scholarly journals Altered Spontaneous Brain Activity of Children with Unilateral Amblyopia: A Resting State fMRI Study

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Peishan Dai ◽  
Jinlong Zhang ◽  
Jing Wu ◽  
Zailiang Chen ◽  
Beiji Zou ◽  
...  

Objective. This study is aimed at investigating differences in local brain activity and functional connectivity (FC) between children with unilateral amblyopia and healthy controls (HCs) by using resting state functional magnetic resonance imaging (rs-fMRI). Methods. Local activity and FC analysis methods were used to explore the altered spontaneous brain activity of children with unilateral amblyopia. Local brain function analysis methods included the amplitude of low-frequency fluctuation (ALFF). FC analysis methods consisted of the FC between the primary visual cortex (PVC-FC) and other brain regions and the FC network between regions of interest (ROIs-FC) selected by independent component analysis. Results. The ALFF in the bilateral frontal, temporal, and occipital lobes in the amblyopia group was lower than that in the HCs. The weakened PVC-FC was mainly concentrated in the frontal lobe and the angular gyrus. The ROIs-FC between the default mode network, salience network, and primary visual cortex network (PVCN) were significantly reduced, whereas the ROIs-FC between the PVCN and the high-level visual cortex network were significantly increased in amblyopia. Conclusions. Unilateral amblyopia may reduce local brain activity and FC in the dorsal and ventral visual pathways and affect the top-down attentional control. Amblyopia may also alter FC between brain functional networks. These findings may help understand the pathological mechanisms of children with amblyopia.

Author(s):  
Benedikt Sundermann ◽  
Mona Olde lütke Beverborg ◽  
Bettina Pfleiderer

Information derived from functional magnetic resonance imaging (fMRI) during wakeful rest has been introduced as a candidate diagnostic biomarker in unipolar major depressive disorder (MDD). Multiple reports of resting state fMRI in MDD describe group effects. Such prior knowledge can be adopted to pre-select potentially discriminating features, for example for diagnostic classification models with the aim to improve diagnostic accuracy. Purpose of this analysis was to consolidate spatial information about alterations of spontaneous brain activity in MDD to serve such feature selection and as a secondary aim to improve understanding of disease mechanisms. 32 studies were included in final analyses. Coordinates extracted from the original reports were assigned to two categories based on directionality of findings. Meta-analyses were calculated using the non-additive activation likelihood estimation approach with coordinates organized by subject group to account for non-independent samples. Results were compared with established resting state networks (RSNs) and spatial representations of recently introduced temporally independent functional modes (TFMs) of spontaneous brain activity. Converging evidence revealed a distributed pattern of brain regions with increased or decreased spontaneous activity in MDD. The most distinct finding was hyperactivity/ hyperconnectivity presumably reflecting the interaction of cortical midline structures (posterior default mode network components associated with self-referential processing and the subgenual anterior cingulate cortex) with lateral frontal areas related to externally-directed cognition. One particular TFM seems to better comprehend the findings than classical RSNs. Alterations that can be captured by resting state fMRI show considerable overlap with those identifiable with other neuroimaging modalities though differing in some aspects.


2020 ◽  
Vol 11 ◽  
pp. 204201882096029
Author(s):  
Yao Yu ◽  
Dong-Yi Lan ◽  
Li-Ying Tang ◽  
Ting Su ◽  
Biao Li ◽  
...  

Purpose: In this study, we aimed to investigate the differences in the intrinsic functional connectivity (iFC) of the primary visual cortex (V1), based on resting-state functional magnetic resonance imaging (rs-fMRI), between patients with proliferative diabetic retinopathy (PDR) and healthy controls (HCs). Methods: In total, 26 patients (12 males, 14 females) with PDR and 26 HCs (12 males, 14 females), matched for sex, age, and education status, were enrolled in the study. All individuals underwent rs-fMRI scans. We acquired iFC maps and compared the differences between PDR patients and the HCs. Results: The PDR group had significantly increased FC between the left V1 and the right middle frontal gyrus (RMFG), and significantly reduced FC between the left V1 and the cuneus/calcarine/precuneus. In addition, the PDR patients had significantly increased FC between the right V1 and the right superior frontal gyrus (RSFG), and significantly reduced FC between the right V1 and the cuneus/calcarine/precuneus. The individual areas under the curve (AUCs) of FC values for the left V1 were as follows: RMFG (0.871, p < 0.001) and the cuneus/calcarine/precuneus (0.914, p < 0.001), while the AUCs of FC values for the right V1 were as follows: RSFG (0.895, p < 0.001) and the cuneus/calcarine/precuneus (0.918, p < 0.001). Conclusions: The results demonstrated that, in PDR patients, altered iFC in distinct brain regions, including regions related to visual information processing and cognition. Considering the rise in the diabetes mellitus incidence rate and the consequences of PDR, the results could provide promising clues for exploring the neural mechanisms related to PDR and possible approaches for the early identification of PDR.


