New resting-state fMRI related studies at PubMed

Pleasantness of mind wandering is positively associated with focus back effort in daily life: Evidence from resting state fMRI

Sun, 04/18/2021 - 10:00

Brain Cogn. 2021 Apr 15;150:105731. doi: 10.1016/j.bandc.2021.105731. Online ahead of print.


Despite the dynamic property of consciousness, little research has explored the characteristic of the effort in trying to focus back, in which attention is shifted from mind wandering to ongoing activities. In the current study, we assessed the frequency of daily mind wandering, the pleasantness of daily mind wandering content, and the daily focus back effort of 69 participants, and then collected their resting-state functional magnetic resonance imaging (rsfMRI) scans. Our results revealed that (1) participants who experienced more daily pleasant mind wandering tended to have higher effort in trying to focus back than individuals with less pleasant mind wandering whereas there were no significant relations between pleasantness of mind wandering and mind wandering frequency or between focus back effort and mind wandering frequency in everyday life; (2) the pleasantness of mind wandering and focus back effort were associated with two functional connectivity that related to focus back episodes (right dorsolateral prefrontal cortex-right middle frontal gyrus, right inferior parietal - right middle frontal gyrus). The nodes forming these functional connections belonged to the executive network. Taken together, these findings support the content regulation hypothesis that humans maintain their minds wandering away from unpleasant topics by engaging in executive control processes.

PMID:33866054 | DOI:10.1016/j.bandc.2021.105731

Targeting Location Relates to Treatment Response in Active but not Sham rTMS Stimulation

Sun, 04/18/2021 - 10:00

Brain Stimul. 2021 Apr 15:S1935-861X(21)00080-2. doi: 10.1016/j.brs.2021.04.010. Online ahead of print.


BACKGROUND: Precise targeting of brain functional networks is believed critical for treatment efficacy of rTMS (repetitive pulse transcranial magnetic stimulation) in treatment resistant major depression.

OBJECTIVE: /Hypothesis: To use imaging data from a "failed" clinical trial of rTMS in Veterans to test whether treatment response was associated with rTMS coil location in active but not sham stimulation, and compare fMRI functional connectivity between those stimulation locations.

METHODS: An imaging substudy of 49 Veterans (mean age, 56 years; range, 27-78 years; 39 male) from a randomized, sham-controlled, double-blinded clinical trial of rTMS treatment, grouping participants by clinical response, followed by group comparisons of treatment locations identified by individualized fiducial markers on structural MRI and resting state fMRI derived networks.

RESULTS: The average stimulation location for responders versus nonresponders differed in the active but not in the sham condition (P=.02). The average responder location derived from the active condition showed significant negative functional connectivity with the subgenual cingulate (P<.001) while the nonresponder location did not (P=.17), a finding replicated in independent cohorts of 84 depressed and 35 neurotypical participants. The responder and nonresponder stimulation locations evoked different seed based networks (FDR corrected clusters, all P<0.03), revealing additional brain regions related to rTMS treatment outcome.

CONCLUSION: These results provide evidence from a randomized controlled trial that clinical response to rTMS is related to accuracy in targeting the region within DLPFC that is negatively correlated with subgenual cingulate. These results support the validity of a neuro-functionally informed rTMS therapy target in Veterans.

PMID:33866020 | DOI:10.1016/j.brs.2021.04.010

The functional and structural connectomes associated with geriatric depression and anxiety symptoms in mild cognitive impairment: Cross-syndrome overlap and generalization

Sun, 04/18/2021 - 10:00

Prog Neuropsychopharmacol Biol Psychiatry. 2021 Apr 15:110329. doi: 10.1016/j.pnpbp.2021.110329. Online ahead of print.


