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Improving brain function of pediatric acute lymphoblastic leukemia patients after induction chemotherapy, a pilot self-contrast study by fractional amplitude of low-frequency fluctuation.

Tue, 05/21/2019 - 20:16
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Improving brain function of pediatric acute lymphoblastic leukemia patients after induction chemotherapy, a pilot self-contrast study by fractional amplitude of low-frequency fluctuation.

J Clin Neurosci. 2019 May 16;:

Authors: Zou D, Wen F, Zeng H, Mai H, Yuan X, Wang L, Li Y, Liu L, Liu S, Liu G

Abstract
Our previous study revealed altered resting-stated brain function in children with acute lymphoblastic leukemia (ALL) on new-onset stage. To investigate the effects after induction chemotherapy, a pilot self-contrast study was conducted to compare the difference in resting-stated brain function between pre- and post-induction chemotherapy of ALL. Fractional amplitude of low-frequency fluctuation (fALFF) was employed for fMRI data analysis. Clinical and resting state functional magnetic resonance imaging (RS-fMRI) data of 14 new-onset pediatric ALL patients were collected before and after 3 months of induction chemotherapy. Fourteen age- and gender-matched healthy controls (HCs) were recruited for comparison. Before induction chemotherapy, fALFF values of ALL patients decreased globally, especially in the default mode network (DMN), left frontal lobe, left occipital lobe, and bilateral postcentral gyri as compared to HCs. After induction chemotherapy, fALFF values of ALL patients decreased significantly in the bilateral cuneus, left lingual and calcarine gyri, and left mid frontal gyrus. Paired-sample t-tests and self-contrast analysis showed fALFF increased in the left precuneus, bilateral cuneus, left occipital lobe, bilateral frontal gyri, and bilateral temporal lobes, whereas fALFF in the bilateral precuneus decreased in the ALL patients after induction, which suggests potential side-effects of the treatment. The alteration of fALFF values suggested that resting brain function was impaired before induction chemotherapy and mostly recovered after treatment. This study suggested that fALFF is a reliable and feasible tool in detecting spontaneous brain activity to monitor early neurocognitive impairments in pediatric ALL to better understand the underlying neurobiological mechanisms of chemotherapy on the brain.

PMID: 31104963 [PubMed - as supplied by publisher]

Abnormal intrinsic brain functional network dynamics in unmedicated depressed bipolar II disorder.

Mon, 05/20/2019 - 23:13
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Abnormal intrinsic brain functional network dynamics in unmedicated depressed bipolar II disorder.

J Affect Disord. 2019 May 01;253:402-409

Authors: Wang J, Wang Y, Huang H, Jia Y, Zheng S, Zhong S, Huang L, Huang R

Abstract
BACKGROUND: Previous studies analyzed brain functional connectivity (FC) based on resting-state fMRI (RS-fMRI) data to reveal the neuropathology of bipolar disorder (BD) and suggested that their FC alterations are at widespread network-level. However, few studies have analyzed the dynamic functional network connectivity (dFNC) in BD. Thus, we aimed to reveal the dFNC properties of BD in this study.
METHODS: The RS-fMRI data were collected from 51 unmedicated depressed BD II patients and 50 healthy controls. We analyzed the dFNC properties by using an independent component analysis, sliding window correlation, k-means clustering, and graph theory methods.
RESULTS: The intrinsic brain FNC could be clustered into three configuration states, one with sparse connections between all functional networks (State 1), another with negative correlations between the salience network, cerebellum, basal ganglia and the sensory networks (State 2), and a third with negative correlations between the default mode network and the other functional networks (State 3). The BD patients had increased time in State 2, decreased time in State 3, and increased transition number between states. And the time spent in State 2 was positively correlated with the HDRS24 score in the BD patients. In addition, the BD patients had increased dynamic variance in the small-world properties of FNC.
LIMITATIONS: This study did not examine data from BD patients in other episodes and other BD types.
CONCLUSIONS: This study detected abnormal dFNC properties in BD, which indicated their FNC unstability and provided new insights into the neuropathology of their affective and cognitive deficits.

PMID: 31103805 [PubMed - as supplied by publisher]

The effects of psychiatric history and age on self-regulation of the default mode network.

Mon, 05/20/2019 - 23:13
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The effects of psychiatric history and age on self-regulation of the default mode network.

