强迫症患者静息态功能磁共振低频振幅和功能连接改变

目的探讨强迫症患者静息态下脑神经元自发活动情况。方法纳入强迫症患者48例及年龄、性别、受教育年限相匹配的正常对照者50名,使用3.0 T功能磁共振采集静息态脑影像,分析患者与对照低频振幅(amplitude of low-frequency fluctuation, ALFF)有统计学差异的脑区,以差异脑区为种子点分析全脑功能连接(functional connectivity, FC),对ALFF和FC分析中的差异脑区与强迫症状进行相关分析。结果与对照组相比,强迫症患者左侧背外侧额上回的ALFF值增高(t=4.305,P0.01)。以左侧背外侧额上回为兴趣区全脑FC分析(基于MNI模板)示,与对照相比,患者左侧背外侧额上回与右侧眶部额下回(t=3.897,P0.001)、左侧扣带回前部(t=3.37,P0.001)、右侧扣带回前部(t=4.299,P0.001)、左侧扣带回中部(t=3.220,P0.001)、右侧扣带回中部(t=4.607,P0.001)FC强度增强;患者左侧背外侧额上回与左侧岛盖部额下回(t=-4.630,P0.001)FC强度减弱。强迫症患者左侧背外侧额上回与左侧岛盖部额下回的FC强度与耶鲁-布朗强迫症状量表强迫思维因子分(r=-0.369,P=0.014)、强迫行为因子分(r=-0.392,P=0.009)以及量表总分(r=-0.393,P=0.008)呈负相关。结论强迫症患者静息状态下左侧背外侧额上回自发神经元活动增强,与多个脑区间的FC异常;并且左侧背外侧额上回与左侧岛盖部额下回的FC强度与强迫症状相关。     

Altered functional connectivity networks of hippocampal subregions in remitted late-onset depression:a longitudinal resting-state study

The regional specifi city of hippocampal abnormalities in late-life depression(LLD) has been demonstrated in previous studies. In this study,we sought to examine the functional connectivity(FC) patterns of hippocampal subregions in remitted late-onset depression(r LOD),a special subtype of LLD. Fourteen r LOD patients and 18 healthy controls underwent clinical and cognitive evaluations as well as resting-state functional magnetic resonance imaging scans at baseline and at ~21 months of follow-up. Each hippocampus was divided into three parts,the cornu ammonis(CA),the dentate gyrus,and the subicular complex,and then six seed-based hippocampal subregional networks were established.Longitudinal changes of the six networks over time were directly compared between the rL OD and control groups. From baseline to follow-up,the r LOD group showed a greater decline in connectivity of the left CA to the bilateral posterior cingulate cortex/precuneus(PCC/PCUN),but showed increased connectivity of the right hippocampal subregional networks with the frontal cortex(bilateral medial prefrontal cortex/anterior cingulate cortex and supplementary motor area). Further correlative analyses revealed thatthe longitudinal changes in FC between the left CA and PCC/PCUN were positively correlated with longitudinal changes in the Symbol Digit Modalities Test(r = 0.624,P = 0.017) and the Digit Span Test(r = 0.545,P = 0.044) scores in the r LOD group. These results may provide insights into the neurobiological mechanism underlying the cognitive dysfunction in r LOD patients.     

强迫障碍患者脑自发活动的对照研究

目的:探讨强迫障碍(OCD)患者与健康人静息状态下脑自发活动的差异,以及差异脑区与临床症状的相关性。方法:对21例OCD患者(OCD组)和21名与OCD组人口学资料相匹配的健康志愿者(健康对照组)进行头部磁共振扫描后,采用低频振幅(ALFF)的方法比较两组间脑自发活动的差异;用耶鲁-布朗强迫量表(Y-BOCS)对OCD组进行症状评估,并对两组间有差异脑区的ALFF值与OCD病程、Y-BOCS总分进行相关分析。结果:与健康对照组比较,OCD组右侧眶额回及右侧小脑脚ALFF值显著增高(t=5.92,t=3.87;P0.05);右侧中央旁小叶、右侧枕下回ALFF值显著减低(t=-4.11,t=-3.20;P0.05)。进一步相关分析发现,右侧眶额回ALFF值与OCD病程呈正相关(r=0.571,P=0.009)。结论:OCD患者额叶、尤其是眶额回的功能活动存在异常;小脑、枕叶等后脑区功能活动异常可能也参与了OCD的发生。     

