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ObjectiveChildhood trauma （CT） is considered one of the major risk factors for developing major depressive disorder （MDD） in adulthood. However， the neural basis of MDD patients with CT （CT-MDD） remains poorly understood. Therefore， the objective of our study is to explore the resting-state global brain functional connectivity （FC） in CT-MDD. MethodsA total of 34 CT-MDD and 34 healthy controls performed resting-state fMRI. Whole-brain voxel-level degree centrality （DC） analysis was performed， and the brain regions with significant differences between the two groups were selected as region of interest （ROI） for further estimating the global brain FC. Subsequently， correlation analysis was performed between DC values， FC values in abnormal brain areas and clinical characteristics. ResultsThe CT-MDD group showed increased DC value of the right middle frontal gyrus （MFG） compared with the healthy controls. Seed-based FC revealed that the CT-MDD group showed increased connections between the left precuneus and the right MFG or the right medial prefrontal cortex， relative to healthy controls （threshold at P<0.05）. Additionally， the DC value of the right MFG was correlated with the severity of CT. ConclusionOur results show the increased FC between the left precuneus and the ROI （right MFG） as well as the right medial prefrontal cortex， which are two important brain regions within the default mode network （DMN）， and might suggest increased synchronism between the cognitive executive networks and DMN in CT-MDD. These findings may provide insights into the pathophysiological mechanisms underlying CT-MDD.
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Objective To investigate the influence of type 2 diabetes mellitus(T2DM)on cognitive function and the effective connectivity with in the default mode network(DMN)in the brain.Methods A total of 93 hospitalized patients diagnosed with T2DM were enrolled in this study as T2DM group from The First Affiliated Hospital of Guangzhou University of Chinese Medicine during September 2021 to December 2022.Simultaneously,108 healthy individuals were recruited from the community as normal control(NC)group.The cognitive functions were evaluated in the two groups.A random dynamic causal modeling approach was employed to analyze the effective connectivity within DMN in both groups.Additionally,Pearson correlation analysis was performed to examine the association between differential connectivity,clinical indicators,and cognitive scores in both groups.Results In comparison to the NC group,T2DM individuals exhibited statistically significant reductions in scores in the auditory verbal learning test(AVLT)for immediate recall and the digit symbol substitution test(DSST)(P＜0.05).Additionally,they displayed a notable decrease in effective connectivity from the left lateral parietal cortex(LLPC)to the posterior cingulate cortex(PCC),as well as from the LLPC to the right lateral parietal cortex(RLPC)within the DMN(P＜0.05).Pearson correlation analysis unveiled a negative association between HbA1c levels and the strength of effective connectivity from LLPC to PCC.Conversely,a positive correlation was observed between AVLT(immediate)scores and the strength of effective connectivity from LLPC to PCC and LLPC to RLPC.Additionally,DSST scores displayed a positive correlation with the strength of effective connectivity from LLPC to PCC(P＜0.05).Conclusion Patients with T2DM display compromised effective connectivity from LLPC to PCC and LLPC to RLPC within the DMN network,and this alteration may associated with cognitive impairment.
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Primary insomnia is one of the common sleep disorders. It is a type of insomnia with unknown causes， which is often accompanied by a variety of daytime dysfunction and sleep-wake disorders. Neuroimaging and neuroelectrophysiology studies suggest that there may be default mode network dysfunction in patients with primary insomnia， which is closely related to daytime dysfunction and sleep-wake disorder. This article summarizes the characteristics of default mode network dysfunction of primary insomnia and introduces related research in neural structural imaging， functional imaging and neuroelectrophysiology， as well as the role and the mechanism of default mode network impairment leading to daytime dysfunction and sleep-wake disorder of primary insomnia.
