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[A preliminary study of resting-state fMRI in patients with diarrhea-type irritable bowel syndrome after pinaverium bromide combined treatment with flupentixol-melitracen].

Fri, 11/08/2019 - 06:15
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[A preliminary study of resting-state fMRI in patients with diarrhea-type irritable bowel syndrome after pinaverium bromide combined treatment with flupentixol-melitracen].

Zhonghua Yi Xue Za Zhi. 2019 Nov 05;99(41):3266-3272

Authors: Li J, Guo Y, Lu XQ, Li GX, Yang Y, Li L, Ding JP

Abstract
Objective: To observe the difference of brain activity in patients with diarrhea-type irritable bowel syndrome (IBS-D) treated with pinaverium bromide (PB) combined with flupentixol-melitracen (FM), and to explore the mechanism of efficacy of combined with anxiolytic/antidepressant drugs in IBS-D patients at the central level, using resting-state functional magnetic resonance imaging (rs-fMRI). Methods: Forty-eight patients with IBS-D, including 28 males, 20 females, mean age 22-48 (33±7) years, were selected from the Affiliated Hospital of Hangzhou Normal University from October 2015 to October 2018.All patients with IBS-D underwent rs-fMRI scans before and after receiving either PB (basic treatment group, n=16), PB combined with FM (combination therapy group, n=16), or no medication (no treatment group, n=16). Rs-fMRI regional homogeneity (ReHo) parameter among the three groups of patients were compared using One-way ANOVA analysis and post analysis.Partial correlation and mediation analyses were performed on ReHo values and the improvement of symptoms scores (gastrointestinal symptom rating scale(GSRS) and hospital anxiety/depression scale (HAD)) in the two medicated groups. Results: No significant differences in ReHo values were observed among the three groups before treatment. Compared with patients on no-medication, patients receiving either PB or PB-FM showed decreased ReHo in the striatum, insular lobe, medial prefrontal cortex (MPFC) and subcallosal gyrus, and increased ReHo in the occipital cortex. In particular, the combined treatment group showed more extensive decreased ReHo in the left thalamus and left temporal pole, and increased in the left precuneus. Compared with the basic treatment group, the combined treatment group showed decreased ReHo in the right putamen, right insula, right MPFC and subcallosal gyrus, and increased ReHo in the left precuneus. In addition, the combined treatment group demonstrated a positive correlation between ReHo values in the left thalamus and the improvement of HAD score (r=0.653, P=0.011) , and a negative correlation between ReHo values in left precuneus and the improvement of GSRS and HAD score (r=-0.771, P=0.001; r=-0.716, P=0.004). ReHo values in the left precuneus were observed to mediate between gastrointestinal symptoms and anxiety-depressive symptoms in the combined treatment group. Conclusions: The efficacy of PB combined with FM is superior to PB alone in the treatment of IBS. In addition to more extensive changes in pain-related brain areas, IBS-D patients treated with anxiolytic/antidepressant also show changes in default network and brain areas related to emotional regulation, and are associated with improvement in gastrointestinal symptoms, anxiety and depression.

PMID: 31694124 [PubMed - in process]

Resting-state functional connectivity predicts individual language impairment of patients with left hemispheric gliomas involving language network.

Fri, 11/08/2019 - 06:15
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Resting-state functional connectivity predicts individual language impairment of patients with left hemispheric gliomas involving language network.

Neuroimage Clin. 2019 Oct 19;24:102023

Authors: Yuan B, Zhang N, Yan J, Cheng J, Lu J, Wu J

Abstract
Language deficits following brain tumors should consider the dynamic interactions between different tumor growth kinetics and functional network reorganization. We measured the resting-state functional connectivity of 126 patients with left cerebral gliomas involving language network areas, including 77 patients with low-grade gliomas (LGG) and 49 patients with high-grade gliomas (HGG). Functional network mapping for language was performed by construction of a multivariate machine learning-based prediction model of individual aphasia quotient (AQ), a summary score that indicates overall severity of language impairment. We found that the AQ scores for HGG patients were significantly lower than those of LGG patients. The prediction accuracy of HGG patients (R2 = 0.27, permutation P = 0.007) was much higher than that of LGG patients (R2 = 0.09, permutation P = 0.032). The rsFC regions predictive of LGG's AQ involved the bilateral frontal, temporal, and parietal lobes, subcortical regions, and bilateral cerebro-cerebellar connections, mainly in regions belonging to the canonical language network. The functional network of language processing for HGG patients showed strong dependence on connections of the left cerebro-cerebellar connections, limbic system, and the temporal, occipital, and prefrontal lobes. Together, our findings suggested that individual language processing of glioma patients links large-scale, bilateral, cortico-subcortical, and cerebro-cerebellar functional networks with different network reorganizational mechanisms underlying the different levels of language impairments in LGG and HGG patients.

PMID: 31693978 [PubMed - as supplied by publisher]

Implications of the putamen in pain and motor deficits in complex regional pain syndrome.