Local synchronization and amplitude of the fluctuation of spontaneous brain activity in attention-deficit/hyperactivity disorder: a resting-state fMRI study

Regional homogeneity（ReHo）and the amplitude of low-frequency fluctuation（ALFF）are two approaches to depicting different regional characteristics of resting-state functional magnetic resonance imaging（RS-fMRI）data.Whether they can complementarily reveal brain regional functional abnormalities in attention-deficit/hyperactivity disorder（ADHD）remains unknown.In this study,we applied ReHo and ALFF to 23 medication-na ve boys diagnosed with ADHD and 25 age-matched healthy male controls using whole-brain voxel-wise analysis.Correlation analyses were conducted in the ADHD group to investigate the relationship between the regional spontaneous brain activity measured by the two approaches and the clinical symptoms of ADHD.We found that the ReHo method showed widely-distributed differences between the two groups in the fronto-cingulo-occipitocerebellar circuitry,while the ALFF method showed a difference only in the right occipital area.When a larger smoothing kernel and a more lenient threshold were used for ALFF,more overlapped regions were found between ALFF and ReHo,and ALFF even found some new regions with group differences.The ADHD symptom scores were correlated with the ReHo values in the right cerebellum,dorsal anterior cingulate cortex and left lingual gyrus in the ADHD group,while no correlation was detected between ALFF and ADHD symptoms.In conclusion,ReHo may be more sensitive to regional abnormalities,at least in boys with ADHD,than ALFF.And ALFF may be complementary to ReHo in measuring local spontaneous activity.Combination of the two may yield a more comprehensive pathophy-siological framework for ADHD.     

抑郁症患者情绪图片反应特征及杏仁核反应模式的研究

Objective To explore the behavioral and related amygdaiar temporal response to emotional pictures in individuals with major depressive disorder(MDD).Methods Functional magnetic resonance imaging(fMRI)was adopted to examine the neural substrates of emotional pictures processing in 12 first-episode unmedicated MDD subjects(MDD)and 13 healthy controls(HC).Analyses were focused on the temporal dynamics of the blood-oxygen level dependant(BOLD)signal change in the amygdala across blocks of positive,neutral and negative emotional pictures.The crude score to emotional pictures was also recorded.Results(1)The crude score wag(6.6 ±0.2)to positive pictures and(4.7 ±0.1)to neutral pictures in depressed subjects,lower than that in HC(P＜0.01),and(3.4 ±0.3)to negativc pictures in depressed subjects,which was higher than that in HC(2.2±0.2,P＜0.01).(2)The bilateral amygdala showed attenuated and delayed response to the positive pictures.in which the right amygdala showed"group×time"interaction effect to positive pictures(P=0.002).For the negative pictures,there was"group×time"interaction effect in the left amygdala(P=0.008)and group main effect in the right amygdaia(P=0.007),with the attenuated BOLD signal change in MDD group.Conclusions It suggests that amygdala is one of the key neural substrates to the character of the depressed mood or loss of interest in individuals with MDD.Depressed subiects show the attenuated and blunted behavioral and amygdala response to emotional stimuli,which support the hypothesis of the unspecially blunted emotional response in major depressive disorder.     