Neuroimage. 2019 May 16;:

Authors: Skouras S, Scharnowski F

Abstract
Real-time neurofeedback enables human subjects to learn to regulate their brain activity, effecting behavioral changes and improvements of psychiatric symptomatology. Neurofeedback up-regulation and down-regulation have been assumed to share common neural correlates. Neuropsychiatric pathology and aging incur suboptimal functioning of the default mode network. Despite the exponential increase in real-time neuroimaging studies, the effects of aging, pathology and the direction of regulation on neurofeedback performance remain largely unknown. Using real-time fMRI data shared through the Rockland Sample Real-Time Neurofeedback project (N = 136) and open-access analyses, we first modeled neurofeedback performance and learning in a group of subjects with psychiatric history (na = 74) and a healthy control group (nb = 62). Subsequently, we examined the relationship between up-regulation and down-regulation learning, the relationship between age and neurofeedback performance in each group and differences in neurofeedback performance between the two groups. For interpretative purposes, we also investigated functional connectomics prior to neurofeedback. Results show that in an initial session of default mode network neurofeedback with real-time fMRI, up-regulation and down-regulation learning scores are negatively correlated. This finding is related to resting state differences in the eigenvector centrality of the posterior cingulate cortex. Moreover, age correlates negatively with default mode network neurofeedback performance, only in absence of psychiatric history. Finally, adults with psychiatric history outperform healthy controls in default mode network up-regulation. Interestingly, the performance difference is related to no up-regulation learning in controls. This finding is supported by marginally higher default mode network centrality during resting state, in the presence of psychiatric history.

PMID: 31103786 [PubMed - as supplied by publisher]

Disruption and lateralization of cerebellar-cerebral functional networks in right temporal lobe epilepsy: A resting-state fMRI study.

Sun, 05/19/2019 - 23:09
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Disruption and lateralization of cerebellar-cerebral functional networks in right temporal lobe epilepsy: A resting-state fMRI study.

Epilepsy Behav. 2019 May 15;96:80-86

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

Abstract
Numerous studies have highlighted important roles for the cerebellum in cognition and movement, based on numerous fiber connections between the cerebrum and cerebellum. Abnormal cerebellar activity caused by epileptic discharges has been reported in previous studies, but researchers have not clearly determined whether aberrant cerebellar activity contributes to the disruption of the cerebellar-cerebral networks in right temporal lobe epilepsy (rTLE). Here, thirty patients with rTLE and 30 age- and sex-matched healthy controls (HCs) were recruited. All participants underwent the Attention Network Test (ANT) and resting-state functional magnetic resonance imaging (rs-fMRI) scanning. Cerebellar functional networks were extracted and analyzed by defining seeds in the cerebellum. A correlation analysis was performed between attentional performance and voxels that showed differences in functional connectivity (FC) in patients compared with HCs. Relative to HCs, patients exhibited significantly decreased FC in the dentate nucleus (DN) network (right DN with the left postcentral gyrus, left precentral gyrus, left cuneus, and left calcarine gyrus) and motor network (right cerebellar lobule V with the right putamen) and increased FC in the executive control network (right cerebellar crus I with the right inferior parietal lobule). Alerting, orienting, and executive control performances were impaired in patients with rTLE. Furthermore, the executive control effect was significantly correlated with aberrant FC strength between the right DN and the left precentral/postcentral gyrus. Our findings highlight that the disrupted cerebellar-cerebral functional network ipsilateral to the epileptogenic focus causes both impairments in and compensatory effects on attentional deficits in patients with rTLE. These findings contribute to our understanding of the cerebellar damage caused by epileptic discharges and the corresponding effect on attentional performance.

PMID: 31103016 [PubMed - as supplied by publisher]

Age attenuates noise and increases symmetry of head movements during sleep resting-state fMRI in healthy neonates, infants, and toddlers.

Sun, 05/19/2019 - 23:09
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Age attenuates noise and increases symmetry of head movements during sleep resting-state fMRI in healthy neonates, infants, and toddlers.

Infant Behav Dev. 2019 May 15;57:101317

Authors: Denisova K

Abstract
Newborns produce spontaneous movements during sleep that are functionally important for their future development. This nuance has been previously studied using animal models and more recently using movement data from sleep resting-state fMRI (rs-fMRI) scans. Age-related trajectory of statistical features of spontaneous movements of the head is under-examined. This study quantitatively mapped a developmental trajectory of spontaneous head movements during an rs-fMRI scan acquired during natural sleep in 91 datasets from healthy children from ∼birth to 3 years old, using the Open Science Infancy Research upcycling protocol. The youngest participants studied, 2-3 week-old neonates, showed increased noise-to-signal levels as well as lower symmetry features of their movements; noise-to-signal levels were attenuated and symmetry was increased in the older infants and toddlers (all Spearman's rank-order correlations, P < 0.05). Thus, statistical features of spontaneous head movements become more symmetrical and less noisy from birth to ∼3 years in children. Because spontaneous movements during sleep in early life may trigger new neuronal activity in the cortex, the key outstanding question for in vivo, non-invasive neuroimaging studies in young children is not "How can we correct head movement better?" but rather: How can we represent all important sources of neuronal activity that shape functional connections in the still-developing human central nervous system?

PMID: 31102945 [PubMed - as supplied by publisher]

Resting-state functional connectivity, cognition, and fatigue in response to cognitive exertion: a novel study in adolescents with chronic fatigue syndrome.

Sun, 05/19/2019 - 23:09
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Resting-state functional connectivity, cognition, and fatigue in response to cognitive exertion: a novel study in adolescents with chronic fatigue syndrome.