Fri, 11/08/2019 - 06:15
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Implications of the putamen in pain and motor deficits in complex regional pain syndrome.

Pain. 2019 Nov 04;:

Authors: Azqueta-Gavaldon M, Youssef AM, Storz C, Lemme J, Schulte-Göcking H, Becerra L, Azad SC, Reiners A, Ertl-Wagner B, Borsook D, Upadhyay J, Kraft E

Abstract
Complex regional pain syndrome (CRPS) develops after limb injury, with persistent pain and deficits in movement frequently co-occurring. The striatum is critical for mediating multiple mechanisms that are often aberrant in CRPS, which includes sensory and pain processing, motor function and goal-directed behaviors associated with movement. Yet much remains unknown with regards to the morphological and functional properties of the striatum and its sub-regions in this disease. Thus, we investigated 20, patients (15 female, age 58 ± 9 years, right-handed) diagnosed with chronic (6+ months of pain duration) CRPS in the right hand and 20 matched, healthy controls with anatomical and resting-state, functional magnetic resonance imaging (fMRI). In addition, a comprehensive clinical and behavioral evaluation was performed, where each participant's pain, motor function and medical history were assessed. CRPS patients harbored significant abnormalities in hand coordination, dexterity and strength. These clinical pain and movement-related findings in CRPS patients were concomitant with bilateral decreases in gray matter density in the putamen as well as functional connectivity increases and decreases amongst the putamen and pre-/postcentral gyri and cerebellum, respectively. Importantly, higher levels of clinical pain and motor impairment were associated with increased putamen-pre-/postcentral gyri functional connectivity strengths. Collectively, these findings suggest that putaminal alterations, specifically the functional interactions with sensorimotor structures, may underpin clinical pain and motor impairment in chronic CRPS patients.

PMID: 31693538 [PubMed - as supplied by publisher]

Real-time presurgical resting-state fMRI in patients with brain tumors: Quality control and comparison with task-fMRI and intraoperative mapping.

Fri, 11/08/2019 - 06:15
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Real-time presurgical resting-state fMRI in patients with brain tumors: Quality control and comparison with task-fMRI and intraoperative mapping.

Hum Brain Mapp. 2019 Nov 06;:

Authors: Vakamudi K, Posse S, Jung R, Cushnyr B, Chohan MO

Abstract
Resting-state functional magnetic resonance imaging (rsfMRI) is a promising task-free functional imaging approach, which may complement or replace task-based fMRI (tfMRI) in patients who have difficulties performing required tasks. However, rsfMRI is highly sensitive to head movement and physiological noise, and validation relative to tfMRI and intraoperative electrocortical mapping is still necessary. In this study, we investigate (a) the feasibility of real-time rsfMRI for presurgical mapping of eloquent networks with monitoring of data quality in patients with brain tumors and (b) rsfMRI localization of eloquent cortex compared with tfMRI and intraoperative electrocortical stimulation (ECS) in retrospective analysis. Five brain tumor patients were studied with rsfMRI and tfMRI on a clinical 3T scanner using MultiBand(8)-echo planar imaging (EPI) with repetition time: 400 ms. Moving-averaged sliding-window correlation analysis with regression of motion parameters and signals from white matter and cerebrospinal fluid was used to map sensorimotor and language resting-state networks. Data quality monitoring enabled rapid optimization of scan protocols, early identification of task noncompliance, and head movement-related false-positive connectivity to determine scan continuation or repetition. Sensorimotor and language resting-state networks were identifiable within 1 min of scan time. The Euclidean distance between ECS and rsfMRI connectivity and task-activation in motor cortex, Broca's, and Wernicke's areas was 5-10 mm, with the exception of discordant rsfMRI and ECS localization of Wernicke's area in one patient due to possible cortical reorganization and/or altered neurovascular coupling. This study demonstrates the potential of real-time high-speed rsfMRI for presurgical mapping of eloquent cortex with real-time data quality control, and clinically acceptable concordance of rsfMRI with tfMRI and ECS localization.

PMID: 31692177 [PubMed - as supplied by publisher]

Finger Tapping Task Activation vs. TMS Hotspot: Different Locations and Networks.

Fri, 11/08/2019 - 06:15
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Finger Tapping Task Activation vs. TMS Hotspot: Different Locations and Networks.

Brain Topogr. 2019 Nov 06;:

Authors: Wang J, Meng HJ, Ji GJ, Jing Y, Wang HX, Deng XP, Feng ZJ, Zhao N, Zang YF, Zhang J

Abstract
Both functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) have been used to non-invasively localize the human motor functional area. These locations can be clinically used as stimulation target of TMS treatment. However, it has been reported that the finger tapping fMRI activation and TMS hotspot were not well-overlapped. The aim of the current study was to measure the distance between the finger tapping fMRI activation and the TMS hotspot, and more importantly, to compare the network difference by using resting-state fMRI. Thirty healthy participants underwent resting-state fMRI, task fMRI, and then TMS hotspot localization. We found significant difference of locations between finger tapping fMRI activation and TMS hotspot. Specifically, the finger tapping fMRI activation was more lateral than the TMS hotspot in the premotor area. The fMRI activation peak and TMS hotspot were taken as seeds for resting-state functional connectivity analyses. Compared with TMS hotspot, finger tapping fMRI activation peak showed more intensive functional connectivity with, e.g., the bilateral premotor, insula, putamen, and right globus pallidus. The findings more intensive networks of finger tapping activation than TMS hotspot suggest that TMS treatment targeting on the fMRI activation area might result in more remote effects and would be more helpful for TMS treatment on movement disorders.

