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Cognitive Dysfunction and Neurophysiological Mechanism of Breast Cancer Patients undergoing Chemotherapy Based on RS fMRI Images.

Sat, 10/24/2020 - 23:31

Cognitive Dysfunction and Neurophysiological Mechanism of Breast Cancer Patients undergoing Chemotherapy Based on RS fMRI Images.

World Neurosurg. 2020 Oct 20;:

Authors: Bai X, Zheng J, Zhang B, Luo Y

Abstract
Thesis studied chemotherapy-related cognitive impairment via RS-fMRI and DTI. Chemotherapy were included 19 cases of patients with early breast cancer, neuropsychological tests were carried out before and after chemotherapy, RS-fMRI and DTI evaluation. In RS-fMRI with ReHo reflects brain activity. In the DTI with FA reflect the integrity of the white matter. Determining the region of interest by image analysis, neuropsychological test score is calculated by paired t-test, and FA change ReHo values of ROIs. Finally, in the chemotherapy group for pairing correlation analysis t test scores change in meaningful inspection and change ReHo and FA. Chemotherapy after chemotherapy than before chemotherapy difference memory test and self-evaluation of cognitive (P <0.05). ReHo value increased brain regions are: the right orbitofrontal region and the left dorsolateral prefrontal cortex; decline in brain regions are: the anterior inferior cerebellar lobe, cerebellar lobe, right middle temporal gyrus and the superior temporal gyrus, the lower right of the centre area, as well as central gyrus. This prospective study resting state and RS-fMRI functional magnetic resonance diffusion tensor imaging study DTI sequence combination chemotherapy for breast cancer-related cognitive disorders, supporting "chemo brain" point of view exists. Chemotherapy can cause memory decline, accompanied by a partial area of the brain and white matter integrity in brain activity changes. Tips RS-fMRI and DTI have potential applications in assessing chemotherapy-related cognitive impairment.

PMID: 33096278 [PubMed - as supplied by publisher]

Attenuated link between the medial prefrontal cortex and the amygdala in children with autism spectrum disorder: Evidence from effective connectivity within the "social brain".

Sat, 10/24/2020 - 23:31

Attenuated link between the medial prefrontal cortex and the amygdala in children with autism spectrum disorder: Evidence from effective connectivity within the "social brain".

Prog Neuropsychopharmacol Biol Psychiatry. 2020 Oct 20;:110147

Authors: Li L, He C, Jian T, Guo X, Xiao J, Li Y, Chen H, Kang X, Chen H, Duan X

Abstract
Although accumulating neuroimaging studies have reported that social behavior deficits in children with autism spectrum disorders (ASD) are commonly attributed to the dysfunction of social brain regions underlying social cognition, the dynamic interaction within the social brain network and its association with social deficits remain unclear. Here, resting-state functional magnetic resonance imaging data obtained from Autism Brain Imaging Data Exchange (I and II) were analyzed in 105 children with ASD and 102 demographically matched typically developing controls (TDCs) (age range: 7-12 years old). Term-based meta-analysis combined the prior reference and anatomical labeling were used to define the regions of interests of the social brain network, and multivariate Granger causality analysis with blind deconvolution was employed to assess the effective connectivity within the social brain network in the ASD and TDC groups. Between-group comparison revealed significantly attenuated effective connectivity from the medial prefrontal cortex (mPFC) to the bilateral amygdala in children with the ASD group compared with TDC group. In addition, raw values of the effective connectivity from the mPFC to the bilateral amygdala were used to predict social deficits in ASD. Our findings indicate the impaired mPFC-amygdala pathway and its association with social deficits in children with ASD and provide a new perspective into the neuropathology of the developing autistic brain.

PMID: 33096157 [PubMed - as supplied by publisher]

Hippocampal connectivity in Amyotrophic Lateral Sclerosis (ALS): more than Papez circuit impairment.

Sat, 10/24/2020 - 23:31

Hippocampal connectivity in Amyotrophic Lateral Sclerosis (ALS): more than Papez circuit impairment.

