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The conventional approach to investigating functional connectivity in the block-designed study usually concatenates task blocks or employs residuals of task activation. While providing many insights into brain functions, the block design adds more manipulation in functional network analysis that may reduce the purity of the blood oxygenation level-dependent signal. Recent studies utilized one single long run for task trials of the same condition, the so-called continuous design, to investigate functional connectivity based on task functional magnetic resonance imaging. Continuous brain activities associated with the single-task condition can be directly utilized for task-related functional connectivity assessment, which has been examined for working memory, sensory, motor, and semantic task experiments in previous research. But it remains unclear how the block and continuous design influence the assessment of task-related functional connectivity networks. This study aimed to disentangle the separable effects of block/continuous design and working memory load on task-related functional connectivity networks, by using repeated-measures analysis of variance. Across 50 young healthy adults, behavioral results of accuracy and reaction time showed a significant main effect of design as well as interaction between design and load. Imaging results revealed that the cingulo-opercular, fronto-parietal, and default model networks were associated with not only task activation, but significant main effects of design and load as well as their interaction on intra- and inter-network functional connectivity and global network topology. Moreover, a significant behavior-brain association was identified for the continuous design. This work has extended the evidence that continuous design can be used to study task-related functional connectivity and subtle brain-behavioral relationships.
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Objective:To investigate the regional homogeneity (ReHo) among the major depressive disorder patients without mixed features (MDD noMF), major depressive disorder with mixed features (MMF), bipolar disorder with mixed features (BMF) and bipolar disorder patients without mixed features (BD noMF) patients, and to explore the brain activity and functional connectivity patterns of the MMF and BMF patients. Methods:This was a cross-sectional study. The MDD noMF patients (MDD noMF group), MMF patients (MMF group), BMF patients (BMF group), BD noMF patients (BD noMF group), and age-and gender-matched healthy controls (HC group) were recruited from Beijing Anding Hospital, Capital Medical University between April, 2021 and June, 2022. All the participants underwent resting-state functional MRI scanning. The ReHo values was computed with the DPABI software based on the MATLAB. Firstly, the difference in ReHo among the patients with MDD noMF, MMF, BMF, BD noMF and HC group were estimated by the analysis of covariance and the post-hoc method (LSD or Games-Howell). And then, the brain regions with significant different ReHo values were selected as the seeds to calculate the functional connectivity with the whole brain. Results:A total of 29 cases in the MDD noMF group, 24 cases in the MMF group, 26 cases in the BMF group, 29 cases in the BD noMF group, and 42 in the HC group were included. The differences in ReHo values in the left fusiform and the left precuneus of the 5 groups were statistically significant ( P<0.05). Among of them, the ReHo values of the left fusiform were lower in the MMF, BMF and BD noMF groups compared with the HC group ( P<0.05), while the ReHo values of the left precuneus in MDD noMF, MMF, BMF and BD noMF groups were higher than that in the HC group ( P<0.05). The ReHo value of the left fusiform was lower in the MMF group compared with the MDD noMF group ( P=0.001); the ReHo value of the left fusiform was lower in the BMF group compared with the MDD noMF and BD noMF groups ( P<0.05). The functional connectivity between the left fusiform and vermis, left insula, right putamen, and left medial superior frontal gyrus, and functional connectivity between the left precuneus and right superior frontal gyrus (dorsolateral) showed significant difference among the MDD noMF, MMF, BMF, BD noMF and HC groups ( P<0.05). Compared with HC group, MDD noMF, MMF, BD noMF groups showed higher functional connectivity between the left fusiform and the vermis, and MDD noMF, MMF, BMF, BD noMF group showed higher functional connectivityy between the the left fusiform and the left insula, left medial superior frontal gyrus and right putamen ( P<0.05). Compared with the MDD noMF group, the MMF, BMF and BD noMF groups showed higher functional connectivity between the left fusiform and the left insula ( P<0.05). Compared with the MDD noMF group, the BMF and BD noMF groups had higher functional connectivity between the left fusiform and the left medial superior frontal gyrus ( P<0.05). The BMF group showed higher functional connectivity of the left fusiform with the right putamen than the MDD noMF and BD noMF groups. Additonally, the BMF and BD noMF groups showed higher functional connectivity between the left precuneus and the right superior frontal gyrus (dorsolateral) than HC, MDD noMF and MMF groups ( P<0.05). Conclusions:MMF and BMF patients have local abnormalities of functional activity synchronization in the left fusiform and precuneus and abnormal functional connectivity patterns with multiple brain regions. MMF and BMF patients have specific neuroimaging features compared to MDD noMF or BD noMF patients and also share similar neuroimaging pathogenesis.