PMID: 31691912 [PubMed - as supplied by publisher]

Neural and functional correlates of impaired reading ability in schizophrenia.

Fri, 11/08/2019 - 06:15
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Neural and functional correlates of impaired reading ability in schizophrenia.

Sci Rep. 2019 Nov 05;9(1):16022

Authors: Dondé C, Martinez A, Sehatpour P, Patel GH, Kraut R, Kantrowitz JT, Javitt DC

Abstract
Deficits in early auditory processing (EAP) are a core component of schizophrenia (SZ) and contribute significantly to impaired overall function. Here, we evaluate the potential contributions of EAP-related impairments in reading to functional capacity and outcome, relative to effects of auditory social cognitive and general neurocognitive dysfunction. Participants included 30-SZ and 28-controls of similar age, sex, and educational achievement. EAP was assessed using an auditory working memory (tone-matching) task. Phonological processing and reading Fluency were assessed using the Comprehensive Test of Phonological Processing and Woodcock-Johnson reading batteries, respectively. Auditory-related social cognition was assessed using measures of emotion/sarcasm recognition. Functional capacity and outcome were assessed using the UCSD Performance-based Skills Assessment and Specific Level of Functioning scale, respectively. fMRI resting-state functional-connectivity (rsFC) was used to evaluate potential underlying substrates. As predicted, SZ patients showed significant and interrelated deficits in both phonological processing (d = 0.74, p = 0.009) and reading fluency (d = 1.24, p < 0.00005). By contrast, single word reading (d = 0.35, p = 0.31) was intact. In SZ, deficits in EAP and phonological reading ability significantly predicted reduced functional capacity, but not functional outcome. By contrast, deficits in reading fluency significantly predicted impairments in both functional capacity and functional outcome. Moreover, deficits in reading fluency correlated with rsFC alterations among auditory thalamus, early auditory and auditory association regions. These findings indicate significant contributions of EAP deficits and functional connectivity changes in subcortical and early auditory regions to reductions in reading fluency, and of impaired reading ability to impaired functional outcome in SZ.

PMID: 31690846 [PubMed - in process]

Tracking the Brain State Transition Process of Dynamic Function Connectivity Based on Resting State fMRI.

Fri, 11/08/2019 - 06:15
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Tracking the Brain State Transition Process of Dynamic Function Connectivity Based on Resting State fMRI.

Comput Intell Neurosci. 2019;2019:9027803

Authors: Liu C, Xue J, Cheng X, Zhan W, Xiong X, Wang B

Abstract
BOLD-fMRI technology provides a good foundation for the research of human brain dynamic functional connectivity and brain state analysis. However, due to the complexity of brain function connectivity and the high dimensionality expression of brain dynamic attributions, more research studies are focusing on tracking the time-varying characteristics through the transition between different brain states. The transition process is considered to occur instantaneously at some special time point in the above research studies, whereas our work found the brain state transition may be completed in a time section gradually rather than instantaneously. In this paper, a brain state conversion rate model is constructed to observe the procedure of brain state transition trend at each time point, and the state change can be observed by the values of conversion rate. According to the results, the transition of status always lasts for a few time points, and a brain state network model with both steady state and transition state is presented. Network topological overlap coefficient is built to analyze the features of time-varying networks. With this method, some common regular patterns of time-varying characteristics can be observed strongly in healthy children but not in the autism children. This distinct can help us to distinguish children with autism from healthy children.

PMID: 31687008 [PubMed - in process]

Abnormal intrinsic functional activity in patients with cervical spondylotic myelopathy: a resting-state fMRI study.

Fri, 11/08/2019 - 06:15
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Abnormal intrinsic functional activity in patients with cervical spondylotic myelopathy: a resting-state fMRI study.