Brain Imaging Behav. 2020 Oct 23;:

Authors: Trojsi F, Di Nardo F, Caiazzo G, Siciliano M, D'Alvano G, Ferrantino T, Passaniti C, Ricciardi D, Esposito S, Lavorgna L, Russo A, Bonavita S, Cirillo M, Santangelo G, Esposito F, Tedeschi G

Abstract
Emerging evidence suggests that memory deficit in amyotrophic lateral sclerosis (ALS), a neurodegenerative disease with varying impairment of motor abilities and cognitive profile, may be independent from executive dysfunction. Our multimodal magnetic resonance imaging (MRI) approach, including resting state functional MRI (RS-fMRI), diffusion tensor imaging (DTI) and voxel-based morphometry (VBM), aimed to investigate structural and functional changes within and beyond the Papez circuit in non-demented ALS patients (n = 32) compared with healthy controls (HCs, n = 21), and whether these changes correlated with neuropsychological measures of verbal and non-verbal memory. We revealed a decreased functional connectivity between bilateral hippocampus, bilateral parahippocampal gyri and cerebellum in ALS patients compared with HCs. Between-group comparisons revealed white matter abnormalities in the genu and body of the corpus callosum and bilateral cortico-spinal tracts, superior longitudinal and uncinate fasciculi in ALS patients (p < .05, family-wise error corrected). Interestingly, changes of Digit Span forward performance were inversely related to RS-fMRI signal fluctuations in the cerebellum, while changes of both episodic and visual memory scores were inversely related to mean and radial diffusivity abnormalities in several WM fiber tracts, including middle cerebellar peduncles. Our findings revealed that ALS patients showed significant functional and structural connectivity changes across the regions comprising the Papez circuit, as well as more extended areas including cerebellum and frontal, temporal and parietal areas, supporting the theory of a multi-system pathology in ALS that spreads from cortical to subcortical structures.

PMID: 33095382 [PubMed - as supplied by publisher]

Task-related brain activity and functional connectivity in upper limb dystonia: a functional magnetic resonance imaging (fMRI) and functional near-infrared spectroscopy (fNIRS) study.

Sat, 10/24/2020 - 23:31

Task-related brain activity and functional connectivity in upper limb dystonia: a functional magnetic resonance imaging (fMRI) and functional near-infrared spectroscopy (fNIRS) study.

Neurophotonics. 2020 Oct;7(4):045004

Authors: de Faria DD, Paulo AJM, Balardin J, Sato JR, Junior EA, Baltazar CA, Lucca RPD, Borges V, Silva SMCA, Ferraz HB, de Carvalho Aguiar P

Abstract
Significance: Dystonia is a dynamic and complex disorder. Real-time analysis of brain activity during motor tasks may increase our knowledge on its pathophysiology. Functional near-infrared spectroscopy (fNIRS) is a noninvasive method that enables the measurement of cortical hemodynamic activity in unconstrained environments. Aim: We aimed to explore the feasibility of using fNIRS for the study of task-related brain activity in dystonia. Task-related functional magnetic resonance imaging (fMRI) and resting-state functional connectivity were also analyzed. Approach: Patients with idiopathic right-upper limb dystonia and controls were assessed through nonsimultaneous fMRI and fNIRS during a finger-tapping task. Seed-based connectivity analysis of resting-state fMRI was performed in both groups. Results: The fMRI results suggest nonspecific activation of the cerebellum and occipital lobe in dystonia patients during the finger-tapping task with the affected hand. Moreover, fNIRS data show lower activation in terms of oxyhemoglobin and total hemoglobin in the frontal, ipsilateral cortex, and somatosensory areas during this task. In dystonia, both fMRI and fNIRS data resulted in hypoactivation of the frontal cortex during finger tapping with both hands simultaneously. Resting-state functional connectivity analysis suggests that the cerebellar somatomotor network in dystonia has an increased correlation with the medial prefrontal cortex and the paracingulate gyrus. Conclusions: These data suggest that unbalanced activation of the cerebellum, somatosensory, and frontal cortical areas are associated with dystonia. To our knowledge, this is the first study using fNIRS to explore the pathophysiology of dystonia. We show that fNIRS and fMRI are complementary methods and highlight the potential of fNIRS for the study of dystonia and other movement disorders as it can overcome movement restrictions, enabling experiments in more naturalistic conditions.

PMID: 33094125 [PubMed]

Abnormal Spatial Patterns of Intrinsic Brain Activity in Osteonecrosis of the Femoral Head: A Resting-State Functional Magnetic Resonance Imaging Study.

Sat, 10/24/2020 - 23:31

Abnormal Spatial Patterns of Intrinsic Brain Activity in Osteonecrosis of the Femoral Head: A Resting-State Functional Magnetic Resonance Imaging Study.