Brain Imaging Behav. 2019 May 17;:

Authors: Josev EK, Malpas CB, Seal ML, Scheinberg A, Lubitz L, Rowe K, Knight SJ

Abstract
Emerging evidence suggests that central nervous system dysfunction may underlie the core symptoms of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) in adults, such as cognitive disturbance, fatigue and post-exertional malaise. Research into brain dysfunction in the pediatric CFS/ME context, however, is severely lacking. It is unclear whether the adolescent CFS/ME brain functions differently compared with healthy peers, particularly in situations where significant mental effort is required. This study used resting-state functional MRI in a novel repeated-measures design to evaluate intrinsic connectivity, cognitive function, and subjective fatigue, before and after a period of cognitive exertion in 48 adolescents (25 CFS/ME, 23 healthy controls). Results revealed little evidence for a differential effect of cognitive exertion in CFS/ME compared with controls. Both groups demonstrated a similar rate of reduced intrinsic functional connectivity within the default mode network (DMN), reduced sustained attentional performance, slower processing speed, and increased subjective fatigue as a result of cognitive exertion. However, CFS/ME adolescents consistently displayed higher subjective fatigue, and controls outperformed the CFS/ME group overall on cognitive measures of processing speed, sustained attention and new learning. No brain-behavior relationships were observed between DMN connectivity, cognitive function, and fatigue over time. These findings suggest that effortful cognitive tasks may elicit similar levels of energy expenditure across all individuals in the form of reduced brain functioning and associated fatigue. However, CFS/ME may confer a lower starting threshold from which to access energy reserves and cognitive resources when cognitive effort is required.

PMID: 31102168 [PubMed - as supplied by publisher]

Dysregulation of resting-state functional connectivity in patients with Cushing's disease.

Sun, 05/19/2019 - 23:09
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Dysregulation of resting-state functional connectivity in patients with Cushing's disease.

Neuroradiology. 2019 May 17;:

Authors: Wang X, Zhou T, Wang P, Zhang L, Feng S, Meng X, Yu X, Zhang Y

Abstract
PURPOSE: To explore the anatomical distance-dependent functional connectivity patterns in patients with active phase of Cushing's disease (CD) and to evaluate the associations between hypercortisol exposure and regional normalized functional connectivity strengths (nFCSs).
METHODS: Based on the fMRI data in 32 CD patients and 32 healthy controls (HCs), we computed the nFCSs for each voxel in the brain and further divided them into long-range and short-range nFCSs. General linear models was used to investigate between-group differences in these nFCS metrics and the correlations between the nFCSs and clinical variables.
RESULTS: Compared with HC, CD patients showed dysregulation of the nFCSs mainly in the default mode network. They showed an overall higher nFCS in bilateral parahippocampal cortex mainly owing to the disruption of long-range nFCS and a relatively lower nFCS in bilateral posterior cingulate cortex (PCC), bilateral lateral parietal cortex (LP), and right prefrontal cortex (PFC). In addition, their long-range nFCS was lower in the bilateral anterior cingulate cortex, PCC, and LP; short-range nFCS was lower in the bilateral PFC. Notably, the positive correlation between the nFCSs in their right parahippocampal cortex and serum cortisol levels at 08:00 remained significant after taking the anatomical distance into consideration.
CONCLUSION: The discrepant functional connectivity patterns found in our study indicated a hypercortisol-associated, distance-dependent disruption of resting-state functional connectivity in patients with active CD. We provide novel insights into the impacts of hypercortisol exposure and the pathophysiologic mechanisms of CD, which may facilitate advances in CD intervention ultimately.

PMID: 31101946 [PubMed - as supplied by publisher]

fMRI biomarkers of social cognitive skills training in psychosis: Extrinsic and intrinsic functional connectivity.

Sat, 05/18/2019 - 20:07
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fMRI biomarkers of social cognitive skills training in psychosis: Extrinsic and intrinsic functional connectivity.

PLoS One. 2019;14(5):e0214303

Authors: Lee J, Jimenez AM, Horan WP, Green MF

Abstract
Social cognitive skills training interventions for psychotic disorders have shown improvement in social cognitive performance tasks, but little was known about brain-based biomarkers linked to treatment effects. In this pilot study, we examined whether social cognitive skills training could modulate extrinsic and intrinsic functional connectivity in psychosis using functional magnetic resonance imaging (fMRI). Twenty-six chronic outpatients with psychotic disorders were recruited from either a Social Cognitive Skills Training (SCST) or an activity- and time-matched control intervention. At baseline and the end of intervention (12 weeks), participants completed two social cognitive tasks: a Facial Affect Matching task and a Mental State Attribution Task, as well as resting-state fMRI (rs-fMRI). Extrinsic functional connectivity was assessed using psychophysiological interaction (PPI) with amygdala and temporo-parietal junction as a seed region for the Facial Affect Matching Task and the Mental State Attribution task, respectively. Intrinsic functional connectivity was assessed with independent component analysis on rs-fMRI, with a focus on the default mode network (DMN). During the Facial Affect Matching task, we observed stronger PPI connectivity in the SCST group after intervention (compared to baseline), but no treatment-related change in the Control group. Neither group showed treatment-related changes in PPI connectivity during the Mental State Attribution task. During rs-fMRI, we found treatment-related changes in the DMN in the SCST group, but not in Control group. This study found that social cognitive skills training modulated both extrinsic and intrinsic functional connectivity in individuals with psychotic disorders after a 12-week intervention. These findings suggest treatment-related changes in functional connectivity as a potential brain-based biomarker of social cognitive skills training.

