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Objective:To explore the interaction effects on brain activity between the smoking addiction and weight status by resting-state functional magnetic resonance imaging.Methods:Retrospective analysis of clinical data and resting-state functional magnetic resonance imaging data were analyzed from 99 recruited subjects from January 2019 to December 2021. All participants were divided into four groups: overweight smokers ( n=24), normal-weight smokers ( n=28), overweight non-smokers ( n=19), and normal weight non-smokers ( n=28). Calculate regional homogeneity (ReHo) to reflect the internal brain activity of the subjects. Two-way ANOVA was used to detect the interaction effects between smoking addiction and overweight on ReHo by SPM12 software, correcting for age, years of education and head motion. Results:The interaction effect between smoking addiction and overweight on ReHo was significant in right superior frontal gyrus(x, y, z=15, 9, 60)(GRF corrected, Pvoxel<0.005, Pcluster<0.05). The ReHo value in the right superior frontal gyrus of overweight smokers was significantly higher than that of normal weight smokers ( t=3.768, P<0.001, Bonferroni corrected). The ReHo values in the right superior frontal gyrus of overweight non-smokers were significantly lower than those of normal weight non-smokers ( t=-3.242, P=0.002, Bonferroni corrected). The ReHo values in the right superior frontal gyurs of normal-weight smokers were significantly lower than those of normal weight non-smokers( t=-3.540, P=0.001, Bonferroni corrected). The ReHo values in the right superior frontal gyrus of overweight smokers were significantly higher than those of overweight non-smokers ( t=3.392, P=0.002, Bonferroni corrected). Correlation analyses showed that the strengthen ReHo value in right superior frontal gyrus was positively associated with pack-year in smoking addicts( r=0.387, P=0.007, Bonferroni corrected). Conclusion:Smoking addiction and overweight have an antagonistic effect on brain activity in the right superior frontal gyrus, which may provide potential therapeutic targets for individuals with comorbidity of smoking addiction and overweight.
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Objective To compare the immediate effects of acupuncture at the true and false acupoints of Yanglingquan on functional connectivity in sensorimotor network(SMN)and dorsal attentional network(DAN)of stroke patients based on functional magnetic resonance imaging(fMRI)technology;To explore the central regulatory mechanism and acupoint specificity of acupuncture in stroke patients with hemiplegia.Methods Totally 20 patients with stroke and hemiplegia were included in the study.fMRI scans of acupuncture at the true and false acupoints of Yanglingquan were performed once every 2 weeks,and motion-related SMN and DAN were extracted by independent component analysis to compare the differences in functional connectivity.Results In SMN,after acupuncture at the Yanglingquan true acupoint,the functional connectivity was enhanced compared with before acupuncture.The enhanced brain areas included the right anterior central gyrus,superior temporal gyrus,inferior frontal gyrus,cuneiform lobe,and anterior cuneiform lobe,as well as the left middle temporal gyrus,occipital gyrus,superior temporal gyrus,parahippocampal gyrus,inferior frontal gyrus,and superior temporal gyrus.After acupuncture at the Yanglingquan false acupoint,the functional connectivity was enhanced compared with before acupuncture.The enhanced brain areas included the right anterior central gyrus,superior frontal gyrus,middle frontal gyrus,and cingulate gyrus,as well as the left medial frontal gyrus,anterior cingulate gyrus,lentiform nucleus,and caudate nucleus.In DAN,after acupuncture at the Yanglingquan true acupoint,the functional connectivity was enhanced compared with before acupuncture.The enhanced brain areas included the right anterior cingulate lobe,superior temporal gyrus,middle temporal gyrus,and occipital gyrus,as well as the left cingulate gyrus,posterior cingulate gyrus,and anterior cingulate lobe.After acupuncture at the Yanglingquan false acupoint,the functional connectivity was enhanced compared with before acupuncture,and the enhanced brain areas included the right anterior cingulate gyrus,left anterior cingulate gyrus,and medial frontal gyrus.Conclusion Acupuncture at Yanglingquan can activate SMN and DAN bilateral related brain regions in patients with hemiplegia,which may promote the recovery of motor function by regulating the initiation and execution of motor activities,and has more acupoint specificity compared with false acupoint.
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After kidney transplantation , timely detection of changes in transplanted kidney function may guide clinical managements and prevent or delay irreversible damage to transplanted kidney. Functional magnetic resonance imaging (fMRI) of transplanted kidney is a promising non-invasive technique of acquiring microstructural and microfunctional profiles of transplanted kidney. In recent years, various diffusion imaging modalities, arterial spin labeling (ASL) and blood oxygen level dependent-magnetic resonance imaging (BOLD-MRI) have gradually been applied for transplant kidneys. Transplant kidney function may be evaluated non-invasively from such microscopic perspectives as water molecule diffusion, blood flow perfusion and blood oxygen level. This review focused upon evaluating the renal function and identifying the causes of the renal function decline of transplanted kidney through various fMRI techniques and provide new rationales for clinical diagnosis.