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Objective:To investigate the changes in dynamic functional connectivity density (dFCD) and its relationship with Fagerstr?m test for nicotine dependence (FTND) scores in individuals with smoking addiction based on functional MR.Methods:The clinical and imaging data of 176 volunteers recruited through wechat and other online platforms from September 2019 to December 2020 in the First Affiliated Hospital of Zhengzhou University were retrospectively analyzed. The 176 volunteers were male, aged 20 to 55 years old, and were divided into light smoking addiction group (59 cases), heavy smoking addiction group (61 cases) and control group (56 cases). All subjects underwent resting state functional MR scanning and dFCD was calculated. The dFCD values of three groups were analyzed by ANOVA analysis (GRF corrected, voxel level P<0.005, cluster level P<0.01). Bonferroni correction was used for pairwise comparison. Pearson partial correlation analysis was used to analyze the correlation between dFCD values of brain regions with statistically significant differences and FTND scores. Results:Differences in dFCD among light smoking addiction group, heavy smoking addiction group and control group were mainly distributed in the right orbitofrontal cortex, left caudate nucleus, right putamen, bilateral calcarine sulcus cortex, right cuneus, left parahippocampal gyrus, left precuneus, left middle temporal gyrus and bilateral thalamus (GRF corrected, voxel level P<0.005, cluster level P<0.01). Compared with the control group, both the light and heavy smoking addiction groups showed decreased dFCD in the bilateral calcarine sulcus cortex, right cuneus and left precuneus, as well as increased dFCD in the right orbitofrontal cortex, right putamen, left caudate nucleus and left thalamus (Bonferroni corrected, P<0.05). Compared with the control group, the heavy smoking addiction group showed increased dFCD in the right thalamus, and the light smoking addiction group showed decreased dFCD in the left middle temporal gyrus (Bonferroni corrected, P<0.001). Compared with the light smoking addiction group, the heavy smoking addiction group showed increased dFCD in the left middle temporal gyrus and right thalamus, and decreased dFCD in the left parahippocampal gyrus (Bonferroni corrected, P<0.05). The mean value of dFCD in the right thalamus was positively correlated with FTND scores in smoking addiction patients ( r=0.227, P=0.014), and the mean value of dFCD in the right thalamus of the heavy smoking addiction subgroup was positively correlated with FTND scores ( r=0.323, P=0.013). There was no correlation between FTND scores and dFCD in the right thalamus of the light smoking addiction group ( P>0.05). Conclusion:There are changes of neural activity in brain regions related to smoking behaviors among people with different severity of smoking addiction, and smoking behaviors of people with heavy smoking addiction tend to be habitual compared with those with light smoking addiction.
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Objective:To investigate the alterations of amplitude of low frequency fluctuation (ALFF) and functional connectivity (FC) in patients with Parkinson′s disease (PD) with apathy.Methods:From May 2016 to August 2019, PD patients and age-, gender-and education level-matched healthy controls (HC) in the First Affiliated Hospital of Nanjing Medical University were prospectively recruited. The clinical and resting-state functional MRI (rs-fMRI) data of PD patients and HC were analyzed. According to the Starkstein Apathy Scale (SAS) scores, PD patients were divided into PD with apathy (PD-A) group and PD without apathy (PD-NA) group. Rs-fMRI images were processed by DPABI based on MATLAB. ALFF values were calculated and the standard ALFF (zALFF) were obtained. ANOVA and Post-Hoc t test were performed to compare the differences in local brain activity among the three groups. The brain regions with significant different zALFF values were selected as the seeds to calculate the FC values of the whole brain. The associations between FC values and the SAS scores were performed using pearson correlation analyses. Results:A total of 75 PD patients (50 males, 25 females, aged from 44 to 88 years) and 41 HC (25 males, 16 females, aged from 54 to 72 years) were enrolled. There were 42 patients in the PD-A group and 33 patients in the PD-NA group. Significant differences were found in zALFF values among the PD-A, PD-NA and HC groups ( P<0.05). After Post-Hoc t test, compared with the HC group, zALFF values were significantly increased in the right middle frontal gyrus in the PD-A group ( P<0.05) and significantly decreased in the left precuneus in the PD-NA group; The zALFF values of the right middle frontal gyrus and left precuneus in the PD-A group were significantly higher than those in PD-NA group ( P<0.05). Brain regions with different zALFF values were used as seeds for whole-brain FC. Compared with PD-NA group, FC values between the right middle frontal gyrus and bilateral precuneus, left superior frontal gyrus and its medial side, left middle frontal gyrus, left angular, left anterior cingulate gyrus, left posterior cingulate gyrus, left parahippocampal gyrus were significantly decreased in the PD-A group ( P<0.05). Additionally, FC values of PD patients between the right middle frontal gyrus with the left precuneus, the left superior frontal gyrus and its medial side, and the left middle frontal gyrus were negatively correlated with SAS scores ( r=-0.31, -0.30 and -0.34, both P<0.05). Conclusion:PD-A and PD-NA patients have different brain functional activities and connections in the frontal lobe, parietal lobe and limbic system, suggesting that apathy in PD may be associated with the abnormal functional connections of the frontal-parietal cortical circuit and the frontal-limbic-striatal loop.