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Objective:To investigate the changes in gray matter volume of the subsystems as well as intra-subsystem and inter-subsystem functional connectivity in the default mode network (DMN) of relapsing-remitting multiple sclerosis (RRMS) patients with preserved cognitive function.Methods:In this prospective study, thirty-seven RRMS patients with preserved cognitive function who were admitted to Huashan Hospital of Fudan University from April 2020 to January 2021 (RRMS group) and 43 healthy volunteers (HC group) were recruited. Patients in the RRMS group received the cognitive assessment using a clinical cognitive functioning scale. Three-dimensional T 1WI and resting-state functional MRI were performed to obtain the brain structural and functional data. The DMN was divided into three subsystems: CORE, dorsal medial prefrontal cortex (DMPFC), and medial temporal lobe (MTL). The gray matter volume of the three subsystems were extracted from the gray matter volume map generated by spatial normalization; 24 regions of interest (ROIs) of the DMN were defined based on Yeo′s 17 networks, and their functional connectivity values were calculated to derive the mean intra-subsystem and inter-subsystem functional connectivity values. Differences in gray matter volume and functional connectivity between the RRMS and HC groups were compared using independent sample t-tests; Spearman′s partial correlation was used to analyze the correlation between subsystems′ gray matter volume and functional connectivity, as well as between subsystems′ functional connectivity and clinical scale scores. Results:Compared to the HC group, the gray matter volume of the three subsystems of the DMN were considerably reduced in the RRMS group ( P<0.05). The functional connectivity within and between the three subsystems were not statistically significantly different between the HC and RRMS groups ( P>0.05). Based on the ROI analysis, patients with RRMS the brain regions with significantly reduced DMN intra-subsystem functional connectivity values were mainly located in the left dorsomedial prefrontal cortex of the DMPFC, the right lateral temporal cortex of the DMPFC, and the left medial temporal cortex of the MTL, as compared with the HC group ( P<0.01). The gray matter volume of DMPFC was positively correlated with the functional connectivity within DMPFC in the control group ( r=0.326, P=0.040). In the RRMS group, the gray matter volume of CORE was positively correlated with the functional connectivity between CORE and DMPFC ( r=0.363, P=0.038), and the functional connectivity within CORE was positively correlated with scores on the memory and executive screening scale ( r=0.430, P=0.036). Conclusions:RRMS patients with preserved cognitive function exhibit gray matter atrophy in all three DMN subsystems. There is no correlation between the structure and function of the DMPFC subsystem. The functional connectivity within CORE subsystem may reflect memory and execution status; DMPFC and CORE may be critical encephalic regions for neurodegeneration and brain functional changes in RRMS patients with preserved cognitive function.
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Objective:To investigate the resting state functional connectivity changes of the " triple network model" composed of salient network (SN), executive control network (ECN) and default mode network (DMN) in patients with acute mild traumatic brain injury (mTBI).Methods:From August 2020 to December 2021, forty-five acute mTBI patients (mTBI group) and 40 healthy controls (HC group) with matched sex, age, and education were included.The Montreal cognitive assessment (MoCA) scale was used to evaluate the cognitive status of all subjects.The resting state network (RNS) was established based on independent component analysis (ICA), and the SN, ECN and DMN were extracted, then functional network connectivity (FNC) was analyzed.Subsequently, the correlation between functional connectivity abnormalities and the performance of cognitive impairment was analyzed.SPSS 19.0 was used for statistical analysis and double sample t test was used for comparison between the tow groups. Results:Compared with HC group, mTBI group had enhanced functional connectivity between SN(L-insula) (MNI: x, y, z=-36, 15, 0, t=3.693)and ECN (left superior parietal gyrus, L-SPG) (MNI: x, y, z=-33, -69, 54, t=3.333)(FDR adjust, P<0.05), and decreased functional connectivity between DMN(left superior frontal gyrus, L-SFG) (MNI: x, y, z=-30, 30, 42, t=-4.063)and DMN(L-angular gyrus)(MNI: x, y, z=-21, -66, 33, t=-4.101)(FDR adjust, P<0.05). For FNC analysis, functional network connectivity in SN(IC26)-DMN(IC8) was enhanced in the acute mTBI group and decreased between SN(IC26)-DMN(IC12) and ECN(IC3)-DMN(IC12). The changes of left superior parietal gyrus functional connection were negatively correlated with MoCA score ( r=-0.627, P<0.01), and SN (IC26) -DMN(IC12) connection was positively correlated with MoCA score ( r=0.411, P=0.005). Conclusions:In patients with acute mTBI, the resting functional connectivity changes within and between the networks of the " triple network model" composed of SN, ECN and DMN, and is related to the decline of cognitive function.This will help to better understand the neuropathological mechanism of acute mTBI and post-traumatic cognitive impairment, and may become an effective imaging marker for identifying and predicting cognitive impairment after mTBI.