PMID: 31100068 [PubMed - in process]

Methamphetamine acutely alters frontostriatal resting state functional connectivity in healthy young adults.

Sat, 05/18/2019 - 20:07
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Methamphetamine acutely alters frontostriatal resting state functional connectivity in healthy young adults.

Addict Biol. 2019 May 16;:e12775

Authors: Weafer J, Van Hedger K, Keedy SK, Nwaokolo N, de Wit H

Abstract
Chronic use of methamphetamine impairs frontostriatal structure and function, which may result in increased incentive-motivational responses to drug cues and decreased regulation of drug-seeking behavior. However, less is known regarding how the drug affects these circuits after acute administration. The current study examined the effects of a single dose of methamphetamine on resting state frontostriatal functional connectivity in healthy volunteers. Participants (n = 22, 12 female) completed two sessions in which they received methamphetamine (20 mg) and placebo before a resting state scan during functional magnetic resonance imaging. Participants also provided self-report measures of euphoria and stimulation at regular intervals. We conducted seed-based voxelwise functional connectivity analyses using three bilateral striatal seed regions: nucleus accumbens (NAcc), caudate, and putamen and compared connectivity following methamphetamine versus placebo administration. Additionally, we conducted correlational analyses to assess if drug-induced changes in functional connectivity were related to changes in subjective response. Methamphetamine increased NAcc functional connectivity with medial frontal regions (ie, orbitofrontal cortex, medial frontal gyrus, and superior frontal gyrus) and decreased NAcc functional connectivity with subgenual anterior cingulate cortex (ACC). Methamphetamine also increased functional connectivity between putamen and left inferior frontal gyrus (IFG), and individuals who displayed greater drug-induced increase in connectivity reported less euphoria and stimulation. These findings provide important information regarding the effects of methamphetamine on brain function in nonaddicted individuals. Further studies will reveal whether such effects contribute to the abuse potential of the drug and whether they are related to the frontostriatal impairments observed after chronic methamphetamine use.

PMID: 31099141 [PubMed - as supplied by publisher]

Intrinsic functional connectivity during continuous maintenance and suppression of emotion in bipolar disorder.

Sat, 05/18/2019 - 20:07
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Intrinsic functional connectivity during continuous maintenance and suppression of emotion in bipolar disorder.

Brain Imaging Behav. 2019 May 16;:

Authors: Anand A, Grandhi J, Karne H, Spielberg JM

Abstract
Resting-state connectivity studies, which examine unconstrained low frequency BOLD fluctuations, have reported inconsistent abnormalities in bipolar disorder (BP). In this study, we investigated intrinsic brain connectivity under the constraints of a Continuous Emotion Regulation Task (CERT) in BP patients in depressed (BPD) and manic (BPM) states, along with healthy control participants. Medication-free participants, with either a diagnosis of BP (BPD = 27, BPM = 30) or healthy controls (N = 33) were included. We collected 2 fMRI scans using the CERT paradigm, in which participants continuously watched negative pictures and either maintained emotions (MAINTAIN) or suppressed emotion using reappraisal techniques (SUPPRESS). Network-based statistic and graph theory analyses were examined for (i) the main effect of condition (within-group) and (ii) group and condition interactions. In healthy participants, MAINTAIN largely involved occipital and parietal cortices (p < .001), whereas SUPPRESS also recruited the frontal and cingulate cortices (p = .023). The interaction between group (BPD vs. BPM) and condition revealed a network involving the inferior frontal lobe which was stronger during MAINTAIN for BPD and during SUPPRESS for BPM (p = .037). Graph theory properties (i.e., clustering coefficient) for key nodes also evidenced significant group by condition interactions. We observed BP-related changes in network properties involved in normal and abnormal emotion regulation, which provide insights into the neural bases for affective disturbances in BP.

PMID: 31098939 [PubMed - as supplied by publisher]

Effects of sound therapy on resting-state functional brain networks in patients with tinnitus: A graph-theoretical-based study.

Fri, 05/17/2019 - 20:06
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Effects of sound therapy on resting-state functional brain networks in patients with tinnitus: A graph-theoretical-based study.