Neuropsychiatr Dis Treat. 2019;15:2371-2383

Authors: Kuang C, Zha Y

Abstract
Purpose: We employed resting-state fMRI analyses to reveal central functional reorganization in the brains of patients with cervical spondylotic myelopathy (CSM) and to provide complementary evidence of cortex reorganization in these patients.
Patients and methods: We obtained Fisher's z transformation amplitude of low-frequency fluctuations (zALFF) and Fisher's z transformation regional homogeneity (zReHo) measurements from 33 patients with CSM and 33 healthy controls (HC) and used the brain regions with significant alterations in the zALFF or zReHo values as seed regions. Then, we calculated Pearson's correlation coefficients between the resting-state time courses of each seed and the time series of the rest of the brain. Lastly, we computed correlations between the altered zALFF, zReHo, and functional connectivity with Japanese Orthopaedic Association scores, Neck Disability Index score, and the duration of symptoms in patients with CSM.
Results: zALFF and zReHo values were increased in the left medial superior frontal gyrus (lSFGmed) and left supramarginal gyrus (lSMG) in patients with CSM compared with those in the HC group. Selecting lSFGmed as the seed, we observed increased functional connectivity between it and the left postcentral gyrus (lPoCG) and left rolandic operculum and decreased functional connectivity with the right medial superior frontal gyrus in patients with CSM. In addition, there was a significant increase in the functional connectivity between the lSMG (seed) and the left calcarine and lPoCG in patients with CSM. However, we did not find any significant correlation between the resting-state findings and the clinical performance of patients with CSM.
Conclusion: These observed intrinsic functional changes in the patients with CSM may be related to functional reorganization and reflect the innate cortical plasticity in patients with CSM. Notably, the increased connectivity between the lPoCG and the two seed ROIs indicates the adaptive changes in patients with CSM. These findings provide complementary evidence of cortex reorganization in CSM.

PMID: 31686821 [PubMed]

Intrinsic Functional Connectivity is Organized as Three Interdependent Gradients.

Fri, 11/08/2019 - 06:15
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Intrinsic Functional Connectivity is Organized as Three Interdependent Gradients.

Sci Rep. 2019 Nov 04;9(1):15976

Authors: Zhang J, Abiose O, Katsumi Y, Touroutoglou A, Dickerson BC, Barrett LF

Abstract
The intrinsic functional architecture of the brain supports moment-to-moment maintenance of an internal model of the world. We hypothesized and found three interdependent architectural gradients underlying the organization of intrinsic functional connectivity within the human cerebral cortex. We used resting state fMRI data from two samples of healthy young adults (N's = 280 and 270) to generate functional connectivity maps of 109 seeds culled from published research, estimated their pairwise similarities, and multidimensionally scaled the resulting similarity matrix. We discovered an optimal three-dimensional solution, accounting for 98% of the variance within the similarity matrix. The three dimensions corresponded to three gradients, which spatially correlate with two functional features (external vs. internal sources of information; content representation vs. attentional modulation) and one structural feature (anatomically central vs. peripheral) of the brain. Remapping the three dimensions into coordinate space revealed that the connectivity maps were organized in a circumplex structure, indicating that the organization of intrinsic connectivity is jointly guided by graded changes along all three dimensions. Our findings emphasize coordination between multiple, continuous functional and anatomical gradients, and are consistent with the emerging predictive coding perspective.

PMID: 31685830 [PubMed - in process]

Functional connectome of the fetal brain.

Fri, 11/08/2019 - 06:15
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Functional connectome of the fetal brain.

J Neurosci. 2019 Nov 04;:

Authors: Turk E, van den Heuvel MI, Benders MJ, de Heus R, Franx A, Manning JH, Hect JL, Hernandez-Andrade E, Hassan SS, Romero R, Kahn RS, Thomason ME, van den Heuvel MP

Abstract
Large-scale functional connectome formation and re-organization is apparent in the second trimester of pregnancy, making it a crucial and vulnerable time window in connectome development. Here we identified which architectural principles of functional connectome organization are initiated prior to birth, and contrast those with topological characteristics observed in the mature adult brain. A sample of 105 pregnant women participated in human fetal resting-state fMRI studies (fetal gestational age between 20 and 40 weeks). Connectome analysis was used to analyze weighted network characteristics of fetal macroscale brain wiring. We identified efficient network attributes, common functional modules and high overlap between the fetal and adult brain network. Our results indicate that key features of the functional connectome are present in the second and third trimesters of pregnancy. Understanding the organizational principles of fetal connectome organization may bring opportunities to develop markers for early detection of alterations of brain function.SIGNIFICANCE STATEMENTThe fetal to neonatal period is well known as a critical stage in brain development. Rapid neurodevelopmental processes establish key functional neural circuits of the human brain. Prenatal risk factors may interfere with early trajectories of connectome formation and thereby shape future health outcomes. Recent advances in MRI have made it possible to examine fetal brain functional connectivity. In this study, we evaluate the network topography of normative functional network development during connectome genesis in utero Understanding the developmental trajectory of brain connectivity provides a basis for understanding how the prenatal period shapes future brain function and disease dysfunction.

PMID: 31685648 [PubMed - as supplied by publisher]

Brain functional basis of subjective well-being during negative facial emotion processing task-based fMRI.

Tue, 11/05/2019 - 21:13
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Brain functional basis of subjective well-being during negative facial emotion processing task-based fMRI.