抑郁症患者情绪图片反应特征及杏仁核反应模式的研究

Objective To explore the behavioral and related amygdaiar temporal response to emotional pictures in individuals with major depressive disorder(MDD).Methods Functional magnetic resonance imaging(fMRI)was adopted to examine the neural substrates of emotional pictures processing in 12 first-episode unmedicated MDD subjects(MDD)and 13 healthy controls(HC).Analyses were focused on the temporal dynamics of the blood-oxygen level dependant(BOLD)signal change in the amygdala across blocks of positive,neutral and negative emotional pictures.The crude score to emotional pictures was also recorded.Results(1)The crude score wag(6.6 ±0.2)to positive pictures and(4.7 ±0.1)to neutral pictures in depressed subjects,lower than that in HC(P＜0.01),and(3.4 ±0.3)to negativc pictures in depressed subjects,which was higher than that in HC(2.2±0.2,P＜0.01).(2)The bilateral amygdala showed attenuated and delayed response to the positive pictures.in which the right amygdala showed"group×time"interaction effect to positive pictures(P=0.002).For the negative pictures,there was"group×time"interaction effect in the left amygdala(P=0.008)and group main effect in the right amygdaia(P=0.007),with the attenuated BOLD signal change in MDD group.Conclusions It suggests that amygdala is one of the key neural substrates to the character of the depressed mood or loss of interest in individuals with MDD.Depressed subiects show the attenuated and blunted behavioral and amygdala response to emotional stimuli,which support the hypothesis of the unspecially blunted emotional response in major depressive disorder.     

抑郁症患者情绪图片反应特征及杏仁核反应模式的研究

Objective To explore the behavioral and related amygdaiar temporal response to emotional pictures in individuals with major depressive disorder(MDD).Methods Functional magnetic resonance imaging(fMRI)was adopted to examine the neural substrates of emotional pictures processing in 12 first-episode unmedicated MDD subjects(MDD)and 13 healthy controls(HC).Analyses were focused on the temporal dynamics of the blood-oxygen level dependant(BOLD)signal change in the amygdala across blocks of positive,neutral and negative emotional pictures.The crude score to emotional pictures was also recorded.Results(1)The crude score wag(6.6 ±0.2)to positive pictures and(4.7 ±0.1)to neutral pictures in depressed subjects,lower than that in HC(P＜0.01),and(3.4 ±0.3)to negativc pictures in depressed subjects,which was higher than that in HC(2.2±0.2,P＜0.01).(2)The bilateral amygdala showed attenuated and delayed response to the positive pictures.in which the right amygdala showed"group×time"interaction effect to positive pictures(P=0.002).For the negative pictures,there was"group×time"interaction effect in the left amygdala(P=0.008)and group main effect in the right amygdaia(P=0.007),with the attenuated BOLD signal change in MDD group.Conclusions It suggests that amygdala is one of the key neural substrates to the character of the depressed mood or loss of interest in individuals with MDD.Depressed subiects show the attenuated and blunted behavioral and amygdala response to emotional stimuli,which support the hypothesis of the unspecially blunted emotional response in major depressive disorder.     

抑郁症患者情绪图片反应特征及杏仁核反应模式的研究

Objective To explore the behavioral and related amygdaiar temporal response to emotional pictures in individuals with major depressive disorder(MDD).Methods Functional magnetic resonance imaging(fMRI)was adopted to examine the neural substrates of emotional pictures processing in 12 first-episode unmedicated MDD subjects(MDD)and 13 healthy controls(HC).Analyses were focused on the temporal dynamics of the blood-oxygen level dependant(BOLD)signal change in the amygdala across blocks of positive,neutral and negative emotional pictures.The crude score to emotional pictures was also recorded.Results(1)The crude score wag(6.6 ±0.2)to positive pictures and(4.7 ±0.1)to neutral pictures in depressed subjects,lower than that in HC(P＜0.01),and(3.4 ±0.3)to negativc pictures in depressed subjects,which was higher than that in HC(2.2±0.2,P＜0.01).(2)The bilateral amygdala showed attenuated and delayed response to the positive pictures.in which the right amygdala showed"group×time"interaction effect to positive pictures(P=0.002).For the negative pictures,there was"group×time"interaction effect in the left amygdala(P=0.008)and group main effect in the right amygdaia(P=0.007),with the attenuated BOLD signal change in MDD group.Conclusions It suggests that amygdala is one of the key neural substrates to the character of the depressed mood or loss of interest in individuals with MDD.Depressed subiects show the attenuated and blunted behavioral and amygdala response to emotional stimuli,which support the hypothesis of the unspecially blunted emotional response in major depressive disorder.     

