Altered regional homogeneity in patients with diabetic vitreous hemorrhage

BACKGROUND Diabetic vitreous hemorrhage(DVH)is a common complication of diabetes.While the diagnostic methods nowadays only concentrate on the eye injury in DVH patients,whether DVH leads to abnormalities of other visual systems,including the eye,the visual cortex,and other brain regions,remains unknown.AIM To explore the potential changes of brain activity in DVH using regional homogeneity(ReHo)and their relationships with clinical features.METHODS Thirty-one DVH patients and 31 matched healthy controls(HCs)were recruited.All subjects were examined by resting-state functional magnetic resonance imaging.The neural homogeneity in the brain region was estimated by ReHo method.Pearson correlation analysis was used to evaluate the relationships between average ReHo values and clinical manifestations in DVH patients.RESULTS Compared with HCs,the ReHo values in the bilateral cerebellar posterior lobes,right superior(RS)/middle occipital gyrus(MOG),and bilateral superior frontal gyrus were significantly increased.In contrast,in the right insula,bilateral medial frontal gyri,and right middle frontal gyrus,the ReHo values were significantly decreased.Furthermore,we found that best-corrected visual acuity of the contralateral eye in patients with DVH presented a positive correlation with the mean ReHo value of the RS/MOG.We also found that depression score of the DVH group presented a negative correlation with the mean ReHo values of the right insula,bilateral medial frontal gyrus,and right middle frontal gyrus.CONCLUSION We found that DVH may cause dysfunction in multiple brain areas,which may benefit the exploration of pathologic mechanisms in DVH patients.

Altered spontaneous brain activity in patients with diabetic optic neuropathy:A resting-state functional magnetic resonance imaging study using regional homogeneity

BACKGROUND Diabetes is a common chronic disease.Given the increasing incidence of diabetes,more individuals are affected by diabetic optic neuropathy(DON),which results in decreased vision.Whether DON leads to abnormalities of other visual systems,including the eye,the visual cortex,and other brain regions,remains unknown.AIM To investigate the local characteristics of spontaneous brain activity using regional homogeneity(ReHo)in patients with DON.METHODS We matched 22 patients with DON with 22 healthy controls(HCs).All subjects underwent resting-state functional magnetic resonance imaging.The ReHo technique was used to record spontaneous changes in brain activity.Receiver operating characteristic(ROC)curves were applied to differentiate between ReHo values for patients with DON and HCs.We also assessed the correlation between Hospital Anxiety and Depression Scale scores and ReHo values in DON patients using Pearson correlation analysis.RESULTS ReHo values of the right middle frontal gyrus(RMFG),left anterior cingulate(LAC),and superior frontal gyrus(SFG)/left frontal superior orbital gyrus(LFSO)were significantly lower in DON patients compared to HCs.Among these,the greatest difference was observed in the RMFG.The result of the ROC curves suggest that ReHo values in altered brain regions may help diagnose DON,and the RMFG and LAC ReHo values are more clinically relevant than SFG/LFSO.We also found that anxiety and depression scores of the DON group were extremely negatively correlated with the LAC ReHo values(r=-0.9336,P<0.0001 and r=-0.8453,P<0.0001,respectively).CONCLUSION Three different brain regions show ReHo changes in DON patients,and these changes could serve as diagnostic and/or prognostic biomarkers to further guide the prevention and treatment of DON patients.

Regional homogeneity of intrinsic brain activity related to the main alexithymia dimensions

Background Alexithymia is a multidimensional personality construct.Objective This study aims to investigate the neuronal correlates of each alexithymia dimension by examining the regional homogeneity(ReHo) of intrinsic brain activity in a resting situation.Methods From university freshmen, students with alexithymia and non-alexlthymia were recruited. Their alexithymic traits were assessed using the Toronto Alexithymia Scale-20. The ReHo was examined using a resting-state functional MRI approach.Results This study suggests significant gro叩 differences in ReHo in multiple brain regions distributed in the frontal lobe, parietal lobe, temporal lobe, occipital lobe and insular cortex. However, only the ReHo in the insula was positively associated with difficulty identifying feelings, a main dimension of alexithymia. The ReHo in the lingual gyrus,precentral gyrus and postcentral gyrus was positively associated with difficulty describing feelings in participants with alexithymia. Lastly, the ReHo in the right dorsomedial prefrontal cortex(DMPFC_R) was negatively related to the externally oriented thinking style of participants with alexithymia.Conclusion In conclusion, these results suggest that the main dimensions of alexithymia are correlated with specific brain regions' function, and the role of the insula,lingual gyrus, precentral gyrus, postcentral gyrus and DMPFC_R in the neuropathology of alexithymia should be further investigated.

