抑郁症患者眶额叶皮层功能连接偏离的研究

目的 通过功能磁共振成像技术,研究抑郁症患者和健康对照组在情感处理时眶额叶皮层的功能连接偏离,为抑郁症的早期诊断和疗效评估提供影像学依据.方法 对25例重度抑郁症患者和15名健康对照组在执行面貌一致性任务时进行功能性磁共振成像.结果 和健康对照组相比重度抑郁症患者的背侧前扣带回皮层、楔前叶、小脑与眶额叶的活动连接减少;抑郁症患者的眶额叶皮层和背外侧前额叶皮层、右额叶岛盖部、左运动区之间的功能连接比健康对照组有所增加.结论 眶额叶皮层在抑郁症的病理生理学机制中发挥着关键作用.眶额叶皮层连接的失衡似乎代表加工偏离的神经机制.从神经生物学的角度来看,楔前叶和扣带回的连接解离活动与眶额叶皮层的自我架构规则的问题相关,而背外侧前额叶皮层到眶额叶的连接增加可能代表更高消极刺激的神经反应.     

Frequency-specific alterations in functional connectivity in treatment-resistant and -sensitive major depressive disorder

Major depressive disorder (MDD) may involve alterations in brain functional connectivity in multiple neural circuits and present large-scale network dysfunction. Patients with treatment-resistant depression (TRD) and treatment-sensitive depression (TSD) show different responses to antidepressants and aberrant brain functions. This study aims to investigate functional connectivity patterns of TRD and TSD at the whole brain resting state. Seventeen patients with TRD, 17 patients with TSD, and 17 healthy controls matched with age, gender, and years of education were recruited in this study. The brain was divided using an automated anatomical labeling atlas into 90 regions of interest, which were used to construct the entire brain functional networks. An analysis method called network-based statistic was used to explore the dysconnected subnetworks of TRD and TSD at different frequency bands. At resting state, TSD and TRD present characteristic patterns of network dysfunction at special frequency bands. The dysconnected subnetwork of TSD mainly lies in the fronto-parietal top-down control network. Moreover, the abnormal neural circuits of TRD are extensive and complex. These circuits not only depend on the abnormal affective network but also involve other networks, including salience network, auditory network, visual network, and language processing cortex. Our findings reflect that the pathological mechanism of TSD may refer to impairment in cognitive control, whereas TRD mainly triggers the dysfunction of emotion processing and affective cognition. This study reveals that differences in brain functional connectivity at resting state reflect distinct pathophysiological mechanisms in TSD and TRD. These findings may be helpful in differentiating two types of MDD and predicting treatment responses.     

强迫症患者脑结构异常的多模态研究

目的探讨强迫症患者脑灰质和白质结构改变是否在同一样本中反映了相同环路的异常。方法对54例强迫症患者(强迫症组)和54名健康对照(对照组)进行3D结构磁共振成像扫描和弥散张量成像扫描。基于SPM分析软件,采用基于体素的形态学分析方法分析强迫症组全脑灰质体积与对照组的差异;基于FSL软件,采用基于纤维束示踪的空间统计学探讨强迫症组各向异性分数(fractional anisotropy,FA)与对照组的差异。结果与对照组相比,强迫症组左侧额中回、左侧前扣带和旁扣带脑回、左侧中央前回及右侧颞下回灰质体积减小(P<0.05,Alphasim校正),胼胝体体部和胼胝体膝部FA值减小(P<0.05,FWE校正)。结论强迫症患者的灰质体积和白质完整性均存在异常,且异常区域多位于皮质-纹状体-丘脑-皮质环路相关脑区,强迫症的灰、白质结构异常可能同时出现。     