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【Objective】 To explore the correlation between abnormal thalamic functional connectivity (FC) and memory loss in maintenance hemodialysis patients with end-stage renal disease (ESRD). 【Methods】 An auditory verbal learning test (AVLT-H) was conducted on 22 patients with ESRD and 28 age-, sex-, and education-matched healthy controls (HC) to evaluate memory function. After that, resting-state functional magnetic resonance imaging (rs-fMRI) data were gathered, and a whole-brain FC analysis centered on the thalamus was executed to discern variations in thalamic FC between the two groups. Finally, Pearson and Spearman correlation analyses were carried out. 【Results】 Compared to the HC group, the ESRD group exhibited notably lower scores in IR-S (P=0.002), SR-S (P<0.001), and LR-S (P=0.005). Concurrently, the ESRD group demonstrated diminished FC of the right thalamus with the left superior frontal gyrus, the left parietal lobule, the right suproccipital gyrus, the right anterior cuneus, and the right middle frontal gyrus (P<0.05, TFCE correction). Additionally, reduced FC were observed between the left thalamus and the left gyrus rectus, the left parietal lobule, and the right parietal lobule in the ESRD group (P<0.05, TFCE correction). Moreover, the FC values between the left thalamus and the left gyrus rectus in the ESRD group displayed significant negative correlations with IR-S (r=-0.499), SR-S (r=-0.458), and LR-S (r=-0.455) (all P<0.05). 【Conclusion】 Memory impairment is evident in ESRD patients undergoing maintenance hemodialysis, and it appears to be intricately linked to anomalous FC within the left thalamus and the left gyrus rectus. These findings offer potential imaging markers for monitoring memory dysfunction in individuals with ESRD.
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Objective To explore the differences of regional homogeneity(ReHo)between overweight and normal weight male patients with type 2 diabetes mellitus(T2DM)during rest and their correlations with clinical features.Methods Twenty-five untreated male overweight T2DM(OW-T2DM)patients,25 untreated male normal weight T2DM(NW-T2DM)patients and 25 healthy controls(HC)were enrolled.The brain structure and resting-state functional magnetic resonance imaging(rs-fMRI)data were collected from all subjects.The brain structure and rs-fMRI data were preprocessed,and ReHo values of all brain regions were calculated for all subjects.ReHo values were compared among three groups and between groups respectively via the methods of one-way analysis of variance and two-sample t-test.To address the problem of multiple comparisons,the method of AlphaSim was performed(the threshold was set at P<0.005,the number of voxel clusters was>12).In addition,Pearson correlation analysis was performed to explore the relationships between ReHo values of the abnormal brain regions and clinical features in patients.Results(1)The brain regions showed differences of ReHo values among three groups were mainly distributed in the right hemisphere,including the superior parietal gyrus,superior marginal gyrus and superior occipital gyrus;(2)Compared with HC,NW-T2DM patients showed significantly decreased ReHo values in the right medial superior frontal gyrus,right middle cingulate gyrus and left anterior cingulate gyrus;(3)Compared with HC,OW-T2DM patients showed significantly decreased ReHo values in the bilateral postcentral gyrus and bilateral middle cingulate gyrus;(4)Compared with NW-T2DM patients,OW-T2DM patients showed significantly decreased ReHo values in the right superior parietal gyrus,right superior occipital gyrus and left cuneus;(5)ReHo values of the right medial superior frontal gyrus and right superior parietal gyrus were negatively correlated with hemoglobinA1c(HbA1c)level and body mass index(BMI),respectively,in all patients.Conclusion The occurrence of T2DM in male patients may lead to the declined activity of brain regions located in the default mode network(DMN),while overweight may further lead to decreased brain activity within the attention and visual recognition network in male T2DM patients.
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Objective To investigate the immediate brain effect of acupuncture at Fengchi using amplitude of low-frequency fluctuation(ALFF)and functional connectivity by the resting-state functional magnetic resonance imaging(rs-fMRI)in patients with posterior circulation ischemia vertigo(PCIV).Methods Twenty patients with PCIV were enrolled.The dizziness handicap inventory(DHI)was used to evaluate the severity of vertigo.The patients were randomly divided into acupuncture group and sham acupoint acupuncture group.Rs-fMRI scan was performed before and after acupuncture.MATLAB-based DPABI 6.1 software was used to analyze rs-fMRI data.Correlation analysis was used between the altered ALFF values and DHI scores.The regions of altered ALFF were taken as seeds to analyze functional connectivity.Results Compared with the sham acupoint acupuncture group,the increased ALFF values were mainly located on the left precuneus,left superior frontal gyrus and left caudate nucleus after acupuncture in the acupuncture group;the decreased ALFF values were mainly located on the left cerebellum and right inferior occipital gyrus.The ALFF value of the left superior frontal gyrus was negatively correlated with the DHI score(P=0.04).The increased functional connectivity was mainly found between left precuneus and the right middle frontal gyrus,the right superior frontal gyrus,the decreased functional connectivity was mainly found between left precuneus and the bilateral paracentral lobule and right cerebellum.Conclusion The ALFF value and functional connectivity are different before and after acupuncture,indicating that the vestibular network,visual and motor brain regions functional activities are changed after needling at Fengchi,which may be the brain functional basis of Fengchi for vertigo in PCIV.