Neuroscience. 2019 Nov 01;:

Authors: Ren Z, Shi L, Wei D, Qiu J

Abstract
Subjective well-being (SWB) is the eternal pursuit of all mankind. Individual differences in SWB may reflect the way of emotional processing. Neuroimaging studies have partly examined the neural mechanism of the individual differences in SWB using resting-state functional magnetic resonance imaging (rs-fMRI). However, few studies have investigated the relationship between the individual differences in SWB and brain functional connectivity during facial emotion processing task. Here, we applied negative facial emotion processing task-based fMRI to explore the brain functional basis of the individual differences in SWB. Results showed that SWB is positively correlated with the activation of right posterior cingulate cortex, left interior temporal gyrus and left angular gyrus for the comparison of negative stimulus and neutral stimulus, revealing that happy individuals may be more proactive to use attention transfer and behavioral inhibition strategies to decrease negative experiences during negative emotional processing. In addition, high SWB is associated with strong functional connectivity between high-level cognitive networks (e.g., frontal-parietal network) and low-level perceptual networks (e.g., sensorimotor network), and weak functional connectivity within default mode network and within low-level perceptual networks, indicating that the self-reflection, emotional regulation and cognitive control during negative facial emotion processing underlies the individual differences in SWB. These findings provide a novel insight to characterize the brain functional basis of the individual differences in SWB.

PMID: 31682958 [PubMed - as supplied by publisher]

Exploring the effects of near infrared light on resting and evoked brain activity in humans using magnetic resonance imaging.

Tue, 11/05/2019 - 21:13
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Exploring the effects of near infrared light on resting and evoked brain activity in humans using magnetic resonance imaging.

Neuroscience. 2019 Nov 01;:

Authors: El Khoury H, Mitrofanis J, Henderson LA

Abstract
We explore whether near infrared light can change patterns of resting (task-negative) and/or evoked (task-positive; eg finger-tapping) brain activity in normal, young human subjects using fMRI (functional magnetic resonance imaging). To this end, we used a vielight transcranial device (810nm) and compared the scans in subjects after active- and sham-light sessions. Our fMRI results showed that, while light had no effect on cerebral blood flow and global resting state brain activity (task-negative), there were clear differences between the active- and sham-light sessions in the patterns of evoked brain activity after finger-tapping (task-positive). The evoked brain regions included the putamen, primary somatosensory and parietal association cortex, and the overall effect of the light was to suppress or reduce their activity. We also found that while light had no effect on the resting functional connectivity of the putamen and primary somatosensory cortex and the rest of the brain, it did have an effect on the functional connectivity of parietal association cortex. In summary, our fMRI findings indicated that transcranially applied light did have a major impact on brain activity in normal subjects, but only when the brain region was itself functionally active, when undertaking a particular task. We suggest that these light-induced changes, particularly those in parietal association cortex, were associated with attention and novelty, and served to deactivate the so-called default mode network. Our results lay the template for our planned fMRI explorations into the effects of light in both Alzheimer's and Parkinson's disease patients.

PMID: 31682952 [PubMed - as supplied by publisher]

BRAIN FUNCTION ALTERATIONS IN PATIENTS WITH DIABETIC NEPHROPATHY COMPLICATED BY RETINOPATHY UNDER RESTING STATE CONDITIONS ASSESSED BY VOXEL-MIRRORED HOMOTOPIC CONNECTIVITY.

Tue, 11/05/2019 - 21:13
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BRAIN FUNCTION ALTERATIONS IN PATIENTS WITH DIABETIC NEPHROPATHY COMPLICATED BY RETINOPATHY UNDER RESTING STATE CONDITIONS ASSESSED BY VOXEL-MIRRORED HOMOTOPIC CONNECTIVITY.

Endocr Pract. 2019 Nov 04;:

Authors: Wang Y, Wang X, Chen W, Shao Y, Zhou J, Chen Q, Lv J

Abstract
Objective: The voxel-mirrored homologous connection (VHMC) technique was applied to detect resting brain function alterations in patients with diabetic nephropathy and retinopathy (DNRs), and their relationship with clinical manifestations in the kidney and eyes discussed. Methods: Twenty-two DNRs and 22 healthy controls (HCs) similarly matched in age, sex, and educational background were recruited. Resting-state functional magnetic resonance imaging (rs-fMRI) scans were performed for all subjects. Retinal fundus photography and renal biopsy were employed to observe the clinical features of the kidney and retina. Pearson correlation analysis was used to analyze the relationship between clinical manifestations and experimental results. Results: Compared with the HCs, patients with DNR showed decreased mean VMHC values in the bilateral middle temporal gyrus (BMTG), bilateral middle occipital gyrus (BMOG), and bilateral medial frontal gyrus (BMFG). The ROC curve analysis of each brain region confirmed that the accuracy of the area under the curve was excellent. The results showed that the average VHMC value of BMOG signals was positively correlated with the urinary protein to creatinine ratio in female subjects (r = 0.626, p < 0.05). None the less, no such correlation was noted among the male subjects. Conclusions: There were significant changes in brain function in DNR patients compared to the control group. Changes in the central nervous system in patients with DNR mainly due to the dual negative effects of kidney function and diabetes mellitus.