Correlations between hippocampal functional connectivity,structural changes,and clinical data in patients with relapsing-remitting multiple sclerosis:a case-control study using multimodal magnetic resonance imaging

Multiple sclerosis is associated with structural and functional brain alterations leading to cognitive impairments across multiple domains including attention,memory,and the speed of information processing.The hippocampus,which is a brain important structure involved in memory,undergoes microstructural changes in the early stage of multiple sclerosis.In this study,we analyzed hippocampal function and structure in patients with relapsing-remitting multiple sclerosis and explored correlations between the functional connectivity of the hippocampus to the whole brain,changes in local brain function and microstructure,and cognitive function at rest.We retrospectively analyzed data from 20 relapsing-remitting multiple sclerosis patients admitted to the Department of Neurology at the China-Japan Union Hospital of Jilin University,China,from April 2015 to November 2019.Sixteen healthy volunteers were recruited as the healthy control group.All participants were evaluated using a scale of extended disability status and the Montreal cognitive assessment within 1 week before and after head diffusion tensor imaging and functional magnetic resonance imaging.Compared with the healthy control group,the patients with relapsing-remitting multiple sclerosis had lower Montreal cognitive assessment scores and regions of simultaneously enhanced and attenuated whole-brain functional connectivity and local functional connectivity in the bilateral hippocampus.Hippocampal diffusion tensor imaging data showed that,compared with the healthy control group,patients with relapsing-remitting multiple sclerosis had lower hippocampal fractional anisotropy values and higher mean diffusivity values,suggesting abnormal hippocampal structure.The left hippocampus whole-brain functional connectivity was negatively correlated with the Montreal cognitive assessment score(r=-0.698,P=0.025),and whole-brain functional connectivity of the right hippocampus was negatively correlated with extended disability status scale score(r=-0.649,P=0.042).The mean diffusivity value of the left hippocampus was negatively correlated with the Montreal cognitive assessment score(r=-0.729,P=0.017)and positively correlated with the extended disability status scale score(r=0.653,P=0.041).The right hippocampal mean diffusivity value was positively correlated with the extended disability status scale score(r=0.684,P=0.029).These data suggest that the functional connectivity and presence of structural abnormalities in the hippocampus in patients with relapse-remission multiple sclerosis are correlated with the degree of cognitive function and extent of disability.This study was approved by the Ethics Committee of China-Japan Union Hospital of Jilin University,China(approval No.201702202)on February 22,2017.     

综合心理行为干预对军事演习应激状态官兵心理健康和事件相关电位P300的影响

Objective To explore the effects of the comprehensive psychological behavior intervention on the mental health and event-related potentials ( ERPs ) of the servicemen under military exercise. Methods One hundred and twenty-seven servicemen who participated in the military exercise were randomly divided into two groups, named the study group ( n = 63 ) and the control group ( n = 64 ). The servicemen in the study group were given the comprehensive psychological behavior intervention for 6 weeks.They were assessed with the Symptom Checklist-90 ( SCL-90 ) and event-related potential P300( P300 ) preintervention and post-intervention. Results ( 1 )The factors of somatization, interpersonal sensitivity, and anxiety of SCL-90 were significantly decreased after intervention in study group ( P ＜ 0. 05 ). In the control group, the factors of somatization, interpersonal sensitivity, phobic anxiety and total score post-intervention were significantly increased after military exercise ( P ＜0. 05 ). Before intervention, the difference on SCL-90score between the study group and the control group was not significant ( P ＞ 0. 05 ). After intervention, the factors of somatization, interpersonal sensitivity, anxiety, phobic anxiety and total score in the study group were significantly lower than that of the control group ( P ＜0. 05 ). ( 2 )After intervention, the study group showed higher amplitude on target P3 of P300 at Cz and FPz than the baseline ( q = 3.45, 3.46, P ＜ 0. 05 ),and shortened latency on non-target P2 at FPz[( 167.8 ± 23.5 )ms vs. ( 188. 3 ± 25. 2 )ms,q =3.54,P ＜0. 05] . The control group showed higher latency on target P3 at FPz than baseline ( q = 3.64, P ＜ 0. 05 ).Before intervention, there was no significant difference with P300 between two groups ( P ＞0. 05 ). Compared with the controls after intervention, the study group manifested shorter latency on target P3 and non-target P2at Cz and FPz ( P ＜0. 05 ). And higher amplitude on target P3 at Cz and FPz and on non-target P2 at FPz were appeared ( q = 3.34, 3. 35, 3.68, P ＜ 0. 05 ). Conclusion The comprehensive psychological behavior intervention could effectively improve the mental health and partly electrophysiological index of the serviceman in military stress.     