Geriatric depression and anxiety disorders often manifest as neuropsychiatric symptoms among those with mild cognitive impairment. Both tend to co-occur, and overlap in symptomology and etiology. Such commonalities are likely to be reflected in the brain as common neural correlates. Using connectome-based predictive modeling (CPM), we examined the functional and structural connectomes predicting depression and anxiety symptoms, and subsequently the overlap and cross-syndrome generalization of the connectomes associated with either disorder. Ninety-one older adults completed self-reported measures of depression and anxiety, and underwent diffusion tensor imaging and resting-state functional magnetic resonance imaging. Functional connectivity (FC) and structural connectivity (SC) matrices were derived from these scans and, in various combinations, entered into CPM models to predict either type of symptoms. Leave-one-out cross-validation was performed. Predictive accuracy was assessed via the correlation between predicted and observed scores (ρpredicted-observed). While FC or SC features alone significantly predicted either type of symptoms, these symptoms were best predicted by models that consisted of both FC and SC features (depression: ρpredicted-observed = 0.497; anxiety: ρpredicted-observed = 0.455). The features common to depression and anxiety were identified and entered into another model which was similarly accurate in predicting either type of symptoms. Moreover, cross-syndrome generalization was observed- the depression-associated features significantly predicted anxiety symptoms (ρpredicted-observed = 0.403) and vice-versa (ρpredicted-observed = 0.378). These FC and SC features are complementary biomarkers of geriatric depression and anxiety symptoms. Both types of symptoms are largely underpinned by common patterns of altered FC and SC, alluding to the transdiagnostic neurobiological susceptibility in both disorders.

PMID:33865926 | DOI:10.1016/j.pnpbp.2021.110329

A pilot trial of repetitive transcranial magnetic stimulation of the dorsomedial prefrontal cortex in anorexia nervosa: resting fMRI correlates of response

Sun, 04/18/2021 - 10:00

J Eat Disord. 2021 Apr 17;9(1):52. doi: 10.1186/s40337-021-00411-x.


BACKGROUND: Patients with anorexia nervosa (AN) face severe and chronic illness with high mortality rates, despite our best currently available conventional treatments. Repetitive transcranial magnetic stimulation (rTMS) has shown increasing efficacy in treatment-refractory cases across a variety of psychiatric disorders comorbid with AN, including major depression, Obsessive Compulsive Disorder (OCD), and Post traumatic Stress Disorder (PTSD). However, to date few studies have examined the effects of a course of rTMS on AN pathology itself.

METHODS: Nineteen patients with AN underwent a 20-30 session open-label course of dorsomedial prefrontal rTMS for comorbid Major Depressive Disorder (MDD) ± PTSD. Resting-state functional MRI was acquired at baseline in 16/19 patients.

RESULTS: Following treatment, significant improvements were seen in core AN pathology on the EDE global scale, and to a lesser extent on the shape and weight concerns subscales. Significant improvements in comorbid anxiety, and to a lesser extent depression, also ensued. The greatest improvements were seen in patients with lower baseline functional connectivity from the dorsomedial prefrontal cortex (DMPFC) target to regions in the right frontal pole and left angular gyrus.

CONCLUSIONS: Despite the limited size of this preliminary, open-label study, the results suggest that rTMS is safe in AN, and may be useful in addressing some core domains of AN pathology. Other targets may also be worth studying in this population, in future sham-controlled trials with larger sample sizes.

TRIAL REGISTRATION: Trial registration NCT04409704 . Registered May 282,020. Retrospectively registered.

PMID:33865456 | DOI:10.1186/s40337-021-00411-x

Reorganization of auditory-visual network interactions in long-term unilateral postlingual hearing loss

Sat, 04/17/2021 - 10:00

J Clin Neurosci. 2021 May;87:97-102. doi: 10.1016/j.jocn.2021.02.017. Epub 2021 Mar 19.


Long-term unilateral hearing loss could reorganize the functional network association between the bilateral auditory cortices, while alterations of other functional networks need to be further explored. We attempted to investigate the pattern of the reorganization of functional network associations between the auditory and visual cortex caused by long-term postlingual unilateral hearing loss (UHI) and its relationship with clinical characteristics. Therefore, 48 patients with hearing loss caused by unilateral acoustic tumors and 52 matched healthy controls were enrolled, and their high-resolution structural MRI and resting-state functional MRI data were also collected to depict the brain network. Degree centrality (DC) was employed to evaluate the functional network association of the auditory-visual network interaction. Group comparisons were performed to investigate the network reorganization, and its correlations with clinical data were calculated. Compared with the healthy control group, patients with UHI showed significantly increased DC between the auditory network (superior temporal gyrus and the medial geniculate body) and the visual network. Meanwhile, this difference was positively correlated with the extent of hearing impairment, and the correlation was more significant with the ipsilateral superior temporal gyrus in cases of acoustic neuroma. These results suggest that long-term unilateral hearing impairment may lead to enhancement of the visual-auditory network interactions and that the degree of reorganization is positively correlated with the pure tone average (PTA) and is more significant for the ipsilateral superior temporal gyrus, which provides clinical evidence regarding cross-modal plasticity in the UHI and its lateralization.