PMID: 31682517 [PubMed - as supplied by publisher]

Aging Reduces the Functional Brain Networks Strength-a Resting State fMRI Study of Healthy Mouse Brain.

Tue, 11/05/2019 - 21:13
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Aging Reduces the Functional Brain Networks Strength-a Resting State fMRI Study of Healthy Mouse Brain.

Front Aging Neurosci. 2019;11:277

Authors: Egimendia A, Minassian A, Diedenhofen M, Wiedermann D, Ramos-Cabrer P, Hoehn M

Abstract
Resting-state functional magnetic resonance imaging (rsfMRI) is increasingly used to unravel the functional neuronal networks in health and disease. In particular, this technique of simultaneously probing the whole brain has found high interest in monitoring brain wide effects of cerebral disease and in evaluating therapeutic strategies. Such studies, applied in preclinical experimental mouse models, often require long-term observations. In particular during regeneration studies, easily several months of continuous monitoring are required to detect functional improvements. These long periods of following the functional deficits during disease evolution as well as the functional recoveries during therapeutic interventions represent a substantial fraction of the life span of the experimental animals. We have therefore aimed to decipher the role of healthy aging alone for changes in functional neuronal networks in mice, from developmental adolescence via adulthood to progressing aging. For this purpose, four different groups of C57Bl6 mice of varying age between 2 and 13 months were studied twice with 4 weeks separation using resting state fMRI at 9.4T. Dedicated data analysis including both Independent Component Analysis (ICA) followed by seed-based connectivity matrix compilation resulted in an inverse U-shape curve of functional connectivity (FC) strength in both the sensorimotor and default mode network (DMN). This inverse U-shape pattern presented a distinct maximum of FC strength at 8-9 months of age, followed by a continuous decrease during later aging phases. At progressed aging at 12-13 months, the reduction of connectivity strength varied between 25% and 70% with most connectivities showing a reduction in strength by approximately 50%. We recommend that these substantial age-dependent changes in FC strength must be considered in future longitudinal studies to discriminate focused disease-based functional deficits and therapy-related functional improvements from underlying independent age effects.

PMID: 31680932 [PubMed]

Alterations of Regional Homogeneity in Parkinson's Disease Patients With Freezing of Gait: A Resting-State fMRI Study.

Tue, 11/05/2019 - 21:13
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Alterations of Regional Homogeneity in Parkinson's Disease Patients With Freezing of Gait: A Resting-State fMRI Study.

Front Aging Neurosci. 2019;11:276

Authors: Liu Y, Li M, Chen H, Wei X, Hu G, Yu S, Ruan X, Zhou J, Pan X, Li Z, Luo Z, Xie Y

Abstract
Objective: The purposes of this study are to investigate the regional homogeneity (ReHo) of spontaneous brain activities in Parkinson's disease (PD) patients with freeze of gait (FOG) and to investigate the neural correlation of movement function through resting-state functional magnetic resonance imaging (RS-fMRI).
Methods: A total of 35 normal controls (NC), 33 PD patients with FOG (FOG+), and 35 PD patients without FOG (FOG-) were enrolled. ReHo was applied to evaluate the regional synchronization of spontaneous brain activities. Analysis of covariance (ANCOVA) was performed on ReHo maps of the three groups, followed by post hoc two-sample t-tests between every two groups. Moreover, the ReHo signals of FOG+ and FOG- were extracted across the whole brain and correlated with movement scores (FOGQ, FOG questionnaire; GFQ, gait and falls questionnaire).
Results: Significant ReHo differences were observed in the left cerebrum. Compared to NC subjects, the ReHo of PD subjects was increased in the left angular gyrus (AG) and decreased in the left rolandic operculum/postcentral gyrus (Rol/PostC), left inferior opercular-frontal cortex, left middle occipital gyrus, and supramarginal gyrus (SMG). Compared to that of FOG-, the ReHo of FOG+ was increased in the left caudate and decreased in the left Rol/PostC. Within the significant regions, the ReHo of FOG+ was negatively correlated with FOGQ in the left SMG/PostC (r = -0.39, p < 0.05). Negative correlations were also observed between ReHo and GFQ/FOGQ (r = -0.36/-0.38, p < 0.05) in the left superior temporal gyrus (STG) of the whole brain analysis based on AAL templates.
Conclusion: The ReHo analysis suggested that the regional signal synchronization of brain activities in FOG+ subjects was most active in the left caudate and most hypoactive in the left Rol/PostC. It also indicated that ReHo in the left caudate and left Rol/PostC was critical for discriminating the three groups. The correlation between ReHo and movement scores (GFQ/FOGQ) in the STG has the potential to differentiate FOG+ from FOG-. This study provided new insight into the understanding of PD with and without FOG.