Front Hum Neurosci. 2020;14:551470

Authors: Feng S, Li B, Li G, Hua X, Zhu B, Li X, Lu W, Xu J

Abstract
Objective: Osteonecrosis of the femoral head (ONFH) is a common condition that is encountered in clinical practice, and yet, little is known about its characteristics and manifestations in the brain. Therefore, in this study, we aimed to use resting-state functional magnetic resonance imaging (rs-fMRI) to investigate the spatial patterns of spontaneous brain activity in the brain of ONFH patients. Methods: The study included ONFH patients and healthy controls. The pattern of intrinsic brain activity was measured by examining the amplitude of low-frequency fluctuations (ALFF) of blood oxygen level-dependent signals using rs-fMRI. Meanwhile, we also used Harris hip scores to evaluate the functional performance of ONFH patients and healthy controls. Result: Ten ONFH patients and 10 health controls were investigated. We found global ALFF differences between the two groups throughout the occipital, parietal, frontal, prefrontal, and temporal cortices. In the ONFH patients, altered brain activity was found in the brain regions in the sensorimotor network, pain-related network, and emotion and cognition network. The results of the correlation investigations also demonstrated that the regions with ALFF changes had significant correlations with the functional performance of the patients evaluated by Harris hip scores. Conclusions: Our study has revealed the abnormal pattern of brain activity in ONFH patients, and our findings could be used to aid in understanding the mechanisms behind the gait abnormality and intractable pain associated with ONFH at the central level.

PMID: 33093828 [PubMed]

Innate connectivity patterns drive the development of the visual word form area.

Sat, 10/24/2020 - 23:31

Innate connectivity patterns drive the development of the visual word form area.

Sci Rep. 2020 Oct 22;10(1):18039

Authors: Li J, Osher DE, Hansen HA, Saygin ZM

Abstract
What determines the functional organization of cortex? One hypothesis is that innate connectivity patterns, either structural or functional connectivity, set up a scaffold upon which functional specialization can later take place. We tested this hypothesis by asking whether the visual word form area (VWFA), an experience-driven region, was already functionally connected to proto language networks in neonates scanned within one week of birth. Using the data from the Human Connectone Project (HCP) and the Developing Human Connectome Project (dHCP), we calculated intrinsic functional connectivity during resting-state functional magnetic resonance imaging (fMRI), and found that neonates showed similar functional connectivity patterns to adults. We observed that (1) language regions connected more strongly with the putative VWFA than other adjacent ventral visual regions that also show foveal bias, and (2) the VWFA connected more strongly with frontotemporal language regions than with regions adjacent to these language regions. These data suggest that the location of the VWFA is earmarked at birth due to its connectivity with the language network, providing evidence that innate connectivity instructs the later refinement of cortex.

PMID: 33093478 [PubMed - in process]

Aberrant functional connectivity between the suprachiasmatic nucleus and the superior temporal gyrus: Bridging RORA gene polymorphism with diurnal mood variation in major depressive disorder.

Fri, 10/23/2020 - 23:30

Aberrant functional connectivity between the suprachiasmatic nucleus and the superior temporal gyrus: Bridging RORA gene polymorphism with diurnal mood variation in major depressive disorder.

J Psychiatr Res. 2020 Oct 04;132:123-130

Authors: Chen Z, Tao S, Zhu R, Tian S, Sun Y, Wang H, Yan R, Shao J, Zhang Y, Zhang J, Yao Z, Lu Q

Abstract
Diurnal mood variation (DMV), a common symptom of major depressive disorder (MDD), is associated with circadian related genes and dysregulation of the suprachiasmatic nucleus (SCN). Previous research confirmed that the RORA gene is involved in the regulation of circadian rhythms. In this study, we hypothesized that polymorphisms of RORA may affect DMV symptoms of MDD through functional changes in the SCN. A total of 208 patients diagnosed with depression and 120 control subjects were enrolled and underwent a resting-state functional magnetic resonance imaging (rs-fMRI). Blood samples were collected and genotyping of 9 RORA gene SNPs were performed using next-generation sequencing technology. Patients were categorized as an AA genotype or C allele carriers based on RORA rs72752802 polymorphism. SCN-seed functional connectivity (FC) was compared between the two groups and correlation with severity of DMV was analyzed. Finally, a mediation analysis was performed to further determine FC intermediary effects. We observed that rs72752802 was significantly associated with patients' DMV symptoms. C allele carriers of rs72752802 showed significantly decreased FC between the right SCN and right superior temporal gyrus (rSTG). This was also correlated with DMV symptoms. In addition, the rs72752802 SNP influenced DMV symptoms through intermediary effects of SCN-rSTG connectivity. The study presented here provides a neurological and genetic basis for understanding depressed patients experiencing DMV.

PMID: 33091686 [PubMed - as supplied by publisher]

Effect of age at time of injury on long-term changes in intrinsic functional connectivity in traumatic brain injury.

Fri, 10/23/2020 - 23:30

Effect of age at time of injury on long-term changes in intrinsic functional connectivity in traumatic brain injury.