卒中后失语语言和非语言认知功能相关的静息态功能磁共振成像研究

目的 本研究拟借助静息态功能磁共振成像（resting-state functional magnetic resonance imaging,rsfMRI ）,探讨卒中后失语（post-stroke aphasia,PSA）患者语言及非语言认知功能特征及其相关的脑功 能变化情况。 方法 选择2019年3月-2020年1月连续就诊于首都医科大学附属北京天坛医院的PSA患者作为病例 组,筛选年龄、性别、受教育程度相匹配的健康志愿者作为健康对照（healthy controls,HCs）组。应 用西方失语成套测验（western aphasia battery,WAB）及洛文斯顿作业疗法认知评定（Loewenstein occupational therapy cognitive assessment,LOTCA）评估语言及非语言认知功能。应用rs-fMRI采集低 频振幅（amplitude of low frequency fluctuation,ALFF）及功能连接密度（functional connectivity density, FCD）等参数。比较两组影像学参数,并将其与WAB及LOTCA评分进行Pearson相关分析。 结果 本研究纳入16例PSA患者及17例HCs。与HCs组比较,PSA组双侧海马、海马旁回、颞下回等区 域ALFF值升高,左侧额下回岛盖部、岛叶等部位ALFF值降低;右侧海马、海马旁回的FCD值升高,左 侧顶下回、枕上回、枕中回、楔前叶等脑区FCD值降低。ALFF值与WAB及LOTCA评分的相关性分析显 示,左侧额下回岛盖部的ALFF值与WAB-失语商及流畅度得分呈正比（r =0.693,P =0.026;r =0.662, P =0.037）;左侧额下回岛盖部的ALFF值与LOTCA定向得分呈正比（r =0.642,P =0.045）,左侧海马的 ALFF值与LOTCA注意力及专注力评分呈正比（r =0.706,P =0.022）。 结论 PSA患者合并部分脑区局部自发活动的强度变化及脑区间的连通性改变,这些改变与PSA患 者语言障碍和非语言认知功能障碍密切相关,这些影像学改变可以作为PSA重要影像学标记。     

Abnormal baseline brain activity in low-grade hepatic encephalopathy: a resting-state fMRI study

Resting-state functional magnetic resonance imaging (fMRI) has been used to detect the alterations of spontaneous neuronal activity in various neuropsychiatric diseases, but rarely in low-grade hepatic encephalopathy (HE), a common neuropsychiatric complication of liver cirrhosis. We conducted a resting-state fMRI in 19 healthy controls, 18 cirrhotic patients without HE, and 22 cirrhotic patients with low-grade HE. The amplitude of low-frequency fluctuations (ALFF) of fMRI signal was computed to measure the spontaneous neuronal activity. Several regions showing significant ALFF differences among three groups were the precuneus, occipital lobe, left frontal lobe and anterior/middle cingulate cortex, and left cerebellum posterior lobe. Compared to controls or patients without HE, patients with low-grade HE showed decreased ALFF in the precuneus and adjacent cuneus, visual cortex, and left cerebellum posterior lobe. Compared to controls, patients with low-grade HE showed higher ALFF in both cortical and subcortical regions, including the right middle cingulate gyrus, and left anterior/middle cingulate gyrus, inferior frontal gyrus, insula lobe, parahippocampal gyrus, middle temporal gyrus and lentiform nucleus; compared to patients without HE, patients with low-grade HE showed higher ALFF in the left medial frontal gyrus and anterior cingulate gyrus, bilateral superior frontal gyrus, and right middle frontal gyrus. Moreover, correlations between ALFF changes and poor neurocognitive performances were found in patients with low-grade HE. These results suggested the existence of aberrant brain activity at the baseline state in low-grade HE, which may be implicated in the neurological pathophysiology underlying HE.     

