Abnormal cerebellar functional MRI connectivity in patients with paediatric multiple sclerosis

Objectives: We investigated resting state functional connectivity (RSFC) of the cerebellar dentate nuclei in paediatric MS patients and its correlations with clinical, neuropsychological and structural MRI measures. Methods: RSFC analysis was performed using a seed-region correlation approach and SPM8 from 48 paediatric MS patients and 27 matched healthy controls. Results: In both groups, dentate nuclei RSFC was significantly correlated with RSFC of several cerebellar and extra-cerebellar brain regions. Compared with healthy controls, paediatric MS patients had reduced RSFC between the right dentate nuclei and the bilateral caudate nuclei and left thalamus as well as increased RSFC between the right dentate nuclei and the left precentral and postcentral gyri. Cognitively impaired patients showed a reduced RSFC between the dentate nuclei and bilateral regions located in the parietal, frontal and temporal lobes. Decreased RSFC was correlated with longer disease duration and higher T2 lesion volumes, whereas increased RSFC correlated with shorter disease duration, lower T2 lesion volume and a better motor performance. Conclusions: Modifications of cerebellar RSFC occur in paediatric MS and are influenced by the duration of the disease and brain focal lesions. Decreased RSFC may reflect early maladaptive plasticity contributing to cognitive impairment.

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Widespread Cortical Thickness Reductions Following Non-medical Use of Ketamine: a Structural MRI Study of Individuals with Ketamine Dependence

10.1101/2021.02.21.21252178 ◽

2021 ◽

Author(s):

Jinsong Tang ◽

Qiuxia Wu ◽

Chang Qi ◽

An Xie ◽

Jianbin Liu ◽

...

Keyword(s):

Cortical Thickness ◽

Structural Mri ◽

Brain Regions ◽

Analysis Of Covariance ◽

P Value ◽

Healthy Controls ◽

Brain Images ◽

Dorsolateral Prefrontal ◽

The Right ◽

Mri Study

AbstractBackgroundA version of ketamine, called Esketamine has been approved for treatment-resistant depression (TRD). Ketamine (“K powder”), a “dissociative” anesthetic agent, however, has been used non-medically alone or with other illicit substances. Our previous studies showed a link between non-medical ketamine use and brain structural and functional alterations. We found dorsal prefrontal gray matter reduction in chronic ketamine users. It is unknown, however, whether these observations might parallel findings of cortical thickness alterations. This study aimed at exploring cortical thickness abnormalities following non-medical, long-term use of ketamine.MethodsStructural brain images were acquired for 95 patients with ketamine dependence, and 169 drug-free healthy controls. FreeSurfer software was used to measure cortical thickness for 68 brain regions. Cortical thickness was compared between the two groups using analysis of covariance (ANCOVA) with covariates of age, gender, educational level, smoking, drinking, and whole brain mean cortical thickness. Results were considered significant if the Bonferroni corrected P-value < 0.01.ResultsCompared to healthy controls, patients with ketamine dependence have widespread decreased cortical thickness, with the most extensive reductions in the frontal (including the dorsolateral prefrontal cortex, DLPFC) and parietal (including the precuneus) lobes. Increased cortical thickness was not observed in ketamine users relative to comparison subjects. Estimated total lifetime ketamine consumption is correlated with the right inferior parietal and the right rostral middle frontal cortical thickness reductions.ConclusionsThis study provides first evidence that, compared with healthy controls, chronic ketamine users had cortical thickness reductions.

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Aberrant Resting-State Functional Connectivity of the Dorsal Attention Network in Tinnitus

Neural Plasticity ◽

10.1155/2021/2804533 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

Haimeng Hu ◽

Yining Lyu ◽

Shihong Li ◽

Zheng Yuan ◽

Chuntao Ye ◽

...