Brain Inj. 2020 Oct 22;:1-9

Authors: de Souza NL, Parker R, Gonzalez CS, Ryan JD, Esopenko C

Abstract
BACKGROUND: Alterations in resting-state functional connectivity (rsFC) occur in the acute and chronic phases following traumatic brain injury (TBI); however, few studies have assessed long-term (>1 year) changes in rsFC.
METHODS: Resting-state functional magnetic resonance imaging (rsfMRI) scans were obtained from the Federal Interagency Traumatic Brain Injury Research Informatics Systems. Patients with primarily mild TBI (n = 39) completed rsfMRI scans at the sub-acute (~10 days) and long-term (~18 months) phases. We examined changes in voxel-based rsFC from anterior medial prefrontal cortex (aMPFC) and posterior cingulate cortex (PCC) seeds in the default mode network (DMN) between both phases. The effect of age at the time of injury on long-term rsFC was also examined.
RESULTS: Increased rsFC from the aMPFC and the PCC to frontal and temporal regions was shown at ~18-months post-injury. Widespread increases in rsFC from the aMPFC and between the PCC and frontal regions were shown for younger patients at time of injury, but limited increases of rsFC were noted at ~18 months in older patients.
CONCLUSION: Long-term increases in rsFC were found following TBI, but age at the time of injury was associated with distinct rsFC profiles suggesting that younger patients show greater increases in rsFC over time.

PMID: 33090913 [PubMed - as supplied by publisher]

Simultaneous BOLD-fMRI and constant infusion FDG-PET data of the resting human brain.

Fri, 10/23/2020 - 23:30

Simultaneous BOLD-fMRI and constant infusion FDG-PET data of the resting human brain.

Sci Data. 2020 Oct 21;7(1):363

Authors: Jamadar SD, Ward PGD, Close TG, Fornito A, Premaratne M, O'Brien K, Stäb D, Chen Z, Shah NJ, Egan GF

Abstract
Simultaneous [18 F]-fluorodeoxyglucose positron emission tomography and functional magnetic resonance imaging (FDG-PET/fMRI) provides the capability to image two sources of energetic dynamics in the brain - cerebral glucose uptake and the cerebrovascular haemodynamic response. Resting-state fMRI connectivity has been enormously useful for characterising interactions between distributed brain regions in humans. Metabolic connectivity has recently emerged as a complementary measure to investigate brain network dynamics. Functional PET (fPET) is a new approach for measuring FDG uptake with high temporal resolution and has recently shown promise for assessing the dynamics of neural metabolism. Simultaneous fMRI/fPET is a relatively new hybrid imaging modality, with only a few biomedical imaging research facilities able to acquire FDG PET and BOLD fMRI data simultaneously. We present data for n = 27 healthy young adults (18-20 yrs) who underwent a 95-min simultaneous fMRI/fPET scan while resting with their eyes open. This dataset provides significant re-use value to understand the neural dynamics of glucose metabolism and the haemodynamic response, the synchrony, and interaction between these measures, and the development of new single- and multi-modality image preparation and analysis procedures.

PMID: 33087725 [PubMed - in process]

Resting activity of the hippocampus and amygdala in obese individuals predicts their response to food cues.

Thu, 10/22/2020 - 23:29

Resting activity of the hippocampus and amygdala in obese individuals predicts their response to food cues.

Addict Biol. 2020 Oct 21;:e12974

Authors: Li G, Hu Y, Zhang W, Ding Y, Wang Y, Wang J, He Y, Lv G, von Deneen KM, Zhao Y, Chen A, Han Y, Cui G, Ji G, Manza P, Tomasi D, Volkow ND, Nie Y, Wang GJ, Zhang Y

Abstract
Obese individuals exhibit brain functional abnormalities in multiple regions implicated in reward/motivation, emotion/memory, homeostatic regulation, and executive control when exposed to food cues and during rest. However, it remains unclear whether abnormal brain responses to food cues might account for or relate to their abnormal activity in resting state. This information would be useful for understanding the neural mechanisms behind hyperactive responses to food cues, a critical marker of obesity. Resting-state functional magnetic resonance imaging (RS-fMRI) and a cue-reactivity fMRI task with high- (HiCal) and low-caloric (LoCal) food cues were employed to investigate brain baseline activity and food cue-induced activation differences in 44 obese participants (OB), in 37 overweight participants (OW), and in 37 normal weight (NW) controls. One-way analyses of variance showed there was a group difference in the left hippocampus/amygdala activity during resting state and during food-cue stimulation (pFWE < 0.05); post-hoc tests showed the OB group had both greater basal activity and greater food cue-induced activation than the OW and NW groups; OW had higher activity in the hippocampus/amygdala than the NW group, which was only significant during resting state. In the OB group, resting-state activity in the left hippocampus/amygdala was positively correlated with activation induced by HiCal food cues, and both of these measures correlated with body mass index (BMI). Mediation analysis showed that the relationship between BMI and hippocampus/amygdala response to HiCal food cues was mediated by their resting-state activity. These findings suggest a close association between obesity and brain functional abnormality in the hippocampus/amygdala. They also indicate that resting-state activity in the hippocampus/amygdala may impact these regions' responses to food cues.