J Magn Reson Imaging. 2019 May 16;:

Authors: Han L, Yawen L, Hao W, Chunli L, Pengfei Z, Zhengyu Z, Zhaodi W, Zhenghan Y, Shusheng G, Zhenchang W

Abstract
BACKGROUND: Tinnitus is considered to be triggered by aberrant neural activity in the brain. Sound therapy is regarded as a reasonable management option for tinnitus treatment and has been applied in the clinical setting for decades.
HYPOTHESIS: We hypothesized that sound therapy, a commonly used tinnitus treatment method, would alter the functional connectivity (FC) of brain regions in tinnitus models.
STUDY TYPE: Longitudinal.
POPULATION: Resting-state functional MRI data were collected from 27 tinnitus patients before and after 12 weeks of sound therapy. Twenty-seven age- and sex-matched healthy controls were also longitudinally scanned at the 12-week timepoint.
FIELD STRENGTH: 3.0T MRI system and echo planar imaging (EPI) sequence, 3D brain volume imaging (BRAVO) sequence.
ASSESSMENT: Functional connectivity strength (FCS), a graph-theoretical-based analytic method, was applied to analyze the FC features in the whole brain.
STATISTICAL TESTS: Student's t-test and chi-square test were used for analyses between two groups. A two-way analysis of covariance (ANCOVA) followed by post-hoc analyses was performed to determine differences of FC.
RESULTS: The interaction effect between the two groups and two scans on FCS was observed in the bilateral thalami and left anterior cingulate cortex (ACC). The fitted FCS values in the bilateral thalami were significantly higher in tinnitus patients at baseline and decreased to a relatively normal range after sound therapy compared with healthy controls. Conversely, the fitted FCS values in the left ACC were within the normal range, but increased after treatment (1.08 ± 0.29, P < 0.02); however, there was no change in the control group. Importantly, significant correlations were observed between the FCS changes in the right thalamus (P = 0.028), the FC of the right thalamus-right inferior frontal gyrus (P = 0.015), and symptomatic improvement.
DATA CONCLUSION: Sound therapy may modulate the brain network by altering the gating function of the thalamus as well as enhancing the tinnitus-canceling system.
LEVEL OF EVIDENCE: 2 Technical Efficacy Stage: 4.

PMID: 31095830 [PubMed - as supplied by publisher]

3D-Deep Learning Based Automatic Diagnosis of Alzheimer's Disease with Joint MMSE Prediction Using Resting-State fMRI.

Fri, 05/17/2019 - 20:06
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3D-Deep Learning Based Automatic Diagnosis of Alzheimer's Disease with Joint MMSE Prediction Using Resting-State fMRI.

Neuroinformatics. 2019 May 16;:

Authors: Duc NT, Ryu S, Qureshi MNI, Choi M, Lee KH, Lee B

Abstract
We performed this research to 1) evaluate a novel deep learning method for the diagnosis of Alzheimer's disease (AD) and 2) jointly predict the Mini Mental State Examination (MMSE) scores of South Korean patients with AD. Using resting-state functional Magnetic Resonance Imaging (rs-fMRI) scans of 331 participants, we obtained functional 3-dimensional (3-D) independent component spatial maps for use as features in classification and regression tasks. A 3-D convolutional neural network (CNN) architecture was developed for the classification task. MMSE scores were predicted using: linear least square regression (LLSR), support vector regression, bagging-based ensemble regression, and tree regression with group independent component analysis (gICA) features. To improve MMSE regression performance, we applied feature optimization methods including least absolute shrinkage and selection operator and support vector machine-based recursive feature elimination (SVM-RFE). The mean balanced test accuracy was 85.27% for the classification of AD versus healthy controls. The medial visual, default mode, dorsal attention, executive, and auditory related networks were mainly associated with AD. The maximum clinical MMSE score prediction accuracy with the LLSR method applied on gICA combined with SVM-RFE features had the lowest root mean square error (3.27 ± 0.58) and the highest R2 value (0.63 ± 0.02). Classification of AD and healthy controls can be successfully achieved using only rs-fMRI and MMSE scores can be accurately predicted using functional independent component features. In the absence of trained clinicians, AD disease status and clinical MMSE scores can be jointly predicted using 3-D deep learning and regression learning approaches with rs-fMRI data.

PMID: 31093956 [PubMed - as supplied by publisher]

Differential effects of anesthetics on resting state functional connectivity in the mouse.

Fri, 05/17/2019 - 20:06
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Differential effects of anesthetics on resting state functional connectivity in the mouse.

