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Neural network connectivity in ADHD children: an independent component and functional connectivity analysis of resting state fMRI data.

Tue, 01/07/2020 - 22:33

Neural network connectivity in ADHD children: an independent component and functional connectivity analysis of resting state fMRI data.

Brain Imaging Behav. 2020 Jan 04;:

Authors: Kumar U, Arya A, Agarwal V

Abstract
Resting-state functional magnetic resonance imaging (rsfMRI) is a novel approach that has the potential to examine abnormalities in the default mode network (DMN) component. Two different approaches were used in the present study to characterize the functional connectivities of various DMN components in 16 non-medicated ADHD and a similar number of TD (typically developing) children. rsfMRI data were analysed using independent component analysis (ICA) and region-of-interest (ROI) seed to voxel correlation analysis. ICA results indicated a strong coherence of the left dorsal anterior cingular cortex (dACC) with the DMN components in children with ADHD. In addition, seed-to-voxel functional connectivity analysis using the left dorsal anterior cingulate as a seed region suggested higher temporal coherence with other neural networks upon comparison with TD children. These results imply children with ADHD exhibit a higher dispersed resting state connectivity pattern in DMN and other networks.

PMID: 31903529 [PubMed - as supplied by publisher]

Age at onset reveals different functional connectivity abnormalities in prodromal Alzheimer's disease.

Tue, 01/07/2020 - 22:33

Age at onset reveals different functional connectivity abnormalities in prodromal Alzheimer's disease.

Brain Imaging Behav. 2020 Jan 04;:

Authors: Pini L, Geroldi C, Galluzzi S, Baruzzi R, Bertocchi M, Chitò E, Orini S, Romano M, Cotelli M, Rosini S, Magnaldi S, Morassi M, Cobelli M, Bonvicini C, Archetti S, Zanetti O, Frisoni GB, Pievani M

Abstract
Age at symptom onset (AAO) underlies different Alzheimer's disease (AD) clinical variants: late-onset AD (LOAD) is characterized by memory deficits, while early-onset AD (EOAD) presents predominantly with non-memory symptoms. The involvement of different neural networks may explain these distinct clinical phenotypes. In this study, we tested the hypothesis of an early and selective involvement of neural networks based on AAO in AD. Twenty memory clinic patients with prodromal AD (i.e., mild cognitive impairment with an AD-like cerebrospinal fluid profile) and 30 healthy controls underwent a cognitive evaluation and a resting state functional MRI exam. Independent component analysis was performed to assess functional connectivity (FC) in the following networks: default mode, frontoparietal, limbic, visual, and sensorimotor. Patients were stratified into late-onset (pLOAD) and early-onset (pEOAD) prodromal AD according to the AAO and controls were stratified into younger and older groups accordingly. Decreased FC within the default mode and the limbic networks was observed in pLOAD, while pEOAD showed lower FC in the frontoparietal and visual networks. The sensorimotor network did not show differences between groups. A significant association was found between memory and limbic network FC in pLOAD, and between executive functions and frontoparietal network FC in pEOAD, although the latter association did not survive multiple comparison correction. Our findings indicate that aberrant connectivity in memory networks is associated with pLOAD, while networks underlying executive and visuo-spatial functions are affected in pEOAD. These findings are in line with the hypothesis that the pathophysiological mechanisms underlying EOAD and LOAD are distinct.

PMID: 31903525 [PubMed - as supplied by publisher]

Does Generalized Linear Model Support Functional Default Mode Network Studies.

Tue, 01/07/2020 - 22:33

Does Generalized Linear Model Support Functional Default Mode Network Studies.

Noro Psikiyatr Ars. 2019 Dec;56(4):277-282

Authors: Koçak OM, Rezakı HÖ, Türkel Y, İnal M, Visal Buturak Ş

Abstract
Introduction: A growing body of research has emerged on the resting state and the default mode of the brain. Functional connectivity studies, which lately dominate this research area, have confirmed that regions such as the cortical mid-line structures, as well as parietal-temporal regions are tightly interconnected within the default mode network (DMN). However, little is known about the activity patterns of resting state related brain regions detected in fMRI studies using the generalized linear model (GLM) in a whole brain analysis. The aim of the current study was to investigate the activity changes among brain regions identified through GLM during the transition from task to rest and the prolongation of rest.
Methods: A picture imagination task, as a controlled thought content task, was used in order to minimize confounding factors such as a visual stimulus or a motor response.
Results: The present study revealed a consistent fluctuating activation pattern of the dorsal anterior cingulate cortex (dACC), the posterior cingulate cortex (PCC), thalamus, primer motor area (PMA), insula, brain stem and bilateral putamen during the transition from task to the early phase of the resting state and the prolongation of the resting state. All regions showed increased activation during the detachment from task. However, this increased activation was not sustained during the extension of rest, replaced with a decreased activation at the late phase of rest. The increased activation of resting state regions might help with the detachment from the current task. Among these regions dACC, insula and putamen were correlated in all conditions.
Conclusion: These findings underline the importance of the activation increase of the cortical mid-line regions and insula in the transition from task to the resting state.