未服药强迫症患者双侧杏仁核静息态功能连接的初步观察

目的探讨静息状态下未服药强迫症患者双侧杏仁核功能连接的模式。方法纳入符合ICD-10中强迫症诊断标准的40例未服药强迫症患者(强迫症组),38名在性别、年龄和受教育程度与之相匹配的健康对照者(对照组)。采用Y-BOCS、HAMD17、HAMA评估强迫思维、强迫行为以及抑郁、焦虑症状。所有被试者进行全脑静息态fMRI,以左右杏仁核为种子点,采用基于体素的全脑功能连接方法分析强迫症患者静息状态下双侧杏仁核的功能连接模式;采用皮尔逊相关分析方法探讨强迫症患者异常功能连接与临床症状之间的关系。结果与对照组相比,强迫症组左侧杏仁核与右背侧前脑岛(0.16±0.13与0.27±0.13,t=-2.75,P<0.05,高斯随机场理论校正)、左侧杏仁核与左腹侧前扣带回(0.09±0.12与0.19±0.13,t=-3.40,P<0.05,高斯随机场理论校正)功能连接降低;强迫症组左侧杏仁核与右背侧前脑岛之间功能连接Z值与HAMA总分呈正相关(r=0.377,P=0.016,未校正)。结论静息状态下未服药强迫症患者情绪调节网络功能连接降低;左侧杏仁核与右背侧前脑岛之间降低的功能连接可能与强迫症患者的焦虑症状相关。     

Abnormal functional connectivity in patients with vascular cognitive impairment, no dementia: a resting-state functional magnetic resonance imaging study

The functional connectivity (FC) method was used to investigate the changes in the resting state of patients with vascular cognitive impairment, no dementia (VCIND). Resting-state functional magnetic resonance images (fMRIs) were acquired from 16 patients with subcortical ischemic vascular disease (SIVD) who fulfilled the criteria for VCIND, as well as 18 age- and sex-matched subjects with SIVD with no cognitive impairment (control group). Posterior cingulate cortex connectivity was gathered by investigating synchronic low-frequency fMRI signal fluctuations with a temporal correlation method. Compared with the control group, the patients showed FC decrease in the left middle temporal gyrus, the left anterior cingulate/left middle frontal gyrus, the right caudate, the right middle frontal gyrus, and the left medial frontal gyrus/paracentral lobule. There were also some regions that showed increased connectivity. These regions included the right inferior temporal gyrus, the left middle temporal gyrus, the left precentral gyrus, and the left superior parietal lobule. Our findings revealed the change in resting-state patterns of neuronal activity in patients with VCIND. This change may be caused by subcortical white matter lesions that destroyed direct and indirect fiber tract connectivity across the cerebral white matter and influenced the cortical FC and hypoperfusion resulted from small vascular disease. The results of the increased connectivity may be evoked by the compensatory recruitment and plasticity mechanism. Our findings suggest that the simplicity and noninvasiveness of this method makes it a potential tool to help thoroughly understand the pathogenesis of VCIND.     

No disgust recognition deficit in obsessive-compulsive disorder

BACKGROUND: Patients with basal ganglia abnormalities misclassify facial expressions of disgust as expressions of anger when asked to identify the emotion depicted in photographs of individuals displaying different emotions. Sprengelmeyer, Young, Pundt et al. (1997) reported a similar disgust recognition deficit in patients with obsessive-compulsive disorder (OCD)--an anxiety disorder associated with basal ganglia abnormality. METHODS: In the present experiment, we attempted to replicate Sprengelmeyer, Young, Pundt et al.'s (1997) findings. RESULTS: We failed to replicate Sprengelmeyer, Young, Pundt et al.'s finding of disgust recognition deficits in OCD patients relative to healthy control subjects. One patient with especially severe OCD did, however, exhibit impairment by misclassifying disgust expressions as anger expressions. DISCUSSION: These data do not confirm the presence of disgust recognition deficits in individuals with OCD. In light of the deficits exhibited by one subject with severe OCD, disgust recognition deficits may be confined to an unidentified subset of people with OCD.     

Altered fMRI-derived functional connectivity in patients with high-tension glaucoma

BackgroundHigh-tension glaucoma (HTG) is associated with functional changes in the brain, and elevated intraocular pressure (IOP) is one of the major causes.PurposeTo evaluate the effects of high IOP on the brain in patients with HTG by using resting-state functional magnetic resonance imaging (rs-fMRI).Materials and methodsThirty-six patients with HTG and 20 age- and gender-matched healthy controls (HCs) were recruited and underwent IOP examination and rs-fMRI scan. Voxel-wise functional connectivity (FC) values were obtained between the Brodmann Area (BA) 17 (primary visual cortex) and the rest of the brain, two-sample t test was performed between HTG group and HCs. Correlation analysis was performed between FC and clinical information.ResultsCompared with HCs, HTG patients demonstrated decreased FC between BA 17 and the right precuneus gyrus, decreased FC between BA 17 and the right superior frontal gyrus (SFG) (GRF corrected at voxel level P < 0.001 and cluster level P < 0.05, two-tailed). FC between BA 17 and the right SFG showed significantly negative correlation with right eyes’ IOP and mean IOP.ConclusionHTG patients had abnormal FC changes between the visual cortex and multiple functional brain regions related to visual sense, memory consolidation and cognitive processing, which provided image support for the pathophysiology research of HTG, and revealed new targets for the accurate treatment of HTG.     