J Cereb Blood Flow Metab. 2019 May 15;:271678X19847123

Authors: Xie H, Chung DY, Kura S, Sugimoto K, Aykan SA, Wu Y, Sakadžić S, Yaseen MA, Boas DA, Ayata C

Abstract
Blood oxygen level-dependent (BOLD) functional MRI (fMRI) is a standard approach to examine resting state functional connectivity (RSFC), but fMRI in animal models is challenging. Recently, functional optical intrinsic signal imaging-which relies on the same hemodynamic signal underlying BOLD fMRI-has been developed as a complementary approach to assess RSFC in mice. Since it is difficult to ensure that an animal is in a truly resting state while awake, RSFC measurements under anesthesia remain an important approach. Therefore, we systematically examined measures of RSFC using non-invasive, widefield optical intrinsic signal imaging under five different anesthetics in male C57BL/6J mice. We find excellent seed-based, global, and interhemispheric connectivity using tribromoethanol (Avertin) and ketamine-xylazine, comparable to results in the literature including awake animals. Urethane anesthesia yielded intermediate results, while chloral hydrate and isoflurane were both associated with poor RSFC. Furthermore, we found a correspondence between the strength of RSFC and the power of low-frequency hemodynamic fluctuations. In conclusion, Avertin and ketamine-xylazine provide robust and reproducible measures of RSFC in mice, whereas chloral hydrate and isoflurane do not.

PMID: 31092086 [PubMed - as supplied by publisher]

Downward cross-modal plasticity in single-sided deafness.

Thu, 05/16/2019 - 20:06
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Downward cross-modal plasticity in single-sided deafness.

Neuroimage. 2019 May 12;:

Authors: Qiao Y, Li X, Shen H, Zhang X, Sun Y, Hao W, Guo B, Ni D, Gao Z, Guo H, Shang Y

Abstract
The auditory cortex has been shown to participate in visual processing in individuals with complete auditory deprivation. However, it remains unclear whether partial hearing deprivation like single-sided deafness (SSD) leads to similar cross-modal plasticity. To investigate this, we enrolled individuals with long-term SSD, into functional MRI scans under resting-state and a visuo-spatial working memory task. Contrary to previous findings in bilateral deafness, our study revealed decreased activation in the auditory cortex in both left (LSSD) and right (RSSD) single-sided deafness compared to normal hearing controls, with statistical significance in RSSD. The degree of involvement was correlated with residual hearing ability in RSSD. These observations suggest that SSD can lead to a downward cross-modal plasticity: the more hearing ability lost, the fewer brain resources in the auditory cortex can be applied to visual tasks. In addition, the fronto-parietal cortex was observed to be less activated during the visual task in RSSD while the resting-state fMRI revealed increased functional connectivity between the fronto-parietal cortex and the auditory cortex, suggesting fronto-parietal resources may be recruited less by vision but more by hearing. The LSSD showed a similar alteration trend with RSSD, but without statistical significance. Together these findings may indicate that when hearing is partially deprived in SSD, there may be redistribution for brain resources between hearing and vision, and vision tends to allocate less resources. Our findings in this pilot study of unilateral auditory-deprived individuals enrich the understanding of cross-modal plasticity in the brain.

PMID: 31091475 [PubMed - as supplied by publisher]

Altered brain network centrality in patients with trigeminal neuralgia: a resting-state fMRI study.

Thu, 05/16/2019 - 20:06
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Altered brain network centrality in patients with trigeminal neuralgia: a resting-state fMRI study.

Acta Radiol. 2019 May 14;:284185119847678

Authors: Zhu PW, Chen Y, Gong YX, Jiang N, Liu WF, Su T, Ye L, Min YL, Yuan Q, He LC, Shao Y

Abstract
BACKGROUND: Neuroimaging studies revealed that trigeminal neuralgia was related to alternations in brain anatomical function and regional function. However, the functional characteristics of network organization in the whole brain is unknown.
PURPOSE: The aim of the present study was to analyze potential functional network brain-activity changes and their relationships with clinical features in patients with trigeminal neuralgia via the voxel-wise degree centrality method.
MATERIAL AND METHODS: This study involved a total of 28 trigeminal neuralgia patients (12 men, 16 women) and 28 healthy controls matched in sex, age, and education. Spontaneous brain activity was evaluated by degree centrality. Correlation analysis was used to examine the correlations between behavioral performance and average degree centrality values in several brain regions.
RESULTS: Compared with healthy controls, trigeminal neuralgia patients had significantly higher degree centrality values in the right lingual gyrus, right postcentral gyrus, left paracentral lobule, and bilateral inferior cerebellum. Receiver operative characteristic curve analysis of each brain region confirmed excellent accuracy of the areas under the curve. There was a positive correlation between the mean degree centrality value of the right postcentral gyrus and VAS score (r = 0.885, P < 0.001).
CONCLUSIONS: Trigeminal neuralgia causes abnormal brain network activity in multiple brain regions, which may be related to underlying disease mechanisms.

PMID: 31088124 [PubMed - as supplied by publisher]

Neuroimaging signatures of brain plasticity in adults with prenatal exposure to polychlorinated biphenyls: Altered functional connectivity on functional MRI.

Thu, 05/16/2019 - 20:06
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Neuroimaging signatures of brain plasticity in adults with prenatal exposure to polychlorinated biphenyls: Altered functional connectivity on functional MRI.