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With the advent of an aging society,Alzheimer's disease(AD)has gradually become a major ailment affecting the elderly.AD is a neurodegenerative disorder associated with cognitive impairments.In AD patients,brain network connections are disrupted,and their topological properties are also affected,leading to the disintegration of anatomical and functional connections.Anatomical connections can be tracked and evaluated using structural magnetic imaging(MRI)and diffusion tensor imaging(DTI),while functional connections are detected through functional MRI to assess their connectivity status.This review incorporates the findings of previous scholars and summarizes the current research of AD.It mainly discusses the imaging characteristics of large-scale brain network changes in AD patients,so as to provide researchers with scientific and objective imaging markers for AD prediction and early diagnosis,as well as future research.
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BACKGROUND:This review explores the current research status and frontier hot spots of functional magnetic resonance imaging(fMRI)in the field of traditional Chinese medicine(TCM)for the treatment of ischemic stroke,and attempts to grasp future research trends,with a view to providing a reference for subsequent research in this field. OBJECTIVE:To visualize and analyze the hotspots and frontiers in the TCM treatment of ischemic stroke based on fMRI using CiteSpace knowledge mapping combined with binary logistic regression equations,in order to grasp the future research trends and further explore the distribution of brain regions with abnormal neural activity related to the types of post-stroke dysfunction. METHODS:CNKI,WanFang,VIP,Chinese Biomedical Literature Database and Web of Science core set database were searched.CiteSpace was used to plot keyword co-occurrence,keyword clustering timeline,burst term detection,co-cited literature mapping to analyze hotpots and frontiers in this field.Binary logistic regression analysis fitted the distribution of brain regions with abnormal neural activity associated with different dysfunction after ischemic stroke. RESULTS AND CONCLUSION:A total of 354 articles were included for CiteSpace knowledge mapping analysis.The number of annual publications showed that the research popularity has been raised from 2000 to 2022 with a good development prospect,but the core strength is mainly concentrated in China.Keywords co-occurrence and clustering time line analysis showed that aphasia,hemiplegia and cognitive impairment are the hot poststroke dysfunction types.Electroacupuncture,acupuncture and head acupuncture are hotspot intervention measures.Functional connectivity is a hotspot analysis method,and resting fMRI is a hotspot scanning technology.The time span of each research hotspot is long,indicating that it has a certain research value and the relevant research is gradually deepening,promoting the research progress in this field.However,acupuncture is the main intervention measure,and there is a lack of research on traditional Chinese medicine,Chinese patent medicine,acupuncture and medicine combination and other TCM therapy.Burst term detection results showed that functional connectivity,graph theory,degree centrality,default mode network,randomized controlled trials have great influence and strong explosive power.They are the current and future frontier hot spots in this field,suggesting that future research should focus on the brain network information integration and strengthen the scientific and rigorous clinical trial design.The results of co-cited literature analysis showed that the epidemiological investigation of ischemic stroke,the safety and effectiveness of acupuncture in the treatment of stroke,the brain activation patterns under different tasks,and the neuropathological mechanism of brain network dysfunction after stroke are the theoretical basis of this field.Future research direction in this field is to explore TCM-targeted brain regions and neural networks to reveal the brain effect mechanism of TCM promoting neural remodeling after stroke.A total of 255 articles were included for binary Logistic regression analysis.The results showed that sensorimotor cortex and premotor area dysfunction are positively correlated with the incidence of motor dysfunction after stroke;hippocampus,cerebellum posterior lobe,precuneus,inferior temporal gyrus and anterior cingulate nerve dysfunction are positively correlated with the incidence of cognitive impairment after stroke;cuneus,angular gyrus and prefrontal lobe neural dysfunction were positively correlated with the incidence of affective disorder after stroke;anterior cingulate,cerebellum posterior lobe neural dysfunction are positively correlated with the incidence of swallowing disorder after stroke.The above brain regions are the core brain regions of the sensorimotor network,default mode network and reward loop,suggesting that functional abnormalities within or between brain networks related to dysfunction may be potential target areas for TCM intervention,but the specific changes in neural activity activation or inhibition still need to be refined.