PMID:33863544 | DOI:10.1016/j.jocn.2021.02.017

Multimodal brain predictors of current weight and weight gain in children enrolled in the ABCD study ®

Fri, 04/16/2021 - 10:00

Dev Cogn Neurosci. 2021 Mar 30;49:100948. doi: 10.1016/j.dcn.2021.100948. Online ahead of print.


Multimodal neuroimaging assessments were utilized to identify generalizable brain correlates of current body mass index (BMI) and predictors of pathological weight gain (i.e., beyond normative development) one year later. Multimodal data from children enrolled in the Adolescent Brain Cognitive Development Study® at 9-to-10-years-old, consisted of structural magnetic resonance imaging (MRI), diffusion tensor imaging (DTI), resting state (rs), and three task-based functional (f) MRI scans assessing reward processing, inhibitory control, and working memory. Cross-validated elastic-net regression revealed widespread structural associations with BMI (e.g., cortical thickness, surface area, subcortical volume, and DTI), which explained 35% of the variance in the training set and generalized well to the test set (R2 = 0.27). Widespread rsfMRI inter- and intra-network correlations were related to BMI (R2train = 0.21; R2test = 0.14), as were regional activations on the working memory task (R2train = 0.20; (R2test = 0.16). However, reward and inhibitory control tasks were unrelated to BMI. Further, pathological weight gain was predicted by structural features (Area Under the Curve (AUC)train = 0.83; AUCtest = 0.83, p < 0.001), but not by fMRI nor rsfMRI. These results establish generalizable brain correlates of current weight and future pathological weight gain. These results also suggest that sMRI may have particular value for identifying children at risk for pathological weight gain.

PMID:33862325 | DOI:10.1016/j.dcn.2021.100948

A multimodal meta-analysis of regional structural and functional brain alterations in type 2 diabetes

Fri, 04/16/2021 - 10:00

Front Neuroendocrinol. 2021 Apr 13:100915. doi: 10.1016/j.yfrne.2021.100915. Online ahead of print.


Neuroimaging studies have identified brain structural and functional alterations of type 2 diabetes mellitus (T2DM) patients; however, there is no systematic information on the relations between abnormalities in these two domains. We conducted a multimodal meta-analysis of voxel-based morphometry and regional resting-state functional MRI studies in T2DM, including fifteen structural datasets (693 patients and 684 controls) and sixteen functional datasets (378 patients and 358 controls). We found, in patients with T2DM compared to controls, conjoint decreased regional gray matter volume (GMV) and altered intrinsic activity mainly in the default mode network including bilateral superior temporal gyrus/Rolandic operculum, left middle and inferior temporal gyrus, and left supramarginal gyrus; decreased GMV alone in the limbic system; and functional abnormalities alone in the cerebellum, insula, and visual cortex. This meta-analysis identified complicated patterns of conjoint and dissociated brain alterations in T2DM patients, which may help provide new insight into the neuropathology of T2DM.

PMID:33862036 | DOI:10.1016/j.yfrne.2021.100915

Dysfunctional Brain Reward System in Child Obesity

Fri, 04/16/2021 - 10:00

Cereb Cortex. 2021 Apr 16:bhab092. doi: 10.1093/cercor/bhab092. Online ahead of print.