2021 ◽  
Vol 15 ◽  
Author(s):  
Xueying He ◽  
Jie Hong ◽  
Qian Wang ◽  
Yanan Guo ◽  
Ting Li ◽  
...  

The purpose of this study is to investigate brain functional changes in patients with intermittent exotropia (IXT) by analyzing the amplitude of low-frequency fluctuation (ALFF) of brain activity and functional connectivity (FC) using resting-state functional magnetic resonance imaging (rs-fMRI). There were 26 IXT patients and 22 age-, sex-, education-, and handedness-matched healthy controls (HCs) enrolled who underwent rs-fMRI. The ALFF, fractional ALFF (fALFF) values in the slow 4 and slow 5 bands, and FC values were calculated and compared. The correlations between ALFF/fALFF values in discrepant brain regions and clinical features were evaluated. Compared with HCs, ALFF/fALFF values were significantly increased in the right angular gyrus (ANG), supramarginal gyrus (SMG), inferior parietal lobule (IPL), precentral gyrus (PreCG), and the bilateral inferior frontal gyri (IFG), and decreased in the right precuneus gyrus (PCUN), left middle occipital gyrus (MOG), and postcentral gyrus (PoCG) in IXT patients. The Newcastle Control Test score was negatively correlated with ALFF values in the right IFG (r = −0.738, p &lt; 0.001). The duration of IXT was negatively correlated with ALFF values in the right ANG (r = −0.457, p = 0.049). Widespread increases in FC were observed between brain regions, mainly including the right cuneus (CUN), left superior parietal lobule (SPL), right rolandic operculum (ROL), left middle temporal gyrus (MTG), left IFG, left median cingulate gyrus (DCG), left PoCG, right PreCG, and left paracentral gyrus (PCL) in patients with IXT. No decreased FC was observed. Patients with IXT exhibited aberrant intrinsic brain activities and FC in vision- and eye movement-related brain regions, which extend current understanding of the neuropathological mechanisms underlying visual and oculomotor impairments in IXT patients.


2021 ◽  
Author(s):  
Xiao-Man Yu ◽  
Lin-Lin Qiu ◽  
Hai-Xia Huang ◽  
Xiang Zuo ◽  
Zhen-He Zhou ◽  
...  

Abstract Background: Schizophrenia (SZ) and Obsessive-compulsive disorder (OCD) share many demographic and clinical symptoms, genetic risk factors, pathophysiological underpinnings, and brain structure and function. However, the differences in the spontaneous brain activity patterns between the two diseases remain unclear. Here this study aimed to compare the features of intrinsic brain activity in treatment-naive patients with schizophrenia (SZ) and obsessive-compulsive disorder (OCD) and to explore the relationship between spontaneous brain activity and the severity of symptoms. Methods: Twenty-two treatment-naive patients with SZ, twenty-seven treatment-naive patients with OCD, and sixty healthy controls underwent resting-state functional magnetic resonance imaging (fMRI). The amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo) and degree of centrality (DC) of SZ group, OCD group and healthy control (HC) group were compared. Results: Compared with SZ group and HC group, patients with OCD had significantly higher ALFF in the right angular gyrus and the left middle frontal gyrus/precentral gyrus, and significantly lower ALFF in the left superior temporal gyrus/insula/rolandic operculum and the left postcentral gyrus. Compared with HC group, lower ALFF values in the right supramarginal gyrus/inferior parietal lobule and DC values of the right lingual gyrus/calcarine fissure and surrounding cortex of the two patient groups, higher ReHo values in OCD group and lower ReHo values in SZ group in the right angular gyrus/middle occipital gyrus brain region, and higher DC values in the right inferior parietal lobule/angular gyrus in SZ group were documented in the present study. In addition, the ALFF values of the left postcentral gyrus were positively correlated with positive subscale score and general psychopathology subscale score respectively on the Positive and Negative Syndrome Scale (PANSS) in SZ group. The ALFF values in the left superior temporal gyrus/insula/rolandic operculum of patients with OCD were positively correlated with compulsion subscale score and total score respectively on the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). Conclusion: Our data showed various patterns of spontaneous brain activity damage in resting-state between treatment-naive patients with SZ and OCD, which might imply different underlying neurobiological mechanisms in SZ and OCD.