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BACKGROUND:Current studies have shown that electronic moxibustion can improve memory function in amnestic mild cognitive impairment;however,its mechanism of action needs to be further investigated.The atrophy of hippocampal volume and impairment of functional connectivity are important imaging markers of amnestic mild cognitive impairment.Whether electronic moxibustion can regulate the volume of hippocampal subregion of partients with amnestic mild cognitive impairment is worth studying. OBJECTIVE:To observe the effect of electronic moxibustion on the volume of hippocampal subregions in patients with amnestic mild cognitive impairment. METHODS:Forty patients with amnestic mild cognitive impairment were recruited from April 1,2018 to January 31,2019 at the community service centers around the Second Affiliated Hospital of Shenzhen University(Baoan Hospital of Southern Medical University),Shenzhen,China.They were randomly divided into treatment group(n=20)and control group(n=20).The treatment group was treated with electronic moxibustion of regulating the mind and benefiting the intelligence,while the control group was treated with placebo moxibustion.Moxibustion was given at 45 oC,20 minutes each time,once a day,5 times a week,for 8 weeks in total.Memory evaluation using Rivermead behavioral memory test and magnetic resonance imaging scanning for detecting the hippocampal subregion volume were performed for each patient before and after treatment,and cognitive function of each patient was assessed using Montreal cognitive assessment and mini-mental state examination.Correlation of hippocampal subregion volumes with scores on each scale was analyzed. RESULTS AND CONCLUSION:After treatment,the volumes of the left parasubiculum and the left hippocampal-amygdala migrating area increased in the treatment group but decreased in the control group,and there was a significant difference between the two groups(P＜0.05).Compared with the pre-treatment data,the Rivermead behavioral memory test,Montreal cognitive assessment,and mini-mental state examination scores were significantly higher in the treatment group after treatment(P＜0.05),while there was no significant change in the three scale scores in the control group after treatment(P＞0.05).The three scale scores were higher in the treatment group than in the control group after treatment(P＜0.05).Pearson correlation analysis showed that the changes in the volume of the left parasubiculum was significantly and positively correlated with the Rivermead behavioral memory test scale score in the treatment group(r=0.418,P=0.014).To conclude,electronic moxibustion can improve memory in patients with amnestic mild cognitive impairment,and the mechanism may be the regulation of structural plasticity in hippocampal subregions.
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BACKGROUND:Olfactory dysfunction is an early biological marker of various diseases.However,the neuroimaging mechanism by which olfactory dysfunction occurs following cerebral small vessel disease is unclear. OBJECTIVE:To explore the different neuroimaging mechanisms of olfactory function regulation in patients with cerebral small vessel disease and Parkinson's disease,and explore the potential application value of olfactory function assessment in patients with cerebral small vessel disease. METHODS:Neuropsychological and olfactory tests,high-resolution structural magnetic resonance and resting-state functional magnetic resonance data were collected in 80 patients with cerebral small vessel disease,44 healthy controls and 29 patients with Parkinson's disease.DPABI,SPM12 and SPSS were used to analyze and compare the amplitude of low frequency fluctuation,regional homogeneity and functional connectivity values between the cerebral small vessel disease,control and Parkinson's disease groups.Correlations between the significantly altered resting-state functional magnetic resonance imaging measures and olfactory and cognitive scores were evaluated. RESULTS AND CONCLUSION:Compared with the control group,low-frequency fluctuation amplitude of the right dorsolateral superior frontal gyrus and the regional homogeneity of the left wedge leaf were significantly reduced in the cerebral small vessel disease and Parkinson's disease groups.The right dorsolateral superior frontal gyrus and the left cuneiform lobe are the seed points.Compared with the Parkinson's disease group,the functional connectivity values of the right anterior cunei,inferior temporal gyrus,anterior central gyrus and dorsolateral superior frontal gyrus,left posterior central gyrus and inferior temporal gyrus were significantly enhanced in the control and cerebral small vessel disease groups.The left cuneiform lobe was the seed point.Compared with the control group,the functional connectivity of the left lingual gyrus was significantly weakened in the cerebral small vessel disease and Parkinson's disease groups.The functional connectivity values of the left middle temporal gyrus and the right posterior central gyrus were enhanced in the control group compared with the cerebral small vessel disease and Parkinson's disease group,and that was enhanced in the cerebral small vessel disease group compared with the Parkinson's disease group.Correlation analysis showed that the olfactory score and cognitive score were positively correlated in the cerebral small vessel disease group,and the regional homogeneity of the left wedge lobe was negatively correlated with the Montreal Cognitive Assessment Scale score,while the functional connectivity of left wedge lobe-left middle temporal gyrus in the Parkinson's disease group was positively correlated with the olfactory recognition score,and the functional connectivity values of the left wedge lobe-left posterior central gyrus and left wedge lobe-left lingual gyrus were positively correlated with the olfactory identification score and the total olfactory score,respectively.The regulation of olfactory function in patients with cerebral small vessel disease has a different neuroimaging mechanism from that of olfactory dysfunction in patients with Parkinson's disease.The olfactory function of patients with cerebral small vessel disease is related to cognitive function.It is speculated that the olfactory function following cerebral small vessel disease is a secondary change of brain dysfunction,while olfactory dysfunction following Parkinson's disease is directly caused by abnormal function of olfactory-related brain areas.Olfactory function assessment in patients with cerebral small vessel disease has potential application in predicting cognitive function.