Eating habits leading to obesity may reflect nonhomeostatic behavior based on excessive immediate-reward seeking. However, it is currently unknown to what extent excess weight is associated with functional alterations in the brain's reward system in children. We tested the integrity of reward circuits using resting-state functional connectivity magnetic resonance imaging in a population of 230 children aged 8-12 years. The major components of the reward system were identified within the ventral striatum network defined on the basis of the nucleus accumbens connectivity pattern. The functional structure of the cerebral cortex was characterized using a combination of local functional connectivity measures. Higher body mass index was associated with weaker connectivity between the cortical and subcortical elements of the reward system, and enhanced the integration of the sensorimotor cortex to superior parietal areas relevant to body image formation. Obese children, unlike WHO-defined overweight condition, showed functional structure alterations in the orbitofrontal cortex and amygdala region similar to those previously observed in primary obsessive-compulsive disorder and Prader-Willi syndrome associated with obsessive eating behavior. Results further support the view that childhood obesity is not simply a deviant habit with restricted physical health consequences but is associated with reward system dysfunction characterizing behavioral control disorders.

PMID:33861860 | DOI:10.1093/cercor/bhab092

Emulative, coherent, and causal dynamics between large-scale brain networks are neurobiomarkers of Accelerated Cognitive Ageing in epilepsy

Fri, 04/16/2021 - 10:00

PLoS One. 2021 Apr 16;16(4):e0250222. doi: 10.1371/journal.pone.0250222. eCollection 2021.


Accelerated cognitive ageing (ACA) is an ageing co-morbidity in epilepsy that is diagnosed through the observation of an evident IQ decline of more than 1 standard deviation (15 points) around the age of 50 years old. To understand the mechanism of action of this pathology, we assessed brain dynamics with the use of resting-state fMRI data. In this paper, we present novel and promising methods to extract brain dynamics between large-scale resting-state networks: the emulative power, wavelet coherence, and granger causality between the networks were extracted in two resting-state sessions of 24 participants (10 ACA, 14 controls). We also calculated the widely used static functional connectivity to compare the methods. To find the best biomarkers of ACA, and have a better understanding of this epilepsy co-morbidity we compared the aforementioned between-network neurodynamics using classifiers and known machine learning algorithms; and assessed their performance. Results show that features based on the evolutionary game theory on networks approach, the emulative powers, are the best descriptors of the co-morbidity, using dynamics associated with the default mode and dorsal attention networks. With these dynamic markers, linear discriminant analysis could identify ACA patients at 82.9% accuracy. Using wavelet coherence features with decision-tree algorithm, and static functional connectivity features with support vector machine, ACA could be identified at 77.1% and 77.9% accuracy respectively. Granger causality fell short of being a relevant biomarker with best classifiers having an average accuracy of 67.9%. Combining the features based on the game theory, wavelet coherence, Granger-causality, and static functional connectivity- approaches increased the classification performance up to 90.0% average accuracy using support vector machine with a peak accuracy of 95.8%. The dynamics of the networks that lead to the best classifier performances are known to be challenged in elderly. Since our groups were age-matched, the results are in line with the idea of ACA patients having an accelerated cognitive decline. This classification pipeline is promising and could help to diagnose other neuropsychiatric disorders, and contribute to the field of psychoradiology.

PMID:33861794 | DOI:10.1371/journal.pone.0250222

Resting-State fMRI in Studies of Acupuncture

Fri, 04/16/2021 - 10:00

Evid Based Complement Alternat Med. 2021 Mar 23;2021:6616060. doi: 10.1155/2021/6616060. eCollection 2021.


Research exploring the mechanism of acupuncture has been a hot topic in medicine. Resting-state functional magnetic resonance imaging (rs-fMRI) research is a noninvasive and extensive method, which is aimed at the research of the mechanism of acupuncture. Researchers use fMRI technologies to inspect the acupuncture process. The authors reviewed the application of rs-fMRI in acupuncture research in recent 10 years from the aspects of studying acupoints, subjects, acupuncture methods, and intensities. The results found that the application of rs-fMRI in acupuncture research mainly includes research on the onset mechanism of acupuncture treatment; visual evidence of diagnosis and treatment of dominant diseases; efficacy assessments; physiological mechanism of acupoint stimulation; and specific visualization of acupoints.

PMID:33859708 | PMC:PMC8009717 | DOI:10.1155/2021/6616060

Botulinum toxin injection changes resting state cerebellar connectivity in cervical dystonia

Fri, 04/16/2021 - 10:00

Sci Rep. 2021 Apr 15;11(1):8322. doi: 10.1038/s41598-021-87088-z.