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Electroconvulsive therapy (ECT) is a physical therapy method with rapid onset and remarkable effect for schizophrenia(SZ). It is widely used in patients with agitated impulses, stupor and refractory patients with poor drug treatment effect. The neurophysiological mechanism of ECT effect has not been elucidated. In the past decade, the magnetic resonance imaging (MRI) studies of ECT for SZ have been gradually reported in domestic and international journal, involving magnetic resonance spectroscopy, structural state and resting state analysis, preliminary findings suggest that there may be a correlation between ECT efficacy and structural and functional brain changes, mainly involving morphological changes in brain regions such as the thalamus, hippocampus, insula and left medial prefrontal lobe, as well as functional changes in core resting state networks, particularly the dorsal frontoparietal network, default network and limbic network. More research and exploration are needed in the future to provide valuable clues to further explore the therapeutic mechanism of ECT treatment.
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Objective:To investigate the alterations of resting-state functional connectivity (RSFC) in ventral tegmental area (VTA) and substantia nigra (SN) among male smokers, and its correlation with clinical characteristics of smoking.Methods:The resting-state functional magnetic resonance data of 131 subjects recruited from January 2014 to December 2018 were analyzed retrospectively, including 76 smokers (smoking group) and 55 non-smokers (control group). VTA/SN was selected as regions of interest (ROI), and then calculated RSFC between VTA/SN and the whole brain.Based on SPM12 software, independent sample t-test was conducted to compare the differences in RSFC between smoking group and control group.Based on SPSS 22.0 software, Pearson correlation analysis was used to investigate the relationships between the RSFC of brain regions with significant differences and Fagerstr?m test for nicotine dependence (FTND) score, pack-year of smokers. Results:Compared with control group, the results showed decreased RSFC between VTA and the brain regions related default mode network (DMN)(including posterior cingulate cortex, right anterior cuneiform lobe, bilateral superior temporal gyrus, right middle temporal gyrus and right inferior parietal lobule), and regions of limbic system(including right marginal lobe and right angular gyrus), right calcarine (MNI: x, y, z=24, -55, -14) and left insula(MNI: x, y, z=-35, -11, 9) in smoking group(GRF corrected, voxel level P<0.005, cluster level P<0.05). Taking SN as the seed, there was no significant difference between smoking group and control group ( P>0.05). RSFC of VTA-left superior temporal gyrus was positively correlated with pack-year( r=0.243, P=0.034) and FTND ( r=0.282, P=0.014). VTA-left insula RSFC was positively correlated with FTND ( r=0.316, P=0.006). Conclusion:The RSFC in the mesolimbic system and the VTA-DMN circuit exist abnormal changes in smokers.To some extent, it may explain the reward deficits and dysfunction of emotion regulation in smokers, which may provide clues for further understanding the mechanism of tobacco addiction.