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Objective To study the brain functional connectivity(FC)changes in patients with normal tension glau-coma(NTG)and healthy volunteers using FC technique of resting-state functional magnetic resonance imaging(rs-fMRI)based on V1 region seed point(ROI),so as to explore the pathogenesis and early diagnosis of NTG.Methods Fourteen NTG patients(NTG group)who met the inclusion criteria and 14 healthy controls(HCs group)were enrolled.The clinical data of all subjects were collected,and rs-fMRI was performed in both groups.The magnetic resonance data was pre-pro-cessed by software,and bilateral A1 regions were taken as the ROI to analyze their correction with the whole brain voxel time series and obtain the FC value between the ROI and the whole brain by comparison of FC values in resting state be-tween the groups.Pearson correlation analysis was used to explore the relationship between FC value in the brain regions with significant differences with the ROI and clinical variables in the NTG group.Results Compared with the subjects in the HCs group,there were no statistically significant differences in age,gender,body weight,cup-disc ratio and 24 h mean intraocular pressure of patients in the NTG group(all P＞0.05),and there were statistically significant differences in the best corrected visual acuity(BCVA)of both eyes and peripapillary retinal nerve fiber layer thickness(RNFLT)(all P＜0.05).The Pearson correlation analysis showed that FC value of the brain regions with abnormal FC to V1 region were cor-related with RNFLT in the NTG group(P＜0.05).ROI1-left superior frontal gyrus,ROI1-right superior frontal gyrus,ROI2-left cingulate gyrus and ROI2-right middle frontal gyrus were significantly positively correlated with RNFLT(all P＜0.05).Compared with the HCs group,the brain regions with reduced FC to the right ROI in the NTG group were the left superior frontal gyrus and right superior frontal gyrus;the brain regions with reduced FC to the left ROI were the left cingulate gyrus and right middle frontal gyrus.Conclusion Compared to healthy individuals,NTG patients have significant changes in the functional connections between certain specific brain regions and V1 region,including bilateral superior frontal gyrus,left cingulate gyrus,and middle frontal gyrus.The changes in brain functional activity may be caused by visual dysfunction caused by NTG,leading to functional impairment of the visual and cognitive emotion processing brain regions,which may be one of the potential neuropathological mechanisms in NTG patients.
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Objective To explore the effects of cognitive reserve on brain networks based on rest state functional magnetic resonance imaging(rsfMRI).Methods Firstly,7 973 healthy middle-aged and elderly individuals were selected for rsfMRI images at UK Biobank(UKB),and 21 resting-state networks were obtained through group independent component analysis.Secondly,the parameters of network node efficiency,shortest path length and node degree centrality were extracted using graph theory analysis.Finally,four indicators of resting-state networks including activeness,network node efficiency,node shortest path length and node degree centrality were compared and analyzed,whose relationships with five cognitive reserve proxies such as education level,early fluid intelligence,sports,leisure activities and socialization level.Results The education level,early fluid intelligence and sports,and the activity correlated positively with the activeness of multi resting-state networks and the node efficiency and node degree centrality of most of cognitive control networks and default mode networks,while negatively with the shortest path length of most of cognitive control networks and default mode networks.Leisure activities,socialization level and sports had negative correlations with the activeness of the resting-state network,and had little effects on the overall topological properties of the functional network.Conclusion Resting-state networks may be affected positively by education level,early fluid intelligence and sports,while negatively by two cognitive reserve proxies including leisure activities and socialization level.[Chinese Medical Equipment Journal,2024,45(1):1-8]
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Objective:To explore the correlations of brain network functional connectivity (FC) alterations with cerebrospinal fluid (CSF) pathological biomarkers in patients with Alzheimer's disease (AD).Methods:A total of 39 patients with cognitive impairment, admitted to Department of Neurology, Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University from January 2020 to December 2022 were recruited; 23 patients were with AD and 16 with non-AD. Clinical data were compared between the 2 groups. Resting-state functional MRI (rs-fMRI) data were collected, and FC differences between brain networks and FC differences within brain networks were compared by independent component analysis. Correlations of FC differences between brain networks and FC differences within brain networks with concentrations of β-amyloid protein 1-42 (Aβ 1-42) and Tau protein in CSF were analyzed. Results:Compared with the non-AD group, AD group had significantly lower Aβ 1-42 in CSF ( P<0.05). Compared with those in the non-AD group, FC alterations between the left frontoparietal network (lFPN) and anterior default mode network (aDMN) and between the visual network (VN) and posterior cingulate cortex (PCC), as well as FC alterations in lFPN, were significantly increased in AD group ( P<0.05). Compared with those in the non-AD group, FC alterations between lFPN and cerebellar network (CEN), and FC alterations in aDMN, sensorimotor network (SMN) and VN were significantly decreased in AD group ( P<0.05). In AD group, FC in SMN was positively correlated with total Tau and phosphorylated-Tau181 in CSF ( P<0.05); FC between VN and PCC was positively correlated with total Tau in CSF ( P<0.05). CSF Aβ 1-42 was positively correlated with FC alterations in aDMN and VN, but negatively correlated with FC in FPN ( P<0.05). Conclusion:In AD patients, characteristic changes in FC within and between multiple brain networks are noted, which are related to changes of Tau protein and Aβ 1-42 in CSF.