In cervical dystonia, functional MRI (fMRI) evidence indicates changes in several resting state networks, which revert in part following the botulinum neurotoxin A (BoNT) therapy. Recently, the involvement of the cerebellum in dystonia has gained attention. The aim of our study was to compare connectivity between cerebellar subdivisions and the rest of the brain before and after BoNT treatment. Seventeen patients with cervical dystonia indicated for treatment with BoNT were enrolled (14 female, aged 50.2 ± 8.5 years, range 38-63 years). Clinical and fMRI examinations were carried out before and 4 weeks after BoNT injection. Clinical severity was evaluated using TWSTRS. Functional MRI data were acquired on a 1.5 T scanner during 8 min rest. Seed-based functional connectivity analysis was performed using data extracted from atlas-defined cerebellar areas in both datasets. Clinical scores demonstrated satisfactory BoNT effect. After treatment, connectivity decreased between the vermis lobule VIIIa and the left dorsal mesial frontal cortex. Positive correlations between the connectivity differences and the clinical improvement were detected for the right lobule VI, right crus II, vermis VIIIb and the right lobule IX. Our data provide evidence for modulation of cerebello-cortical connectivity resulting from successful treatment by botulinum neurotoxin.

PMID:33859210 | DOI:10.1038/s41598-021-87088-z

Functional connectivity hemispheric contrast (FC-HC): A new metric for language mapping

Fri, 04/16/2021 - 10:00

Neuroimage Clin. 2021 Mar 1:102598. doi: 10.1016/j.nicl.2021.102598. Online ahead of print.


Development of a task-free method for presurgical mapping of language function is important for use in young or cognitively impaired patients. Resting state connectivity fMRI (RS-fMRI) is a task-free method that may be used to identify cognitive networks. We developed a voxelwise RS-fMRI metric, Functional Connectivity Hemispheric Contrast (FC-HC), to map the language network and determine language laterality through comparison of within-hemispheric language network connections (Integration) to cross-hemispheric connections (Segregation). For the first time, we demonstrated robustness and efficacy of a RS-fMRI metric to map language networks across five groups (total N = 243) that differed in MRI scanning parameters, fMRI scanning protocols, age, and development (typical vs pediatric epilepsy). The resting state FC-HC maps for the healthy pediatric and adult groups showed higher values in the left hemisphere, and had high agreement with standard task language fMRI; in contrast, the epilepsy patient group map was bilateral. FC-HC has strong but not perfect agreement with task fMRI and thus, may reflect related and complementary information about language plasticity and compensation.

PMID:33858809 | DOI:10.1016/j.nicl.2021.102598

Altered amygdala effective connectivity in migraine without aura: evidence from resting-state fMRI with Granger causality analysis

Fri, 04/16/2021 - 10:00

J Headache Pain. 2021 Apr 15;22(1):25. doi: 10.1186/s10194-021-01240-8.


BACKGROUND: Granger causality analysis (GCA) has been used to investigate the pathophysiology of migraine. Amygdala plays a key role in pain modulation of migraine attack. However, the detailed neuromechanism remained to be elucidated. We applied GCA to explore the amygdala-based directional effective connectivity in migraine without aura (MwoA) and to determine the relation with clinical characteristics.

METHODS: Forty-five MwoA patients and forty age-, sex-, and years of education-matched healthy controls(HCs) underwent resting-state functional magnetic resonance imaging (fMRI). Bilateral amygdala were used as seed regions in GCA to investigate directional effective connectivity and relation with migraine duration or attack frequency.

RESULTS: MwoA patients showed significantly decreased effective connectivity from right amygdala to right superior temporal gyrus, left superior temporal gyrus and right precentral gyrus compared with HCs. Furthermore, MwoA patients demonstrated significantly decreased effective connectivity from the left amygdala to the ipsilateral superior temporal gyrus. Also, MwoA patients showed enhanced effective connectivity from left inferior frontal gyrus to left amygdala. Effective connectivity outflow from right amygdala to right precentral gyrus was negatively correlated to disease duration.