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ObjectiveTo explore the efficacy of acupuncture intervention for children with monocular refractive-parallax amblyopia and the possible mechanisms of brain function based on resting-state functional magnetic resonance （rs-fMRI）. MethodsSeventy-six children with anisometropic amblyopia were randomly divided into routine treatment group （38 cases） and acupuncture treatment group （38 cases）. In the conventional group， the children were given three regular treatments of red flash， grating and visual stimulation for 5 mins each time； in the acupuncture group， on the basis of the conventional treatment， the children were given acupuncture for 20 mins each time on bilateral Jingming （BL 1）， Cuanzhu （BL 2）， Guangming （GB 37） and Fengchi （GB 20）； the children in both groups were treated once every other day and three times a week for 4 weeks. The corrected visual acuity was compared between groups before and after treatment. Fifteen children with left-sided refractive amblyopia were randomly selected from each of the above two groups and underwent brain rs-fMRI scans before and after treatment， and 10 healthy children with normal visual acuity of the matched gender and age were included in the normal group and underwent brain rs-fMRI scans. Based on the activation likelihood estimation （ALE） method， we constructed the what visual pathway network， and compared and analyzed the spherical regions of interest （ROIs） of the children with normal children， and both groups of children with differences in functional connectivity （FC values） within the what pathway in the brain before and after treatment. ResultsTwo cases dropout in the acupuncture group， and finally 36 cases in the acupuncture group and 38 cases in the conventional group were included in the analysis. Compared with before treatment， the best corrected visual acuity of amblyopia in both groups was significantly improved after treatment （P＜0.05）， and the improvement of vision in the acupuncture group was significantly better than that in the conventional group （P＜0.05）. The results of rs-fMRI showed that the FC values of the primary optic cortex and the right fusiform gyrus， the left lingual gyrus and the right fusiform gyrus， and the right infraoccipital gyrus and the right middle temporal gyrus were significantly elevated in the brain of the refractive amblyopia children with the whitepathic amblyopia， compared with that of the normal children （P＜0.05）. The FC values of the left lingual gyrus， the right suboccipital gyrus with the right fusiform gyrus， the left lingual gyrus with the right middle temporal gyrus， the right and left lateral middle occipital gyrus， and the right and left lateral middle occipital gyrus with the right suboccipital gyrus were significantly （P＜0.05） lower in the conventional group compared with those in the conventional group before treatment. Compared with that before acupuncture treatment， the FC values of the right lingual gyrus and the right fusiform gyrus， the primary visual cortex and the right middle temporal gyrus increased significantly after acupuncture treatment （P＜0.05）， and the FC values of the left inferior occipital gyrus and the right middle temporal gyrus， the FC values of the left lingual gyrus and the right middle occipital gyrus decreased significantly （P＜0.05）. Compared between groups after treatment， the FC between the left suboccipital gyrus and the right fusiform gyrus in the acupuncture group was significantly higher than that in the conventional group （P＜0.05）， and the FC between the left middle occipital gyrus and the right and left suboccipital gyrus was significantly lower than that in the conventional group （P＜0.05）. ConclusionAcupuncture can significantly improve the corrected vision of anisometropic amblyopic children， and its effect mechanism may focus on regulating the occipito-temporal interlobular functional connectivity within the what pathway， thus improving the children's visual function of shape and color vision and visual learning and memory ability.
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Objective:To observe the temporal variability of functional connectivity between the bilateral inferior frontal gyrus and rest of the brain in persons with Broca′s aphasia (BA) and to compare the connectivity between Uygur and Chinese aphasics.Methods:Thirty Chinese and Uygur BA patients (the patient group) and 30 healthy people speaking Uygur and Chinese (the healthy group) were included. rs-fMRI images were acquired, and the patient group was divided then into a Uygur language patient group (9 cases) and a Chinese language patient group (12 cases). The healthy group was divided into a Uygur language healthy group (13 cases) and a Chinese language healthy group (15 cases). Dynamic functional connectivity (dFC) calculations were performed, and a two-factor analysis of covariance was used to obtain the brain regions in which there was an interaction between language and aphasia and to analyze the correlation between the brain regions with abnormal dFCs and linguistic behavior.Results:Interaction between the bilateral inferior frontal gyrus and the left medial and paracentral cingulate gyrus and the right postcentral gyrus dFC was observed to vary. Temporal variability among the Uygur patients was significantly less than among the Uygur healthy and Chinese patient groups. The temporal variability of Broca′s mirror area and the right postcentral gyrus in the Chinese patient group was significantly greater than in the Chinese healthy group or the Uygur patient group. Variability of Broca′s area and the left medial and paracingulate cingulate gyrus in the Uygur patients group correlated positively with oral fluency, reading comprehension and writing.Conclusion:There are differences in the temporal variability of the dFC in the bilateral inferior frontal gyrus between Uygur and Chinese BA patients. The lower variability of Broca′s area with the left medial and paracingulate and cingulate gyrus may help to identify impaired language function in BA patients. The enhanced variability of the Broca′s mirror image area with the right postcentral gyrus may be the result of reorganization of the linguistic network in Chinese BA patients.
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Objective:To explore the characteristics of functional connectivity (FC) and regional spontaneous brain activity in patients in a minimally-conscious state (MCS).Methods:Resting-state functional near-infrared spectroscopy (rs-fNIRS) was used. Ten minimally-conscious patients were studied along with 12 healthy counterparts as healthy controls (HC). Five minutes of rs-fNIRS data were recorded from each subject and FC and the fractional amplitude of low-frequency fluctuations (fALFFs) of 53 channels were computed using the NIRS-KIT toolbox. The results were compared between the two groups.Results:Compared with the HC group, a significant decrease was observed in the average FC strength of seventeen channel pairs after false discovery rate (FDR) correction. Most were in the right and left frontal pole, as well as the dorsolateral prefrontal lobe. Compared with the HC group, the average fALFF values of Broca′s area (channel 2), the premotor cortex and the supplementary motor cortex (channels 4, 10, and 40), the dorsolateral prefrontal lobe (channels 6, 11, 25, 39), the eye motor area of the frontal lobe (channel 12) and the frontal pole (channels 23, 27, 36) were significantly greater in the MCS group. The fluctuations of the frontal pole (channel 19) were significantly less (after FDR correction).Conclusion:In an MCS spontaneous neural activity is over-active in the prefrontal lobe and some speech- and motor-related brain regions, and coordination of the internal prefrontal functional network is disordered.