Temporal variability of regional intrinsic neural activity in drug‐naïve patients with obsessive–compulsive disorder

Obsessive–compulsive disorder (OCD) displays alterations in regional brain activity represented by the amplitude of low‐frequency fluctuation (ALFF), but the time‐varying characteristics of this local neural activity remain to be clarified. We aimed to investigate the dynamic changes of intrinsic brain activity in a relatively large sample of drug‐naïve OCD patients using univariate and multivariate analyses. We applied a sliding‐window approach to calculate the dynamic ALFF (dALFF) and compared the difference between 73 OCD patients and age‐ and sex‐matched healthy controls (HCs). We also utilized multivariate pattern analysis to determine whether dALFF could differentiate OCD patients from HCs at the individual level. Compared with HCs, OCD patients exhibited increased dALFF mainly within regions of the cortical–striatal–thalamic–cortical (CSTC) circuit, including the bilateral dorsal anterior cingulate cortex, medial prefrontal cortex and striatum, and right dorsolateral prefrontal cortex (dlPFC). Decreased dALFF was identified in the bilateral inferior parietal lobule (IPL), posterior cingulate cortex, insula, fusiform gyrus, and cerebellum. Moreover, we found negative correlations between illness duration and dALFF values in the right IPL and between dALFF values in the left cerebellum and Hamilton Depression Scale scores. Furthermore, dALFF can distinguish OCD patients from HCs with the most discriminative regions located in the IPL, dlPFC, middle occipital gyrus, and cuneus. Taken together, in the current study, we demonstrated a characteristic pattern of higher variability of regional brain activity within the CSTC circuits and lower variability in regions outside the CSTC circuits in drug‐naïve OCD patients.     

Comprehensive evaluation of cortical structure abnormalities in drug-naïve, adult patients with obsessive-compulsive disorder: A surface-based morphometry study

The study objective was to comprehensively evaluate drug-naïve, adult patients with Obsessive Compulsive Disorder (OCD) for cortical structure abnormalities in comparison with healthy controls. In this cross-sectional study of case–control design, Magnetic Resonance Imaging (1-mm) was performed in drug-naïve OCD patients (N = 50) &; age- sex-, education- and handedness-matched healthy controls (N = 40). We examined cortical volume, thickness, surface area &; local Gyrification Index (LGI) through a completely automated surface-based morphometric analysis using FreeSurfer software. OCD symptoms and insight were assessed using Yale-Brown Obsessive Compulsive Symptom (Y-BOCS) check-list and severity scale. Illness severity was assessed using Clinical Global Impression Severity (CGI-S) Scale. OCD patients had significantly deficient volume, thickness and surface area of right anterior cingulate gyrus (ACG). Right lingual gyrus surface area was found to be significantly decreased in patients. Y-BOCS obsession score had significant negative correlation with left frontal pole volume. Y-BOCS compulsion score had significant negative correlations with right ACG volume and surface area and right lateral orbitofrontal cortex LGI. CGI-Severity score had significant negative correlations with right lingual gyrus volume, thickness and surface area as well as right lateral orbitofrontal area. Y-BOCS insight score showed a significant negative correlation with LGI of left medial OFC and left rostral ACG. Identification of novel deficits involving occipital brain regions and first-time observations of relevant correlations between various illness characteristics and cortical measures in OCD patients supports a network involving anterior cingulate, orbitofrontal and occipital brain regions in the pathogenesis of OCD.     

早发精神分裂症静息态脑功能低频振幅研究

目的通过静息态功能磁共振研究早发未用药精神分裂症患者局部脑功能低频振幅(amplitude of low-frequency fluctuation,ALFF)的变化,探讨其静息态下功能异常的脑区。方法收集20例早发未用药精神分裂症患者与20名性别、年龄、受教育年限相匹配的正常对照,分别对其进行全脑静息态功能磁共振扫描,计算ALFF值。结果与对照组相比,患者组左侧额上回、左侧楔前叶、左侧扣带回、左侧枕叶、左侧海马旁回、左侧距状沟ALFF值增高(P0.05,Alpha Sim校正),右侧颞上回和右侧小脑后叶ALFF值降低(P0.05,Alpha Sim校正)。结论早发精神分裂症患者在静息态下有多处脑区ALFF值改变,提示其在静息态下存在脑功能异常。     