强迫症首次发病未服药患者脑静息态低频振幅研究

目的 探讨强迫症首次发病未服药患者静息脑神经活动的特点.方法 采用磁共振成像低频振幅(ALFF)方法,对昆明医学院第一附属医院22例强迫症患者(患者组)和22名健康志愿者(对照组)静息态脑血氧水平依赖(BOLD)信号活动的改变进行分析;采用功能磁共振成像技术进行数据采集,计算出各受试者的ALFF值;采用两样本t检验,以P<0.001水平统计患者组与对照组的差异.结果 与对照组比较,患者组BOLD信号ALFF改变只存在增高的区域,主要分布在左前扣带回和左中扣带回;未发现患者组左前中扣带回的ALFF值与病程(r=0.004,P=0.985)、年龄(r=0.090,P=0.689)和受教育程度(r=0.048,P=0.831)、Yale-Brown强迫量表总分(r=0.007,P=0.977)、强迫思维分量表分(r=0.140,P=0.530)和强迫行为分量表分(r=0.100,P=0.660)的相关性.结论 静息状态下强迫症患者脑神经活动的ALFF存在异常,ALFF增高可能反映了患者大脑异常的情绪及行为监控.

Abstract：

Objective To study the changes of amplitude of low-frequency fluctuation (ALFF) of the resting-fMRI in the patients with obsessive-compulsive disorder (OCD). Methods The resting-fMRI data of 22 OCD patients and 22 healthy controls were performed ALFF analysis. The amplitude of the blood oxygenation level dependent activation of the resting-state brain was investigated. Results The increased ALFF was only found in first-episode, drug-native OCD group compared with controls. The regions with increased ALFF were the left anterior cingulate and left middle cingulate gyrus (P<0. 001, corrected,K≥33). No significant correlations between ALFF value in these regions and course of disease (r = 0. 004,P = 0. 985) , age (r = 0. 090, P = 0. 689) and level of education (r = 0. 048 , P =0. 831) , no significant correlations between ALFF value and Y-BOCS score (r= 0.007, P= 0.977) , obsessive score (r=0. 140,P =0.530) and compulsive score (r=0. 100, P = 0.660) were found. Conclusion Abnormal ALFF may exist in OCD in the resting-state. The increased ALFF might reflect the strengthening of the emotional management and action monitoring.     

Left anterior subregion of orbitofrontal cortex volume reduction and impaired organizational strategies in obsessive-compulsive disorder

The orbitofrontal cortex (OFC) may be involved in the clinical and cognitive expressions of obsessive-compulsive disorder (OCD) and is a heterogenous region with respect to its cytoarchitecture, function and connectivity. This study was designed to examine the morphological abnormality of the anterior subregion of OFC and its relationship to clinical symptoms and cognitive performance in patients with OCD. We divided the OFC into anterior and posterior subregions using an external landmark and measured the gray matter volumes of each by three-dimensional magnetic resonance imaging in age- and sex-matched groups, which consisted of 34 OCD and 34 normal volunteers. Clinical and cognitive evaluations were completed using Yale-Brown Obsessive Compulsive Scale (YBOCS) and four sets of neuropsychological tests that assessed executive functions and visual memory. Volume reduction of the left anterior OFC was observed in patients with OCD versus normal controls. Also, a significant positive correlation was found between left anterior OFC gray matter volume and the copy score of the Rey-Osterrieth Complex Figure Test in patients with OCD. These results suggest that left anterior subregion volume reduction of the OFC may be related to impaired organizational strategies in patients with OCD.     