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ObjectiveTo study the brain network during balance control tasks in older adults. MethodsFrom January to April, 2022, 22 healthy young adults and 20 healthy older adults were recruited from the Fifth Affiliated Hospital of Guangzhou Medical University and communities. They were asked to finish standing tasks on the plantar pressure plate with eyes opening and closing, while the functional connectivities (FC) of prefrontal cortex (PFC) and primary motor cortex (PMC) were measured with functional near-infrared spectroscopy. ResultsCompared with the young adults, the area of the ellipse (Z = -2.884, P < 0.01) and the maximum swing (Z = -2.481, P < 0.05) increased in the older adults as eyes closing. During the standing task, the intra-FC of left (t = 2.978, P < 0.01) and right (Z = -3.123, P < 0.01) PFC decreased in the older adults, and the inter-FC of right PMC to left PFC (t = 2.087, P < 0.05) and right PFC to left PFC (t = 3.471, P < 0.001) decreased, too. ConclusionThe FC of PFC decreased in healthy older adults during balance control tasks, which may be a indicator for aging brain.
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Background Occupational aluminum exposure may associate with cognitive impairment in workers. At present, brain functional imaging data are not available for evaluating cognitive dysfunction in workers with occupational exposure to aluminum. The role of brain functional connectivity in cognitive decline associated with occupational aluminum exposure is not clear yet. Objective To explore potential mediating effect of brain functional connectivity value on cognitive decline induced by occupational aluminum exposure, to assess the relationship between cognitive impairment and brain functional connectivity, and to identify appropriate imaging evidence of early cognitive changes induced by occupational aluminum exposure. Methods This study used a subset data from a previous cross-sectional survey. Based on the data of aluminum-exposed workers, over 40 years old, aluminum-exposed working years >1 year, Montreal International Cognitive Assessment (MoCA) (Beijing version) score <26 points, 20 workers were selected as the case group, and 40 healthy workers with the same basic conditions (age, smoking, drinking, etc.) in non-aluminum production were selected as the control group with a 1∶2 matching ratio. The basic information of the subjects was collected, plasma aluminum level and cognitive function level were evaluated, and different brain functional connectivity values of default mode network (DMN) were measured by magnetic resonance imaging. The mediating effect analysis was conducted to examine the role of brain functional connectivity in the relationship between aluminum exposure and cognitive function. Results The plasma aluminum concentration of the case group was 1.76 times higher than that of the control group [(33.04±12.02) µg·L−1 vs (18.74±8.95) µg·L−1, P<0.05]; the MoCA score was 9.5 points lower [(18.35±2.64) vs (27.85±0.92), P<0.05]. The mean functional connection values of DMN1 and DMN2 in the case group were lower than those in the control group (P<0.05). The mean functional connection values of the left precuneus, left middle cingulate cortex, left superior medial gyrus, left precentral gyrus, and left cerebellum also decreased in the case group compared with the control group (P<0.05). Plasma aluminum concentration was negatively correlated with DMN1 functional connectivity value and MoCA scores (b=−0.004, 95%CI: −0.008–−0.001; b=−0.15, 95%CI: −0.233–−0.067; P<0.05). The mean functional connection values of DMN1 and DMN2 were positively correlated with MoCA scores (b=10.945, 95%CI: 5.574–16.316; b=10.107, 95%CI: 2.457–17.758; P<0.05). With the increase of plasma aluminum concentration, MoCA score decreased, but when the plasma aluminum concentration exceeded 19.50 µg·L−1, MoCA score decreased slowly. With the increase of the mean functional connectivity value of DMN1, MoCA score increased, but when the mean functional connectivity value of DMN1 exceeded 1.05 and continued to increase, the increase of MoCA score slowed down. The results of mediating effect analysis showed that the functional connectivity value of DMN1 partially mediated the relationship between plasma aluminum concentration and MoCA score, and the mediating effect was 25.80%. Conclusion Cognitive impairment in occupational aluminum-exposed workers is closely related to brain resting-state functional connectivity. There is a dose-response relationship of plasma aluminum concentration with DMN1 functional connectivity value and MoCA scores, and DMN1 functional connectivity value partially mediates the relationship between plasma aluminum concentration and MoCA scores. The brain functional connectivity value can be used as meaningful imaging data to study the cognitive decline induced by chronic aluminum exposure.