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ObjectiveTo explore the impact of autonomic nerve function on motor function in patients with post-stroke depression (PSD) from the perspective of regional homogeneity (ReHo). MethodsFrom January to December, 2020, a total of 60 inpatients and outpatients with cerebral infarction in the Affiliated Brain Hospital of Nanjing Medical University were divided into control group (n = 30) and PSD group (n = 30). Two groups were assessed using Fugl-Meyer Assessment (FMA), modified Barthel Index (MBI) and Hamilton Depression Scale (HAMD). Heart rate variability (HRV) was measured. Ten patients in each group were selected randomly to undergo resting state functional magnetic resonance imaging (rs-fMRI) to calculate ReHo. ResultsAll HRV indices were lower in PSD group than in the control group (|t| > 2.092, P < 0.05). In PSD group, FMA and MBI scores showed positive correlations with 24-hour standard deviation of normal-to-normal R-R intervals (SDNN), the root mean square of successive differences between normal heartbeats over 24 hours (RMSSD), the percentage of differences between adjacent normal R-R intervals over 24 hours that were greater than 50 ms (PNN50), total power (TP), very low frequency power (VLF) and low frequency power (LF) (r > 0.394, P < 0.05), and showed negative correlations with HAMD scores (|r| > 0.919, P < 0.001). HAMD scores in PSD group were negatively correlated with SDNN, RMSSD, PNN50, TP and VLF (|r| > 0.769, P < 0.001). Compared with the control group, the ReHo increased in PSD group in the right rectus gyrus (142 voxels, t = 6.575), the left medial and paracingulate gyri (204 voxels, t = 4.925) (GRF correction, P-Voxel < 0.005，P-Cluster < 0.05); and reduced in the right cerebellum (191 voxels, t = -6.487), the left middle temporal gyrus (140 voxels, t = -5.516), and the left precentral gyrus (119 voxels, t = -4.764) (GRF correction, P-Voxel < 0.005，P-Cluster < 0.05) in PSD group. ConclusionAutonomic nerve function is related to motor dysfunction in patients with PSD. The modulation of emotional, cognitive and motor brain regions by the autonomic nervous system may play a role in influencing the motor function in patients with PSD.
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RESUMEN Las técnicas de neuroimagenología otorgan información relevante del estado funcional y anatómico del cerebro humano. Esta información es particularmente importante cuando existe una lesión cerebral causada por alguna patología, tal como la enfermedad vascular cerebral (EVC). En pacientes afectados por esta enfermedad, se ha determinado que la neuroplasticidad es el mecanismo principal de recuperación de la función motora perdida. Debido a la alta prevalencia de la EVC a nivel mundial y especialmente en países en vías de desarrollo, es necesario continuar investigando los mecanismos de recuperación involucrados en esta patología. La resonancia magnética funcional (RMF) y la imagenología por tensor de difusión (ITD) son dos de las técnicas de neuroimagenología más utilizadas con este fin. La RMF permite analizar la actividad neuronal generada al ejecutar tareas de movimiento, mientras que la ITD proporciona información estructural de la anatomía cerebral. En esta revisión narrativa, se presentan diversos estudios que han utilizado estas técnicas de neuroimagenología en la cuantificación de los cambios de neuroplasticidad en pacientes con EVC tras participar en algún programa de neurorrehabilitación. Comprender mejor estos cambios de neuroplasticidad permitiría diseñar esquemas de rehabilitación que proporcionen un mayor beneficio a los pacientes con EVC.