2017 ◽  
Vol 2 (20;2) ◽  
pp. E303-E314 ◽  
Author(s):  
Buwei Yu

Background: Postherpetic neuralgia (PHN) patients suffer debilitating chronic pain, hyperalgesia, and allodynia, as well as emotional disorders such as insomnia, anxiety, and depression. The brain structure and functional basis of PHN are still not fully understood. Objectives: To identify the changes of regional brain activity in resting-state PHN patients using regional homogeneity (ReHo) and fractional aptitude of low-frequency fluctuation (fALFF) methods. Correlations between spontaneous pain intensity and ReHo or fALFF were analyzed. Study Design: Observational study. Setting: University hospital. Methods: ReHo, fALFF change was analyzed in 19 PHN patients and 19 healthy controls to detect the functional abnormality in the brains of PHN patients. Correlations between ReHo, fALFF, and PHN pain intensity were assessed in the PHN group. Results: PHN patients exhibited significantly abnormal ReHo and fALFF intensity in several brain regions, including the brainstem, thalamus, limbic system, temporal lobe, prefrontal lobe, and cerebellum compared with healthy controls. Correlation analysis showed that most of the ReHo values of the aforementioned brain regions positively correlated with visual analog scale (VAS) values. But much less correlation was found between fALFF and VAS. Limitations: (a) No specific emotional assessment was given for PHN patients before fMRI scans, therefore we cannot exclude whether the emotional disorders exist in these patients. (b) Relatively short pain duration (mean 5.4 months) and small sample size (n = 19) for the PHN group. Conclusions: For PHN patients, the local brain activity abnormality was not restricted to the pain matrix. Besides regions related to pain perception, areas in charge of affective processes, emotional activity, and pain modulation also showed abnormal local brain activity in a resting state, which may suggest complicated supraspinal function and plasticity change in PHN patients. ReHo was more closely correlated with pain intensity of PHN patients than fALFF. This work indicates that besides physical and emotional pain perception, mood disorder and pain modulation could be characteristics of PHN patients. This also supports the potential use of therapeutic interventions not only restricted to pain alleviation, but also those that attempt to ameliorate the cognitive and emotional comorbidities. Key words: Postherpetic neuralgia, resting-state fMRI (rs-fMRI), mood disorder, limbic sy


2021 ◽  
Vol 12 ◽  
Author(s):  
Sijia Liu ◽  
Ruihua Ma ◽  
Yang Luo ◽  
Panqi Liu ◽  
Ke Zhao ◽  
...  

Objective: To explore the characteristics of expression recognition and spontaneous activity of the resting state brain in major depressive disorder (MDD) patients to find the neural basis of expression recognition and emotional processing.Methods: In this study, two of the six facial expressions (happiness, sadness, anger, fear, aversion, and surprise) were presented in quick succession using a short expression recognition test. The differences in facial expression recognition between MDD patients and healthy people were compared. Further, the differences in ReHo values between the two groups were compared using a resting-state functional magnetic resonance imaging (fMRI) scan to investigate the characteristics of spontaneous brain activity in the resting state and its relationship with clinical symptoms and the accuracy of facial expression recognition in patients with MDD.Results: (1) The accuracy of facial expression recognition in patients with MDD was lower than that of the HC group. There were differences in facial expression recognition between the two groups in sadness-anger (p = 0.026), surprise-aversion (p = 0.038), surprise-happiness (p = 0.014), surprise-sadness (p = 0.019), fear-happiness (p = 0.027), and fear-anger (p = 0.009). The reaction time for facial expression recognition in the patient group was significantly longer than that of the HC group. (2) Compared with the HC group, the ReHo values decreased in the left parahippocampal gyrus, left thalamus, right putamen, left putamen, and right angular gyrus, and increased in the left superior frontal gyrus, left middle temporal gyrus, left medial superior frontal gyrus, and right medial superior frontal gyrus in the patient group. (3) Spearman correlation analysis showed no statistical correlation between ReHo and HAMD-17 scores in MDD patients (p &gt; 0.05). The ReHo value of the left putamen was negatively correlated with the recognition of fear-surprise (r = −0.429, p = 0.016), the ReHo value of the right angular gyrus was positively correlated with the recognition of sadness-anger (r = 0.367, p = 0.042), and the ReHo value of the right medial superior frontal gyrus was negatively correlated with the recognition of fear-anger (r = −0.377, p = 0.037).Conclusion: In view of the different performance of patients with MDD in facial expression tasks, facial expression recognition may have some suggestive effect on the diagnosis of depression and has clinical guiding significance. Many brain regions, including the frontal lobe, temporal lobe, striatum, hippocampus, and thalamus, in patients with MDD show extensive ReHo abnormalities in the resting state. These brain regions with abnormal spontaneous neural activity are important components of LCSPT and LTC circuits, and their dysfunctional functions cause disorder of emotion regulation. The changes in spontaneous activity in the left putamen, right angular gyrus, and right medial superior frontal gyrus may represent the abnormal pattern of spontaneous brain activity in the neural circuits related to emotion perception and may be the neural basis of facial expression recognition.