Keyword(s):

Functional Connectivity ◽

Brain Regions ◽

Anterior Cingulate ◽

Healthy Controls ◽

Resting State Functional Connectivity ◽

Attention Network ◽

Superior Frontal Gyrus ◽

Functional Connections ◽

Dorsal Attention Network ◽

The Right

Previous functional magnetic resonance imaging (fMRI) analyses have shown that the dorsal attention network (DAN) is involved in the pathophysiological changes of tinnitus, but few relevant studies have been conducted, and the conclusions to date are not uniform. The purpose of this research was to test whether there is a change in intrinsic functional connectivity (FC) patterns between the DAN and other brain regions in tinnitus patients. Thirty-one patients with persistent tinnitus and thirty-three healthy controls were enrolled in this study. A group independent component analysis (ICA), degree centrality (DC) analysis, and seed-based FC analysis were conducted. In the group ICA, the tinnitus patients showed increased connectivity in the left superior parietal gyrus in the DAN compared to the healthy controls. Compared with the healthy controls, the tinnitus patients showed increased DC in the left inferior parietal gyrus and decreased DC in the left precuneus within the DAN. The clusters within the DAN with significant differences in the ICA or DC analysis between the tinnitus patients and the healthy controls were selected as regions of interest (ROIs) for seeds. The tinnitus patients exhibited significantly increased FC from the left superior parietal gyrus to several brain regions, including the left inferior parietal gyrus, the left superior marginal gyrus, and the right superior frontal gyrus, and decreased FC to the right anterior cingulate cortex. The tinnitus patients exhibited decreased FC from the left precuneus to the left inferior occipital gyrus, left calcarine cortex, and left superior frontal gyrus compared with the healthy controls. The findings of this study show that compared with healthy controls, tinnitus patients have altered functional connections not only within the DAN but also between the DAN and other brain regions. These results suggest that it may be possible to improve the disturbance and influence of tinnitus by regulating the DAN.

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Effects of amnesia on processing in the hippocampus and default mode network during a naturalistic memory task: a case study

10.31234/osf.io/e9n8c ◽

2018 ◽

Author(s):

Christiane Oedekoven ◽

James L. Keidel ◽

Stuart Anderson ◽

Angus Nisbet ◽

Chris Bird

Keyword(s):

Functional Connectivity ◽

Episodic Memory ◽

Memory Performance ◽

Memory Task ◽

Structural Mri ◽

Brain Regions ◽

Left Hippocampus ◽

Cortical Regions ◽

The Right ◽

Encoding And Retrieval

Despite their severely impaired episodic memory, individuals with amnesia are able to comprehend ongoing events. Online representations of a current event are thought to be supported by a network of regions centred on the posterior midline cortex (PMC). By contrast, episodic memory is widely believed to be supported by interactions between the hippocampus and these cortical regions. In this MRI study, we investigated the encoding and retrieval of lifelike events (video clips) in a patient with severe amnesia likely resulting from a stroke to the right thalamus, and a group of 20 age-matched controls. Structural MRI revealed grey matter reductions in left hippocampus and left thalamus in comparison to controls. We first characterised the regions activated in the controls while they watched and retrieved the videos. There were no differences in activation between the patient and controls in any of the regions. We then identified a widespread network of brain regions, including the hippocampus, that were functionally connected with the PMC in controls. However, in the patient there was a specific reduction in functional connectivity between the PMC and a region of left hippocampus when both watching and attempting to retrieve the videos. A follow up analysis revealed that in controls the functional connectivity between these regions when watching the videos was correlated with memory performance. Taken together, these findings support the view that the interactions between the PMC and the hippocampus enable the encoding and retrieval of multimodal representations of the contents of an event.

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Modulation of hippocampal brain networks produces changes in episodic simulation and divergent thinking

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2003535117 ◽

2020 ◽

Vol 117 (23) ◽

pp. 12729-12740 ◽

Cited By ~ 2

Author(s):

Preston P. Thakral ◽

Kevin P. Madore ◽

Sarah E. Kalinowski ◽

Daniel L. Schacter

Keyword(s):