ABSTRACT Neuroimaging techniques provide relevant information of the functional and anatomical status of the human brain. This information is of particular importance when a pathology, like stroke, produces a brain injury. In stroke patients, it has been determined that neuroplasticity is the primary recovery mechanism of the lost motor function. Due to worldwide high prevalence, especially in developing countries, it is necessary to continue the research of the recovery mechanisms involved in this pathology. To this end, functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) are two of the most used neuroimaging techniques. In stroke patients, fMRI allows the analysis of the neural activity produced by the execution of motor tasks, whereas DTI provides structural information of the brain anatomy. In this narrative review, multiple studies that employ these neuroimaging techniques for quantification of neuroplasticity changes in stroke patients after undergoing a neurorehabilitation program are presented. Better understanding of these neuroplasticity changes would allow researchers to design and provide more beneficial rehabilitation schemes to stroke patients.
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Resumen Objetivo: Explorar si voluntarios sanos presentarían correlación entre su puntaje en un test psicológico emocional y las activaciones de áreas cerebrales relacionadas con las emociones medidas con resonancia magnética funcional (RMf). Material y métodos: Estudio exploratorio de prueba diagnóstica, prospectivo, con diseño del propio individuo como control, con muestra de 12 participantes. Se categorizó a cada participante con un puntaje de estabilidad emocional derivado de un test psicológico y se utilizaron estímulos emocionales audiovisuales durante las adquisiciones de RMf. Resultados: La sumatoria de clusters de activación medidos en cantidad total de vóxeles durante los estímulos negativos en áreas cerebrales relacionadas con las emociones mostró una correlación negativa estadísticamente significativa para nuestro tamaño de muestra respecto de los puntajes en el test emocional, con rho de Spearman de −0,623 y p = 0,0428. Conclusiones: Los paradigmas de RMf utilizados permitieron cuantificar las activaciones cerebrales ante estímulos emocionales de valencia positiva y negativa, y los resultados obtenidos abren una perspectiva hacia la posibilidad de utilizar test psicológicos y secuencias de RMf para predecir la posibilidad de aparición de síntomas de patologías psicológicas o psiquiátricas ante factores desencadenantes en población sana que presente en estos test valores cercanos al límite de la normalidad.
Abstract Objective: To explore if healthy volunteers would present a correlation between their score in emotional psychological test and the activations of brain areas related to emotions measured with functional magnetic resonance imaging (fMRI). Material and methods: Exploratory study of a prospective diagnostic test, with the individuals own design as a control, with a sample of 12 participants. Each participant was categorized with an emotional stability score derived from a psychological test and audiovisual emotional stimuli were used during fMRI acquisitions. Results: The sum of activation clusters measured in total number of voxels during negative stimuli in brain areas related to emotions showed a statistically significant negative correlation for our sample size with respect to the scores in the emotional test, with Spearmans rho of −0.623 and p = 0.0428. Conclusions: The fMRI paradigms used made it possible to quantify brain activations in response to emotional stimuli of positive and negative valence, and the results obtained open a perspective towards the possibility of using psychological tests and fMRI sequences to predict the possibility of the appearance of symptoms of psychological or psychiatric pathologies in response to triggering factors in a healthy population that present values close to the normal limit in these tests.
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In this study, we explored the neural mechanism underlying impaired stereopsis and possible functional plasticity after strabismus surgery. We enrolled 18 stereo-deficient patients with intermittent exotropia before and after surgery, along with 18 healthy controls. Functional magnetic resonance imaging data were collected when participants viewed three-dimensional stimuli. Compared with controls, preoperative patients showed hypoactivation in higher-level dorsal (visual and parietal) areas and ventral visual areas. Pre- and postoperative activation did not significantly differ in patients overall; patients with improved stereopsis showed stronger postoperative activation than preoperative activation in the right V3A and left intraparietal sulcus. Worse stereopsis and fusional control were correlated with preoperative hypoactivation, suggesting that cortical deficits along the two streams might reflect impaired stereopsis in intermittent exotropia. The correlation between improved stereopsis and activation in the right V3A after surgery indicates that functional plasticity may underlie the improvement of stereopsis. Thus, additional postoperative strategies are needed to promote functional plasticity and enhance the recovery of stereopsis.