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Subjective tinnitus refers to the subjective sound perception of patients in the absence of an external sound stimulus.Tinnitus patients are often accompanied by emotional disorders, such as depression and anxiety, which seriously affect the quality of life of patients.Therefore, understanding the mechanism underlying the occurrence of tinnitus emotional disorders can help relieve the pain of tinnitus.Tinnitus was considered a simple ear disease in the early stages, but with the progress of neuroimaging technology and the development of animal models, increasing attention has been given to the changes in the neural structure and function of tinnitus patients.As a powerful technique for in vivo investigation of neural activity in the brain, multimodal magnetic resonance has been widely used in the study of subjective tinnitus.By observing the changes of brain structure in subjective tinnitus patients, the neural mechanism of the occurrence and development of tinnitus has been explored.This article reviewed recent multimodal magnetic resonance imaging studies on the neuroimaging mechanisms of tinnitus with mood disorders, compared the differences in neural activity between subjective tinnitus patients and healthy people, and found that the limbic system, default mode network and other neural network abnormalities were closely related to the mood disorders of tinnitus.The application and development of multimodal magnetic resonance techniques in subjective tinnitus were also discussed to elucidate the neural mechanism of subjective tinnitus accompanied by mood disorders with the help of multimodal magnetic resonance techniques.
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Autism spectrum disorder (ASD) is a multifactorial disease, with social difficulties and repetitive behaviors as its core symptoms. With the improvement of diagnostic methods, the detection rate of ASD is increasing year by year.Cognitive flexibility impairment is very obvious in most autistic patients.More and more studies have shown that cognitive flexibility impairment is related to the occurrence and development of core symptoms. However, the mechanism of cognitive flexibility impairment in autism remains unclear. The frontal lobe plays an important role in advanced cognition, and its complete development is related to cognitive function. Recent studies have shown that frontal lobe dysfunction is closely related to cognitive flexibility deficits in autistic patients, and the abnormal changes in the frontal lobe, the associated default mode network dysfunction and frontal striatal circuit defects may be the important mechanisms of cognitive flexibility impairment. Based on the recent clinical and basic studies on cognitive flexibility in autism, this article reviews the mechanisms of frontal lobe and related circuits involved in the impairment of cognitive flexibility in autism.
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El rol de la Red Neuronal por Defecto en la aparición del trastorno de déficit atencional ha recibido evidencia científica creciente en los últimos 20 años. Este artículo tuvo por objetivo sistematizar la evidencia empírica y cuantitativa disponible en investigaciones sobre el rol de la Red Neuronal por Defecto en la atención sostenida y déficits atencionales en niños y adolescentes de etapa escolar; se usó la metodología de revisión sistemática de la literatura científica disponible entre 2010 y 2020. Se seleccionó una muestra de 13 estudios. Los resultados evidenciaron que la atención sostenida es rítmica y fluctúa junto a la memoria de trabajo. En cuanto a los niños con déficit atencional, se reportan anomalías en la disponibilidad de dopamina, adelgazamientos de las aéreas de la corteza cerebral interconectadas con la Red Neuronal por Defecto, así como hipo e híper conectividad de los tractos de materia blanca asociados a esta red. Estos hallazgos interpretados en su conjunto aportan evidencia valiosa acerca del rol emergente de la Red Neuronal por Defecto en los procesos subyacentes de la atención sostenida y la aparición de déficits atencionales. Estos hallazgos sistematizados pueden tener implicancias profundas en la didáctica y el diseño instruccional debido a que se cuenta con evidencia suficiente y validada como para adaptar las tareas de aprendizaje a los ritmos de atención y descanso puesto que estos obedecen a limitaciones biológicas y no a prescripciones administrativas.