Disrupted functional connectivity of default mode and salience networks in chronic pancreatitis patients

ObjectiveThe functional connectivity of the brain in chronic pancreatitis (CP) remains unknown. This study aimed to investigate functional connectivity in CP patients using resting state functional magnetic resonance imaging (fMRI) and explore the associations to clinical parameters and altered cerebral metabolites.MethodsSeed-based and ROI-to-ROI analyses were performed to assess connectivity within and between the default mode network (DMN) and salience network (SN). Additionally, functional connectivity in these networks were investigated in relation to clinical parameters (CP etiology, pain, medication, etc.) and cerebral glutamate/creatine level in the anterior cingulate cortex.ResultsThirty CP patients and 23 healthy controls were analyzed. CP patients showed hyper-connectivity in DMN and SN as compared to healthy controls. Furthermore, CP patients had reduced anti-correlated functional connectivity between DMN and SN (all P ≤ 0.009). The altered DMN connectivity correlated to glutamate/creatine level (r = 0.503, P = 0.020) in patients with pain, but not to the clinical parameters.ConclusionsCP patients had altered functional connectivity within and between brain networks. Altered DMN functional connectivity had an association to cerebral metabolic changes.SignificanceAltered functional connectivity in CP share similarities with other chronic pain conditions, and support our understanding of altered brain circuitry associated with the CP disease.     

Regional cerebral blood flow in obsessive-compulsive patients with and without a chronic tic disorder. A SPECT study.

The main goal of the present study was to explore whether regional cerebral blood flow (rCBF) differs between obsessive-compulsive disorder (OCD) patients without chronic motor tic disorder and those OCD patients with a comorbid chronic tic disorder. Twenty-seven patients suffering from OCD (DSM-IV criteria), including 7 OCD patients who met DSM-IV criteria for simple chronic motor dic disorder, and 16 healthy volunteers were examined at rest using a high resolution SPECT. Seven regions of interest (ROIs) were manually traced and quantified as a percentage of the mean cerebellar uptake. Severity of obsessive-compulsive symptoms (OCS), anxiety and depressive symptoms and presence of motor tics were assessed with the Y-BOCS, HRS-A, HRS-D, MADRS, and Yale Global Tics Severity Scale, respectively. We found a significant relative decrease in rCBF in OCD patients without motor tics compared to healthy volunteers in the right orbitofrontal cortex (OCD without tics = 0.87; healthy volunteers = 0.94; p = 0.02). No significant differences in rCBF were seen when OCD patients with and without chronic tics were directly compared. A lower severity of OCS in OCD patients with chronic tics was found. These results are consistent with previous functional neuroimaging studies at rest that have widely involved the orbitofrontal cortex in the pathophysiology of the OCD. However, our results do not support the idea that OCD patients with chronic tics may constitute a biological subgroup within the OCD. Received: 11 May 1998 / Accepted: 1 April 1999     

Reduced cortical thickness in non-medicated patients with obsessive-compulsive disorder

Increasing evidence suggests the presence of grey matter volume abnormalities in patients with obsessive-compulsive disorder (OCD) and the mediation of the expression of different OCD symptoms by discrete neural systems of the brain. However, limited studies have investigated the abnormalities of cortical thickness, and their results are comparatively inconsistent, possibly owing to the inclusion of medicated patients. Therefore, this study investigated cortical thickness abnormalities using surface-based analysis to identify distinct neural correlates of each symptom dimension in non-medicated patients with OCD. Thirty non-medicated patients with OCD and 30 age- and gender-matched healthy controls underwent magnetic resonance imaging. Group comparison of cortical thickness was performed using surface-based analysis. We also conducted correlation analysis between cortical thickness and each symptom dimension score. Compared to the healthy controls, the OCD patients had statistically significant reduction in cortical thickness in the cluster that contained the left superior temporal gyrus and posterior insular cortex (p<.05, corrected); no areas of the brain had significantly greater cortical thickness. Negative correlation was also found between cortical thickness and "cleaning" dimension scores in the left postcentral and right superior parietal gyri. The present results suggest that cortical thinning in the region that contains the left superior temporal gyrus and posterior insula may underlie pathophysiology of OCD and that discrete neural systems may mediate the "cleaning" symptom dimension.     

