New resting-state fMRI related studies at PubMed

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

Sun, 01/05/2020 - 12:00
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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 - 12:00
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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 - 12:00
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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 - 12:00
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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 - 12:00
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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.

Sat, 01/04/2020 - 17:20
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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.

Sat, 01/04/2020 - 17:20
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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.

Sat, 01/04/2020 - 17:20
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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.

Sat, 01/04/2020 - 17:20
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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.

Sat, 01/04/2020 - 17:20
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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.

Sat, 01/04/2020 - 17:20
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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.

Sat, 01/04/2020 - 17:20
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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]

Ketamine normalizes subgenual cingulate cortex hyper-activity in depression.

Fri, 01/03/2020 - 16:20
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Ketamine normalizes subgenual cingulate cortex hyper-activity in depression.

Neuropsychopharmacology. 2020 Jan 02;:

Authors: Morris LS, Costi S, Tan A, Stern ER, Charney D, Murrough JW

Abstract
Mounting evidence supports the rapid anti-depressant efficacy of the N-methyl-D-aspartate receptor antagonist, ketamine, for treating major depressive disorder (MDD); however, its neural mechanism of action remains poorly understood. Subgenual anterior cingulate cortex (sgACC) hyper-activity during rest has been consistently implicated in the pathophysiology of MDD, potentially driven by excessive hippocampal gluatmatergic efferents to sgACC. Reduction of sgACC activity has been associated with successful anti-depressant treatment. This study aimed to examine whether task-based sgACC activity was also higher in MDD patients compared to controls and to determine whether this activity was altered by single-dose ketamine. In Study 1, patients with MDD (N = 28) and healthy controls (N = 20) completed task-based functional magnetic resonance imaging using an established incentive-processing task. In Study 2, a second cohort of patients with MDD (N = 14) completed the same scanning protocol pre and post intravenous infusion of 40 min (0.5 mg/kg) ketamine treatment. Task-based activation of sgACC was examined with a seed-driven analysis assessing group differences and changes from pre to post treatment. Patients with MDD showed higher sgACC activation to positive and negative monetary incentives compared to controls, associated with anhedonia and anxiety, respectively. In addition, patients with MDD also had higher resting-state functional connectivity between hippocampus and sgACC, associated with sgACC hyper-activation to positive incentives, but not negative incentives. Finally, ketamine reduced sgACC hyper-activation to positive incentives, but not negative incentives. These findings suggest a neural mechanism by which ketamine exerts its anti-depressant efficacy, via rapid blunting of aberrant sgACC hyper-reactivity to positive incentives.

PMID: 31896116 [PubMed - as supplied by publisher]

Cortical Connectivity Moderators of Antidepressant vs Placebo Treatment Response in Major Depressive Disorder: Secondary Analysis of a Randomized Clinical Trial.

Fri, 01/03/2020 - 16:20
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Cortical Connectivity Moderators of Antidepressant vs Placebo Treatment Response in Major Depressive Disorder: Secondary Analysis of a Randomized Clinical Trial.

JAMA Psychiatry. 2020 Jan 02;:

Authors: Rolle CE, Fonzo GA, Wu W, Toll R, Jha MK, Cooper C, Chin-Fatt C, Pizzagalli DA, Trombello JM, Deckersbach T, Fava M, Weissman MM, Trivedi MH, Etkin A

Abstract
Importance: Despite the widespread awareness of functional magnetic resonance imaging findings suggesting a role for cortical connectivity networks in treatment selection for major depressive disorder, its clinical utility remains limited. Recent methodological advances have revealed functional magnetic resonance imaging-like connectivity networks using electroencephalography (EEG), a tool more easily implemented in clinical practice.
Objective: To determine whether EEG connectivity could reveal neural moderators of antidepressant treatment.
Design, Setting, and Participants: In this nonprespecified secondary analysis, data were analyzed from the Establishing Moderators and Biosignatures of Antidepressant Response in Clinic Care study, a placebo-controlled, double-blinded randomized clinical trial. Recruitment began July 29, 2011, and was completed December 15, 2015. A random sample of 221 outpatients with depression aged 18 to 65 years who were not taking medication for depression was recruited and assessed at 4 clinical sites. Analysis was performed on an intent-to-treat basis. Statistical analysis was performed from November 16, 2018, to May 23, 2019.
Interventions: Patients received either the selective serotonin reuptake inhibitor sertraline hydrochloride or placebo for 8 weeks.
Main Outcomes and Measures: Electroencephalographic orthogonalized power envelope connectivity analyses were applied to resting-state EEG data. Intent-to-treat prediction linear mixed models were used to determine which pretreatment connectivity patterns were associated with response to sertraline vs placebo. The primary clinical outcome was the total score on the 17-item Hamilton Rating Scale for Depression, administered at each study visit.
Results: Of the participants recruited, 9 withdrew after first dose owing to reported adverse effects, and 221 participants (150 women; mean [SD] age, 37.8 [12.7] years) underwent EEG recordings and had high-quality pretreatment EEG data. After correction for multiple comparisons, connectome-wide analyses revealed moderation by connections within and between widespread cortical regions-most prominently parietal-for both the antidepressant and placebo groups. Greater alpha-band and lower gamma-band connectivity predicted better placebo outcomes and worse antidepressant outcomes. Lower connectivity levels in these moderating connections were associated with higher levels of anhedonia. Connectivity features that moderate treatment response differentially by treatment group were distinct from connectivity features that change from baseline to 1 week into treatment. The group mean (SD) score on the 17-item Hamilton Rating Scale for Depression was 18.35 (4.58) at baseline and 26.14 (30.37) across all time points.
Conclusions and Relevance: These findings establish the utility of EEG-based network functional connectivity analyses for differentiating between responses to an antidepressant vs placebo. A role emerged for parietal cortical regions in predicting placebo outcome. From a treatment perspective, capitalizing on the therapeutic components leading to placebo response differentially from antidepressant response should provide an alternative direction toward establishing a placebo signature in clinical trials, thereby enhancing the signal detection in randomized clinical trials.
Trial Registration: ClinicalTrials.gov identifier: NCT01407094.