PMID: 33084195 [PubMed - as supplied by publisher]

Cerebral effects of GLP-1 receptor blockade before and after Roux-en-Y Gastric Bypass in obese women: a proof-of-concept resting-state fMRI study.

Thu, 10/22/2020 - 23:29

Cerebral effects of GLP-1 receptor blockade before and after Roux-en-Y Gastric Bypass in obese women: a proof-of-concept resting-state fMRI study.

Diabetes Obes Metab. 2020 Oct 20;:

Authors: van Duinkerken E, Bernardes G, van Bloemendaal L, Veltman DJ, Barkhof F, Mograbi DC, Gerdes VE, Deacon CF, Holst JJ, Drent ML, Diamant M, Ten Kulve J, IJzerman RG

Abstract
AIMS: Roux-en-Y Gastric Bypass (RYGB) is an intervention to achieve long term weight loss in obesity. RYGB provokes increases in glucagon-like peptide-1 (GLP-1) production and sensitivity, which have been implicated in RYGB-related changes in brain responses to food cues and food intake. The effects of these RYGB-related changes in GLP-1 on cerebral resting-state functioning are unknown.
MATERIALS AND METHODS: In 9 middle-aged obese females in the fasted state, we studied the effects of RYGB and GLP-1 on 5 a priori selected networks implicated in food- and reward-related processes as well as environment monitoring (default mode, right frontoparietal, basal ganglia, insula/anterior cingulate, and anterior cingulate/orbitofrontal networks).
RESULTS: Before surgery, GLP-1 receptor blockade (using exendin9-39), was associated with increased right caudate nucleus (basal ganglia network) and decreased right middle frontal (right frontoparietal network) connectivity compared to placebo. RYGB resulted in decreased right orbitofrontal (insula/anterior cingulate network) connectivity. In the default mode network, after surgery, GLP-1 receptor blockade had a larger effect on connectivity in this region than GLP-1 receptor blockade before RYGB (all PFWE <0.05). Results remained similar after correction for changes in body weight. Default mode and right frontoparietal network connectivity changes were related to changes in BMI and food scores after RYGB.
CONCLUSIONS: These findings suggest GLP-1 involvement in resting-state networks related to food and reward processes and monitoring of the internal and external environment, pointing to a potential role for GLP-1 induced changes in resting-state connectivity in RYGB-mediated weight loss and appetite control. This article is protected by copyright. All rights reserved.

PMID: 33084088 [PubMed - as supplied by publisher]

Psychological resilience is correlated with dynamic changes in functional connectivity within the default mode network during a cognitive task.

Thu, 10/22/2020 - 23:29

Psychological resilience is correlated with dynamic changes in functional connectivity within the default mode network during a cognitive task.

Sci Rep. 2020 Oct 20;10(1):17760

Authors: Miyagi T, Oishi N, Kobayashi K, Ueno T, Yoshimura S, Murai T, Fujiwara H

Abstract
Resilience is a dynamic process that enables organisms to cope with demanding environments. Resting-state functional MRI (fMRI) studies have demonstrated a negative correlation between resilience and functional connectivities (FCs) within the default mode network (DMN). Considering the on-demand recruitment process of resilience, dynamic changes in FCs during cognitive load increases may reflect essential aspects of resilience. We compared DMN FC changes in resting and task states and their association with resilience. Eighty-nine healthy volunteers completed the Connor-Davidson Resilience Scale (CD-RISC) and an fMRI with an auditory oddball task. The fMRI time series was divided into resting and task periods. We focused on FC changes between the latter half of the resting period and the former half of the task phase (switching), and between the former and latter half of the task phase (sustaining). FCs within the ventral DMN significantly increased during "switching" and decreased during "sustaining". For FCs between the retrosplenial/posterior cingulate and the parahippocampal cortex, increased FC during switching was negatively correlated with CD-RISC scores. In individuals with higher resilience, ventral DMN connectivities were more stable and homeostatic in the face of cognitive demand. The dynamic profile of DMN FCs may represent a novel biomarker of resilience.

PMID: 33082442 [PubMed - in process]

Prevalent and sex-biased breathing patterns modify functional connectivity MRI in young adults.