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Tinnitus refers to the perception of abnormal sound in the absence of external sound stimulation. It can have an impact on a person's mood, memory, attention, and mental state, although the mechanism of tinnitus is still unclear. In recent years, the research on the central neural mechanism of tinnitus has attracted the attention of scholars.Functional magnetic resonance imaging （fMRI）,as an effective imaging technology, has been actively employed in this field. This paper provides a systematic summary of studies on the central neural mechanism of tinnitus by fMRI in recent years,revealed the changes of functional connections among tinnitus-related neural networks,such as auditory network,limbic system,default mode network and salience network. The central neural mechanism of tinnitus involves multiple networks that interact with each other. By understanding this mechanism, we hope to develop more targeted prevention and treatment strategies to help patients alleviate long-term tinnitus.
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Humans , Tinnitus/diagnostic imaging , Magnetic Resonance Imaging/methods , AttentionABSTRACT
Introducción: La epilepsia y la enfermedad de Parkinson han sido descritos como trastornos de redes neurales. El estudio de la conectividad por modalidades moleculares puede ser más relevante fisiológicamente que los basados en señales hemodinámicas. Objetivo: Proponer una metodología para la descripción de patrones de conectividad funcional a partir de la perfusión cerebral por tomografía por emisión de fotón único. Métodos: La metodología incluye cuatro pasos principales: preprocesamiento espacial, corrección del volumen parcial, cálculo del índice de perfusión y obtención de la matriz de conectividad funcional mediante el coeficiente de correlación de Pearson. Se implementó en 25 pacientes con distintos trastornos neurológicos: 15 con epilepsia farmacorresistente y 10 con enfermedad de Parkinson. Resultados: Se encontraron diferencias significativas entre los índice de perfusión de varias regiones de los hemisferios ipsilateral y contralateral tanto en pacientes con epilepsia del lóbulo frontal como en pacientes con epilepsia del lóbulo temporal. Igual resultado se obtuvo en los pacientes con enfermedad de Parkinson con distintos estadios de la enfermedad. Para cada grupo se identificaron patrones de conectividad funcional que involucran a regiones relacionadas con la patología en estudio. Conclusiones: Con el desarrollo de esta metodología se ha demostrado que la tomografía por emisión de fotón único aporta información valiosa para estudiar la organización de las redes funcionales del cerebro. Futuras investigaciones con mayor número de pacientes contribuirían a hacer inferencias sobre los correlatos neurales de los distintos trastornos cerebrales.
Introduction: Epilepsy and Parkinson's disease have been described as disorders of neural networks. The study of connectivity by molecular modalities may be more physiologically relevant than those based on hemodynamic signals. Aim: The aim of the present work is to propose a methodology for the description of functional connectivity patterns from brain perfusion by single photon emission tomography. Methods: The methodology includes four main steps: spatial preprocessing, partial volume correction, calculation of the perfusion index and obtaining the functional connectivity matrix using Pearson's correlation coefficient. It was implemented in 25 patients with different neurological disorders: 15 with drug-resistant epilepsy and 10 suffering Parkinson's disease. Results: Significant differences were found between the perfusion indexes of various regions of the ipsilateral and contralateral hemispheres in both patients with frontal lobe epilepsy and patients with temporal lobe epilepsy. The same result was obtained in Parkinson's disease patients with different stages of the disease. For each group, functional connectivity patterns involving regions related to the pathology under study were identified. Conclusions: With the development of this methodology, it has been demonstrated that single photon emission tomography provides valuable information to study the organization of functional brain networks. Future research with a larger number of patients would contribute to make inferences about the neural correlates of the different brain disorders.
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ObjectiveTo compare the functional connectivity of brain networks in stroke patients with upper limb motor dysfunction during unilateral or bilateral upper limb movement using functional near-infrared spectroscopy (fNIRS). MethodsFrom April to June, 2021, 40 stroke patients with upper limb motor dysfunction in Department of Rehabilitation Medicine, Huashan Hospital, finished unilateral (affected) and bilateral upper limb movement. Eight-minute fNIRS data were collected before and after movement, and the functional activities and connectivity of prefrontal cortex (PFC), upper limb and hand functional area (H), primary sensory cortex (S1) were analyzed based on oxygenated hemoglobin. ResultsFunctional activities increased in affected H after unilateral task (t = -3.135, P < 0.05), while the functional connectivity increased between affected H and affected S1, affected H and unaffected S1, and affected S1 and unaffected S1 (|t| > 3.218, P < 0.05). There was no significant difference in the functional activities and connectivity of all the areas after bilateral upper limb task (|t| < 2.385, P > 0.05). The improvement of affected H was more after unilateral task than after bilateral upper limb task (t = 2.026, P < 0.05). ConclusionUnilateral affected upper limb training is more effective on functional activities and connectivity for corresponding brain regions than bilateral task.