PMID: 31895437 [PubMed - as supplied by publisher]

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

Fri, 01/03/2020 - 16:20
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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]

Simultaneous R2, R2' and R2* measurement of skeletal muscle in a rabbit model of unilateral artery embolization.

Fri, 01/03/2020 - 16:20
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Simultaneous R2, R2' and R2* measurement of skeletal muscle in a rabbit model of unilateral artery embolization.

Magn Reson Imaging. 2019 09;61:149-157

Authors: Wang Y, Zhang R, Zhang B, Wang C, Wang H, Zhang X, Zhao K, Yang M, Wang X, Zhang J

Abstract
PURPOSE: To demonstrate the feasibility of using a susceptibility-based MRI technique with multi-echo gradient and spin echo (MEGSE) sequence to achieve simultaneous R2, R2' and R2* measurement and assess skeletal muscle oxygenation alternations in a rabbit model of unilateral artery embolization.
MATERIALS AND METHODS: Approved by the local institutional review board for experimental animal studies, nine New Zealand White rabbits were included in this study. The MEGSE sequence consists of embedding a set of gradient echoes around the echo of a single spin-echo sequence using several gradient echoes to collect the magnetization intensity during the formation and attenuation of spin-echo simultaneously after 180° radio frequency pulse. Within-session and between-day tests were conducted to evaluate the reproducibility of this skeletal muscle oxygenation alternations measurement. Furthermore, all the MEGSE scans of skeletal muscle were conducted using a 3-T clinical MRI scanner during resting state (before unilateral artery embolization operation, pre), 1 h after unilateral artery embolization operation (post1) and 2 h after unilateral artery embolization operation (post2) model to verify the feasibility and sensitivity of this method.
RESULTS: The within-session coefficient of variations (CVs) of R2, R2' and R2* measurements were 1.57%, 3.33% and 2.57%, while the between-day CVs of were 1.42%, 5.85% and 2.85%. In all rabbits, the mean R2 decreased significantly from 36.46 ± 1.03 s-1 (pre) to 30.58 ± 2.11 s-1 (post1,**P < 0.01, relative to pre) and 28.62 ± 1.53 s-1 (post2, **P < 0.01, relative to post1), and the mean R2' went up markedly from 9.88 ± 2.14 s-1 (pre) to 16.10 ± 2.74 s-1 (post1, **P < 0.01) and 17.33 ± 2.25 s-1 (post2, **P < 0.05). The mean R2* increased from 43.27 ± 3.75 s-1 (pre) to 47.90 ± 5.08 s-1 (post1, *P < 0.05) and to 48.04 ± 4.42 s-1 (post2, NS, P > 0.05).
CONCLUSION: This study demonstrates the feasibility of simultaneous R2, R2' and R2* measurement method for the evaluation of skeletal muscle ischemia. Besides, this study indicates the sensitivity of the R2 and R2' compared with R2* and especially the necessity of R2 and R2' measurement for the further evaluation of skeletal muscle ischemia which always causes both edema and hypoxia in a rabbit model of unilateral artery embolization.

PMID: 31129281 [PubMed - indexed for MEDLINE]

MRI-guided laser interstitial thermal thalamotomy for medically intractable tremor disorders.

Fri, 01/03/2020 - 16:20
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MRI-guided laser interstitial thermal thalamotomy for medically intractable tremor disorders.