PMID: 31903037 [PubMed]

Differences in Functional Connectivity Networks Related to the Midbrain Dopaminergic System-Related Area in Various Psychiatric Disorders.

Tue, 01/07/2020 - 22:33

Differences in Functional Connectivity Networks Related to the Midbrain Dopaminergic System-Related Area in Various Psychiatric Disorders.

Schizophr Bull. 2020 Jan 05;:

Authors: Nakamura Y, Okada N, Koshiyama D, Kamiya K, Abe O, Kunimatsu A, Okanoya K, Kasai K, Koike S

Abstract
OBJECTIVE: Disruptions in the dopamine system have been observed in psychiatric disorders. Since dopamine is mainly produced in the ventral tegmental area (VTA), elucidating the differences in the VTA neural network across psychiatric disorders would facilitate a greater understanding of the pathophysiological mechanisms underlying these disorders. However, no study has compared VTA-seed-based functional connectivity across psychiatric disorders. Therefore, we conducted a resting-state functional magnetic resonance imaging (rs-fMRI) study to perform a seed-based fMRI analysis, using the VTA as a seed.
METHODS: We included participants with major depressive disorder (MDD; n = 45), schizophrenia (n = 32), and bipolar disorder (BPD; n = 30), along with healthy control participants (n = 46) who were matched for age, gender, and handedness.
RESULTS: The results showed that patients with MDD and BPD had altered VTA-related connectivity in the superior frontal gyrus, frontal pole regions, hippocampus, cerebellum, and posterior cingulate cortex. Some of these differences in connectivity were also found between affective disorders and schizophrenia; however, there were no differences between the schizophrenia and control groups. Connectivity between the VTA and the hippocampus was correlated with positive symptoms in the schizophrenia group. The connectivity was not associated with medication dose, and the results remained significant after controlling for dose.
CONCLUSIONS: The results suggest that altered brain functional connectivity related to VTA networks could be associated with the distinctive pathophysiologies of psychiatric disorders, especially affective disorders.

PMID: 31901932 [PubMed - as supplied by publisher]

The Impact of Echo Time Shifts and Temporal Signal Fluctuations on BOLD Sensitivity in Presurgical Planning at 7 T.

Tue, 01/07/2020 - 22:33
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The Impact of Echo Time Shifts and Temporal Signal Fluctuations on BOLD Sensitivity in Presurgical Planning at 7 T.

Invest Radiol. 2019 06;54(6):340-348

Authors: Dymerska B, De Lima Cardoso P, Bachrata B, Fischmeister F, Matt E, Beisteiner R, Trattnig S, Robinson SD

Abstract
OBJECTIVES: Gradients in the static magnetic field caused by tissues with differing magnetic susceptibilities lead to regional variations in the effective echo time, which modifies both image signal and BOLD sensitivity. Local echo time changes are not considered in the most commonly used metric for BOLD sensitivity, temporal signal-to-noise ratio (tSNR), but may be significant, particularly at ultrahigh field close to air cavities (such as the sinuses and ear canals) and near gross brain pathologies and postoperative sites.
MATERIALS AND METHODS: We have studied the effect of local variations in echo time and tSNR on BOLD sensitivity in 3 healthy volunteers and 11 patients with tumors, postoperative cavities, and venous malformations at 7 T. Temporal signal-to-noise ratio was estimated from a 5-minute run of resting state echo planar imaging with a nominal echo time of 22 milliseconds. Maps of local echo time were derived from the phase of a multiecho GE scan. One healthy volunteer performed 10 runs of a breath-hold task. The t-map from this experiment served as a criterion standard BOLD sensitivity measure. Two runs of a less demanding breath-hold paradigm were used for patients.
RESULTS: In all subjects, a strong reduction in the echo time (from 22 milliseconds to around 11 milliseconds) was found close to the ear canals and sinuses. These regions were characterized by high tSNR but low t-values in breath-hold t-maps. In some patients, regions of particular interest in presurgical planning were affected by reductions in the echo time to approximately 13-15 milliseconds. These included the primary motor cortex, Broca's area, and auditory cortex. These regions were characterized by high tSNR values (70 and above). Breath-hold results were corrupted by strong motion artifacts in all patients.
CONCLUSIONS: Criterion standard BOLD sensitivity estimation using hypercapnic experiments is challenging, especially in patient populations. Taking into consideration the tSNR, commonly used for BOLD sensitivity estimation, but ignoring local reductions in the echo time (eg, from 22 to 11 milliseconds), would erroneously suggest functional sensitivity sufficient to map BOLD signal changes. It is therefore important to consider both local variations in the echo time and temporal variations in signal, using the product metric of these two indices for instance. This should ensure a reliable estimation of BOLD sensitivity and to facilitate the identification of potential false-negative results. This is particularly true at high fields, such as 7 T and in patients with large pathologies and postoperative cavities.