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@#Objective To investigate the changes of functional brain connectivity over multiple frequency bands in resting-state electroencephalography (EEG) for lower limb amputation patients. Methods Resting-state EEG was collected from 18 lower limb amputees and 22 healthy controls from November, 2020 to June, 2021. Functional connectivity matrix was constructed with phase-locked values (PLV), and compared between groups. Results The functional connectivity was weaker in the amputees than in the controls on α band (t = 3.433, P = 0.001) and β band (t = 3.806, P = 0.001), and there was no significant difference on δ band (t = 1.429, P = 0.161) and θ band (t = 1.211, P = 0.233). Conclusion EEG functional connectivity weakens in lower limb amputees in on the α and β band, which results in neuroplasticity of multiple brain regions, not only for limb-respond cortex, but also for frontal, temporal and occipital cortices.
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The research shows that personality assessment can be achieved by regression model based on electroencephalogram (EEG). Most of existing researches use event-related potential or power spectral density for personality assessment, which can only represent the brain information of a single region. But some research shows that human cognition is more dependent on the interaction of brain regions. In addition, due to the distribution difference of EEG features among subjects, the trained regression model can not get accurate results of cross subject personality assessment. In order to solve the problem, this research proposes a personality assessment method based on EEG functional connectivity and domain adaption. This research collected EEG data from 45 normal people under different emotional pictures (positive, negative and neutral). Firstly, the coherence of 59 channels in 5 frequency bands was taken as the original feature set. Then the feature-based domain adaptation was used to map the feature to a new feature space. It can reduce the distribution difference between training and test set in the new feature space, so as to reduce the distribution difference between subjects. Finally, the support vector regression model was trained and tested based on the transformed feature set by leave-one-out cross-validation. What's more, this paper compared the methods used in previous researches. The results showed that the method proposed in this paper improved the performance of regression model and obtained better personality assessment results. This research provides a new method for personality assessment.
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Humans , Algorithms , Brain , Electroencephalography/methods , Emotions , Personality AssessmentABSTRACT
Objective:To explore the changes of brain activity in drug-resistant or drug-controlled medial temporal lobe epilepsy patients by the method of functional connectivity density (FCD), and to analyze their correlation with the course of the disease.Methods:According to the definition of drug-resistant epilepsy by the International League Against Epilepsy in 2010, 146 patients with medial temporal lobe epilepsy who were clearly diagnosed as unilateral hippocampal sclerosis in Jinling Hospital, Nanjing University School of Medicine from July 2009 to February 2019 were divided into drug control group ( n=73) and drug-resistant group ( n=73). The 3.0 T resting state functional magnetic resonance scan was performed on all subjects to compare the difference in FCD between the two groups, and calculate the correlation between the FCD value of the brain area and the course of the disease between the two groups of patients. Results:There was significant difference between the two groups in FCD. Compared with the drug control group, the drug-resistant group had significantly lower FCD values in the insula, lenticular nucleus, thalamus, hippocampus and precentral gyrus on the side of the epileptogenic focus. The FCD value of the precuneus on the side of the epileptogenic focus in the drug-resistant group was negatively correlated with the duration ( r=-0.30, P=0.01). Conclusions:The FCD of patients with drug-resistant medial temporal lobe epilepsy was lower than that of the drug control group. In addition, there may be progressive damage to the brain. The difference is helpful for exploring the pathophysiological mechanisms related to drug resistance in patients with medial temporal lobe epilepsy, and finding reliable neuroimaging markers related to drug resistance.