Divergent Thinking ◽

Brain Networks ◽

Brain Regions ◽

Angular Gyrus ◽

Seed Region ◽

Core Network ◽

Control Task ◽

Resting State Functional Connectivity ◽

Target Region ◽

Episodic Simulation

Prior functional magnetic resonance imaging (fMRI) studies indicate that a core network of brain regions, including the hippocampus, is jointly recruited during episodic memory, episodic simulation, and divergent creative thinking. Because fMRI data are correlational, it is unknown whether activity increases in the hippocampus, and the core network more broadly, play a causal role in episodic simulation and divergent thinking. Here we employed fMRI-guided transcranial magnetic stimulation (TMS) to assess whether temporary disruption of hippocampal brain networks impairs both episodic simulation and divergent thinking. For each of two TMS sessions, continuous θ-burst stimulation (cTBS) was applied to either a control site (vertex) or to a left angular gyrus target region. The target region was identified on the basis of a participant-specific resting-state functional connectivity analysis with a hippocampal seed region previously associated with memory, simulation, and divergent thinking. Following cTBS, participants underwent fMRI and performed a simulation, divergent thinking, and nonepisodic control task. cTBS to the target region reduced the number of episodic details produced for the simulation task and reduced idea production on divergent thinking. Performance in the control task did not statistically differ as a function of cTBS site. fMRI analyses revealed a selective and simultaneous reduction in hippocampal activity during episodic simulation and divergent thinking following cTBS to the angular gyrus versus vertex but not during the nonepisodic control task. Our findings provide evidence that hippocampal-targeted TMS can specifically modulate episodic simulation and divergent thinking, and suggest that the hippocampus is critical for these cognitive functions.

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

Acta Radiologica ◽

10.1177/0284185119847678 ◽

2019 ◽

Vol 61 (1) ◽

pp. 67-75 ◽

Cited By ~ 2

Author(s):

Pei-Wen Zhu ◽

You Chen ◽

Ying-Xin Gong ◽

Nan Jiang ◽

Wen-Feng Liu ◽

...

Keyword(s):

Trigeminal Neuralgia ◽

Brain Activity ◽

Characteristic Curve ◽

Brain Regions ◽

Brain Network ◽

Network Activity ◽

Degree Centrality ◽

Healthy Controls ◽

Postcentral Gyrus ◽

The Right

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.

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VTA-insula Connectivity and Avolition in Subjects with Schizophrenia

European Psychiatry ◽

10.1016/j.eurpsy.2017.01.039 ◽

2017 ◽

Vol 41 (S1) ◽

pp. S57-S57

Author(s):

A. Mucci ◽

G.M. Giordano ◽

M. Stanziano ◽

M. Papa ◽

S. Galderisi

Keyword(s):

Negative Symptoms ◽

Occipital Cortex ◽

Advisory Board ◽

Strong Impact ◽

Seed Region ◽

Resting State Functional Connectivity ◽

Potential Conflict ◽

Deficit Syndrome ◽

Dopamine Circuits ◽

The Right

IntroductionAvolition represents an important domain of negative symptoms in schizophrenia with a strong impact on functional outcome. Primary and persistent avolition is refractory to available pharmacological and psychological treatments. A better understanding of its pathophysiological mechanisms is fundamental to promote development of new treatments. Recent models of avolition converge on dopaminergic circuits involved in motivation and its translation in goal-directed behavior. Deficits in task-related activation or connectivity within mesolimbic and mesocortical dopamine circuits were reported in schizophrenia but the relationship with avolition was not fully established.AimsThe present study aimed to investigate resting-state functional connectivity (RS-FC) within the motivation circuits in schizophrenia patients and its relationships with primary and persistent avolition.MethodsRS-FC, using VTA as a seed region, was investigated in 22 healthy controls (HC) and in 26 schizophrenia patients (SCZ) divided in high (HA) and low avolition (LA) subgroups. Avolition was assessed using the Schedule for the Deficit Syndrome.ResultsHA, in comparison to LA and HC, showed significantly reduced RS-FC with the right ventrolateral prefrontal cortex (R-VLPFC), right insula (R-INS) and right lateral occipital cortex (R-LOC). The RS-FC of these regions was negatively correlated to avolition.ConclusionsOur findings demonstrate that avolition in schizophrenia is linked to dysconnection of VTA from key cortical regions involved in retrieval of outcome values of instrumental actions to motivate behavior.Disclosure of interestAM received honoraria or advisory board/consulting fees from the following companies: Janssen Pharmaceuticals, Otsuka, Pfizer and Pierre Fabre. SG received honoraria or advisory board/consulting fees from the following companies: Lundbeck, Janssen Pharmaceuticals, Hoffman-La Roche, Angelini-Acraf, Otsuka, Pierre Fabre and Gedeon-Richter. All other Authors declare no potential conflict of interest.