PMID: 30724813 [PubMed - indexed for MEDLINE]

Frequency-specific alternations in the moment-to-moment BOLD signals variability in schizophrenia.

Sun, 01/05/2020 - 19:30
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Frequency-specific alternations in the moment-to-moment BOLD signals variability in schizophrenia.

Brain Imaging Behav. 2020 Jan 03;:

Authors: Zhang Y, Yang R, Cai X

Abstract
Variability of neuronal activity is considered as the fundamental mechanism for the flexible and optimal brain function. Moreover, different frequency neuro signal is related to specific function. While little is currently known regarding changes in spontaneous BOLD variability of schizophrenia. The current study used resting-state fMRI data from 53 chronic schizophrenic subjects and 67 healthy subjects to investigate this issue. The data-driven method was used to measure the BOLD variability (MSSD: mean square successive difference) in two different frequency bands respectively (slow-5: 0.01-0.027 Hz; slow-4:0.027-0.073 Hz). Schizophrenic subjects exhibited decreased BOLD variability in thalamus region, sensorimotor and visual networks, and increased BOLD variability in salience network compared to matched healthy controls. Moreover, the interaction effects between frequency and group were observed in thalamus and right dorsolateral prefrontal cortex (DLPFC). These findings identified that altered BOLD variability is frequency dependent in schizophrenia. Importantly, the severity of patients' negative symptom was related to the increased BOLD variability of DLPFC within slow-4 frequency band, highlighting the evidence that abnormal BOLD variability of frontal cortex is likely to have effects on the pathophysiology of negative symptom in schizophrenia.

PMID: 31900893 [PubMed - as supplied by publisher]

Altered functional connectivity of the thalamus in tinnitus patients is correlated with symptom alleviation after sound therapy.

Sun, 01/05/2020 - 19:30
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Altered functional connectivity of the thalamus in tinnitus patients is correlated with symptom alleviation after sound therapy.

Brain Imaging Behav. 2020 Jan 03;:

Authors: Lv H, Liu C, Wang Z, Zhao P, Cheng X, Yang Z, Gong S, Wang Z

Abstract
Altered functional connectivity (FC) of the thalamus has been proven to be an important finding in tinnitus patients. Tinnitus can be effectively desensitized by sound therapy. However, it is still unclear whether and how sound therapy affects the FC of the thalamus. Resting-state functional magnetic resonance imaging data and anatomical data were longitudinally collected from 25 idiopathic tinnitus patients before and after 12 weeks of sound therapy by using adjusted narrow band noise and from 25 matched healthy controls at the same time interval without any intervention. The FC of bilateral thalami were analyzed by setting the left and right thalamus as the regions of interest. Significant main effect of group on the FC of the thalamus were found mainly in the key components of the default mode network, limbic network, salience network, cognitive control network, auditory network and occipital region. FC values between the thalamus, inferior frontal gyrus (IFG), and anterior cingulate cortex (ACC) featured higher values in the tinnitus group at baseline compared to the healthy controls and restoration in tinnitus patients after treatment. Decreased Tinnitus Handicap Inventory (THI) scores and decreased FC values between the right thalamus and right IFG were positively correlated (r = 0.476, P = 0.016). Abnormal FC of the thalamus is associated with multiple brain networks. Sound therapy has a normalizing effect on the enhanced FC of the thalamus-IFG and thalamus-ACC, representing decreased tinnitus attention control and less involvement of the noise-canceling system.

PMID: 31900891 [PubMed - as supplied by publisher]

Personode: A Toolbox for ICA Map Classification and Individualized ROI Definition.

Sun, 01/05/2020 - 19:30
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Personode: A Toolbox for ICA Map Classification and Individualized ROI Definition.

Neuroinformatics. 2020 Jan 03;:

Authors: Pamplona GSP, Vieira BH, Scharnowski F, Salmon CEG

Abstract
Canonical resting state networks (RSNs) can be obtained through independent component analysis (ICA). RSNs are reproducible across subjects but also present inter-individual differences, which can be used to individualize regions-of-interest (ROI) definition, thus making fMRI analyses more accurate. Unfortunately, no automatic tool for defining subject-specific ROIs exists, making the classification of ICAs as representatives of RSN time-consuming and largely dependent on visual inspection. Here, we present Personode, a user-friendly and open source MATLAB-based toolbox that semi-automatically performs the classification of RSN and allows for defining subject- and group-specific ROIs. To validate the applicability of our new approach and to assess potential improvements compared to previous approaches, we applied Personode to both task-related activation and resting-state data. Our analyses show that for task-related activation analyses, subject-specific spherical ROIs defined with Personode produced higher activity contrasts compared to ROIs derived from single-study and meta-analytic coordinates. We also show that subject-specific irregular ROIs defined with Personode improved ROI-to-ROI functional connectivity analyses.Hence, Personode might be a useful toolbox for ICA map classification into RSNs and group- as well as subject-specific ROI definitions, leading to improved analyses of task-related activation and functional connectivity.