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Objective:To investigate the effects of single intermittent theta-burst stimulation on functional connectivity in patients with mild cognitive impairment(MCI).Methods:From July to November 2020, forty MCI patients were selected and randomly divided into iTBS true stimulation group and iTBS sham-stimulation group, with 20 patients in each group.iTBS targeted the left dorsolateral prefrontal cortex (DLPFC). Montreal cognitive assessment (MoCA), mini-mental state examination (MMSE), activity of daily living scale(ADL), Hamilton depression scale (HAMD) and Hamilton anxiety scale (HAMA) were evaluated at baseline.The resting state electroencephalography (rsEEG) was collected for 5 minutes before and after iTBS in the two groups.The phase lag index(PLI) of EEG functional connectivity was calculated, and the functional connectivity matrix diagram was drawn.SPSS 26.0 software was used for statistical analysis.Data were statistically analyzed by χ2 test, Wilcoxon rank sum test and independent sample t-test. Results:There were no significant differences in scores of MoCA, ADL, HAMD and HAMA between the two groups(all P>0.05). In the iTBS true stimulation group, compared with that before iTBS treatment(0.140(0.133, 0.144)), the PLI of β band increased significantly after iTBS treatment(0.146(0.136, 0.167))( P<0.05). The region of increased PLI was mainly concentrated in the central region(C3/C4-T7/T8). Compared with that before iTBS treatment(0.251(0.232, 0.299)), the PLI of α band increased after iTBS treatment(0.286(0.241, 0.359)), but the difference was not statistically significant( P>0.05). Conclusion:Single iTBS treatment can significantly increase the EEG functional connectivity in patients with MCI, indicating that iTBS targeting the left DLPFC can effectively regulate the EEG functional connectivity in patients with MCI, which may reveal the mechanism of iTBS in improving cognitive function in patients with MCI.
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Most obsessive-compulsive disorder patients get sick in childhood, adolescence and early adulthood, which has a serious impact on their psychosocial function. Childhood and adolescence are critical period of neurological development. Affected by genetic and environmental factors, individuals often have neuronal damage, abnormal myelination, synaptic overpruning, abnormal synaptic connections and so forth. Pediatric obsessive-compulsive disorder is closely related to neurodevelopmental, which may involve genetic variation, immune activation, neurotransmitter disorders and functional and structural abnormalities of key brain regions in the cortico-striato-thalamo-cortical.With the development of neuroimaging, optogenetics and other advanced technologies, the dynamic development process of the brain has been further understood, and the etiological mechanism of pediatric obsessive-compulsive disorder has been further explored.This paper summarized the latest researches in this field, focusing on neurodevelopment, and expounds the possible pathophysiological mechanism of obsessive-compulsive disorder from the perspectives of neuroimmunology, neurostructure, neuroimaging, neurobiochemistry and other disciplines. It provides a new idea for the early accurate diagnosis, recognition and intervention of obsessive-compulsive disorder.
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Objective:To analyze the changes of gray matter volume and resting-state functional connectivity in children with attention deficit hyperactivity disorder (ADHD) comorbid with oppositional defiant disorder (ODD).Methods:A total of 22 ADHD comorbid with ODD children (ADHD-ODD group, n=22) were selected from a public-assess resting-state fMRI ADHD cohort, namely, ADHD-200.Meanwhile, 22 age- and sex- matched ADHD children without ODD (ADHD group, n=22) and 22 healthy children(control group, n=22) were also included.T1-weighted MRI and resting-state fMRI scans were performed on all of the participants.The voxel-based morphometric (VBM) method was used to compare the volume of gray matter in three groups.The gray matter with aberrant volume was set as the region of interest(ROI) for mapping the functional connectivity of the whole brain.For comparison of gray matter volumes, one-way ANOVA and two-sample t-test analysis were applied, while two-sample t-test analysis was used for comparison of functional connectivity. Results:Compared with the control group, ADHD-ODD group showed decreased gray matter volume in the left cerebellum anterior lobe (MNI coordinate: x, y, z=-19.5, -42, -18) and right cerebellum anterior lobe (MNI coordinate: x, y, z=19.5, -39, -21). The left cerebellum anterior lobe showed increased functional connectivity with left superior frontal gyrus, left middle frontal gyrus (MNI coordinate: x, y, z=-24, 19, 43), right superior frontal gyrus, right middle frontal gyrus (MNI coordinate: x, y, z=30, 9, 45) and bilateral precuneus, posterior cingulate gyrus(MNI coordinate: x, y, z=-6, -35, 24). Compared with the ADHD group, ADHD-ODD group showed decreased gray matter volume in the right cerebellum anterior lobe (MNI coordinate: x, y, z=19.5, -37.5, -22.5). The right cerebellum anterior lobe showed increased functional connectivity with bilateral superior frontal gyrus, bilateral middle frontal gyrus, bilateral medial frontal gyrus, anterior cingulate gyrus and posterior cingulate gyrus(MNI coordinate: x, y, z=18, -12, 42), bilateral cuneus, bilateral lingual gyrus(MNI coordinate: x, y, z=9, -87, 27).Conclusion:ADHD comorbid with ODD children show decreased cerebellum volume and excessive functional connectivity with several brain regions of the cerebral hemispheres, which may be one of the neuropathological bases of cognitive, emotional, and behavioral disorders.