Search

The aim of this study was to systematically investigate structural and functional alterations in amygdala subregions using multimodal magnetic resonance imaging (MRI) in patients with tinnitus with or without affective dysfunction. Sixty patients with persistent tinnitus and 40 healthy controls (HCs) were recruited. Based on a questionnaire assessment, 26 and 34 patients were categorized into the tinnitus patients with affective dysfunction (TPAD) and tinnitus patients without affective dysfunction (TPWAD) groups, respectively. MRI‐based measurements of gray matter volume, fractional anisotropy (FA), fractional amplitude of low‐frequency fluctuations (fALFF), regional homogeneity (ReHo), degree centrality (DC), and functional connectivity (FC) were conducted within 14 amygdala subregions for intergroup comparisons. Associations between the MRI properties and clinical characteristics were estimated via partial correlation analyses. Compared with that of the HCs, the TPAD and TPWAD groups exhibited significant structural and functional changes, including white matter integrity (WMI), fALFF, ReHo, DC, and FC alterations, with more pronounced WMI changes in the TPAD group, predominantly within the left auxiliary basal or basomedial nucleus (AB/BM), right central nucleus, right lateral nuclei (dorsal portion), and left lateral nuclei (ventral portion containing basolateral portions). Moreover, the TPAD group exhibited decreased FC between the left AB/BM and left middle occipital gyrus and right superior frontal gyrus (SFG), left basal nucleus and right SFG, and right lateral nuclei (intermediate portion) and right SFG. In combination, these amygdalar alterations exhibited a sensitivity of 65.4% and specificity of 96.9% in predicting affective dysfunction in patients with tinnitus. Although similar structural and functional amygdala remodeling were observed in the TPAD and TPWAD groups, the changes were more pronounced in the TPAD group. These changes mainly involved alterations in functionality and white matter microstructure in various amygdala subregions; in combination, these changes could serve as an imaging‐based predictor of emotional disorders in patients with tinnitus. [ABSTRACT FROM AUTHOR]

Aims: This study systematically investigated structural and functional alterations in the thalamus and its subregions using multimodal magnetic resonance imaging (MRI) and examined its clinical relevance in tinnitus patients with different outcomes after sound therapy (narrowband noise). Methods: In total, 60 patients with persistent tinnitus and 57 healthy controls (HCs) were recruited. Based on treatment efficacy, 28 patients were categorized into the effective group and 32 into the ineffective group. Five MRI measurements of the thalamus and its seven subregions, including gray matter volume, fractional anisotropy, fractional amplitude of low‐frequency fluctuation, and functional connectivity (FC), were obtained for each participant and compared between the groups. Results: Patients in both the groups exhibited widespread functional and diffusion abnormalities in the whole thalamus and several subregions, with more obvious changes observed in the effective group. All tinnitus patients had abnormal FC compared with the HCs; FC differences between the two patient groups were only observed in the striatal network, auditory‐related cortex, and the core area of the limbic system. We combined the multimodal quantitative thalamic alterations and used it as an imaging indicator to evaluate prognosis before sound therapy and achieved a sensitivity of 71.9% and a specificity of 85.7%. Conclusion: Similar patterns of thalamic alterations were identified in tinnitus patients with different outcomes, with more obvious changes observed in the effective group. Our findings support the tinnitus generation hypothesis of frontostriatal gating system dysfunction. A combination of multimodal quantitative thalamic properties may be used as indicators to predict tinnitus prognosis before sound therapy. [ABSTRACT FROM AUTHOR]

Objective: Although studies have demonstrated the involvement of the nucleus accumbens (NAc) in the neurobiology of eating disorders, its alterations in bulimia nervosa (BN) remain largely unknown. This study investigated the structural and functional properties of NAc in patients with BN. Method: Based on the resting‐state functional MRI and high‐resolution anatomical T1‐weighted imaging data acquired from 43 right‐handed BN patients and 40 sex‐, age‐ and education‐matched right‐handed healthy controls (HCs), the group differences in gray matter volume (GMV) and fractional amplitude of low‐frequency fluctuation (fALFF) in slow‐4 and ‐5 bands and functional connectivity (FC) of NAc subregions (core and shell) were compared. The relationships between MRI and clinical data were explored in the BN group. Results: Compared with HCs, BN patients showed preserved GMV, decreased fALFF in slow‐5 band of the left NAc core and shell, decreased FC between left NAc core and right caudate, and increased FC between all NAc subregions and frontal regions, between all NAc subregions (except the right NAc core) and the supramarginal gyrus (SMG), and between right NAc shell and left middle temporal gyrus. FC between the NAc and SMG was correlated with emotional eating behaviors. Discussion: Our study revealed preserved GMV, local neuronal activity reduction and functional network reorganization of the NAc in BN. The functional network reorganization of the NAc mainly occurred in the frontal cortex and was correlated with emotional eating behavior. These findings may provide novel insights into the BN using NAc as an entry point. Public significance: Although studies have demonstrated the involvement of the nucleus accumbens (NAc) in the neurobiology of eating disorders, its alterations in bulimia nervosa (BN) remain largely unknown. We used a multimodal MRI technique to systematically investigate structural and functional alterations in NAc subregions of BN patients and explored the associations between such alterations and maladaptive eating behaviors, hoping to provide novel insights into BN. [ABSTRACT FROM AUTHOR]