Thu, 10/22/2020 - 23:29

Prevalent and sex-biased breathing patterns modify functional connectivity MRI in young adults.

Nat Commun. 2020 10 20;11(1):5290

Authors: Lynch CJ, Silver BM, Dubin MJ, Martin A, Voss HU, Jones RM, Power JD

Abstract
Resting state functional connectivity magnetic resonance imaging (fMRI) is a tool for investigating human brain organization. Here we identify, visually and algorithmically, two prevalent influences on fMRI signals during 440 h of resting state scans in 440 healthy young adults, both caused by deviations from normal breathing which we term deep breaths and bursts. The two respiratory patterns have distinct influences on fMRI signals and signal covariance, distinct timescales, distinct cardiovascular correlates, and distinct tendencies to manifest by sex. Deep breaths are not sex-biased. Bursts, which are serial taperings of respiratory depth typically spanning minutes at a time, are more common in males. Bursts share features of chemoreflex-driven clinical breathing patterns that also occur primarily in males, with notable neurological, psychiatric, medical, and lifespan associations. These results identify common breathing patterns in healthy young adults with distinct influences on functional connectivity and an ability to differentially influence resting state fMRI studies.

PMID: 33082311 [PubMed - in process]

Alterations in Functional Connectomics Associated With Neurocognitive Changes Following Glioma Resection.

Wed, 10/21/2020 - 23:28

Alterations in Functional Connectomics Associated With Neurocognitive Changes Following Glioma Resection.

Neurosurgery. 2020 Oct 20;:

Authors: Noll KR, Chen HS, Wefel JS, Kumar VA, Hou P, Ferguson SD, Rao G, Johnson JM, Schomer DF, Suki D, Prabhu SS, Liu HL

Abstract
BACKGROUND: Decline in neurocognitive functioning (NCF) often occurs following brain tumor resection. Functional connectomics have shown how neurologic insults disrupt cerebral networks underlying NCF, though studies involving patients with brain tumors are lacking.
OBJECTIVE: To investigate the impact of brain tumor resection upon the connectome and relationships with NCF outcome in the early postoperative period.
METHODS: A total of 15 right-handed adults with left perisylvian glioma underwent resting-state functional magnetic resonance imaging (rs-fMRI) and neuropsychological assessment before and after awake tumor resection. Graph theoretical analysis was applied to rs-fMRI connectivity matrices to calculate network properties. Network properties and NCF measures were compared across the pre- to postoperative periods with matched pairs Wilcoxon signed-rank tests. Associations between pre- to postoperative change in network and NCF measures were determined with Spearman rank-order correlations (ρ).
RESULTS: A majority of the sample showed postoperative decline on 1 or more NCF measures. Significant postoperative NCF decline was found across measures of verbal memory, processing speed, executive functioning, receptive language, and a composite index. Regarding connectomic properties, betweenness centrality and assortativity were significantly smaller postoperatively, and reductions in these measures were associated with better NCF outcomes. Significant inverse associations (ρ = -.51 to -.78, all P < .05) were observed between change in language, executive functioning, and learning and memory, and alterations in segregation, centrality, and resilience network properties.
CONCLUSION: Decline in NCF was common shortly following resection of glioma involving eloquent brain regions, most frequently in verbal learning/memory and executive functioning. Better postoperative outcomes accompanied reductions in centrality and resilience connectomic measures.

PMID: 33080024 [PubMed - as supplied by publisher]

Dissimilarity of functional connectivity uncovers the influence of participant's motion in functional magnetic resonance imaging studies.

Wed, 10/21/2020 - 23:28

Dissimilarity of functional connectivity uncovers the influence of participant's motion in functional magnetic resonance imaging studies.

Hum Brain Mapp. 2020 Oct 20;:

Authors: Yang L, Wu B, Fan L, Huang S, Vigotsky AD, Baliki MN, Yan Z, Apkarian AV, Huang L

Abstract
Head motion is a major confounding factor impairing the quality of functional magnetic resonance imaging (fMRI) data. In particular, head motion can reduce analytical efficiency, and its effects are still present even after preprocessing. To examine the validity of motion removal and to evaluate the remaining effects of motion on the quality of the preprocessed fMRI data, a new metric of group quality control (QC), dissimilarity of functional connectivity, is introduced. Here, we investigate the association between head motion, represented by mean framewise displacement, and dissimilarity of functional connectivity by applying four preprocessing methods in two independent resting-state fMRI datasets: one consisting of healthy participants (N = 167) scanned in a 3T GE-Discovery 750 with longer TR (2.5 s), and the other of chronic back pain patients (N = 143) in a 3T Siemens Magnetom Prisma scanner with shorter TR (0.555 s). We found that dissimilarity of functional connectivity uncovers the influence of participant's motion, and this relationship is independent of population, scanner, and preprocessing method. The association between motion and dissimilarity of functional connectivity, and how the removal of high-motion participants affects this association, is a new strategy for group-level QC following preprocessing.