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Altered Intra- and Interregional Synchronization in Resting-State Cerebral Networks Associated with Chronic Tinnitus

Neural Plasticity ◽

10.1155/2015/475382 ◽

2015 ◽

Vol 2015 ◽

pp. 1-11 ◽

Cited By ~ 20

Author(s):

Yu-Chen Chen ◽

Jian Zhang ◽

Xiao-Wei Li ◽

Wenqing Xia ◽

Xu Feng ◽

...

Keyword(s):

Functional Connectivity ◽

Resting State ◽

Brain Activity ◽

Inferior Frontal Gyrus ◽

Resting State Fmri ◽

Brain Regions ◽

Chronic Tinnitus ◽

Healthy Controls ◽

Tinnitus Distress ◽

The Right

Objective. Subjective tinnitus is hypothesized to arise from aberrant neural activity; however, its neural bases are poorly understood. To identify aberrant neural networks involved in chronic tinnitus, we compared the resting-state functional magnetic resonance imaging (fMRI) patterns of tinnitus patients and healthy controls.Materials and Methods. Resting-state fMRI measurements were obtained from a group of chronic tinnitus patients (n=29) with normal hearing and well-matched healthy controls (n=30). Regional homogeneity (ReHo) analysis and functional connectivity analysis were used to identify abnormal brain activity; these abnormalities were compared to tinnitus distress.Results. Relative to healthy controls, tinnitus patients had significant greater ReHo values in several brain regions including the bilateral anterior insula (AI), left inferior frontal gyrus, and right supramarginal gyrus. Furthermore, the left AI showed enhanced functional connectivity with the left middle frontal gyrus (MFG), while the right AI had enhanced functional connectivity with the right MFG; these measures were positively correlated with Tinnitus Handicap Questionnaires (r=0.459,P=0.012andr=0.479,P=0.009, resp.).Conclusions. Chronic tinnitus patients showed abnormal intra- and interregional synchronization in several resting-state cerebral networks; these abnormalities were correlated with clinical tinnitus distress. These results suggest that tinnitus distress is exacerbated by attention networks that focus on internally generated phantom sounds.

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Building memories on prior knowledge: behavioral and fMRI evidence of impairment in early Alzheimer’s Disease

10.1101/2020.06.17.154104 ◽

2020 ◽

Author(s):

Pierre-Yves Jonin ◽

Quentin Duché ◽

Elise Bannier ◽

Isabelle Corouge ◽

Jean-Christophe Ferré ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Prior Knowledge ◽

Associative Memory ◽

Brain Regions ◽

List Type ◽

Healthy Controls ◽

Experimental Knowledge ◽

Healthy Elderly ◽

The Right

AbstractImpaired memory is a hallmark of prodromal Alzheimer’s Disease (AD). Prior knowledge associated with the memoranda has proved to have a powerful effect on memory in healthy subjects. Yet, barely nothing is known about its effect in early AD. We used functional MRI to ask whether prior knowledge enhanced memory encoding in early AD and whether the nature of prior knowledge mattered. Early AD patients and healthy controls underwent a task-based fMRI experiment, being scanned while learning face-scene associations. Famous faces carried Pre-Experimental Knowledge (PEK) while unknown faces repeatedly familiarized prior to learning carried Experimental Knowledge (EK). As expected, PEK increased subsequent memory in healthy elderly. However, patients did not benefit from PEK. Partly non-overlapping brain networks supported PEK vs. EK encoding in healthy controls. Patients displayed impaired activation in a right subhippocampal region where activity predicted successful associative memory formation of PEK stimuli. These findings call for a thorough consideration of how prior knowledge impacts learning and suggest a possible underestimation of the extent of associative memory impairment in early AD.HighlightsLearning is impaired in prodromal AD, but we currently ignore whether prior knowledge available at encoding promotes learning in AD as it does in healthy controls.Patients with AD failed to benefit from pre-experimental prior knowledge (famous faces) by comparison with experimental knowledge (unknown but familiarized faces).fMRI responses at study revealed distinct networks underlying associative encoding for both pre-experimental and experimental knowledge.A subsequent memory effect found in control subjects for associations carrying pre-experimental knowledge in the right subhippocampal structures, including the perirhinal cortex, was absent in patients.Pre-experimental knowledge-based associative encoding relies on brain regions specifically targeted by early tau pathology.Using unfamiliar materials to probe memory in early AD might underestimate learning impairment.