Author(s):  
Benedikt Sundermann ◽  
Mona Olde lütke Beverborg ◽  
Bettina Pfleiderer

Information derived from functional magnetic resonance imaging (fMRI) during wakeful rest has been introduced as a candidate diagnostic biomarker in unipolar major depressive disorder (MDD). Multiple reports of resting state fMRI in MDD describe group effects. Such prior knowledge can be adopted to pre-select potentially discriminating features, for example for diagnostic classification models with the aim to improve diagnostic accuracy. Purpose of this analysis was to consolidate spatial information about alterations of spontaneous brain activity in MDD to serve such feature selection and as a secondary aim to improve understanding of disease mechanisms. 32 studies were included in final analyses. Coordinates extracted from the original reports were assigned to two categories based on directionality of findings. Meta-analyses were calculated using the non-additive activation likelihood estimation approach with coordinates organized by subject group to account for non-independent samples. Results were compared with established resting state networks (RSNs) and spatial representations of recently introduced temporally independent functional modes (TFMs) of spontaneous brain activity. Converging evidence revealed a distributed pattern of brain regions with increased or decreased spontaneous activity in MDD. The most distinct finding was hyperactivity/ hyperconnectivity presumably reflecting the interaction of cortical midline structures (posterior default mode network components associated with self-referential processing and the subgenual anterior cingulate cortex) with lateral frontal areas related to externally-directed cognition. One particular TFM seems to better comprehend the findings than classical RSNs. Alterations that can be captured by resting state fMRI show considerable overlap with those identifiable with other neuroimaging modalities though differing in some aspects.


2013 ◽  
Vol 110 (8) ◽  
pp. 1811-1821 ◽  
Author(s):  
Dobromir Rahnev ◽  
Peter Kok ◽  
Moniek Munneke ◽  
Linda Bahdo ◽  
Floris P. de Lange ◽  
...  

Continuous theta burst stimulation (cTBS) is a technique that allows for altering of brain activity. Research to date has focused on the effect of cTBS on the target area, but less is known about its effects on the resting state functional connectivity between different brain regions. We investigated this issue by applying cTBS to the occipital cortex and probing its influence in retinotopically defined regions in early visual cortex using functional MRI. We found that occipital cTBS reliably decreased the resting state functional connectivity (i.e., the correlation of spontaneous activity) between regions of the early visual cortex. In the context of a perceptual task, such an effect could mean that cTBS affects the strength of the perceptual signal, its variability, or both. We investigated this issue in a second experiment in which subjects performed a perceptual discrimination task and indicated their level of certainty on each trial. The results showed that occipital cTBS decreased both subjects' accuracy and confidence. Signal detection modeling suggested that these impairments resulted primarily from a decreased strength of the perceptual signal, with a nonsignificant trend of a decrease in signal variability. We discuss the implications of these experiments for understanding the mechanisms by which cTBS influences brain activity and perceptual processes.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Eric Lacosse ◽  
Klaus Scheffler ◽  
Gabriele Lohmann ◽  
Georg Martius

AbstractCognitive fMRI research primarily relies on task-averaged responses over many subjects to describe general principles of brain function. Nonetheless, there exists a large variability between subjects that is also reflected in spontaneous brain activity as measured by resting state fMRI (rsfMRI). Leveraging this fact, several recent studies have therefore aimed at predicting task activation from rsfMRI using various machine learning methods within a growing literature on ‘connectome fingerprinting’. In reviewing these results, we found lack of an evaluation against robust baselines that reliably supports a novelty of predictions for this task. On closer examination to reported methods, we found most underperform against trivial baseline model performances based on massive group averaging when whole-cortex prediction is considered. Here we present a modification to published methods that remedies this problem to large extent. Our proposed modification is based on a single-vertex approach that replaces commonly used brain parcellations. We further provide a summary of this model evaluation by characterizing empirical properties of where prediction for this task appears possible, explaining why some predictions largely fail for certain targets. Finally, with these empirical observations we investigate whether individual prediction scores explain individual behavioral differences in a task.


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