Previous resting-state functional magnetic resonance imaging (fMRI) studies have shown neural connectivity alterations after the treatment of tinnitus. We aim to study the value of the baseline functional connectivity features of neural network nodes to predict outcomes of sound therapy through adjusted narrow band noise. The fMRI data of 27 untreated tinnitus patients and 27 matched healthy controls were analyzed. We calculated the graph-theoretical metric degree centrality (DC) to characterize the functional connectivity of the neural network nodes. Therapeutic outcomes are determined by the changes in the Tinnitus Handicap Inventory (THI) score after a 12-week intervention. The connectivity of 10 brain nodes in tinnitus patients was significantly increased at baseline. The functional connectivity of right insula, inferior parietal lobule (IPL), bilateral thalami, and left middle temporal gyrus was significantly modified with the sound therapy, and such changes correlated with THI changes in tinnitus patients. Receiver operating characteristic curve analyses revealed that the measurements from the five brain regions were effective at classifying improvement after therapy. After age, gender, and education correction, the adjusted area under the curve (AUC) values for the bilateral thalami were the highest (left, 0.745; right, 0.708). Our study further supported the involvement of the fronto-parietal-cingulate network in tinnitus and found that the connectivity of the thalamus at baseline is an object neuroimaging-based indicator to predict clinical outcome of sound therapy through adjusted narrow band noise.

The application of voxel-mirrored homotopic connectivity (VMHC) analysis to study the central mechanism of migraine has been limited. Furthermore, little is known about inter-hemispheric functional connectivity (FC) alterations during resting state in female patients with migraine. This study aimed to investigate potential interictal VMHC impairments in migraine without aura (MwoA) patients and the relationship between connectivity alterations and clinical parameters. Resting-state functional magnetic resonance imaging data and clinical information were acquired from 43 female MwoA patients and 43 matched healthy controls. VMHC analysis was used to compare differences between these two groups, and brain regions showing significant differences were chosen as a mask to perform a seed-based FC group comparison. Subsequent correlation analysis was conducted to explore the relationship between abnormal inter-hemispheric FC and clinical data. Compared with healthy controls, female MwoA patients revealed significantly decreased VMHC in the bilateral cerebellum; cuneus; and lingual, middle occipital, precentral and postcentral gyri. Seed-based FC analysis indicated disrupted intrinsic connectivity in the cerebellum, and default mode, visual and sensorimotor network. These VMHC and FC abnormalities were negatively correlated with clinical indexes including duration of disease, migraine days and visual analogue scale. These inter-hemispheric FC impairments and correlations between abnormal VMHC and FC and clinical scores may improve our understanding of the central mechanism of female-specific migraine. [ABSTRACT FROM AUTHOR]

Topological properties, which serve as the core of the neural network, and their couplings can reflect different therapeutic effects in tinnitus patients. We hypothesized that tinnitus patients with different outcomes after sound therapy (narrowband noise) would have distinct brain network topological alterations. Diffusion tensor imaging and resting‐state functional magnetic resonance imaging (fMRI) were prospectively performed in 60 patients with idiopathic tinnitus and 57 healthy controls (HCs). Graph‐theoretical network analyses of structural connectivity (SC), functional connectivity (FC), and SC and FC coupling were performed. Associations between clinical performance and graph‐theoretical features were also analyzed. Treatment was effective (effective group; EG) in 28 patients and ineffective (ineffective group; IG) in 32 patients. For FC, the patients in the EG showed higher local efficiency than patients in the IG. For SC, patients in both the EG and IG displayed lower normalized characteristic path length, characteristic path length, and global efficiency than the HCs. More importantly, patients in the IG had higher coupling than the HCs, whereas there was no difference in coupling between patients in the EG and HCs. Additionally, there were significant associations between the SC features and clinical performance in patients in the EG. Our findings demonstrate that tinnitus patients exhibited significant brain network topological alterations, especially in the structural brain network. More importantly, patients who demonstrated different curative effects showed distinct SC‐FC topological coupling properties. SC‐FC coupling could be an indicator that could be used to predict prognoses in patients with idiopathic tinnitus before sound therapy. [ABSTRACT FROM AUTHOR]