The role of the Default Neural Network in the emergence of attention deficit disorder has received increasing scientific evidence in the last 20 years. This article aimed to systematize the empirical and quantitative evidence available in research on the role of the Default Neural Network in sustained attention and attention deficits in school children and adolescents; The methodology of systematic review of the scientific literature available between 2010 and 2020 was used. A sample of 13 studies was selected. The results showed that sustained attention is rhythmic and fluctuates along with working memory. Regarding children with attention deficit, anomalies in the availability of dopamine, thinning of the areas of the cerebral cortex interconnected with the Neural Network by Default, as well as hypo and hyper connectivity of the white matter tracts associated with this network are reported. These findings, interpreted as a whole, provide valuable evidence about the emerging role of the Default Neural Network in the underlying processes of sustained attention and the appearance of attentional deficits. These systematized findings can have profound implications in didactics and instructional design, due to the fact that there is sufficient and validated evidence to adapt the learning tasks to the rhythms of attention and rest since these processes obbey biological limitations and not to administrative requirements.
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The incidence of emotion disability-related diseases in adolescents is increasing year by year, causing great harm to their physical and mental health, even affecting them until adulthood. However, the mechanism of this has not been fully clarified. The default mode network is a brain network composed of brain regions that are still active in the resting state. DMN is a hot pot in the field of resting state brain function research, but few studies have focused on its pathological changes in the adolescents with emotion disability-related diseases. In recent years, a number of articles related to adolescent emotion disorders have provided clues for understanding the characteristics and potential mechanisms of adolescent emotion disorders from the perspective of imaging. This paper summarized the related research over the years and found that the occurrence of emotion disorders is closely related to the activation of the default mode network brain regions, cortical thickness, gray matter volume or density, and changes in functional connections between brain areas.Some changes in brain structure and function can be used as predictive factors. In this paper, by summarizing the changes in brain imaging of these emotion disorders, we hope to explore new neuroimaging landmark changes, which can provide theoretical basis for the prevention, diagnosis and treatment of emotion disorders related diseases in adolescents.
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OBJECTIVE@#To explore the modulation of transcutaneous auricular vagus nerve stimulation (taVNS) on default mode network (DMN) in patients with primary insomnia (PI).@*METHODS@#A total of 22 PI patients (one patient dropped off and two patients were excluded) were included and treated with taVNS. The bilateral auricular points of Xin (CO15) and Shen (CO10) were selected and treated with disperse-dense wave at frequency of 4 Hz/20 Hz, the intensity was based on the patient's tolerance. taVNS was given once in the morning and once in the evening for 30 minutes each time. The treatment lasted for at least 5 days a week for 4 weeks. At the same time, 16 healthy subjects matched with gender and age were recruited. The Pittsburgh sleep quality index (PSQI) score was evaluated before and after treatment in PI patients. The resting-state functional magnetic resonance imaging (rs-fMRI) data of PI patients before and after treatment and healthy subjects at baseline period were collected to observe the effect of taVNS on the functional connection (FC) between posterior cingulate cortex (PCC) and whole brain.@*RESULTS@#After treatment, the total score of PSQI in PI patients was lower than that before treatment (P<0.01). Compared with healthy subjects, the FC of the left PCC was increased either with the left orbital superior frontal gyrus or with left middle frontal gyrus (P<0.001), and the FC between right PCC and left middle frontal gyrus was increased in PI patients before treatment (P<0.001). Compared before treatment, the FC between left PCC and left middle frontal gyrus was decreased (P<0.05), and the FC of the right PCC was decreased either with the right medial prefrontal cortex or with the left middle frontal gyrus in PI patients after treatment (P<0.001, P<0.01).@*CONCLUSION@#taVNS can modulate the FC between anterior and posterior DMN, and between DMN and cognitive control network of PI patients, which may be one of the brain effect mechanisms of taVNS in the treatment of PI patients.
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Humains , Encéphale/physiologie , Réseau du mode par défaut , Imagerie par résonance magnétique/méthodes , Troubles de l'endormissement et du maintien du sommeil/thérapie , Nerf vague , Stimulation du nerf vague/méthodesRÉSUMÉ
OBJECTIVE@#To investigate the effect of acupuncture on default mode network (DMN) in migraine patients without aura based on functional Magnetic Resonance Imaging (fMRI).@*METHODS@#Fifteen patients with migraine were included and treated with acupuncture based on "root-knot" theory (Zuqiaoyin [GB 44] for @*RESULTS@#Compared before acupuncture, the functional connections of left parahippocampal cortex (PHC) and anterior medial prefrontal cortex (aMPFC), dorsal medial prefrontal cortex (dMPFC) and lateral temporal cortex (LTC) in DMN after acupuncture were weakened (@*CONCLUSION@#Acupuncture shows good clinical efficacy for migraine without aura, and could adjust the functional connection of DMN.