Altered Brain Regional Homogeneity Following Contralateral Acupuncture at Quchi (LI 11) and Zusanli (ST 36) in Ischemic Stroke Patients with Left Hemiplegia: An fMRI Study

Objective: To study the effect of contralateral acupuncture(CAT) at acupoints of Quchi(LI 11) and Zusanli(ST 36) on the unaffected limbs of ischemic stroke patients with left hemiplegia based on regional homogeneity(ReHo) indices. Methods: Ten ischemic stroke patients with left hemiplegia received CAT on right side at LI 11 and ST 36. Functional magnetic resonance imaging(fMRI) was performed before and after acupuncture. A ReHo analytical method was used to compare brain responses of patients before and after CAT operated by REST software. Results: The stimulation at both LI 11 and ST 36 on the unaffected limbs produced significantly different neural activities. CAT elicited increased ReHo values at the right precentral gyrus and superior frontal gyrus, decreased ReHo value at right superior parietal lobule, left fusiform gyrus and left supplementary motor area. Conclusions: Acupuncture at one side could stimulate bilateral regions. CAT could evoke the gyrus which was possibly related to motor recovery from stroke. A promising indicator of neurobiological deficiencies could be represented by ReHo values in post-stroke patients.

Frequency-dependent alterations in regional homogeneity in young carriers of the apolipoprotein E genotype

Using resting-state functional magnetic resonance imaging(rf MRI),previous studies showed that the APOE e4 allele might affect the functional connectivity between remote brain regions[1,2].However,the local functional connectivity of APOE e4 carriers has rarely been explored.Regional homogeneity(Re Ho)has been widely used to

Regional homogeneity and functional connectivity in resting-state brain activity in tinnitus patients

Objective:Subjective tinnitus is characterized by the perception of sound in the absence of any external auditory stimuli.This perceived sound may be related to altered intrinsic neural activity generated along the central auditory pathway.This retrospective study was designed to investigate regional homogeneity and functional connectivity in the resting-state brain activity of patients with tinnitus.Methods:We recruited tinnitus patients with normal hearing or mild hearing loss(n=17)and age-matched healthy controls(n=20),and examined regional homogeneity and functional connectivity in resting-state brain activity using resting-state functional magnetic resonance imaging data.The present study protocol was approved by the Institutional Review Board on Experimental Ethics at Sun Yat-sen University,China(approval No.SYSEC-KY-KS-2019-083).Results:Compared with normal controls,patients with tinnitus had significantly decreased regional homogeneity in the anterior lobe of the cerebellum and increased homogeneity in the inferior frontal gyrus(P<0.05 corrected at a cluster-level).In addition,tinnitus patients showed enhanced functional connectivity between the inferior frontal gyrus and the ventral striatum and midbrain,as well as increased connectivity between the cerebellum and ventromedial prefrontal cortex(P<0.05 corrected at a cluster-level).We also found decreased connectivity between the cerebellum and the anterior insula compared with controls(P<0.05 corrected at a cluster-level).Conclusion:Abnormal connectivity in non-auditory brain structures,particularly those related to emotion processing,may be associated with tinnitus persistence.

Neuropathological characteristics of abnormal white matter functional signaling in adolescents with major depression