Environ Pollut. 2019 Apr 23;250:960-968

Authors: Chu CP, Wu SW, Huang YJ, Chiang MC, Hsieh ST, Guo YL

Abstract
Prenatal exposure to polychlorinated biphenyls (PCBs), persistent organic pollutants in food chains and environment, exerts negative effects on children's cognitive function. To study the long-term effects, we examined cognitive functions in the male children of women with substantial PCB exposure in Taiwan during 1978-1979 and investigated neural basis of cognitive function changes through structural magnetic resonance imaging (MRI) and functional MRI (fMRI), which included resting-state and task-activated fMRI with two paradigms: a 2-back task and a picture rotation task. Ten men aged 30.0 ± 3.7 years with prenatal exposure to PCBs and 11 unexposed controls aged 28.1 ± 3.1 years participated. Both groups had similar cognitive phenotypes and behavioral results. Structural MRI analysis results showed that the PCB group had increased cortical thickness over the right inferior parietal lobule. In the resting-state study, the PCB group showed alterations in the default mode network. During the tasks, the PCB group showed decreased task-induced deactivation signals in cognition-associated brain areas during the 2-back task but enhanced deactivations during the picture rotation task. This study demonstrated altered structural MRI as well as resting and task-related fMRI in men with prenatal PCB exposure, suggesting altered brain plasticity and compensatory neuropsychological performance.

PMID: 31085483 [PubMed - as supplied by publisher]

Functional brain connectivity abnormalities and cognitive deficits in neuromyelitis optica spectrum disorder.

Tue, 05/14/2019 - 23:04
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Functional brain connectivity abnormalities and cognitive deficits in neuromyelitis optica spectrum disorder.

Mult Scler. 2019 May 13;:1352458519845109

Authors: Savoldi F, Rocca MA, Valsasina P, Riccitelli GC, Mesaros S, Drulovic J, Radaelli M, Filippi M

Abstract
BACKGROUND: Functional magnetic resonance imaging (fMRI) correlates of cognitive deficits have not been thoroughly studied in patients with neuromyelitis optica spectrum disorders (NMOSDs).
OBJECTIVE: To investigate resting state (RS) functional connectivity (FC) abnormalities within the main cognitive networks in NMOSD patients and their correlation with cognitive performance.
METHODS: We acquired RS fMRI from 25 NMOSD patients and 30 healthy controls (HC). Patients underwent an extensive neuropsychological evaluation. Between-group RS FC comparisons and correlations with cognitive performance were assessed on the main cognitive RS networks identified by independent component analysis.
RESULTS: NMOSD patients showed higher RS FC versus HC in the precuneus of the default mode network (DMN) and right working memory network (WMN), as well as in several frontoparietal regions of the salience network (SN) and bilateral WMNs. Reduced frontal RS FC in NMOSD versus HC was detected in the left WMN. Increased RS FC in the DMN and right WMN was correlated with better cognitive performance, while decreased RS FC in the left WMN was associated with worse cognitive performance.
CONCLUSION: Cognitive-network reorganization occurs in NMOSD. Clinico-imaging correlations suggest an adaptive role of increased RS FC. Conversely, reduced RS FC seems to be a maladaptive mechanism associated with a worse cognitive performance.

PMID: 31079538 [PubMed - as supplied by publisher]

A pilot study of combined endurance and resistance exercise rehabilitation for verbal memory and functional connectivity improvement in epilepsy.

Tue, 05/14/2019 - 02:03
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A pilot study of combined endurance and resistance exercise rehabilitation for verbal memory and functional connectivity improvement in epilepsy.

Epilepsy Behav. 2019 May 08;96:44-56

Authors: Allendorfer JB, Brokamp GA, Nenert R, Szaflarski JP, Morgan CJ, Tuggle SC, Ver Hoef L, Martin RC, Szaflarski BA, Kaur M, Lahti AC, Bamman MM

Abstract
Memory impairment is common in persons with epilepsy (PWE), and exercise may be a strategy for its improvement. In this pilot study, we hypothesized that exercise rehabilitation would improve physical fitness and verbal memory and induce changes in brain networks involved in memory processes. We examined the effects of combined endurance and resistance exercise rehabilitation on memory and resting state functional connectivity (rsFC). Participants were randomized to exercise (PWE-E) or control (PWE-noE). The exercise intervention consisted of 18 supervised sessions on nonconsecutive days over 6 weeks. Before and after the intervention period, both groups completed self-report assessments (Short Form-36 (SF-36), Baecke Questionnaire (BQ) of habitual physical activity, and Profile of Mood States (POMS)), cognitive testing (California Verbal Learning Test-II (CVLT-II)), and magnetic resonance imaging (MRI); PWE-E also completed exercise performance tests. After completing the study, PWE-noE were offered cross-over to the exercise arm. There were no differences in baseline demographic, clinical, or assessment variables between 8 PWE-noE and 9 PWE-E. Persons with epilepsy that participated in exercise intervention increased maximum voluntary strength (all strength tests p < 0.05) and exhibited nonsignificant improvement in cardiorespiratory fitness (p = 0.15). Groups did not show significant changes in quality of life (QOL) or habitual physical activity between visits. However, there was an effect of visit on POMS total mood disturbance (TMD) measure showing improvement from baseline to visit 2 (p = 0.023). There were significant group by visit interactions on CVLT-II learning score (p = 0.044) and total recognition discriminability (d') (p = 0.007). Persons with epilepsy that participated in exercise intervention had significant reductions in paracingulate rsFC with the anterior cingulate and increases in rsFC for the cerebellum, thalamus, posterior cingulate cortex (PCC), and left and right inferior parietal lobule (IPL) (corrected p < 0.05). Change in CVLT-II learning score was associated with rsFC changes for the paracingulate cortex (rS = -0.67; p = 0.0033), left IPL (rS = 0.70; p = 0.0019), and right IPL (rS = 0.71; p = 0.0015) while change in d' was associated with change in cerebellum rsFC to angular/middle occipital gyrus (rS = 0.68; p = 0.0025). Our conclusion is that exercise rehabilitation may facilitate verbal memory improvement and brain network functional connectivity changes in PWE and that improved memory performance is associated with changes in rsFC. A larger randomized controlled trial of exercise rehabilitation for cognitive improvement in PWE is warranted.