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Humains , Thérapie par acupuncture , Cartographie cérébrale , Réseau du mode par défaut , Spectroscopie par résonance magnétique , Migraines/thérapie , Qualité de vieRÉSUMÉ
Objective:To investigate regional homogeneity(ReHo)and whole brain functional connectivity(FC)in patients with mild cognitive impairment(MCI), and to explore the mechanisms of MCI in the resting state.Methods:Resting-state functional magnetic resonance imaging(RS-fMRI)was performed on 24 patients with MCI and 30 age, gender and nationality-matched normal controls.Abnormal brain areas in the MCI group were screened and analyzed by using the DPARSFA2.3 and SPM8 software programs.Whole brain FC analysis was performed with the posterior cingulate cortex(PCC)/precuneus as the seed points.Results:Compared with the control group, MCI subjects displayed higher ReHo values in the frontal-middle-Left, precentral-Left, postcentral-Left, rolandic-opercular-Left, and frontal-inferior-opercular-Left and lower ReHo values in the temporal-superior-right, temporal-middle-right, postcentral-right, and temporal -pole -superior -right(Voxel level, Alphasim correction, P<0.05). Whole brain FC analysis showed greater functional connectivity of PCC/precuneus with fusiform-right, thalamus-right, lingual-right and parahippocampal-right in subjects with MCI, and less functional connectivity of the PCC/precuneus with temporal-middle-Left, angular-Left, temporal-superior-Left and occipital-middle-Left in subjects with MCI(Voxel level, Alphasim correction, P<0.05). Conclusions:Abnormalities of the default mode network may be associated with the onset of MCI, and abnormalities in posterior cingulate/precuneus connectivity may be helpful in finding imaging evidence with high sensitivity to MCI.
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OBJECTIVE: To investigate the immediate brain effect of auricular electroacupuncture (EA) in the treatment of primary insomnia (PI). METHODS: In this study, 15 subjects with PI who were diagnosed according to Pitsburgh Sleep Quality Index (PSQI), and other 15 age- and gender-matched subjects without insomnia were recruited in the present study. The PI patients received EA (4 Hz/20 Hz, a tolerable electrical current strength) of auricular concha for 30 min, and their resting state functional magnetic resonance imaging (fMRI) data before and after treatment were collected. The healthy subjects received no any treatment and their resting state fMRI data were collected. The diffe-rence of default mode network functional connectivity between the patients and healthy subjects, and changes of the patient's brain functional connectivity after EA treatment were estimated by using seed-point-based analysis (SPBA). RESULTS: Analysis by taking the posterior cingulate gyrus as the seed-point showed that compared with the healthy participants before treatment, the patient's brain functional connectivity between the posterior cingulate gyrus and the right insula, or the inferior frontal gyrus of the right opercularis region, or the right rolandic operculum was increased. After 30 minutes' EA treatment, the functional connectivity between the posterior cingulate gyrus and the precuneus, the left angular gyrus, the left frontal superior gyrus, the left frontal middle cortex, the right temporalis inferior gyrus, the right temporalis middle gyrus or the left medial orbitofrontal cortex was decreased, while the functional connectivity between the posterior cingulate gyrus and the right lingual gyrus, or the cortex surrounding the right calcarine fissure was increased. CONCLUSION: EA of auricular concha has an instant effect in modulating the brain default mode network in PI patients, which may be its brain mechanism underlying improvement of PI.