Mov Disord. 2019 01;34(1):124-129

Authors: Harris M, Steele J, Williams R, Pinkston J, Zweig R, Wilden JA

Abstract
INTRODUCTION: Medically intractable tremors are a common, difficult clinical situation. Deep brain stimulation decreases Parkinson's disease resting tremor and essential tremor, but not all patients are candidates from a diagnostic, medical, or social standpoint, prompting the need for alternative surgical strategies.
METHODS: We describe 13 patients with medically intractable tremor treated with laser interstitial thermal thalamotomy performed under general anesthesia using live MRI-guidance and the Clearpoint stereotactic system.
RESULTS: All patients had a dramatic decrease in tremor immediately postoperatively, which has been sustained through follow-up (3-17 months) in all but 1 patient (mean tremor score reduction of 62%; 10.33 ± 2.69 to 3.89 ± 3.1). Objective side effects were transient and included imbalance and paresthesia.
CONCLUSION: Medically intractable tremor treated with laser interstitial thermal thalamotomy may be a useful addition to the treatment armamentarium for medically intractable tremor disorders. © 2018 International Parkinson and Movement Disorder Society.

PMID: 30452785 [PubMed - indexed for MEDLINE]

Global signal regression strengthens association between resting-state functional connectivity and behavior.

Thu, 01/02/2020 - 15:00
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Global signal regression strengthens association between resting-state functional connectivity and behavior.

Neuroimage. 2019 08 01;196:126-141

Authors: Li J, Kong R, Liégeois R, Orban C, Tan Y, Sun N, Holmes AJ, Sabuncu MR, Ge T, Yeo BTT

Abstract
Global signal regression (GSR) is one of the most debated preprocessing strategies for resting-state functional MRI. GSR effectively removes global artifacts driven by motion and respiration, but also discards globally distributed neural information and introduces negative correlations between certain brain regions. The vast majority of previous studies have focused on the effectiveness of GSR in removing imaging artifacts, as well as its potential biases. Given the growing interest in functional connectivity fingerprinting, here we considered the utilitarian question of whether GSR strengthens or weakens associations between resting-state functional connectivity (RSFC) and multiple behavioral measures across cognition, personality and emotion. By applying the variance component model to the Brain Genomics Superstruct Project (GSP), we found that behavioral variance explained by whole-brain RSFC increased by an average of 47% across 23 behavioral measures after GSR. In the Human Connectome Project (HCP), we found that behavioral variance explained by whole-brain RSFC increased by an average of 40% across 58 behavioral measures, when GSR was applied after ICA-FIX de-noising. To ensure generalizability, we repeated our analyses using kernel regression. GSR improved behavioral prediction accuracies by an average of 64% and 12% in the GSP and HCP datasets respectively. Importantly, the results were consistent across methods. A behavioral measure with greater RSFC-explained variance (using the variance component model) also exhibited greater prediction accuracy (using kernel regression). A behavioral measure with greater improvement in behavioral variance explained after GSR (using the variance component model) also enjoyed greater improvement in prediction accuracy after GSR (using kernel regression). Furthermore, GSR appeared to benefit task performance measures more than self-reported measures. Since GSR was more effective at removing motion-related and respiratory-related artifacts, GSR-related increases in variance explained and prediction accuracies were unlikely the result of motion-related or respiratory-related artifacts. However, it is worth emphasizing that the current study focused on whole-brain RSFC, so it remains unclear whether GSR improves RSFC-behavioral associations for specific connections or networks. Overall, our results suggest that at least in the case for young healthy adults, GSR strengthens the associations between RSFC and most (although not all) behavioral measures. Code for the variance component model and ridge regression can be found here: https://github.com/ThomasYeoLab/CBIG/tree/master/stable_projects/preprocessing/Li2019_GSR.

PMID: 30974241 [PubMed - indexed for MEDLINE]

Functional network interactions at rest underlie individual differences in memory ability.

Thu, 01/02/2020 - 15:00
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Functional network interactions at rest underlie individual differences in memory ability.

Learn Mem. 2019 01;26(1):9-19

Authors: van Buuren M, Wagner IC, Fernández G

Abstract
Intrinsic network interactions may underlie individual differences in the ability to remember. The default mode network (DMN) comprises subnetworks implicated in memory, and interactions between the DMN and frontoparietal network (FPN) were shown to support mnemonic processing. However, it is unclear if such interactions during resting-state predict episodic memory ability. We investigated whether intrinsic network interactions within and between the DMN and FPN are related to individual differences in memory performance. Resting-state activity was measured using functional MRI in healthy young adults followed by a memory test for object-location associations that were studied 3 d earlier. We identified two subnetworks within the DMN, the main-DMN and the medial temporal lobe, retrosplenial cortex (MTL_RSC)-DMN. Further, we found regions forming the FPN. Memory performance was associated with lower connectivity within the MTL_RSC-DMN, and stronger connectivity between the main-DMN and FPN. Exploratory whole-brain analysis revealed stronger MTL connectivity with the left posterior parietal cortex that was related to better memory performance. Furthermore, we found increased task-evoked activation during successful retrieval within the main-DMN and FPN, but not within the MTL_RSC-DMN. In sum, lower intrinsic connectivity within the MTL_RSC-DMN, combined with stronger connectivity between the main-DMN and FPN, explain individual differences in memory ability.

PMID: 30559115 [PubMed - indexed for MEDLINE]

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

Wed, 01/01/2020 - 14:00
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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]

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