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Humanos , Exotropía/cirugía , Percepción de Profundidad/fisiología , Estrabismo/cirugía , Músculos Oculomotores/cirugíaRESUMEN
Objective To explore the functional connectivity characteristics and intensity of brain network in depression at rest.Methods Patients with major depressive disorder(MDD)and healthy controls(HCs)underwent resting state functional magnetic resonance imaging.The total brain degree centrality(DC)of the two groups was calculated to assess the functional connection strength.Support vector machine(SVM)method was used to investigate whether abnormal DC value can recognize MDD.Results A total of 26 patients and 37 controls were included in the analysis.Compared to HCs,MDD group showed decreased DC value in the left middle frontal gyrus(t=-4.98,P＜0.05,GRF corrected)and increased DC value in the right middle temporal gyrus(t=5.02,P＜0.05,GRF corrected),right parahippocampal gyrus(t=4.80,P＜0.05,GRF corrected),and right posterior cerebellar gyrus(t=4.98,P＜0.05,GRF corrected).Additionally,no significant correlations were found between abnormal DC values and clinical variables(i.e.,17-item Hamilton depression scale and Beck depression scale scores)in MDD group(P＞0.05).SVM analysis showed that decreased DC value in the left middle frontal gyrus might be used to distinguish MDD group from HCs with an accuracy of 84.13%,a specificity of 81.08%,and a sensitivity of 88.46%,the area under the operational characteristic curve is 0.87.Conclusions Altered DC values in the left middle frontal gyrus and right middle temporal gyrus,right parahippocampal gyrus,right posterior cerebellum may contribute to the pathophysiology of MDD.The change of functional connection strength of the left medial frontal gyrus may be helpful for the recognition of MDD.
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Objective To assess the alterations of negative functional connectivity(FC),its relationship with clinical symptoms,and its potential value in schizophrenia(SZ).Methods Resting-state functional magnetic resonance imaging(rs-fMRI)data were acquired from patients with SZ and healthy controls(HC).For each participant,the whole brain image was first divided into 272 regions and then the FC between each pair of these regions was calculated using Pearson's correlation coefficient.Group-level negative FCs were identified using permutation test for each group.Each of the identified negative FCs was then compared between patients and controls to identify the altered negative FCs.Then,Spearman rank correlation was adopted to examine the relationship between the altered negative FCs and clinical variables.Finally,to evaluate the diagnostic value of negative FC in SZ,a multivariate pattern analysis(MVPA)was performed to distinguish between SZ and HC based on negative FCs.Results Ninety-one patients with SZ and 91 HC were included in this study,and 207 negative FCs in total were identified.Among the identified 207 negative FCs,12(constituting 5.80％of the total 207 negative FCs)were significantly altered in SZ compared with HC(Bonferroni correction,P<0.05),of which 11 were significantly decreased(i.e.,closer to 0)in SZ.The correlation analyses identified 2 significant associations-one was between a negative FC and the total score of the psychotic symptoms rating scales-auditory hallucinations(r=-0.24,P=0.02)and the other was between a negative FC and the weighted total score of the scale for the assessment of thought,language,and communication(r=0.26,P=0.01).Furthermore,the model for distinguishing between SZ and HC based on negative FCs achieved a classification accuracy of 72.6％that was significantly higher than chance-level accuracy(permutation test,P<0.001).Conclusion Negative FCs are altered in patients with SZ.Given that negative FCs are associated with clinical symptoms,thus they may serve as an imaging biomarker for assisting the diagnosis of SZ.
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Objectives:To investigate the predictive effect of regional homogeneity (ReHo) from resting-state functional magnetic resonance imaging (rs-fMRI) in acute phase on memory function of chronic phage in ischemic stroke patients and the effects of residual learning (REL) on the predictive performance of machine learning models.Methods:From June 2019 to June 2021, rs-fMRI data of one-week after stroke (acute phase) were collected from 35 first-time ischemic stroke patients, and their memory scores were assessed by the Rey auditory verbal learning test (RAVLT) at 6 months after stroke (chronic phase). Using ReHo from rs-fMRI data in acute phase of ischemic stroke patients, the support vector regression (SVR) and the REL-based SVR (REL-SVR) were constructed to predict the patients’ memory scores at 6 months after stroke, and the performance of the two models was compared using Pearson correlation coefficient.Results:Based on the ReHo from acute phase, the correlation coefficient between the predicted values and the true scores from the SVR model was r=0.524, P=0.001, while the correlation coefficient obtained by the REL-SVR model was r=0.671, P<0.001. Brain regions with relatively higher weights such as Temporal_Pole_Mid_R (weight value: 1.03), Temporal_Mid_R(weight value: 1.03), Temporal_Inf_R (weight value: 1.03), Occipital_Mid_R (weight value: 0.57), Frontal_Mid_L (weight value: 0.32), Frontal_Sup_Medial_L (weight value: 0.53), SupraMarginal_L (weight value: 1.54), Calcarine_L (weight value: 0.65), Lingual_L (weight value: 0.58), Cuneus_L (weight value: 0.65), Precuneus_L (weight value: 0.83), cerebellum(weight value>1.0) made larger contributions to the prediction model. Conclusions:ReHo in the acute-phase can effectively predict memory in the chronic phase of ischemic stroke patients. Furthermore, REL can improve the performance of the traditional SVR model and achieve higher predictive accuracy.