PMID: 31900722 [PubMed - as supplied by publisher]

Functional connectivity of the supplementary motor network is associated with Fried's modified frailty score in the elderly.

Sun, 01/05/2020 - 19:30
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Functional connectivity of the supplementary motor network is associated with Fried's modified frailty score in the elderly.

J Gerontol A Biol Sci Med Sci. 2020 Jan 04;:

Authors: Lammers F, Zacharias N, Borchers F, Mörgeli R, Spies CD, Winterer G

Abstract
Frailty is a geriatric syndrome defined by coexistence of unintentional weight loss, low physical reserve or activity and is associated with adverse health events. Neuroimaging studies reported structural white matter changes in frail patients. In the current study, we hypothesized that clinical frailty is associated also with functional changes in motion-related cortical areas, i. e. (pre-)supplementary motor areas (SMA, pre-SMA). We expected that observed functional changes are related to motor-cognitive test performance. We studied a clinical sample of 143 cognitively healthy patients ≥65 years presenting for elective surgery, enrolled in the BioCog prospective multicentric cohort study on postoperative cognitive disorders. Participants underwent preoperative resting-state fMRI, motor-cognitive testing and assessment of Fried's modified frailty criteria. We analyzed functional connectivity associations with frailty and motor-cognitive test performance. Clinically robust patients (N=60) showed higher connectivity in the SMA network compared to frail (N=13) and pre-frail (N=70) patients. No changes were found in the pre-SMA network. SMA connectivity correlated with motor speed (Trail-Making-Test A) and manual dexterity (Grooved Pegboard Test). Our results suggest that diminished functional connectivity of the SMA is an early correlate of functional decline in the elderly. The SMA may serve as a potential treatment target in frailty.

PMID: 31900470 [PubMed - as supplied by publisher]

Resting-state fMRI reveals increased functional connectivity in the cerebellum but decreased functional connectivity of the caudate nucleus in Parkinson's disease.

Sun, 01/05/2020 - 19:30
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Resting-state fMRI reveals increased functional connectivity in the cerebellum but decreased functional connectivity of the caudate nucleus in Parkinson's disease.

Neurol Res. 2020 Jan 03;:1-6

Authors: Kaut O, Mielacher C, Hurlemann R, Wüllner U

Abstract
Objective: Frequent falls are common in Parkinson's disease (PD). Resting-state fMRI (rs-fMRI) studies have found differences in functional connectivity between PD patients and healthy controls. However, whether functional connectivity in PD patients with frequent falls (PD-fallers) differs from those without falls (PD-non fallers) is unknown. Therefore, to elucidate the underlying mechanisms leading to postural instability in PD patients with frequent falls, we compared changes in functional connectivity between PD-fallers, PD-non fallers and healthy controls.Methods: Thirteen healthy controls (70.7 ± 7.2 years) were compared to thirteen PD-fallers (70.6 ± 5.9 years) and 19 PD-non fallers (71.61 ± 5.8 years) without cognitive impairment. We performed 1.5T rs-fMRI scans and evaluated gait and balance, motor symptoms and cognitive functions.Results: Cerebellar seed regions showed increased functional connectivity in PD-fallers compared to controls in two connections between the cerebellar cortex and vermis (p-value = 0.02). Conversely, in comparison to controls, functional connectivity between the precuneus and caudate nucleus was decreased in PD-non fallers (p-value = 0.015). A similar trend was also observed between controls and PD-fallers, although this difference did not reach statistical significance.Discussion: We found increased functional connectivity among cerebellar structures in PD, which may reflect an adaptive (compensatory) mechanism through activation of additional brain structures to restore gait function. In contrast, a relative disconnection between the precuneus and caudate nucleus in PD patients might indicate an impaired brain network unrelated to the risk of falls. Cerebellar areas might thus be considered as future therapeutic targets for neuromodulatory treatment of postural instability in PD.Abbreviations: DMN: default mode network; FC: functional connectivity; IPL: inferior parietal lobule; MMSE: Minimal Mental Status Examination; PD: Parkinson's disease; rs-fMRI: resting-state functional Magnetic Resonance Imaging; UPDRSIII: Unified Parkinson's disease ranking scale.

PMID: 31900094 [PubMed - as supplied by publisher]

The neural processes of acquiring placebo effects through observation.

Sun, 01/05/2020 - 01:27
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The neural processes of acquiring placebo effects through observation.