PMID: 33079467 [PubMed - as supplied by publisher]

15 Years MR-encephalography.

Wed, 10/21/2020 - 23:28

15 Years MR-encephalography.

MAGMA. 2020 Oct 20;:

Authors: Hennig J, Kiviniemi V, Riemenschneider B, Barghoorn A, Akin B, Wang F, LeVan P

Abstract
OBJECTIVE: This review article gives an account of the development of the MR-encephalography (MREG) method, which started as a mere 'Gedankenexperiment' in 2005 and gradually developed into a method for ultrafast measurement of physiological activities in the brain. After going through different approaches covering k-space with radial, rosette, and concentric shell trajectories we have settled on a stack-of-spiral trajectory, which allows full brain coverage with (nominal) 3 mm isotropic resolution in 100 ms. The very high acceleration factor is facilitated by the near-isotropic k-space coverage, which allows high acceleration in all three spatial dimensions.
METHODS: The methodological section covers the basic sequence design as well as recent advances in image reconstruction including the targeted reconstruction, which allows real-time feedback applications, and-most recently-the time-domain principal component reconstruction (tPCR), which applies a principal component analysis of the acquired time domain data as a sparsifying transformation to improve reconstruction speed as well as quality.
APPLICATIONS: Although the BOLD-response is rather slow, the high speed acquisition of MREG allows separation of BOLD-effects from cardiac and breathing related pulsatility. The increased sensitivity enables direct detection of the dynamic variability of resting state networks as well as localization of single interictal events in epilepsy patients. A separate and highly intriguing application is aimed at the investigation of the glymphatic system by assessment of the spatiotemporal patterns of cardiac and breathing related pulsatility.
DISCUSSION: MREG has been developed to push the speed limits of fMRI. Compared to multiband-EPI this allows considerably faster acquisition at the cost of reduced image quality and spatial resolution.

PMID: 33079327 [PubMed - as supplied by publisher]

Altered amplitude of low-frequency fluctuations and default mode network connectivity in high myopia: a resting-state fMRI study.

Wed, 10/21/2020 - 23:28

Altered amplitude of low-frequency fluctuations and default mode network connectivity in high myopia: a resting-state fMRI study.

Int J Ophthalmol. 2020;13(10):1629-1636

Authors: Zhang XW, Dai RP, Cheng GW, Zhang WH, Long Q

Abstract
AIM: To analyze changes in amplitude of low-frequency fluctuations (ALFFs) and default mode network (DMN) connectivity in the brain, using resting-state functional magnetic resonance imaging (rs-fMRI), in high myopia (HM) patients.
METHODS: Eleven patients with HM (HM group) and 15 age- and sex-matched non-HM controls (non-HM group) were recruited. ALFFs were calculated and compared between HM group and non-HM group. Independent component analysis (ICA) was conducted to identify DMN, and comparisons between DMNs of two groups were performed. Region-of-interest (ROI)-based analysis was performed to explore functional connectivity (FC) between DMN regions.
RESULTS: Significantly increased ALFFs in left inferior temporal gyrus (ITG), bilateral rectus gyrus (REC), bilateral middle temporal gyrus (MTG), left superior temporal gyrus (STG), and left angular gyrus (ANG) were detected in HM group compared with non-HM group (all P<0.01). HM group showed increased FC in the posterior cingulate gyrus (PCC)/precuneus (preCUN) and decreased FC in the left medial prefrontal cortex (mPFG) within DMN compared with non-HM group (all P<0.01). Compared with non-HM group, HM group showed higher FC between mPFG and bilateral middle frontal gyrus (MFG), ANG, and MTG (all P<0.01). In addition, HM patients showed higher FC between PCC/(preCUN) and the right cerebellum, superior frontal gyrus (SFG), left preCUN, superior frontal gyrus (SFG), and medial orbital of the superior frontal gyrus (ORB supmed; all P<0.01).
CONCLUSION: HM patients show different ALFFs and DMNs compared with non-HM subjects, which may imply the cognitive alterations related to HM.

PMID: 33078115 [PubMed]

Common and distinct patterns of intrinsic brain activity alterations in major depression and bipolar disorder: voxel-based meta-analysis.

Wed, 10/21/2020 - 23:28

Common and distinct patterns of intrinsic brain activity alterations in major depression and bipolar disorder: voxel-based meta-analysis.

