTIVE:: Major depressive disorder (MDD) can be characterized as a multidimensional and system-level disorder. The neuropathophysiological abnormalities have been reported to be distributed in emotion regulation system, involving the prefrontal cortex (PFC), limbic and striatum in convergent studies. Decrease of positive affect and increase of negative affect are recognized as a hallmark of MDD. However, the dysfunctions in affective processing in MDD within the emotion regulation system remains largely unclear. In this study, our goals are to characterize the dysconnectivity pattern within this system and explore the relationships between this kind of dysconnectivity pattern and affective symptoms, which might help us better look into the neuropathophysiological mechanisms underlying MDD.
METHODS:: A total of 34 MDD and 34 healthy controls (HCs) underwent resting-state functional magnetic resonance imaging (rsfMRI). The alterations in functional connectivity (FC) within the emotion regulation system and their relationships with affective symptoms were explored.
RESULTS:: Compared with HCs, MDD patients showed aberrant FC within this system. Importantly, deceased FC was mainly involved in the prefrontal-limbic system, while elevated FC was observed in the prefrontal-striatum system. In the MDD group, decreased FC of right posterior hippocampus-left dorsolateral prefrontal cortex (dlPFC) was negatively associated with the negative affect scores and Hamilton Depression Rating Scale scores and the FC of left ventral striatum-left dlPFC was significantly negatively related with the positive affect scores.
CONCLUSIONS:: These findings demonstrated that MDD showed characteristic pathological alterations of the emotion regulation system. Dysconnectivity within prefrontal-limbic system might be more related to the dysregulation of negative affect, whereas dysconnectivity within prefrontal-striatum system might influence more on positive affect processing. The decrease in positive affect and increase in negative affect in MDD might have different pathological basis. These results could help better understand the dysconnectivity pattern in the emotion-regulating system underlying depression.

PMID: 30813750 [PubMed - as supplied by publisher]

Spatial source phase: A new feature for identifying spatial differences based on complex-valued resting-state fMRI data.

Thu, 02/28/2019 - 21:31
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Spatial source phase: A new feature for identifying spatial differences based on complex-valued resting-state fMRI data.

Hum Brain Mapp. 2019 Feb 27;:

Authors: Qiu Y, Lin QH, Kuang LD, Gong XF, Cong F, Wang YP, Calhoun VD

Abstract
Spatial source phase, the phase information of spatial maps extracted from functional magnetic resonance imaging (fMRI) data by data-driven methods such as independent component analysis (ICA), has rarely been studied. While the observed phase has been shown to convey unique brain information, the role of spatial source phase in representing the intrinsic activity of the brain is yet not clear. This study explores the spatial source phase for identifying spatial differences between patients with schizophrenia (SZs) and healthy controls (HCs) using complex-valued resting-state fMRI data from 82 individuals. ICA is first applied to preprocess fMRI data, and post-ICA phase de-ambiguity and denoising are then performed. The ability of spatial source phase to characterize spatial differences is examined by the homogeneity of variance test (voxel-wise F-test) with false discovery rate correction. Resampling techniques are performed to ensure that the observations are significant and reliable. We focus on two components of interest widely used in analyzing SZs, including the default mode network (DMN) and auditory cortex. Results show that the spatial source phase exhibits more significant variance changes and higher sensitivity to the spatial differences between SZs and HCs in the anterior areas of DMN and the left auditory cortex, compared to the magnitude of spatial activations. Our findings show that the spatial source phase can potentially serve as a new brain imaging biomarker and provide a novel perspective on differences in SZs compared to HCs, consistent with but extending previous work showing increased variability in patient data.

PMID: 30811773 [PubMed - as supplied by publisher]

[Preliminary study of auditory cortex resting-state fMRI features for adult post-lingual deafness].

Thu, 02/28/2019 - 21:31
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[Preliminary study of auditory cortex resting-state fMRI features for adult post-lingual deafness].

Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi. 2019 Feb 05;33(2):110-113

Authors: Zhong KB, Wang XQ, Wu PN, Ge RM, Huang HM, Zeng J

Abstract
Objective: To understand the auditory cortex resting-state fMRI features for adult post-lingual deafness.Method: The author performed functional connectivity analysis on the study subjects with resting-state fMRI,the region of interest(ROI) of which were based separately on the left and right sides of primary auditory cortex. The data were collected from 8 cases with severe or above sensorineurally post-lingual deafness,compared to a control group of 8 cases with normal hearing. Result: When ROI were based on the left A1 areas of all subjects, the main activating area in the control group was bilateral superior temporal gyrus(STG), while the post-lingual deafness group included the bilateral STG, pre-central gyri, left Transverse temporal gyrus(TTG), post-central gyri and right TTG (P<0.01); when ROI were based on the right A1 areas of all subjects, the main activating area in the control group was the bilateral STG, while the post-lingual deafness group included the bilateral STG, right precentral gyri and post-central gyr i(P<0.01). The data showed statistical significance(P<0.05). Conclusion: After hearing loss functional reorganization takes place in the brains of adults with post-lingual deafness, resulting in possible enhancement of visual sense, tactile sense and other sensory systems in order to compensate information acquisition in daily life. .

PMID: 30808133 [PubMed - in process]