Neuroimage. 2019 Dec 30;:116510

Authors: Schenk LA, Colloca L

Abstract
Learning through social observation is critical for humans. The present study investigates the neural processes underlying the acquisition of placebo effects through observational learning. We created a new functional magnetic resonance imaging (fMRI) paradigm where participants (n = 38, healthy, both sexes) observed a demonstrator experiencing pain relief by a placebo treatment cream and experiencing pain without a treatment (control cream), and subsequently performed the same procedure themselves. Participants demonstrated placebo hypoalgesia while they performed the procedure themselves, confirming that observational learning can lead to placebo effects. During the observational learning phase, fMRI analysis showed a modulation of the amygdalae, periaqueductal grey, temporoparietal junctions (TPJ), and dorsolateral prefrontal cortex (DLPFC). Connectivity between the DLPFC and TPJ during the observational learning task was modulated by the placebo treatment and predicted subsequent placebo effects. Mediation analysis further confirmed that the DLPFC-TPJ connectivity formally mediated the effect of the observed treatment condition on subsequent placebo effects. Additionally, pre-recorded resting state connectivity between the DLPFC and TPJ also predicted observationally-learned placebo effects. Our findings provide an understanding of the neural processes during the acquisition of placebo effects through observation and indicate a critical role for DLPFC-TPJ integration processes during observational learning of therapeutic outcomes.

PMID: 31899287 [PubMed - as supplied by publisher]

Longitudinal assessment of resting-state fMRI in temporal lobe epilepsy: A two-year follow-up study.

Sun, 01/05/2020 - 01:27
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Longitudinal assessment of resting-state fMRI in temporal lobe epilepsy: A two-year follow-up study.

Epilepsy Behav. 2019 Dec 30;:106858

Authors: Zhang Z, Zhou X, Liu J, Qin L, Yu L, Pang X, Ye W, Zheng J

Abstract
In this study, we aimed to detect longitudinal alterations in local spontaneous brain activity and functional connectivity (FC) of the default mode network (DMN) in patients with temporal lobe epilepsy (TLE) over a two-year follow-up. We used amplitude of low-frequency fluctuation (ALFF) analysis and independent component analysis (ICA) to explore differences in local spontaneous brain activity and FC strength. In total, 33 participants (16 patients with TLE and 17 age- and gender-matched healthy controls (HCs)) were recruited in this study. All participants performed the Attention Network Test (ANT) for evaluation of the executive control function. Compared with healthy patients at baseline, patients with TLE at follow-up exhibited increased ALFF values in the left medial frontal gyrus, as well as reduced FC values in the left inferior parietal gyrus (IPG) within the DMN. Patients with TLE revealed executive dysfunction, but no progressive deterioration was observed during follow-up. This study revealed the abnormal distribution of ALFF values and Rs-FC changes over a two-year follow-up period in TLE, both of which demonstrated different reorganization trajectories and loss of efficiency.

PMID: 31899164 [PubMed - as supplied by publisher]

Consortium on Vulnerability to Externalizing Disorders and Addictions (cVEDA): A developmental cohort study protocol.

Sun, 01/05/2020 - 01:27
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Consortium on Vulnerability to Externalizing Disorders and Addictions (cVEDA): A developmental cohort study protocol.

BMC Psychiatry. 2020 Jan 02;20(1):2

Authors: Sharma E, Jacob P, Murthy P, Jain S, Varghese M, Jayarajan D, Kumar K, Benegal V, Vaidya N, Zhang Y, Desrivieres S, Schumann G, Iyengar U, Holla B, Purushottam M, Chakrabarti A, Fernandes GS, Heron J, Hickman M, Kartik K, Kalyanram K, Rangaswamy M, Bharath RD, Barker G, Orfanos DP, Ahuja C, Thennarasu K, Basu D, Subodh BN, Kuriyan R, Kurpad SS, Kumaran K, Krishnaveni G, Krishna M, Singh RL, Singh LR, Toledano M

Abstract
BACKGROUND: Low and middle-income countries like India with a large youth population experience a different environment from that of high-income countries. The Consortium on Vulnerability to Externalizing Disorders and Addictions (cVEDA), based in India, aims to examine environmental influences on genomic variations, neurodevelopmental trajectories and vulnerability to psychopathology, with a focus on externalizing disorders.
METHODS: cVEDA is a longitudinal cohort study, with planned missingness design for yearly follow-up. Participants have been recruited from multi-site tertiary care mental health settings, local communities, schools and colleges. 10,000 individuals between 6 and 23 years of age, of all genders, representing five geographically, ethnically, and socio-culturally distinct regions in India, and exposures to variations in early life adversity (psychosocial, nutritional, toxic exposures, slum-habitats, socio-political conflicts, urban/rural living, mental illness in the family) have been assessed using age-appropriate instruments to capture socio-demographic information, temperament, environmental exposures, parenting, psychiatric morbidity, and neuropsychological functioning. Blood/saliva and urine samples have been collected for genetic, epigenetic and toxicological (heavy metals, volatile organic compounds) studies. Structural (T1, T2, DTI) and functional (resting state fMRI) MRI brain scans have been performed on approximately 15% of the individuals. All data and biological samples are maintained in a databank and biobank, respectively.
DISCUSSION: The cVEDA has established the largest neurodevelopmental database in India, comparable to global datasets, with detailed environmental characterization. This should permit identification of environmental and genetic vulnerabilities to psychopathology within a developmental framework. Neuroimaging and neuropsychological data from this study are already yielding insights on brain growth and maturation patterns.