Transl Psychiatry. 2020 Oct 19;10(1):353

Authors: Gong J, Wang J, Qiu S, Chen P, Luo Z, Wang J, Huang L, Wang Y

Abstract
Identification of intrinsic brain activity differences and similarities between major depression (MDD) and bipolar disorder (BD) is necessary. However, results have not yet yielded consistent conclusions. A meta-analysis of whole-brain resting-state functional MRI (rs-fMRI) studies that explored differences in the amplitude of low-frequency fluctuation (ALFF) between patients (including MDD and BD) and healthy controls (HCs) was conducted using seed-based d mapping software. Systematic literature search identified 50 studies comparing 1399 MDD patients and 1332 HCs, and 15 studies comparing 494 BD patients and 593 HCs. MDD patients displayed increased ALFF in the right superior frontal gyrus (SFG) (including the medial orbitofrontal cortex, medial prefrontal cortex [mPFC], anterior cingulate cortex [ACC]), bilateral insula extending into the striatum and left supramarginal gyrus and decreased ALFF in the bilateral cerebellum, bilateral precuneus, and left occipital cortex compared with HCs. BD showed increased ALFF in the bilateral inferior frontal gyrus, bilateral insula extending into the striatum, right SFG, and right superior temporal gyrus (STG) and decreased ALFF in the bilateral precuneus, left cerebellum (extending to the occipital cortex), left ACC, and left STG. In addition, MDD displayed increased ALFF in the left lingual gyrus, left ACC, bilateral precuneus/posterior cingulate gyrus, and left STG and decreased ALFF in the right insula, right mPFC, right fusiform gyrus, and bilateral striatum relative to BD patients. Conjunction analysis showed increased ALFF in the bilateral insula, mPFC, and decreased ALFF in the left cerebellum in both disorders. Our comprehensive meta-analysis suggests that MDD and BD show a common pattern of aberrant regional intrinsic brain activity which predominantly includes the insula, mPFC, and cerebellum, while the limbic system and occipital cortex may be associated with spatially distinct patterns of brain function, which provide useful insights for understanding the underlying pathophysiology of brain dysfunction in affective disorders, and developing more targeted and efficacious treatment and intervention strategies.

PMID: 33077728 [PubMed - in process]

Hippocampal functional connectivity in Alzheimer's disease: a resting state 7T fMRI study.

Wed, 10/21/2020 - 23:28

Hippocampal functional connectivity in Alzheimer's disease: a resting state 7T fMRI study.

Int Psychogeriatr. 2020 Oct 20;:1-2

Authors: Velayudhan L, Francis S, Dury R, Paul S, Bestwn S, Gowland P, Bhattacharyya S

PMID: 33076998 [PubMed - as supplied by publisher]

Brain Connectivity and Behavioral Changes in a Spaceflight Analog Environment with Elevated CO2.

Wed, 10/21/2020 - 17:27

Brain Connectivity and Behavioral Changes in a Spaceflight Analog Environment with Elevated CO2.

Neuroimage. 2020 Oct 16;:117450

Authors: McGregor HR, Lee JK, Mulder ER, De Dios YE, Beltran NE, Kofman IS, Bloomberg JJ, Mulavara AP, Seidler RD

Abstract
Astronauts are exposed to microgravity and elevated CO2 levels onboard the International Space Station. Little is known about how microgravity and elevated CO2 combine to affect the brain and sensorimotor performance during and after spaceflight. Here we examined changes in resting-state functional connectivity (FC) and sensorimotor behavior associated with a spaceflight analog environment. Participants underwent 30 days of strict 6o head-down tilt bed rest with elevated ambient CO2 (HDBR+CO2). Resting-state functional magnetic resonance imaging and sensorimotor assessments were collected 13 and 7 days prior to bed rest, on days 7 and 29 of bed rest, and 0, 5, 12, and 13 days following bed rest. We assessed the time course of FC changes from before, during, to after HDBR+CO2. We then compared the observed connectivity changes with those of a HDBR control group, which underwent HDBR in standard ambient air. Moreover, we assessed associations between post-HDBR+CO2 FC changes and alterations in sensorimotor performance. HDBR+CO2 was associated with significant changes in functional connectivity between vestibular, visual, somatosensory and motor brain areas. Several of these sensory and motor regions showed post-HDBR+CO2 FC changes that were significantly associated with alterations in sensorimotor performance. We propose that these FC changes reflect multisensory reweighting associated with adaptation to the HDBR+CO2 microgravity analog environment. This knowledge will further improve HDBR as a model of microgravity exposure and contribute to our knowledge of brain and performance changes during and after spaceflight.

PMID: 33075558 [PubMed - as supplied by publisher]