Abnormal interhemispheric functional connectivity in patients with primary dysmenorrhea: a resting-state functional MRI study

Altered spontaneous regional brain activity in ventromedial prefrontal cortex and visual area of expert table tennis athletes

Sports training may lead to functional changes in the brain, and different types of sports, including table tennis, have different influences on these changes. However, the effects of long-term table tennis practice on brain function in expert athletes are largely undefined. Here, we investigated spontaneous regional brain activity characteristics of expert table tennis athletes by using resting-state functional magnetic resonance imaging to compare differences between 25 athletes and 33 age- and sex-matched non-athletes. We analyzed four metrics-amplitude of low-frequency fluctuation (ALFF), fractional ALFF, regional homogeneity, and degree centrality-because together they identify functional changes in the brain with greater sensitivity than a single indicator and may more comprehensively describe regional functional changes. Additional statistical analysis was conducted to assess whether any correlation existed between brain activity and years of table tennis training for athletes. Results show that compared with non-athletes, table tennis athletes showed altered spontaneous regional brain activity in the ventromedial prefrontal cortex and the calcarine sulcus, a visual area. Furthermore, the functional changes in the calcarine sulcus showed a significant correlation with the number of years of expert sports training. Despite the relatively small sample size, these results indicated that the regional brain function of table tennis athletes was associated with sports training-related changes, providing insights for understanding the neural mechanisms underlying the expert performance of athletes.

Multimodal transformer graph convolution attention isomorphism network (MTCGAIN): a novel deep network for detection of insomnia disorder

Background

In clinic, the subjectivity of diagnosing insomnia disorder (ID) often leads to misdiagnosis or missed diagnosis, as ID may have the same symptoms as those of other health problems.

Methods

A novel deep network, the multimodal transformer graph convolution attention isomorphism network (MTGCAIN) is proposed in this study. In this network, graph convolution attention (GCA) is first employed to extract the graph features of brain connectivity and achieve good spatial interpretability. Second, the MTGCAIN comprehensively utilizes multiple brain network atlases and a multimodal transformer (MT) to facilitate coded information exchange between the atlases. In this way, MTGCAIN can be used to more effectively identify biomarkers and arrive at accurate diagnoses.

Results

The experimental results demonstrated that more accurate and objective diagnosis of ID can be achieved using the MTGCAIN. According to fivefold cross-validation, the accuracy reached 81.29% and the area under the receiver operating characteristic curve (AUC) reached 0.8760. A total of nine brain regions were detected as abnormal, namely right supplementary motor area (SMA.R), right temporal pole: superior temporal gyrus (TPOsup.R), left temporal pole: superior temporal gyrus (TPOsup.L), right superior frontal gyrus, dorsolateral (SFGdor.R), right middle temporal gyrus (MTG.R), left middle temporal gyrus (MTG.L), right inferior temporal gyrus (ITG.R), right median cingulate and paracingulate gyri (DCG.R), left median cingulate and paracingulate gyri (DCG.L).

Conclusions

The brain regions in the default mode network (DMN) of patients with ID show significant impairment (occupies four-ninths). In addition, the functional connectivity (FC) between the right middle occipital gyrus and inferior temporal gyrus (ITG) has an obvious correlation with comorbid anxiety (P=0.008) and depression (P=0.005) among patients with ID.

Alterations of interhemispheric functional homotopic connectivity and corpus callosum microstructure in bulimia nervosa

Background

Accumulating evidence indicates maladaptive neural information interactions between different brain regions underlie bulimia nervosa (BN). However, little is known about the alterations in interhemispheric communication of BN, which is facilitated by the corpus callosum (CC), the major commissural fiber connecting the two hemispheres. To shed light on the interhemispheric communications in BN, the present study aims to explore alterations of interhemispheric homotopic functional connectivity and the CC microstructure in BN.

Methods

Based on magnetic resonance imaging (MRI) data collected from 42 BN patients and 38 healthy controls (HCs), the group differences of voxel-mirrored homotopic connectivity (VMHC) index and CC white matter microstructure were compared. Then brain regions with significant group differences in VMHC were selected as seeds for subsequent functional connectivity (FC) analysis. Seed-based fiber tracking and correlation analysis were used to analyze the relationship between VMHC and CC changes. And correlation analysis was used to reveal the correlation between abnormal imaging variables and the clinical features of BN.

Results

Compared with HCs, the BN group showed decreased fractional anisotropy (FA) in middle part of CC (CCMid) and increased VMHC in bilateral orbitofrontal cortex (OFC) and middle temporal gyrus (MTG) [false discovery rate (FDR) correction with a corrected threshold of P<0.05]. Subsequent FC analyses indicated increased FC between left OFC and right OFC, bilateral MTG, left middle occipital gyrus and right precuneus (PCUN); between right OFC and left cerebellum crus II and right PCUN; and between left MTG and right inferior temporal gyrus, right cerebellum lobule VI and right medial superior frontal gyrus (FDR correction with a corrected threshold of P<0.05). The VMHC values of OFC and MTG showed no correlations with FA values of the CCMid and the white fibers between the bilateral OFC and MTG were not through the CCMid. In addition, several regions with abnormal FC had a potential correlation trend with abnormal eating behaviors in BN patients (P<0.05, uncorrected).