Spatial patterns of intrinsic brain activity in mild cognitive impairment and Alzheimer's disease: a resting-state functional MRI study

We used resting-state functional MRI to investigate spatial patterns of spontaneous brain activity in 22 healthy elderly subjects, as well as 16 mild cognitive impairment (MCI) and 16 Alzheimer's disease (AD) patients. The pattern of intrinsic brain activity was measured by examining the amplitude of low-frequency fluctuations (ALFF) of blood oxygen level dependent signal during rest. There were widespread ALFF differences among the three groups throughout the frontal, temporal, and parietal cortices. Both AD and MCI patients showed decreased activity mainly in the medial parietal lobe region and lentiform nucleus, while there was increased activity in the lateral temporal regions and superior frontal and parietal regions as compared with controls. Compared with MCI, the AD patients showed decreased activity in the medial prefrontal cortex and increased activity in the superior frontal gyrus and inferior and superior temporal gyri. Specifically, the most significant ALFF differences among the groups appeared in the posterior cingulate cortex, with a reduced pattern of activity when comparing healthy controls, MCI, and AD patients. Additionally, we also showed that the regions with ALFF changes had significant correlations with the cognitive performance of patients as measured by mini-mental state examination scores. Finally, while taking gray matter volume as covariates, the ALFF results were approximately consistent with those without gray matter correction, implying that the functional analysis could not be explained by regional atrophy. Together, our results demonstrate that there is a specific pattern of ALFF in AD and MCI, thus providing insights into biological mechanisms of the diseases.     

Gray matter volumes in obsessive-compulsive disorder before and after fluoxetine or cognitive-behavior therapy: a randomized clinical trial

Serotonin reuptake inhibitors and cognitive-behavior therapy (CBT) are considered first-line treatments for obsessive-compulsive disorder (OCD). However, little is known about their modulatory effects on regional brain morphology in OCD patients. We sought to document structural brain abnormalities in treatment-naive OCD patients and to determine the effects of pharmacological and cognitive-behavioral treatments on regional brain volumes. Treatment-naive patients with OCD (n=38) underwent structural magnetic resonance imaging scan before and after a 12-week randomized clinical trial with either fluoxetine or group CBT. Matched-healthy controls (n=36) were also scanned at baseline. Voxel-based morphometry was used to compare regional gray matter (GM) volumes of regions of interest (ROIs) placed in the orbitofrontal, anterior cingulate and temporolimbic cortices, striatum, and thalamus. Treatment-naive OCD patients presented smaller GM volume in the left putamen, bilateral medial orbitofrontal, and left anterior cingulate cortices than did controls (p<0.05, corrected for multiple comparisons). After treatment with either fluoxetine or CBT (n=26), GM volume abnormalities in the left putamen were no longer detectable relative to controls. ROI-based within-group comparisons revealed that GM volume in the left putamen significantly increased (p<0.012) in fluoxetine-treated patients (n=13), whereas no significant GM volume changes were observed in CBT-treated patients (n=13). This study supports the involvement of orbitofronto/cingulo-striatal loops in the pathophysiology of OCD and suggests that fluoxetine and CBT may have distinct neurobiological mechanisms of action.     

Intrinsic brain abnormalities in irritable bowel syndrome and effect of anxiety and depression

This resting-state functional magnetic resonance imaging (rs-fMRI) study investigated intrinsic brain abnormalities in irritable bowel syndrome (IBS) and effect of anxiety and depression. Thirty IBS patients and 31 matched healthy controls underwent rs-fMRI scanning. Regional brain activity was evaluated by measuring the amplitude of low-frequency fluctuation (ALFF) and compared between IBS patients and healthy controls with a two-sample t-test. Areas with abnormal ALFF were further used as seeds in subsequent inter-regional functional connectivity (FC) analysis. Statistical analyses were also performed by including anxiety and depression as covariates to evaluate their effect. Compared to healthy controls, IBS patients showed decreased ALFF in several core default mode network regions (medial prefrontal cortex [MPFC], posterior cingulate cortex [PCC], bilateral inferior parietal cortices [IPC]), and in middle frontal cortex, right orbital part of the superior frontal gyrus (ORBsup), dorsal anterior cingulate cortex (dACC), and ventral anterior cingulated cortex (vACC), while they showed increased ALFF in bilateral posterior insula and cuneus. In addition, IBS patients revealed decreased inter-regional positive FC between MPFC and right ORBsup, between vACC and PCC, as well as decreased negative FC between MPFC and left posterior insula, while they showed increased negative FC between MPFC and cuneus. The inclusion of anxiety and depression as covariates abolished ALFF differences in dACC and vACC, but none of the FC differences. In conclusion: IBS patients had disturbed intrinsic brain function. High levels of anxiety and depression in IBS patients could account for their decreased intrinsic brain activity in regions (the ACC) involved in affective processing.     