Structural and functional brain alterations have been always observed in end-stage renal disease (ESRD) patients undergoing hemodialysis. The present study aimed to investigate the gray matter volume (GMV) changes in hemodialysis patients compared with those noted in healthy subjects, as well as explore the associated functional connectivity alterations based on the abnormal GMV regions. The experiments revealed the effects of regional morphometry aberrance on the brain functional integrity. A total of 46 hemodialysis patients (53.11 ± 1.58 years, 28 males) and 47 healthy subjects (55.57 ± 0.86 years, 22 males) were enrolled in the present study. All subjects underwent high-resolution T1-weighted imaging, resting-state functional MR imaging, and laboratory examinations were performed in hemodialysis patients. The GMV deficits were analyzed using voxel-based morphometry (VBM) and regions with GMV alteration were defined as seeds for functional connectivity analysis. Correlation analyses between significantly different regions and the results of the blood examination were further performed. We found that bilateral thalamus exhibited significantly increased volumes in the hemodialysis patients compared with those of the healthy subjects. However, the bilateral rectus, bilateral caudate, and bilateral temporal gyrus demonstrated significantly decreased volumes. When the regions with GMV alterations were defined as seeds, the hemodialysis patients exhibited decreased integrations in the thalamo-cortical network and within the basal-ganglia connection. The present study revealed the presence of different types of structural and functional brain impairments in hemodialysis patients. [ABSTRACT FROM AUTHOR]

Abnormal neuronal activity and functional connectivity have been reported in patients with venous pulsatile tinnitus (PT). As neuronal activity is closely coupled to regional brain perfusion, the purpose of this study was to investigate the cerebral blood flow (CBF) alterations in patients with unilateral venous PT using arterial spin labeling (ASL). This study included patients with right-sided PT between January 2018 and July 2019. A healthy control (HC) group matched 1:1 for gender and age was also recruited. All subjects underwent ASL scanning using 3.0T MRI. The correlation between altered CBF and Tinnitus Handicap Inventory (THI) score as well as PT duration was analyzed. Twenty-one patients with right-sided PT and 21 HCs were included. The mean PT duration of the patients was 35.9 ± 32.2 months, and the mean THI score was 64.1 ± 20.3. Compared with the HCs, the PT patients exhibited increased CBF in the left inferior parietal gyrus and decreased CBF in the bilateral lingual gyrus (family-wise error corrected, p < 0.05). The increased CBF in the left inferior parietal gyrus showed a positive correlation with the THI score in PT patients (r = 0.501, p = 0.021). PT patients exhibit regional CBF alterations. The increased CBF in the left inferior parietal gyrus may reflect the severity of PT. This study not only presents evidence for the potential neuropathology of PT from the perspective of CBF alterations but also offers a new method for investigating the neuropathological mechanism of PT. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess brain functional alterations in BN patients with affective disorders and their association with maladaptive eating behaviors. A total of 42 BN patients with affective disorders (anxiety and depression) and 47 healthy controls (HCs) were enrolled in this study. The resting-state fMRI data were analyzed for functional changes as indicated by regional homogeneity based on Kendall's coefficient of concordance (KCC-ReHo) and seed-based functional connectivity (FC). A principal component analysis (PCA) model was used to identify the commonalities within the behavioral questionnaires from the BN group. Patients in the BN group showed decreased ReHo in the bilateral middle frontal gyrus (MFG) and right supramarginal gyrus (SMG). Additionally, the BN group showed increased FC between the left MFG and the right inferior temporal gyrus (ITG); decreased FC between the right MFG and the bilateral insula and the left middle temporal gyrus (MTG); and decreased FC between the right SMG and the left superior temporal gyrus (STG) and right inferior frontal gyrus (IFG). In the FC-behavior association analysis, the second principal component (PC2) was negatively correlated with FC between the left MFG and the right ITG. Based on a brain functional analysis (ReHo and FC), this study revealed significant aberrant changes in the frontal-temporal regions of BN patients with affective disorders. These regions, which serve as fronto-temporal circuitry, are associated with restraint and emotional eating behaviors. Our findings shed new light on the neural mechanisms underlying the condition. • Anxiety and depression are the most common affective comorbidities in patients with bulimia nervosa • Little is known about the neuropathic mechanisms underlying comorbid affective disorders in bulimia nervosa • Potential disturbance in the recruitment of fronto-temporal circuitry in BN patients with comorbid affective disorders • The brain functional changes were correlated with disordered eating behaviors • Interplay between BN-specific and comorbid psychopathological effects may contribute to specific brain functional activity [ABSTRACT FROM AUTHOR]