Conclusions

Aberrant interhemispheric homotopic functional connectivity and CC microstructure were observed in BN, and they may be independent of each other. Regions with aberrant interhemispheric homotopic functional connectivity showed hyperconnectivity with regions related to reward processing, body shape perception, and self-reference.

Revealing the Central Mechanism of Acupuncture for Primary Dysmenorrhea Based on Neuroimaging: A Narrative Review

Objective

The central mechanism of acupuncture for primary dysmenorrhea was explored by summarizing the changes in different regional networks of the brain induced by acupuncture stimulation by analyzing the existing studies.

Methods

The original studies were collected and selected from three English databases such as PubMed and four Chinese databases as China Knowledge Network (CNKI). The main keyword clusters are neuroimaging, acupuncture, and primary dysmenorrhea.

Results

The literature review yielded 130 possibly qualified studies, and 23 articles fulfilled the criteria for inclusion. Regarding the type of acupuncture studies, 6 moxibustion studies and 17 manual acupuncture studies for primary dysmenorrhea were included. Based on functional magnetic resonance imaging (fMRI), perfusion-weighted imaging (PWI), and positron emission tomography-computer tomography techniques (PET-CT), one or more analysis methods such as amplitude of low-frequency fluctuations (ALFF), regional homogeneity (ReHo), functional connectivity (FC), and independent components analysis (ICA) were used. The results are summarized. To summarize the high-frequency brain area alterations observed in patients with acupuncture-induced primary dysmenorrhea were the anterior cingulate gyrus, thalamus, insula, precentral gyrus, middle frontal gyrus, postcentral gyrus, putamen, and cerebellum.

Conclusion

The results suggest that the mechanism of acupuncture in the treatment of primary dysmenorrhea is the involvement of networks regulating different areas of the brain in the analgesic effects of acupuncture. The brain regions involved in primary dysmenorrhea acupuncture analgesia were mainly located in the pain matrix, default mode network, salience network, and limbic system.

Changes in brain structure and related functional connectivity during menstruation in women with primary dysmenorrhea

Background

Neuroimaging studies have identified altered brain structures and functions in women with primary dysmenorrhea (PDM). However, previous studies focused on either structural or functional changes in specific brain regions rather than combining structural and functional analysis. Therefore, this prospective cross-sectional study aimed to investigate the changes in whole brain structure, and functional variation along with structural abnormalities in women with PDM during menstruation.

Methods

In all, 31 patients with PDM (PTs) and 31 healthy controls (HCs) were recruited. Voxel-based morphometry (VBM) and surface-based morphometry (SBM) analyses were applied to investigate structural changes based on high-resolution T1-weighted magnetic resonance images. Functional connectivity (FC) analysis was performed to evaluate functional variations related to the brain regions that showed structural group differences. Pearson correlation analysis was performed to assess the relationship between neuroimaging changes and clinical measures.

Results

Compared to HCs, PTs had reduced gray matter volume (GMV) in the right superior temporal gyrus (STG) and reduced thickness in the bilateral orbitofrontal cortex (OFC), left postcentral gyrus (PoCG), and left superior occipital gyrus (SOG). Among these areas, the STG and PoCG are responsible for altered resting-state FC patterns in PTs. Results showed decreased FC between the STG and the left cerebellar posterior lobe (poCb), the right dorsolateral prefrontal cortex (DLPFC), and the left precentral gyrus (PrCG). Results also showed decreased FC between the PoCG and the right precuneus and the right DLPFC. We also found greater FCs between the PoCG and the bilateral poCb, the left middle temporal gyrus (MTG), and the left angular gyrus. In addition, the FCs between the STG and poCb, and DLPFC in PTs were positively correlated with history and Cox menstrual symptom scale (CMSS) scores, respectively, while the FCs between STG and PrCG were negatively correlated with the onset age of PDM.

Conclusions

Our research found structural abnormalities and related FC changes in several brain regions that were mainly involved in the emotional and sensory aspects of menstrual pain in PDM. These findings could help us understand the occurrence of PDM from a neuroimaging perspective.

Bibliometric Analysis of Global Research Landscape and Hotspots on Dysmenorrhea: Where are We Now?

Purpose

Dysmenorrhea is the most common gynecological condition among women of childbearing age and remains a challenging public health issue. This study aimed to visualize profiles and hotspots in dysmenorrhea research through a bibliometric analysis to deepen the understanding of knowledge in this field.

Methods

Articles and reviews on dysmenorrhea published from 2000 to 2021 were collected. We summarized standard bibliometric indicators. Publications were systematically assessed in terms of country, institution, author, journal, reference, and keywords using Citespace, VOSviewer, Bibliometric, and an online platform. Besides, correlation analyses of country-specific characteristics and bibliometric indicators were performed.