Cerebral functional deficits in patients with ankylosing spondylitis- an fMRI study

Neurological impairment plays an important role in the development of Ankylosing spondylitis (AS). Early diagnosis and detection of it may stop the progress of neurological complications and improve the quality of patients’ lives greatly. Somatosensory evoked potential (SSEP) and magnetic motor evoked potentials (MEP) have been proved useful to detect neurological impairments of AS. This study aimed to investigate the cerebral function deficits of AS using functional MRI technology. Twenty seven patients with AS and 28 control subjects were included in this study. All of them underwent structural MRI and resting state-functional MRI (rs-fMRI) scanning. Comparisons of amplitude of low frequency fluctuations (ALFF) of rs-fMRI signals between AS patients and normal controls were performed using two sample t-tests. To examine functional connectivity within the groups, one-sample t tests were performed on the individual z-value maps. The z values were compared between the two groups using two-sample t test. Partial correlations between rs-fMRI measures (ALFF and functional connectivity) of the brain regions which showed group difference and clinical results including the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score, the serum high-sensitivity C-reactive protein (hsCRP), and the erythrocyte sedimentation rate (ESR) were analyzed for AS patients. Compared with normal controls, the AS patients exhibited significant lower ALFF in the left medial frontal gyrus, the right precentral gyrus and the right posterior cingulate, while higher ALFF in the left cerebellum anterior lobe, the left middle temporal gyrus, the left superior occipital gyrus, the left postcentral gyrus and the right precuneus. AS patients showed widespread brain connectivity alterations. Functional connectivity strength of the left precuneus and the left middle temporal gyrus were closely correlated with the the BASDAI scores, ESR and hsCRP in AS patients. Our results enhance the understanding of the pathomechanism of AS and suggest that Rs-fMRI may be a helpful tool in the clinical detection and evaluation of neurological impairment in AS.     

无灶性癫痫患者静息态fMRI与注意功能的相关性研究

目的采用静息态功能磁共振成像的低频振幅技术,探讨无灶性癫痫患者低频振幅与注意功能之间可能存在的关系。方法对16例无灶性癫痫患者和16名正常志愿者进行静息态fMRI数据采集及注意功能行为学测试,采用REST软件计算显示无灶性癫痫患者相对于正常人ALFF增高和减弱的区域,对上述的16例无灶性癫痫患者和16例正常对照进行气球叉掉测试,数字符号转换测试及stroop测试检测其注意功能,观察无灶性癫痫患者静息态fMRI与注意功能之间可能存在的联系。结果①无灶性癫痫组和正常对照组相比,ALFF增强的脑区分布在右侧颞叶(15,-90,21)、内侧额叶(0,24,-24)、腹侧前扣带回(-12,30,27)及右侧小脑半球(-51,-57,-4);②无灶性癫痫组和正常对照组相比ALFF减弱的脑区分布在左侧小脑半球及相邻后缘枕叶(-48,-15,39)、后扣带回(60,-21,33)及楔前叶(-6,-54,66);③无灶性癫痫患者的三项注意功能测试反应时间均较正常对照组延长(P<0.01)。Stroop测试结果表明无灶性癫痫组与对照组相比冲突条件下较一致、中性条件下的错误率显著增加。结论无灶性癫痫患者静息状态下表现出异常的脑功能活动方式。长期异常放电对患者的注意功能有明显损害,其中持续注意能力下降,可能与无灶性癫痫患者的颞叶及额叶的病变相关;选择注意能力下降,可能与腹侧前扣带回的损伤密切相关。