BACKGROUND Major depression disorder(MDD)constitutes a significant mental health concern.Epidemiological surveys indicate that the lifetime prevalence of depression in adolescents is much higher than that in adults,with a corresponding increased risk of suicide.In studying brain dysfunction associated with MDD in adolescents,research on brain white matter(WM)is sparse.Some researchers even mistakenly regard the signals generated by the WM as noise points.In fact,studies have shown that WM exhibits similar blood oxygen level-dependent signal fluctuations.The alterations in WM signals and their relationship with disease severity in adolescents with MDD remain unclear.AIM To explore potential abnormalities in WM functional signals in adolescents with MDD.METHODS This study involved 48 adolescent patients with MDD and 31 healthy controls(HC).All participants were assessed using the Patient Health Questionnaire-9 Scale and the mini international neuropsychiatric interview(MINI)suicide inventory.In addition,a Siemens Skyra 3.0T magnetic resonance scanner was used to obtain the subjects'image data.The DPABI software was utilized to calculate the WM signal of the fractional amplitude of low frequency fluctuations(fALFF)and regional homogeneity,followed by a two-sample t-test between the MDD and HC groups.Independent component analysis(ICA)was also used to evaluate the WM functional signal.Pearson’s correlation was performed to assess the relationship between statistical test results and clinical scales.RESULTS Compared to HC,individuals with MDD demonstrated a decrease in the fALFF of WM in the corpus callosum body,left posterior limb of the internal capsule,right superior corona radiata,and bilateral posterior corona radiata[P<0.001,family-wise error(FWE)voxel correction].The regional homogeneity of WM increased in the right posterior limb of internal capsule and left superior corona radiata,and decreased in the left superior longitudinal fasciculus(P<0.001,FWE voxel correction).The ICA results of WM overlapped with those of regional homogeneity.The fALFF of WM signal in the left posterior limb of the internal capsule was negatively correlated with the MINI suicide scale(P=0.026,r=-0.32),and the right posterior corona radiata was also negatively correlated with the MINI suicide scale(P=0.047,r=-0.288).CONCLUSION Adolescents with MDD involves changes in WM functional signals,and these differences in brain regions may increase the risk of suicide.

Rainfall erosivity and erosivity density through rainfall synthetic series for Sao Paulo State,Brazil:Assessment,regionalization and modeling

Rainfall is the main cause of erosion of Brazilian soils,which makes assessing the rainfall erosivity factor(RE)and the erosivity density(ED)fundamental for soil and water conservation.Therefore,the objectives of this study were:i)to estimate the RE and ED for Sao Paulo State,Brazil,using synthetic series of pluviographic data;ii)to define homogeneous regions regarding rainfall erosivity;and iii)to generate regression models for rainfall erosivity estimates in each of the homogeneous regions.Synthetic series of pluviographic data were initially obtained on a sub-daily scale from the daily rainfall records of 696 rainfall gauges.The RE values were then estimated from the synthetic rainfall data,and ED was calculated from the relationship between erosivity and rainfall amounts.Monthly and annual maps for RE and ED were obtained.Hierarchical clustering analysis was used to define homogeneous regions in terms of rainfall erosivity,and regionalized regression models for estimating RE were generated.The results demonstrate high spatial variability of RE in Sao Paulo,where the highest annual values were observed in the coastal region.December to March concentrate approximately 60%of the intra-annual erosivity.The highest values of annual ED were observed in regions with intense agricultural activity.The definition of five homogeneous regions concerning the rainfall erosive potential evidenced distinct seasonal patterns of the spatial distribution of erosivity.Finally,the high predictive accuracy of the regionalized models obtained characterizes them as essential tools for reliable estimates of rainfall erosivity,and contribute to better soil conservation planning.

Effect and cerebral mechanism of moxibustion at heat-sensitized Yaoyangguan(GV3)in patients with lumbar disc herniation and myofascial pain syndrome by resting-state functionality magnetic resonance imaging:protocol for an observational study

We want to explore the analgesic brain effect of the moxibustion at heat-sensitized Yaoyangguan(GV3)in patients with lumbar disc herniation(LDH)and myofascial pain syndrome(MPS).In an assessor-blinded observational study,we will include 15 LDH and 15 MPS.They will accept same treatment of heat-sensitive moxibustion at Yaoyangguan(GV3).The resting-state functionality magnetic resonance imaging image data of brain activities before and after treatment will be analyzed by mean fractional amplitude of low-frequency fluctuation,regional homogeneity analysis and brain functional connection.We select seed of first sensory cortex,second sensory cortex,insula cortex,periaqueductal gray and anterior cingulate cortex as the regions of interest to analyse the relationship between brain functional connectivity of pain-related networks and clinical data.Our study could disclose key brain targets and central response characteristics of the analgesic brain effect and the brain functional connection of heat-sensitive moxibustion.