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An investigation of resting state functional connectivity of the anterior and posterior Hippocampal subregions in posttraumatic stress disorder and its relationship with symptoms

10.32920/ryerson.14661012.v1 ◽

2021 ◽

Author(s):

Bailee L. Malivoire

Keyword(s):

Posttraumatic Stress Disorder ◽

Functional Connectivity ◽

Posttraumatic Stress ◽

Resting State ◽

Stress Disorder ◽

Brain Regions ◽

Imaging Biomarkers ◽

Resting State Functional Connectivity ◽

Hippocampal Activity ◽

The Right

Posttraumatic stress disorder (PTSD) is associated with abnormal hippocampal activity; however, the functional connectivity (FC) of the hippocampus with other brain regions and its relations with symptoms warrants further attention. I investigated FC of the hippocampus at a subregional level in PTSD during a resting state compared to trauma exposed controls (TECs). Based on imaging literature in PTSD, I targeted the FCs of the hippocampal head and tail subregions with the amygdala, medial prefrontal cortex (mPFC), and the posterior cingulate (PCC). The PTSD group had significantly greater FC compared to the TEC group between the left hippocampal head and the right amygdala, and for the left hippocampal tail with bilateral PCC. Resting state FC predicted symptom severity at time of scan and 4-months post-scan. These results highlight abnormal illness-related FC with both the hippocampal head and tail and provide support for future investigations of imaging biomarkers predictive of disease progression.

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Resting State Functional MRI in Neonates with Prenatal Opioid Exposure: Analysis of Thalamocortical Functional Connectivity

Proceedings of IMPRS ◽

10.18060/24612 ◽

2020 ◽

Vol 3 ◽

Author(s):

Zoe Guckien ◽

Jonathan Dietrich ◽

Ramana Vishnubhotla ◽

MaKayla Picklesimer ◽

Christina Sparks ◽

...

Keyword(s):

Functional Connectivity ◽

Resting State ◽

Public Health Issue ◽

Control Group ◽

Seed Region ◽

Subcortical Structures ◽

Neural Basis ◽

Neurodevelopmental Outcomes ◽

Caudate Nuclei ◽

The Right

Background/Objective: Prenatal opioid exposure (POE) is a growing public health issue that can result in premature birth, Neonatal Abstinence Syndrome (NAS), and adverse neurodevelopmental outcomes. However, the neural basis for these findings remains relatively unknown. In this study, we aimed to investigate the neural correlates of POE based on neonatal thalamocortical functional connectivity using resting state functional magnetic resonance imaging (rs-fMRI). Methods: In this prospective, IRB-approved study, nineteen neonates with POE and twenty opioid naive (ON) controls underwent non-invasive MRI during natural sleep at mean post-menstrual age (PMA) of 44.7 ± 2.6 and 44.6 ± 2.6 weeks respectively. MR imaging included anatomic T2-weighted images and rs-fMRI. General Linear Model (GLM) seed-based whole brain functional connectivity analysis was performed for each subject, with the right and left thalamus as distinct seed regions. Unpaired mixed-effects group analyses between POE and ON groups were conducted for each seed region corrected for PMA and sex. Results: Thalamic connectivity to cortical and subcortical structures differed in the POE group compared to the ON control group. The POE group exhibited higher functional connectivity to deep gray structures, frontal, medial prefrontal, parietal, occipital, and anterior temporal cortices compared to controls. The POE group exhibited lower connectivity to the nuclei accumbentes, bilateral caudate nuclei, posterior cingulate gyri, superior frontal gyri, insular, and dorsolateral prefrontal cortices. Conclusion and Potential Impact: Overall, these novel results suggest the presence of opioid exposure-related alterations in thalamic functional connectivity. Given that the thalamus plays a crucial role in early brain development, the described alterations in thalamocortical and thalamic-subcortical connectivity may have implications in stratifying risk and informing treatment for the adverse neurodevelopmental outcomes associated with POE. Future studies should explore the relationship between POE-associated disruptions in thalamic connectivity and developmental outcomes.

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