PMID: 31898525 [PubMed - in process]

Altered brain network organization in romantic love as measured with resting-state fMRI and graph theory.

Sun, 01/05/2020 - 01:27
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Altered brain network organization in romantic love as measured with resting-state fMRI and graph theory.

Brain Imaging Behav. 2020 Jan 02;:

Authors: Wang C, Song S, d'Oleire Uquillas F, Zilverstand A, Song H, Chen H, Zou Z

Abstract
Romantic love is a complex state that has been seen as similar to addiction. Previous task-based functional magnetic resonance imaging (fMRI) studies have shown that being in love is closely associated with functional brain changes in the reward and motivation system. However, romantic love-related functional connectivity network organization in resting-state fMRI has yet to be elucidated. To that end, here we used resting-state fMRI and graph theory to compare whole-brain functional network topology between an "in-love" group (n = 34, 16 females, currently in love and in a romantic relationship) and a "single" group (n = 32, 14 females, never in love and not in a romantic relationship). Compared to the single group, we found lower network segregation in the love group (i.e., lower small-worldness, mean clustering coefficient, and modularity), and these metrics were negatively associated with scores on the Passionate Love Scale (PLS) (an index of intense passionate/romantic love). Additionally, the love group displayed altered connectivity degree (reflecting the importance of a node): decreased degree in left angular gyrus and left medial orbitofrontal cortex, but increased degree in left fusiform gyrus. Furthermore, local efficiency or degree of these regions was significantly correlated to PLS scores. Taken together, results showed decreased overall brain functional segregation but enhanced emotional-social processing in romantic lovers. These findings provide the first evidence of love-related brain network organization changes and suggest similar but different brain network alterations between romantic love and addiction, providing new insights on the neural systems underlying romantic love.

PMID: 31898089 [PubMed - as supplied by publisher]

Sex-specific effects of cigarette smoking on caudate and amygdala volume and resting-state functional connectivity.

Sun, 01/05/2020 - 01:27
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Sex-specific effects of cigarette smoking on caudate and amygdala volume and resting-state functional connectivity.

Brain Imaging Behav. 2020 Jan 02;:

Authors: Lin F, Han X, Wang Y, Ding W, Sun Y, Zhou Y, Lei H

Abstract
Recent studies have demonstrated sex-specific differences in etiology, course and brain dysfunction that are associated with cigarette smoking. However, little is known about sex-specific differences in subcortical structure and function. In this study, structural and resting-state functional magnetic resonance imaging (fMRI) data were collected from 60 cigarette smokers (25 females) and 67 nonsmokers (28 females). The structural MRI was applied to identify deficits in sex-specific subcortical volume. Using resting-state fMRI, sex-related alterations in resting-state functional connectivity (rsFC) were investigated in subcortical nuclei with volume deficits as seed regions. Compared to nonsmokers, male but not female smokers demonstrated a significantly smaller volume in the left caudate, while female but not male smokers showed a smaller volume in the right amygdala. Resting-state FC analysis revealed that male but not female smokers had increased rsFC between the left caudate and the left prefrontal cortex but decreased rsFC within the bilateral caudate and between the right amygdala and right orbitofrontal cortex (OFC). Furthermore, the right amygdala volume was negatively correlated with the impulsivity score in female but not male smokers. The rsFC of the right amygdala-OFC circuit was negatively associated with the craving score in male but not female smokers. These findings indicate that cigarette smoking may have differential effects on the caudate and amygdala volumes as well as rsFC between men and women, contributing to our knowledge of sex-specific effects of nicotine addiction. Such sex-specific differences in subcortical structure and function may provide a methodological framework for the development of sex-specific relapse prevention therapies.

PMID: 31898088 [PubMed - as supplied by publisher]

Sensory trick phenomenon in cervical dystonia: a functional MRI study.

Sun, 01/05/2020 - 01:27
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Sensory trick phenomenon in cervical dystonia: a functional MRI study.