PMID: 31680931 [PubMed]

Functional Connectivity Patterns and the Role of 5-HTTLPR Polymorphism on Network Architecture in Female Patients With Anorexia Nervosa.

Tue, 11/05/2019 - 21:13
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Functional Connectivity Patterns and the Role of 5-HTTLPR Polymorphism on Network Architecture in Female Patients With Anorexia Nervosa.

Front Neurosci. 2019;13:1056

Authors: Collantoni E, Meneguzzo P, Solmi M, Tenconi E, Manara R, Favaro A

Abstract
Introduction: Recent neuroimaging studies suggest that anorexia nervosa (AN) symptoms emerge from failures in the relationships between spatially distributed networks that support different cognitive, emotional, and somatosensory functions. The 5-HTTLPR genotype has been shown to modulate all these abilities in AN, as well as the connectivity patterns between brain regions that support their functioning. This study aims at exploring the presence of any difference in functional connectome properties between AN patients and healthy controls (HC) by means of graph theory tools. The effect of 5-HTTLPR genotype on regional and global network characteristics in AN and HC was also explored.
Methods: A sample of 74 subjects (38 HC, 36 AN) underwent a resting state functional magnetic resonance imaging and was genotyped for 5-HTTLPR polymorphism. Comparisons of network properties were made between the AN and HC groups and, within each group, between 5-HTTLPR carriers of low-functioning alleles and carriers of the long-long genotype.
Results: Patients with AN displayed lower network clustering than HC (p = 0.04 at Mann-Whitney U test). Based on both degree and betweenness, a different distribution of network hubs emerged in the two groups. In particular, the anterior part of the anterior cingulate cortex was a hub only in the patient group. A correlation emerged between differences in brain volumes between patients and HC and differences in degree values of basal ganglia, nodes in the insula, and those in the parietal cortex. Carriers of the short allele of the 5-HTTLPR polymorphism were characterized by lower small-world properties (p = 0.027) and modularity (p = 0.031) in the patient group, and a trend toward higher modularity (p = 0.033) and small-world values (p = 0.123) in the HC group.
Discussion: Patients with AN showed differences in hubs distribution, providing evidence of the presence of a different functional architectural backbone in this group. Since some correlation emerged between different degree values of nodes and differences in volumes, further longitudinal studies are warranted to better understand the role of malnutrition on brain network architecture. The opposite effects of 5-HTTLPR polymorphism on global network characteristics in the two groups suggest an interaction of the short allele and malnutrition in modulating brain network properties.

PMID: 31680805 [PubMed]

Ketamine-induced changes in plasma brain-derived neurotrophic factor (BDNF) levels are associated with the resting-state functional connectivity of the prefrontal cortex.

Tue, 11/05/2019 - 21:13
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Ketamine-induced changes in plasma brain-derived neurotrophic factor (BDNF) levels are associated with the resting-state functional connectivity of the prefrontal cortex.

World J Biol Psychiatry. 2019 Nov 04;:1-15

Authors: Woelfer M, Li M, Colic L, Liebe T, Di X, Biswal B, Murrough J, Lessmann V, Brigadski T, Walter M

Abstract
Objectives: Synaptic plasticity and brain-derived neurotrophic factor (BDNF) signalling are proposed to play key roles in antidepressant drug action. Ketamine, an N-methyl-D-aspartate receptor antagonist and putative antidepressant, may increase synaptic plasticity in prefrontal cortex through higher expression of BDNF. Furthermore, ketamine was shown to change resting-state functional connectivity (RSFC) of dorsomedial prefrontal cortex (dmPFC).Methods: In a randomised, placebo-controlled study, we investigated acutely (100 min) and at 24 h following subanesthetic ketamine infusion which dmPFC seeded RSFC changes are most strongly associated with plasma BDNF level changes in 53 healthy participants (21 females, age: 24.4 ± 2.9 years) using 7 T-fMRI.Results: We observed higher relative levels of BDNF 2 h and 24 h after ketamine compared to placebo. Whole-brain regression revealed that the change in BDNF after 24 h was associated with RSFC decreases from dmPFC to posterior cingulate cortex and ventromedial PFC at 24 h and exploratively also at the 100 min measurement point. Follow-up analyses revealed that RSFC reductions following ketamine were restricted to subjects showing increased BDNF levels at 24 h.Conclusions: Our findings indicate BDNF level dynamics following ketamine are related to acute and 24 h RSFC changes. Particularly when BDNF increases are observed after ketamine infusion, a disconnection from dmPFC after 24 h is seen and may reflect synaptic plasticity effects.

PMID: 31680600 [PubMed - as supplied by publisher]

Impact of acute sleep deprivation on dynamic functional connectivity states.

Tue, 11/05/2019 - 21:13
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Impact of acute sleep deprivation on dynamic functional connectivity states.