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Objective To observe the change of functional connectivity(FC) between default mode network (DMN) and the other brain regions in patients with depression before and after magnetic seizure therapy(MST),and explore the role of DMN in therapeutic mechanism of MST.Methods Fifteen patients with depression who met the criteria of enrollment underwent rs-fMRI scanning before and after the MST treatmerts.As a very important region of DMN,the posterior cingulate cortex(PCC) was selected as the region of interest(ROI)to make the functional connectivity analysis with other brain regions,then the differences in FC before and after MST treatments were tested.The correlation of FC index changes with the score changes of HAMD-17 and five factors of HAMD-17 was analyzed after MST treatments.Results A comparison of the differences in DMN before and after treatments showed that the connection between left PCC and bilateral medial temporal lobe connectivity decreased significantly (left:MNI:x,y,z =-66,-39,-15,right:MNI:x,y,z =69,-30,-6) (P＜ 0.05).The connection between left PCC with left cerebellum (MNI:x,y,z =-33,-42,-42) and left occipital lobe(MNI:x,y,z=0,-84,24)significantly increased(P＜0.05).The changes of sleep factor of HAMD-17 were positively correlated with the functional connectivity changes of bilateral medial temporal lobe (left:r=0.670,P=0.006;right:r=0.570,P=0.026),but negatively correlated with the functional connectivity changes of the left cerebellum (r=-0.543,P=0.037).Conclusion MST can play an antidepressant role by regulating DMN functional connection of depressive patients and it may be a neuromodulation mechanism of MST in the treatment of depression.
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Mood disorders/psychosis have been associated with dysfunctions in the default mode network (DMN). However, the relative contributions of DMN regions to state and trait disturbances in pediatric bipolar disorder (PBD) remain unclear. The aim of this study was to investigate the possible mechanisms of PBD through brain imaging and explore the influence of psychotic symptoms on functional alterations in PBD patients. Twenty-nine psychotic and 26 non-psychotic PBD patients, as well as 19 age- and sex-matched healthy controls underwent a resting-state functional MRI scan and the data were analyzed by independent component analysis. The DMN component from the fMRI data was extracted for each participant. Spearman's rank correlation analysis was performed between aberrant connectivity and clinical measurements. The results demonstrated that psychotic PBD was characterized by aberrant DMN connectivity in the anterior cingulate cortex/medial prefrontal cortex, bilateral caudate nucleus, bilateral angular gyri, and left middle temporal gyrus, while non-psychotic PBD was not, suggesting further impairment with the development of psychosis. In summary, we demonstrated unique impairment in DMN functional connectivity in the psychotic PBD group. These specific neuroanatomical abnormalities may shed light on the underlying pathophysiology and presentation of PBD.
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OBJECTIVE: Parkinson’s disease (PD) is a neurodegenerative disorder that mainly leads to the impairment of patients’ motor function, as well as of cognition, as it progresses. This study tried to investigate the impact of PD on the resting state functional connectivity of the default mode network (DMN), as well as of the entire brain. METHODS: Sixty patients with PD were included and compared to 60 matched normal control (NC) subjects. For the local connectivity analysis, the resting state fMRI data were analyzed by seed-based correlation analyses, and then a novel persistent homology analysis was implemented to examine the connectivity from a global perspective. RESULTS: The functional connectivity of the DMN was decreased in the PD group compared to the NC, with a stronger difference in the medial prefrontal cortex. Moreover, the results of the persistent homology analysis indicated that the PD group had a more locally connected and less globally connected network compared to the NC. CONCLUSION: Our findings suggest that the DMN is altered in PD, and persistent homology analysis, as a useful measure of the topological characteristics of the networks from a broader perspective, was able to identify changes in the large-scale functional organization of the patients’ brain.
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Humains , Encéphale , Cognition , Imagerie par résonance magnétique , Maladies neurodégénératives , Maladie de Parkinson , Cortex préfrontalRÉSUMÉ
Objective To compare the default mode network (DMN) between patients with gastroesophageal reflux disease (GERD) and healthy controls (HCs).Methods Included for this study were 30 GERD patients who were treated at Department of Digestive Diseases,Zhujiang Hospital from September 2016 to December 2017 and contemporary 49 HCs who received health examination at the out-patient department.Resting-state functional magnetic resonance imaging (fMRI) was conducted for the 2 groups.Fractional amplitude of low-frequency fluctuation (fALFF) and regional homogeneity (ReHo) were used to study significant alterations in their DMN.Results Compared with the HCs,the GERD patients demonstrated the following alterations:the ReHo values were significantly decreased in bilateral superior temporal gyri,middle temporal gyri and dorsal anterior cingulate cortexes (dACC) but significantly increased in bilateral medial prefrontal lobes,dorsal anterior cingutates,posterior cingulates,precunei,and angular gyri;the fALFF value was increased in bilateral dACC and precunei but decreased in the paracentral lobules (P＜0.05).Conjunction analyses using both ReHo and fALFF values of their DMN showed the overlapping activated brain regions lied in the paracentral lobules,dACC and precunei.The fALFF values in the paracentral lobules and the dACC of the GERD patients were negatively correlated with their disease course (r=-0.380,P=0.035;r=-0.375,P=0.041) while the ReHo values in the superior temporal gyri of the GERD patients were also negatively correlated with their disease course (r=-0.446,P=0.016).Conclusion In GERD patients,their DMN might undergo dysfunctional changes because of the abnormal activity of DMN which may be correlated with their disorder of visceral sensation.