J Neurol. 2020 Jan 02;:

Authors: Sarasso E, Agosta F, Piramide N, Bianchi F, Butera C, Gatti R, Amadio S, Del Carro U, Filippi M

Abstract
Sensory trick may relieve dystonic symptoms in patients with idiopathic cervical dystonia (CD). We investigated the patterns of brain functional MRI (fMRI) during resting state, sensory trick simulation and sensory trick imagination in CD patients both with and without an effective sensory trick. We recruited 17 CD patients and 15 healthy controls. Nine patients (CD-trick) had an effective sensory trick, while 8 patients (CD-no-trick) did not. Cervical range of motion validated instrument assessed dystonic posture and sensory trick effect. Participants underwent resting state fMRI, which was repeated by patients while executing the sensory trick. Patients also performed an fMRI task in which they were asked to imagine a sensory trick execution. CD-trick and CD-no-trick patients were comparable in terms of CD severity. Applying the sensory trick, CD-trick patients significantly improved dystonic posture. CD-no-trick patients showed an increased functional connectivity of sensorimotor network relative to controls during classic resting state fMRI. During resting state fMRI with sensory trick, CD-trick patients showed a decrease of sensorimotor network connectivity. During the sensory trick imagination fMRI task, CD-trick relative to CD-no-trick patients increased the recruitment of cerebellum bilaterally. This study suggests a hyper-connectivity of sensorimotor areas during resting state in CD-no-trick subjects. In CD-trick patients, the sensory trick performance was associated with a decreased connectivity of the sensorimotor network. The increased activation of cerebellum in CD-trick patients during the sensory trick imagination suggests a possible role of this area in modulating cortical activity.

PMID: 31897600 [PubMed - as supplied by publisher]

Investigating spontaneous brain activity in bipolar disorder: A resting-state functional magnetic resonance imaging study.

Sun, 01/05/2020 - 01:27
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Investigating spontaneous brain activity in bipolar disorder: A resting-state functional magnetic resonance imaging study.

Indian J Psychiatry. 2019 Nov-Dec;61(6):630-634

Authors: Achalia RM, Jacob A, Achalia G, Sable A, Venkatasubramanian G, Rao NP

Abstract
Background: Despite several neuroimaging studies in the past few years, the exact pathophysiology responsible for the development of bipolar disorder (BD) is still not completely known. Importantly, to the best of our knowledge, no study from India has examined resting state (RS) connectivity abnormalities in BD using regional homogeneity (ReHo). Hence, we examined spontaneous brain activity in patients with BD using RS functional magnetic resonance imaging (RS-fMRI).
Aim: The aim of the study is to examine the spontaneous brain activity in patients with BD-I using ReHo approach and RS-fMRI compared to age- and gender-matched healthy control (HC).
Materials and Methods: A total of 20 patients with BD and 20 age-, gender-, and education-matched HCs participated in the study. The fMRI data were obtained using 1.5T scanner. RS-fMRI abnormalities were analyzed using ReHo method.
Results: Compared to healthy adults, significantly increased ReHo in the BD group was found in the right precuneus, right insula, right supramarginal gyrus, left superior frontal gyrus, right inferior frontal gyrus, right precentral gyrus, and right paracentral lobule. No region had significantly lower ReHo values in BD patients compared to controls.
Conclusion: These results suggested that abnormal local synchronization of spontaneous brain activity is present in the frontoparietoinsular region which may be related to the pathophysiology of BD.

PMID: 31896871 [PubMed]

Human menstrual cycle variation in subcortical functional brain connectivity: a multimodal analysis approach.

Fri, 01/03/2020 - 22:27
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Human menstrual cycle variation in subcortical functional brain connectivity: a multimodal analysis approach.

Brain Struct Funct. 2020 Jan 01;:

Authors: Hidalgo-Lopez E, Mueller K, Harris T, Aichhorn M, Sacher J, Pletzer B

Abstract
Increasing evidence suggests that endogenous sex steroid changes affect human brain functional connectivity, which could be obtained by resting-state fMRI (RS-fMRI). Nevertheless, RS studies on the menstrual cycle (MC) are underrepresented and yield inconsistent results. We attribute these inconsistencies to the use of various methods in exploratory approaches and small sample sizes. Hormonal fluctuations along the MC likely elicit subtle changes that, however, may still have profound impact on network dynamics when affecting key brain nodes. To address these issues, we propose a ROI-based multimodal analysis approach focusing on areas of high functional relevance to adequately capture these changes. To that end, sixty naturally cycling women underwent RS-fMRI in three different cycle phases and we performed the following analyses: (1) group-independent component analyses to identify intrinsic connectivity networks, (2) eigenvector centrality (EC) as a measure of centrality in the global connectivity hierarchy, (3) amplitude of low-frequency fluctuations (ALFF) as a measure of oscillatory activity and (4) seed-based analyses to investigate functional connectivity from the ROIs. For (2)-(4), we applied a hypothesis-driven ROI approach in the hippocampus, caudate and putamen. In the luteal phase, we found (1) decreased intrinsic connectivity of the right angular gyrus with the default mode network, (2) heightened EC for the hippocampus, and (3) increased ALFF for the caudate. Furthermore, we observed (4) stronger putamen-thalamic connectivity during the luteal phase and stronger fronto-striatal connectivity during the pre-ovulatory phase. This hormonal modulation of connectivity dynamics may underlie behavioural, emotional and sensorimotor changes along the MC.