PMID: 31078935 [PubMed - as supplied by publisher]

A comparison of resting state functional magnetic resonance imaging to invasive electrocortical stimulation for sensorimotor mapping in pediatric patients.

Sun, 05/12/2019 - 20:03
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A comparison of resting state functional magnetic resonance imaging to invasive electrocortical stimulation for sensorimotor mapping in pediatric patients.

Neuroimage Clin. 2019 May 04;23:101850

Authors: Roland JL, Hacker CD, Snyder AZ, Shimony JS, Zempel JM, Limbrick DD, Smyth MD, Leuthardt EC

Abstract
Localizing neurologic function within the brain remains a significant challenge in clinical neurosurgery. Invasive mapping with direct electrocortical stimulation currently is the clinical gold standard but is impractical in young or cognitively delayed patients who are unable to reliably perform tasks. Resting state functional magnetic resonance imaging non-invasively identifies resting state networks without the need for task performance, hence, is well suited to pediatric patients. We compared sensorimotor network localization by resting state fMRI to cortical stimulation sensory and motor mapping in 16 pediatric patients aged 3.1 to 18.6 years. All had medically refractory epilepsy that required invasive electrographic monitoring and stimulation mapping. The resting state fMRI data were analyzed using a previously trained machine learning classifier that has previously been evaluated in adults. We report comparable functional localization by resting state fMRI compared to stimulation mapping. These results provide strong evidence for the utility of resting state functional imaging in the localization of sensorimotor cortex across a wide range of pediatric patients.

PMID: 31077983 [PubMed - as supplied by publisher]

Modeling the acute pharmacological response to selective serotonin reuptake inhibitors in human brain using simultaneous PET/MR imaging.

Sun, 05/12/2019 - 20:03
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Modeling the acute pharmacological response to selective serotonin reuptake inhibitors in human brain using simultaneous PET/MR imaging.

Eur Neuropsychopharmacol. 2019 May 07;:

Authors: Gryglewski G, Klöbl M, Berroterán-Infante N, Rischka L, Balber T, Vanicek T, Pichler V, Kautzky A, Klebermass EM, Reed MB, Vraka C, Hienert M, James GM, Silberbauer L, Godbersen GM, Unterholzner J, Michenthaler P, Hartenbach M, Winkler-Pjrek E, Wadsak W, Mitterhauser M, Hahn A, Hacker M, Kasper S, Lanzenberger R

Abstract
Pharmacological imaging of the effects of selective serotonin reuptake inhibitors (SSRI) may aid the clarification of their mechanism of action and influence treatment of highly prevalent neuropsychiatric conditions if the detected effects could be related to patient outcomes. In a randomized double-blind design, 38 healthy participants received a constant infusion of 8 mg citalopram or saline during either their first or second of two PET/MR scans. Resting-state functional MRI (fMRI) was acquired simultaneously with PET data on the binding of serotonin transporters (5-HTT) using [11C]DASB. Three different approaches for modeling of pharmacological fMRI response were tested separately. These relied on the use of regressors corresponding to (1) the drug infusion paradigm, (2) time courses of citalopram plasma concentrations and (3) changes in 5-HTT binding measured in each individual, respectively. Furthermore, the replication of results of a widely used model-free analysis method was attempted which assesses the deviation of signal in discrete time bins of fMRI data acquired after start of drug infusion. Following drug challenge, average 5-HTT occupancy was 69±7% and peak citalopram plasma levels were 111.8 ± 21.1 ng/ml. None of the applied methods could detect significant differences in the pharmacological response between SSRI and placebo scans. The failed replication of SSRI effects reported in the literature despite a threefold larger sample size highlights the importance of appropriate correction for family-wise error in order to avoid spurious results in pharmacological imaging. This calls for the development of analysis methods which take regional specialization and the dynamics of brain activity into account.

PMID: 31076187 [PubMed - as supplied by publisher]