CONCLUSIONS: Altered directional effective connectivity of amygdala demonstrated that neurolimbic pain networks contribute to multisensory integration abnormalities and deficits in pain modulation of MwoA patients.

PMID:33858323 | DOI:10.1186/s10194-021-01240-8

High-order interdependencies in the aging brain

Fri, 04/16/2021 - 10:00

Brain Connect. 2021 Apr 15. doi: 10.1089/brain.2020.0982. Online ahead of print.


Background: Brain interdependencies can be studied from either a structural/anatomical perspective ("structural connectivity"-SC) or by considering statistical interdependencies ("functional connectivity"-FC). Interestingly, while SC is by definition pairwise (white-matter fibers project from one region to another), FC is not. However, most FC analyses only focus on pairwise statistics and they neglect higher-order interactions. A promising tool to study high-order interdependencies is the recently proposed O-Information, which can quantify the intrinsic statistical synergy and the redundancy in groups of three or more interacting variables. Methods: We analyzed functional magnetic resonance imaging (fMRI) data obtained at rest from 164 healthy subjects with ages ranging in 10 to 80 years and used O-Information to investigate how high-order statistical interdependencies are affected by age. Results: Older participants (from 60 to 80 years old) exhibited a higher predominance of redundant dependencies as compared to younger participants, an effect that seems to be pervasive as it is evident for all orders of interaction. In addition, while there is strong heterogeneity across brain regions, we found a 'redundancy core' constituted by the prefrontal and motor cortices in which redundancy was evident at all the interaction orders studied. Discussion: High-order interdependencies in fMRI data reveals a dominant redundancy in functions such as working memory, executive and motor functions. Our methodology can be used for a broad range of applications, and the corresponding code is freely available.

PMID:33858199 | DOI:10.1089/brain.2020.0982

PET/MRI Delivers Multimodal Brain Signature in Alzheimer's Disease with De Novo PSEN1 Mutation

Thu, 04/15/2021 - 10:00

Curr Alzheimer Res. 2021 Apr 13. doi: 10.2174/1567205018666210414111536. Online ahead of print.


BACKGROUND: Little is known so far about the brain phenotype and the spatial interplay of different Alzheimer's disease (AD) biomarkers with structural and functional brain connectivity in the early phase of autosomal-dominant AD (ADAD). Multimodal PET/MRI might be suitable to fill this gap.

MATERIAL AND METHODS: We presented a 31-year-old male patient without a family history of de- mentia with progressive worsening of memory and motor function. Two separate sessions of 3T PET/MRI acquisitions were arranged with the ß-amyloid tracer [18F]Florbetaben and the second-- generation tau tracer [18F]PI-2620. Simultaneously acquired MRI consisted of high-resolution 3D T1, diffusion-tensor imaging (DTI), and resting-state fMRI. PET/MRI data were compared with ten age-matched healthy controls.

RESULTS: Widespread β-amyloid depositions were found in cortical regions, and striatum (Thal stage III) along with tau pathology restricted to the mesial-temporal structures (Braak stage III/IV). Volumetric/shape analysis of subcortical structures revealed atrophy of the hippocampal-amygdala complex. In addition, cortical thinning was detected in the right middle temporal pole. Alterations of multiple DTI indices were noted in the major white matter fiber bundles, together with disrup- tion of default mode and sensory-motor network functional connectivity. Molecular genetic analy- sis by next-generation sequencing revealed a heterozygote missense pathogenic variant of the PSEN1 (Met233Val).

CONCLUSION: Multimodal PET/MR imaging is able to deliver, in a one-stop-shop approach, an ar- ray of molecular, structural and functional brain information in AD due to de novo pathogenic variant, which can be studied for spatial interplay and might provide a rationale for initiating an- ti-amyloid/tau therapeutic approaches.

PMID:33855944 | DOI:10.2174/1567205018666210414111536

Repetitive deep TMS for the reduction of body weight: Bimodal effect on the functional brain connectivity in "diabesity"

Thu, 04/15/2021 - 10:00

Nutr Metab Cardiovasc Dis. 2021 Feb 25:S0939-4753(21)00084-3. doi: 10.1016/j.numecd.2021.02.015. Online ahead of print.