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Objective Transient brain function inhibition is a common symptom after mild brain injury,but some patients show persistent post-concussional syndrome (PCS).The aims of this study are to assess functional and causal connectivity of attention and default mode network using resting-state functional MR imaging (fMRI) to investigate the abnormal connectivity and its significance in PCS patients.Methods Resting-state fMRI data were collected from 23 PCS patients with attention disorders,admitted to our hospital from November 2015 to October 2016 and 21 age-,gender,and education-matched healthy controls recruited at the same period.The fMRI data were analyzed by group independent component analysis (ICA) toolbox to attention networks and default mode network (DMN).The components of the selected networks were compared in PCS and healthy controls to explore the changes of functional connectivity (FC).Granger causality analysis (GCA) was performed by taking the above significant brain areas as regions of interest (ROIs) to calculate bivariate coefficient of each pair of ROIs.Comparisons were performed to find the significant different causal connectivity of the two groups.Results In attention networks,the FC value of left frontal eye field (FEF),bilateral intraparietal sulcus (IPS),bilateral ventral prefrontal cortex (vPFC) and bilateral temporo-parietal junction (TPJ) was decreased.In DMN,the FC value of bilateral medial prefrontal cortex (mPFC) was reduced and bilateral precuneus (PCUN) was enhanced.Correlating GCA value,it was increased significantly from left FEF to left PCUN and IPS,while it was reduced from left PCUN and IPS to left FEF;and it was decreased from left IPS to left vPFC and increased from left TPJ to left PCUN.Conclusion The attention networks are restrained in resting state,which may influence the attention function in PCS patients;and the causal connection is altered in the above ROIs,and these changes may be related to inhibition of activation of default network to compensate for the loss of attention function by antagonistic effects in PCS patients.
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@#A lot of researches indicate the relationship between cognitive impairment and functional connectivity of default mode network,salience network and central executive network.The changes of networks are various in different cognitive dys-function.It is important to apply resting state functional magnetic resonance in the old adults with cognitive dysfunction.
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The purpose of this study was to explore the differences in interhemispheric functional connectivity in patients with Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI) based on a triple network model consisting of the default mode network (DMN), salience network (SN), and executive control network (ECN). The technique of voxel-mirrored homotopic connectivity (VMHC) analysis was applied to explore the aberrant connectivity of all patients. The results showed that: (1) the statistically significant connections of interhemispheric brain regions included DMN-related brain regions (i.e. precuneus, calcarine, fusiform, cuneus, lingual gyrus, temporal inferior gyrus, and hippocampus), SN-related brain regions (i.e. frontoinsular cortex), and ECN-related brain regions (i.e. frontal middle gyrus and frontal inferior); (2) the precuneus and frontal middle gyrus in the AD group exhibited lower VMHC values than those in the aMCI and healthy control (HC) groups, but no significant difference was observed between the aMCI and HC groups; and (3) significant correlations were found between peak VMHC results from the precuneus and Mini Mental State Examination (MMSE) and Montreal Cognitive Scale (MOCA) scores and their factor scores in the AD, aMCI, and AD plus aMCI groups, and between the results from the frontal middle gyrus and MOCA factor scores in the aMCI group. These findings indicated that impaired interhemispheric functional connectivity was observed in AD and could be a sensitive neuroimaging biomarker for AD. More specifically, the DMN was inhibited, while the SN and ECN were excited. VMHC results were correlated with MMSE and MOCA scores, highlighting that VMHC could be a sensitive neuroimaging biomarker for AD and the progression from aMCI to AD.