Abnormal cortical surface-based spontaneous and functional connectivity in the whole brain in lifelong premature ejaculation patients

Recent research has highlighted structural and functional abnormalities in the cerebral cortex of patients with premature ejaculation(PE).These anomalies could play a pivotal role in the physiological mechanisms underlying PE.This study leveraged functional magnetic resonance imaging(fMRI),a noninvasive technique,to explore these neural mechanisms.We conducted resting-state fMRI scans on 36 PE patients and 22 healthy controls(HC),and collected data on Premature Ejaculation Diagnostic Tool(PEDT)scores and intravaginal ejaculation latency time(IELT).Employing a surface-based regional homogeneity(ReHo)approach,we analyzed local neural synchronous spontaneous activity,diverging from previous studies that utilized a volume-based ReHo method.Areas with significant ReHo differences between PE and HC groups underwent surface-based functional connectivity(FC)analysis.Significant discrepancies in ReHo and FC across the cortical surface were observed in the PE cohort.Notably,PE patients exhibited decreased ReHo in the left triangular inferior frontal gyrus and enhanced ReHo in the right middle frontal gyrus.The latter showed heightened connectivity with the left lingual gyrus and the right orbital superior frontal gyrus.Furthermore,a correlation between ReHo and FC values with PEDT scores and IELT was found in the PE group.Our findings,derived from surface-based fMRI data,underscore specific brain regions linked to the neurobiological underpinnings of PE.

Alterations of brain local functional connectivity in amnestic mild cognitive impairment

Background:Resting-state functional magnetic resonance imaging studies using a regional homogeneity(ReHo)method have reported that amnestic mild cognitive impairment(aMCI)was associated with abnormalities in local functional connectivity.However,their results were not conclusive.Methods:Seed-based d Mapping was used to conduct a coordinate-based meta-analysis to identify consistent ReHo alterations in aMCI.Results:We identified 10 studies with 11 datasets suitable for inclusion,including 378 patients with aMCI and 435 healthy controls.This meta-analysis identified significant ReHo alterations in patients with aMCI relative to healthy controls,mainly within the default mode network(DMN)(bilateral posterior cingulate cortex[PCC],right angular gyrus,bilateral middle temporal gyri,and left parahippocampal gyrus/hippocampus),executive control network(right superior parietal lobule and dorsolateral prefrontal cortex),visual network(right lingual gyrus and left middle occipital gyrus),and sensorimotor network(right paracentral lobule/supplementary motor area,right postcentral gyrus and left posterior insula).Significant heterogeneity of ReHo alterations in the bilateral PCC,left parahippocampal gyrus/hippocampus,and right superior parietal lobule/angular gyrus was observed.Exploratory meta-regression analyses indicated that general cognitive function,gender distribution,age,and education level partially contributed to this heterogeneity.Conclusions:This study provides provisional evidence that aMCI is associated with abnormal ReHo within the DMN,executive control network,visual network,and sensorimotor network.These local functional connectivity alterations suggest coexistence of functional deficits and compensation in these networks.These findings contribute to the modeling of brain functional connectomes and to a better understanding of the neural substrates of aMCI.Confounding factors merit much attention and warrant future investigations.

Altered brain activity in juvenile myoclonic epilepsy with a monotherapy:a resting-state fMRI study

Background:Juvenile myoclonic epilepsy(JME)is the most common syndrome of idiopathic generalized epilepsy.Although resting-state functional magnetic resonance imaging(rs-fMRI)studies have found thalamocortical circuit dysfunction in patients with JME,the pathophysiological mechanism of JME remains unclear.In this study,we used three complementary parameters of rs-fMRI to investigate aberrant brain activity in JME patients in comparison to that of healthy controls.Methods:Rs-fMRI and clinical data were acquired from 49 patients with JME undergoing monotherapy and 44 ageand sex-matched healthy controls.After fMRI data preprocessing,the fractional amplitude of low-frequency fluctuation(fALFF),regional homogeneity(ReHo),and degree centrality(DC)were calculated and compared between the two groups.Correlation analysis was conducted to explore the relationship between local brain abnormalities and clinical features in JME patients.Results:Compared with the controls,the JME patients exhibited significantly decreased fALFF,ReHo and DC in the cerebellum,inferior parietal lobe,and visual cortex(including the fusiform and the lingual and middle occipital gyri),and increased DC in the right orbitofrontal cortex.In the JME patients,there were no regions with reduced ReHo compared to the controls.No significant correlation was observed between regional abnormalities of fALFF,ReHo or DC,and clinical features.Conclusions:We demonstrated a wide range of abnormal functional activity in the brains of patients with JME,including the prefrontal cortex,visual cortex,default mode network,and cerebellum.The results suggest dysfunctions of the cerebello-cerebral circuits,which provide a clue on the potential pathogenesis of JME.