BACKGROUND AND AIMS: Deep repetitive Transcranial Magnetic Stimulation (deep rTMS) over the bilateral insula and prefrontal cortex (PFC) can promote weight-loss in obesity, preventing cardiometabolic complications as Type 2 Diabetes (T2D). To investigate the changes in the functional brain integration after dTMS, we conducted a resting-state functional connectivity (rsFC) study in obesity.

METHODS AND RESULTS: This preliminary study was designed as a randomized, double-blind, sham-controlled study: 9 participants were treated with high-frequency stimulation (realTMS group), 8 were sham-treated (shamTMS group). Out of the 17 enrolled patients, 6 were affected by T2D. Resting-state fMRI scans were acquired at baseline (T0) and after the 5-week intervention (T1). Body weight was measured at three time points [T0, T1, 1-month follow-up visit (FU1)]. A mixed-model analysis showed a significant group-by-time interaction for body weight (p = .04), with a significant decrease (p < .001) in the realTMS group. The rsFC data revealed a significant increase of degree centrality for the realTMS group in the medial orbitofrontal cortex (mOFC) and a significant decrease in the occipital pole.

CONCLUSION: An increase of whole-brain functional connections of the mOFC, together with the decrease of whole-brain functional connections with the occipital pole, may reflect a brain mechanism behind weight-loss through a diminished reactivity to bottom-up visual-sensory processes in favor of increased reliance on top-down decision-making processes.


PMID:33853721 | DOI:10.1016/j.numecd.2021.02.015

Neurovascular coupling dysfunction in end-stage renal disease patients related to cognitive impairment

Thu, 04/15/2021 - 10:00

J Cereb Blood Flow Metab. 2021 Apr 14:271678X211007960. doi: 10.1177/0271678X211007960. Online ahead of print.


We aimed to investigate the neurovascular coupling (NVC) dysfunction in end-stage renal disease (ESRD) patients related with cognitive impairment. Twenty-five ESRD patients and 22 healthy controls were enrolled. To assess the NVC dysfunctional pattern, resting-state functional MRI and arterial spin labeling were explored to estimate the coupling of spontaneous neuronal activity and cerebral blood perfusion based on amplitude of low-frequency fluctuation (ALFF)-cerebral blood flow (CBF), fractional ALFF (fALFF)-CBF, regional homogeneity (ReHo)-CBF, and degree centrality (DC)-CBF correlation coefficients. Multivariate partial least-squares correlation and mediation analyses were used to evaluate the relationship among NVC dysfunctional pattern, cognitive impairment and clinical characteristics. The NVC dysfunctional patterns in ESRD patients were significantly decreased in 34 brain regions compared with healthy controls. The decreased fALFF-CBF coefficients in the cingulate gyrus (CG) were associated positively with lower kinetic transfer/volume urea (Kt/V) and lower short-term memory scores, and were negatively associated with higher serum urea. The relationship between Kt/V and memory deficits of ESRD patients was partially mediated by the fALFF-CBF alteration of the CG. These findings reveal the NVC dysfunction may be a potential neural mechanism for cognitive impairment in ESRD. The regional NVC dysfunction may mediate the impact of dialysis adequacy on memory function.

PMID:33853410 | DOI:10.1177/0271678X211007960

Intranasal vasopressin modulates resting state brain activity across multiple neural systems: evidence from a brain imaging machine learning study

Wed, 04/14/2021 - 10:00

Neuropharmacology. 2021 Apr 11:108561. doi: 10.1016/j.neuropharm.2021.108561. Online ahead of print.


Arginine vasopressin (AVP), a neuropeptide with widespread receptors in brain regions important for socioemotional processing, is critical in regulating various mammalian social behavior and emotion. Although a growing body of task-based brain imaging studies have revealed the effects of AVP on brain activity associated with emotion processing, social cognition and behaviors, the potential modulations of AVP on resting-state brain activity remain largely unknown. Here, the current study addressed this issue by adopting a machine learning approach to distinguish administration of AVP and placebo, employing the amplitude of low-frequency fluctuation (ALFF) as a measure of resting-state brain activity. The brain regions contributing to the classification were then subjected to functional connectivity and decoding analyses, allowing for a data-driven quantitative inference on psychophysiological functions. Our results indicated that ALFF across multiple neural systems were sufficient to distinguish between AVP and placebo at individual level, with the contributing regions distributed across the social cognition network, sensorimotor regions and emotional processing network. These findings suggest that the role of AVP in socioemotional functioning recruits multiple brain networks distributed across the whole brain rather than specific localized neural pathways. Beyond these findings, the current data-driven approach also opens a novel avenue to delineate neural underpinnings of various neuropeptides or hormones.