Hum Brain Mapp. 2019 Nov 04;:

Authors: Li C, Fronczek-Poncelet J, Lange D, Hennecke E, Kroll T, Matusch A, Aeschbach D, Bauer A, Elmenhorst EM, Elmenhorst D

Abstract
Sleep deprivation (SD) could amplify the temporal fluctuation of spontaneous brain activities that reflect different arousal levels using a dynamic functional connectivity (dFC) approach. Therefore, we intended to evaluate the test-retest reliability of dFC characteristics during rested wakefulness (RW), and to explore how the properties of these dynamic connectivity states were affected by extended durations of acute sleep loss (28/52 hr). We acquired resting-state fMRI and neuropsychological datasets in two independent studies: (a) twice during RW and once after 28 hr of SD (n = 15) and (b) after 52 hr of SD and after 14 hr of recovery sleep (RS; n = 14). Sliding-window correlations approach was applied to estimate their covariance matrices and corresponding three connectivity states were generated. The test-retest reliability of dFC properties demonstrated mean dwell time and fraction of connectivity states were reliable. After SD, the mean dwell time of a specific state, featured by strong subcortical-cortical anticorrelations, was significantly increased. Conversely, another globally hypoconnected state was significantly decreased. Subjective sleepiness and objective performances were separately positive and negative correlated with the increased and decreased state. Two brain connectivity states and their alterations might be sufficiently sensitive to reflect changes in the dynamics of brain mental activities after sleep loss.

PMID: 31680379 [PubMed - as supplied by publisher]

Static and dynamic network properties of the repetitive transcranial magnetic stimulation target predict changes in emotion regulation in obsessive-compulsive disorder.

Tue, 11/05/2019 - 21:13
Related Articles

Static and dynamic network properties of the repetitive transcranial magnetic stimulation target predict changes in emotion regulation in obsessive-compulsive disorder.

Brain Stimul. 2019 Oct 24;:

Authors: Douw L, Quaak M, Fitzsimmons SMDD, de Wit SJ, van der Werf YD, van den Heuvel OA, Vriend C

Abstract
BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive neuromodulation technique to treat psychiatric disorders, such as obsessive-compulsive disorder (OCD). However, the rTMS response varies across subjects.
OBJECTIVE/HYPOTHESIS: We hypothesize that baseline network properties of the rTMS target may help understand this variation and predict response.
METHODS: Excitatory rTMS to the dorsolateral prefrontal cortex (dlPFC) was applied in 19 unmedicated OCD patients, while inhibitory dlPFC-rTMS was applied in 17 healthy controls. The vertex was used as an active control target (19 patients, 18 controls). The rTMS response was operationalized as the individual change in state distress rating during an emotion regulation task. At baseline, subjects underwent resting-state functional MRI. The brain network was constructed by calculating wavelet coherence between regional activity of regions in the Brainnetome atlas. Local and integrative static connectivity and the dynamic network role of the target were calculated. Baseline target region network features were non-parametrically correlated to rTMS response.
RESULTS: In the dlPFC-stimulated patients, greater local connectivity (Kendall's Tau = -0.415, p = 0.013) and less promiscuous role of the target (Kendall's Tau = 0.389, p = 0.025) at baseline were related to greater distress reduction after excitatory rTMS. There were no significant associations in healthy subjects nor in the active control stimulated patients.
CONCLUSIONS: Pre-treatment network topological indices predict rTMS-induced emotional response changes in OCD, such that greater baseline resting-state local connectivity and less temporal integration of the target region imply greater stimulation effects. These results may lead the way towards personalized neuromodulation in OCD.

PMID: 31679906 [PubMed - as supplied by publisher]

A joint network optimization framework to predict clinical severity from resting state functional MRI data.

Tue, 11/05/2019 - 03:13
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A joint network optimization framework to predict clinical severity from resting state functional MRI data.

Neuroimage. 2019 Oct 31;:116314

Authors: D'Souza NS, Nebel MB, Wymbs N, Mostofsky SH, Venkataraman A

Abstract
We propose a novel optimization framework to predict clinical severity from resting state fMRI (rs-fMRI) data. Our model consists of two coupled terms. The first term decomposes the correlation matrices into a sparse set of representative subnetworks that define a network manifold. These subnetworks are modeled as rank-one outer-products which correspond to the elemental patterns of co-activation across the brain; the subnetworks are combined via patient-specific non-negative coefficients. The second term is a linear regression model that uses the patient-specific coefficients to predict a measure of clinical severity. We validate our framework on two separate datasets in a ten fold cross validation setting. The first is a cohort of fifty-eight patients diagnosed with Autism Spectrum Disorder (ASD). The second dataset consists of sixty three patients from a publicly available ASD database. Our method outperforms standard semi-supervised frameworks, which employ conventional graph theoretic and statistical representation learning techniques to relate the rs-fMRI correlations to behavior. In contrast, our joint network optimization framework exploits the structure of the rs-fMRI correlation matrices to simultaneously capture group level effects and patient heterogeneity. Finally, we demonstrate that our proposed framework robustly identifies clinically relevant networks characteristic of ASD.

PMID: 31678501 [PubMed - as supplied by publisher]