PMID: 31894405 [PubMed - as supplied by publisher]

Acute alcohol intake alters resting state functional connectivity of nucleus accumbens with pain-related corticolimbic structures.

Thu, 01/02/2020 - 01:24
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Acute alcohol intake alters resting state functional connectivity of nucleus accumbens with pain-related corticolimbic structures.

Drug Alcohol Depend. 2019 Dec 24;207:107811

Authors: Boissoneault J, Stennett B, Robinson ME

Abstract
BACKGROUND: The nucleus accumbens (NAc) is a ventral striatal structure underlying reward, reinforcement, and motivation, with extensive anatomic and functional connections to a wide range of affective processing structures (medial prefrontal cortex (mPFC), amygdala, and insula). Characterizing how acute alcohol intake affects resting state functional connectivity (rsFC) between the nucleus accumbens (NAc) and these regions will improve mechanistic understanding of alcohol's neurobehavioral effects, including the neural overlap between acute alcohol effects and pain processing.
METHODS: Fifteen healthy social drinkers (10 women; age: 25-45 years) were included in the study. Participants completed one session in which they consumed an alcohol dose targeting a breath alcohol concentration of 0.08 g/dL, and in a second a placebo beverage. Nine-minute resting state fMRI scans were acquired 30-35 min after beverage administration during each session. rsFC between NAc and a priori corticolimbic regions of interest (mPFC, amgydala, and insula), were compared between beverage conditions. We also conducted an exploratory whole-brain seed-to-voxel analysis of NAc FC.
RESULTS: Alcohol intake reduced rsFC between NAc and mPFC, as well as NAc and amygdala. Alcohol also reduced rsFC between NAc and a 97-voxel cluster including bilateral paracingulate cortex and anterior cingulate cortex.
CONCLUSIONS: Findings suggest that acute alcohol intake reduces rsFC between NAc and several structures, including mPFC, amygdala, and rostral ACC in healthy social drinkers. These structures underlie reward, motivated behavior, and emotion regulation, and may provide mechanistic insight to how alcohol affects related processes, including pain.

PMID: 31891860 [PubMed - as supplied by publisher]

Altered functional connectivity density in the brains of hemodialysis end-stage renal disease patients: An in vivo resting-state functional MRI study.

Thu, 01/02/2020 - 01:24
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Altered functional connectivity density in the brains of hemodialysis end-stage renal disease patients: An in vivo resting-state functional MRI study.

PLoS One. 2019;14(12):e0227123

Authors: Shi Y, Tong C, Zhang M, Gao X

Abstract
BACKGROUND: End-stage renal disease (ESRD) patients usually suffer from a high prevalence of central nervous system abnormalities, including cognitive impairment and emotional disorders, which severely influence their quality of life. There have been many neuroimaging research developments in ESRD patients with brain function abnormalities; however, the dysfunction of the salience network (SN) of them has received little attention. The purpose of this study was to investigate the changes of global functional connectivity density (gFCD) in brains of ESRD patients undergoing hemodialysis using resting-state functional magnetic resonance imaging (re-fMRI).
METHODS: re-fMRI data were collected from 30 ESRD patients undergoing hemodialysis (14 men, 38.33±7.44 years old) and 30 matched healthy controls (13 men, 39.17±5.7 years old). Neuropsychological tests including the Montreal Cognitive Assessment (MoCA) and Beck Depression Inventory (BDI) were used to evaluate the neurocognitive and psychiatric conditions of the subjects. Blood biochemistry tests, including hemoglobin level, serum albumin level, blood urea level, serum phosphate, serum calcium, and parathyroid hormone level, and dialysis-related indicators, including blood pressure fluctuations in dialysis, single-pool Kt/V(spKt/V), and ultrafiltration volume of dialysis were obtained from the ESRD patients. A two-sample t-test was used to examine the group differences in gFCD between ESRD patients and healthy controls after controlling for age, gender and education.
RESULTS: Compared with healthy controls, ESRD patients exhibited a significantly increased gFCD in the salience network, including the bilateral insula, and dorsal anterior cingulated cortex (dACC), and there was no significant correlation between gFCD and the structural mean grey matter volume in patients for every cluster in the brain regions showing significant different gFCD between the two groups. Furthermore, there were significant negative correlations between the degree of connectivity in the right insula and spKt/V.
CONCLUSION: Our findings revealed abnormal intrinsic dysconnectivity pattern of salience network-related regions in ESRD patients from the whole brain network perspective. The negative correlation between the right insula and spKt/V suggested that increased fractional removal of urea may reduce the pathological activity in the insula.

PMID: 31891646 [PubMed - in process]