Background: Bulimia nervosa is a recurrent eating disorder with uncertain pathogenesis. Recently, there has been growing interest in using neuroimaging techniques to explore brain structural and functional alterations in bulimia nervosa, but the findings of previous studies have a great number of inconsistencies. Methods: Here, we collected anatomical and resting‐state functional magnetic resonance imaging data from 43 bulimia nervosa patients and 34 matched healthy controls (HCs). We applied a surface‐based morphology analysis to explore brain cortical morphology differences and a novel surface‐based functional connectivity (FC) analysis to investigate functional abnormalities. Principal component analysis was performed to analyze the behavioral data of the participants. We further analyzed the relationships between abnormalities in cortical characteristics or FC and clinical features. Results: We observed increased greater sulcal depth in the right superior temporal gyrus (STG) and the right medial orbitofrontal cortex (mOFC) in bulimia nervosa patients than in the HCs. Additionally, the patients exhibited increased FC between the right STG and right ventral tegmental area but decreased function between the right mOFC and right putamen, which was significantly negatively correlated with the first principal component reflecting the severity of bulimia nervosa symptom. Conclusions: Our findings provide evidence of neuroanatomical and functional abnormalities in bulimia nervosa patients. Moreover, the FC between the right mOFC and right putamen was associated with symptom severity of bulimia nervosa, which may be a neural marker and involved in the neuropathological mechanism of bulimia nervosa. [ABSTRACT FROM AUTHOR]

Objective: Previous studies demonstrated altered regional neural activations in several brain areas in patients with pulsatile tinnitus (PT), especially indicating an important role of posterior cingulate cortex (PCC). However, few studies focused on the degree of functional connectivity (FC) of this area in PT patients. In this study, we will compare the FC of PCC in patients affected with this condition and normal controls by using resting-state functional magnetic resonance imaging (fMRI).Methods: Structural and functional MRI data were obtained from 36 unilateral PT patients with single etiology and 36 matched healthy controls. FC feature of the region of interest (PCC) were characterized using a seed-based correlation method with the voxels in the whole-brain.Results: Compared with healthy controls, patients showed significant decreased FC to the right middle temporal gyrus (MTG), right thalamus and bilateral insula. By contrast, PCC demonstrated increased functional connectivity between the precuneus, bilateral inferior parietal lobule and middle occipital gyrus. We also found correlations between the disease duration of PT and FC of PCC-right MTG (r=-0.616, p<0.001).Conclusions: Unilateral PT patients could have abnormal FC to the PCC bilaterally in the brain. PCC, as a highly integrated brain area, is an example of nucleus that was involved in mediation between different neural networks. It might be a modulation core between visual network and auditory network. The decreased FC of MTG to PCC may indicate a down regulation of activity between PCC and auditory associated brain cortex. Decreased FC between limbic system (bilateral AI) and PCC may reflect the emotional message control in patient group. This study facilitated understanding of the underlying neuropathological process in patients with pulsatile tinnitus. [ABSTRACT FROM AUTHOR]

The functional connectivity of the auditory network is considered to be important in the development of tinnitus. We hypothesized that sound therapy, as a commonly used effective treatment for tinnitus, can modulate the functional connectivity of the auditory network. In this prospective observational study, we recruited 27 tinnitus patients who had undergone 12 weeks of sound therapy and 27 matched healthy controls. For the two groups of subjects, resting-state functional magnetic resonance imaging was acquired both at baseline and at the 12th week. We utilized independent component analysis and seed-based functional connectivity analysis to characterize the connectivity features of the auditory network. Interaction effects between the two groups and the two scans within the auditory network were observed, which were driven by increased functional connectivity in the left primary auditory cortex (PAC) and decreased values in the secondary auditory cortex (SAC) in tinnitus patients after treatment. Increased connections between the auditory network and limbic network, as well as decreased values with the bilateral thalami, were identified. The effects were mainly driven by the functional connectivity alterations of the SAC rather than that of the PAC. Significant positive correlations between the percent improvement in the Tinnitus Handicap Inventory (THI) score and the percentage change rates of functional connectivity between the SAC and bilateral thalami were observed. Our study contributes to the understanding of the mechanism of tinnitus and effective sound therapy, providing evidence to support the theory of a gain adaptation mechanism that quantifies the recovered gating function of the thalamus in tinnitus patients. • We hypothesized that sound therapy can modulate the functional connectivity (FC) of the auditory network. • This is the first longitudinal investigation that specifically analyzed the FC of the auditory network after therapy. • Results supported the theory of a gain adaptation mechanism of the tinnitus onset. • Secondary auditory cortex may be a better candidate for therapies applying neural suppression techniques. [ABSTRACT FROM AUTHOR]