PMID:33852823 | DOI:10.1016/j.neuropharm.2021.108561

Cortico-subcortical functional connectivity modifications in fatigued ms patients treated with fampridine and amantadine

Wed, 04/14/2021 - 10:00

Eur J Neurol. 2021 Apr 14. doi: 10.1111/ene.14867. Online ahead of print.


BACKGROUND: Fatigue in multiple sclerosis (MS) is common and disabling; medication efficacy is still not fully proven. Aim of this study was to investigate four-week modifications of fatigue severity in 45 relapsing-remitting MS patients following different symptomatic treatments, and concomitant resting state (RS) functional connectivity (FC) changes.

METHODS: Patients were randomly, blindly assigned to treatment with fampridine (n=15), amantadine (n=15) or placebo (n=15), and underwent clinical/3T RS fMRI at baseline (t0) and after four weeks (w4) of treatment. Fifteen healthy controls (HC) were also studied. Changes of modified fatigue impact scale (MFIS) and network RS FC were assessed.

RESULTS: In MS, abnormalities of network RS FC at t0 did not differ between treatment groups and correlated with fatigue severity. At w4, global and subscore MFISs decreased in all groups, with no time-by-treatment interaction. At w4, all patient groups had changes of RS FC in several networks, with significant time-by-treatment interactions in basal ganglia, sensorimotor and default-mode networks in fampridine patients vs the other groups, and in fronto-parietal network in amantadine patients. In fampridine-group, RS FC changes correlated with concurrently decreased MFIS (r range=-0.75 to 0.74, p range=0.003-0.05).

CONCLUSIONS: Fatigue improved in all MS groups, independently from treatment. Concomitant RS FC modifications were located in sensorimotor, inferior frontal and subcortical regions for fampridine and amantadine patients, and in associative sensory cortices for placebo patients.

PMID:33852752 | DOI:10.1111/ene.14867

Conduct disorder symptomatology is associated with an altered functional connectome in a large national youth sample

Wed, 04/14/2021 - 10:00

Dev Psychopathol. 2021 Apr 14:1-12. doi: 10.1017/S0954579421000237. Online ahead of print.


Conduct disorder (CD), characterized by youth antisocial behavior, is associated with a variety of neurocognitive impairments. However, questions remain regarding the neural underpinnings of these impairments. To investigate novel neural mechanisms that may support these neurocognitive abnormalities, the present study applied a graph analysis to resting-state functional magnetic resonance imaging (fMRI) data collected from a national sample of 4,781 youth, ages 9-10, who participated in the baseline session of the Adolescent Brain Cognitive DevelopmentSM Study (ABCD Study®). Analyses were then conducted to examine the relationships among levels of CD symptomatology, metrics of global topology, node-level metrics for subcortical structures, and performance on neurocognitive assessments. Youth higher on CD displayed higher global clustering (β = .039, 95% CIcorrected [.0027 .0771]), but lower Degreesubcortical (β = -.052, 95% CIcorrected [-.0916 -.0152]). Youth higher on CD had worse performance on a general neurocognitive assessment (β = -.104, 95% CI [-.1328 -.0763]) and an emotion recognition memory assessment (β = -.061, 95% CI [-.0919 -.0290]). Finally, global clustering mediated the relationship between CD and general neurocognitive functioning (indirect β = -.002, 95% CI [-.0044 -.0002]), and Degreesubcortical mediated the relationship between CD and emotion recognition memory performance (indirect β = -.002, 95% CI [-.0046 -.0005]). CD appears associated with neuro-topological abnormalities and these abnormalities may represent neural mechanisms supporting CD-related neurocognitive disruptions.

PMID:33851904 | DOI:10.1017/S0954579421000237