Results

3407 publications were included. Dysmenorrhea-related publications have been increasing steadily annually. China and the United States were the most productive and academically influential countries, respectively. Correlation analysis revealed that economic power is an essential factor influencing scientific activity. However, collaboration in dysmenorrhea research remained weak. Natl Yang Ming Univ and Vercellini P were the most productive institution and influential author, respectively. A significant proportion of dysmenorrhea research was published in high-impact journals and it was explored at a multidisciplinary level. Current research topics focus on two primary areas: (1) pathophysiology, such as pathogenesis, oxidative stress, and functional connectivity, and (2) public health impacts, such as quality of life, burden, depression, and exercise.

Conclusion

Dysmenorrhea research has received extensive attention from scholars and is rapidly evolving. Improved collaboration and interdisciplinary exploration may advance this field. Public health research and pathophysiological exploration of dysmenorrhea are current research hotspots and may also be a focus of research in the coming years.

Moxibustion for primary dysmenorrhea: A resting-state functional magnetic resonance imaging study exploring the alteration of functional connectivity strength and functional connectivity

Introduction

Primary dysmenorrhea (PDM) is a common gynecological disease and chronic pain disorder. Moxibustion, a form of traditional Chinese medicine therapy, has proven to be effective for PDM. However, the central mechanisms of PDM and moxibustion for PDM are still unclear. This study aims to explore the potential central mechanism of PDM and clarify the possible mechanism of moxibustion for relieving pain.

Materials and methods

A total of 23 PDM patients and 23 matched healthy controls (HCs) were enrolled. For PDM patients, resting-state functional magnetic resonance imaging (rs-fMRI) data were collected pre- and post-moxibustion treatment of 3 consecutive menstrual cycles, respectively. For HCs, rs-fMRI data were collected in the baseline. The resting-state functional connectivity strength (rs-FCS) analysis and the resting-state functional connectivity (rs-FC) analysis based on the region of interest (ROI) were combined to be conducted.

Results

Compared to HCs, PDM patients showed weaker rs-FCS in the left inferior frontal gyrus (IFG). After the moxibustion treatment, rs-FCS in the left IFG was increased with clinical improvement. Then, the left IFG was chosen as ROI, and the rs-FC analysis was conducted. It showed that the left IFG rs-FC in the bilateral anterior cingulate cortex (ACC)/middle cingulate cortex (MCC), the left posterior cingulate cortex (PCC)/precuneus (PCU), and the left parahippocampal gyrus (PHG) decreased after moxibustion treatment, most of which belong to the default mode network (DMN).

Conclusion

Our results highlight the role of the left IFG and the DMN in PDM. Specifically, the central mechanism of moxibustion for analgesia may be related to modulating the disorders of the reappraisal and processing of pain stimuli through influencing the cognition of pain.

Disrupted Spontaneous Neural Activity and Its Interaction With Pain and Emotion in Temporomandibular Disorders

Background and Purpose

Temporomandibular disorders (TMD), especially pain-related TMD, are closely related to social and psychological factors. We aimed to measure changes in spontaneous brain activity and its related functional connectivity (FC), as well as FC characteristics within the mood-regulating circuits (MRC) in TMD patients by resting-state functional magnetic resonance imaging (RS-fMRI), and to analyze the relationship between these parameters and emotional symptoms.

Materials and Methods

Twenty-one adult TMD patients and thirty demographically matched healthy controls (HCs) underwent clinical scale evaluation and RS-fMRI scanning. After processing RS-fMRI data, the values of the amplitude of low-frequency fluctuation (ALFF) between the two groups were compared. Regions with abnormal ALFF values were selected as areas of interest (ROIs) to compare the differences of whole-brain seed-based FC between groups. The FCs between regions within MRC were also analyzed and compared. In addition, the relationships between RS-fMRI characteristics and pain and mood were explored by correlation and mediation analyses.

Results

Compared with HCs, TMD patients showed increased ALFF in the right parahippocampal gyrus (PHG), the right supplementary motor area, and the bilateral precentral gyrus, with decreased ALFF in the right cerebelum_crus2. Patients showed enhanced right PHG-related FC in the vermis and posterior cingulate cortex, orbitofrontal cortex (OFC)-related FC in the striatal-frontal regions, while decreased dorsolateral prefrontal cortex-related FC in the amygdala. In TMD patients, ALFF values in the right PHG and FC values between the right PHG and the vermis were positively correlated with depressive symptoms. Abnormal FCs in the left striatal-orbitofrontal pathway were correlated with pain and depressive symptoms. More importantly, mediation analysis revealed that chronic pain mediates the relationship between FC of right PHG with vermis and depressive symptoms, and abnormal FC in the left striatal-orbitofrontal pathway can mediate the association between pain and depressive symptoms.

Conclusion

TMD patients have dysregulated spontaneous activity and FC in the default mode network, sensorimotor network and pain-related regions, as well as dysfunction of the fronto-striatal-limbic circuits. The development of negative emotions in TMD may be related to the dysfunction of components within the reward system (especially hippocampus complex, OFC, striatum) due to chronic pain.