长期海洛因成瘾者前额叶功能连接的静息态fMRI研究

目的 利用静息态fMRI探讨长期海洛因成瘾者前额叶功能连接的变化情况.方法 13例长期海洛因成瘾者和14例正常者接受静息态fMRI检查,对数据进行相关的预处理后,以前额叶为种子点与全脑每个体素进行相关分析,比较海洛因成瘾组与正常对照组前额叶功能连接的变化情况.结果 以左侧前额叶为种子点进行功能连接分析,海洛因成瘾组左侧前额叶与左侧海马、右侧前扣带回、左侧额中回、右侧额中回、右侧楔前叶功能连接明显低于正常对照组:以右侧前额叶为种子点进行功能连接分析,海洛因成瘾组右侧前额叶与左侧眶额叶、左侧额中回功能连接明显低于正常对照组.结论 长期海洛因成瘾者前额叶与相关脑区的功能连接减弱,前额叶可能参与了海洛因成瘾的维持与戒断后复吸.

Abstract：

Objective To explore the changes of functional connectivity of the prefrontal cortex in chronic heroin addicts under resting-state functional MRI (fMRI). Methods Resting fMRI examination was performed on 13 chronic heroin addicts and 14 healthy volunteers. After pre-processing the resting-state fMRI data, the prefrontal cortex was selected as the seed region, with which a whole-brain voxel temporal correlation in Iow frequency fMRI fluctuations was analyzed and the changes of functional connectivity of the prefrontal lobe in both chronic heroin addicts and healthy volunteers were calculated with SPM5 software. Results Compared with that in the control group, the functional connectivity between the left prefrontal cortex and the left hippocampus, right anterior cingulate, left middle frontal gyrus, right middle frontal gyrus, right precuneus in the heroin addiction group was significantly decreased. The functional connectivity between the right prefrontal cortex and the left orbital frontal cortex, left middle frontal gyrus in thc heroin addiction group was also significantly decreased as compared with that in the control group. Conclusion Functional connectivity of prefrontal cortex in chronic heroin addicts decreases, indicating that the prefrontal cortex may be involved in the maintenance of heroin addiction and relapse after withdrawal.     

A longitudinal functional connectivity analysis of the amygdala in bipolar I disorder across mood states

Cerullo MA, Fleck DE, Eliassen JC, Smith MS, DelBello MP, Adler CM, Strakowski SM. A longitudinal functional connectivity analysis of the amygdala in bipolar I disorder across mood states. Bipolar Disord 2012: 14: 175–184. © 2012 The Authors. Journal compilation © 2012 John Wiley & Sons A/S. Objective: Bipolar I disorder is characterized by affective symptoms varying between depression and mania. The specific neurophysiology responsible for depression in bipolar I disorder is unknown but previous neuroimaging studies suggest impairments in corticolimbic regions that are responsible for regulating emotion. The amygdala seems to play a central role in this network and is responsible for appraisal of emotional stimuli. To further understand the role of the amygdala in the generation of mood symptoms, we used functional magnetic resonance imaging (fMRI) to examine a group of patients with bipolar I disorder longitudinally. Methods: fMRI was used to study regional brain activation in 15 bipolar I disorder patients followed for up to one year. Patients received an fMRI scan during an initial manic episode and a subsequent depressive episode. During the scans, patients performed an attentional task that incorporated emotional pictures. Fifteen healthy comparison subjects were also scanned at baseline and then at four months. Whole‐brain functional connectivity analysis was performed using the left and right amygdala as seed regions. Results: Significant changes in amygdala functional connectivity were found between the manic and depressed phases of illness. The right amygdala was significantly more positively correlated with the left inferior frontal gyrus during mania and with the right insula during depression. There were no significant differences in left amygdala correlations across mood states in the bipolar I disorder group. Conclusions: In the transition from a manic/mixed episode to a depressive episode, subjects with bipolar I disorder showed unique changes in cortical–amygdala functional connectivity. Increased connectivity between the insula and right amygdala may generate excessive positive feedback, in that both of these regions are involved in the appraisal of emotional stimuli. Increased correlation between the right amygdala and the inferior frontal gyrus in mania is consistent with previous findings of decreased prefrontal modulation of limbic regions in mania. These differences in connectivity may represent neurofunctional markers of mood state as they occurred in the same individuals across manic and depressive episodes.     

Dynamic frontostriatal functional peak connectivity (in alcohol use disorder)

Alcohol use disorder (AUD) is associated with changes in frontostriatal connectivity, but functional magnetic resonance imaging (fMRI) functional connectivity (FC) approaches are usually not adapted to these circuits. We developed a circuit‐specific fMRI analysis approach to detect dynamic changes in frontostriatal FC inspired by medial‐ventral‐rostral to lateral‐dorsal‐caudal frontostriatal gradients originally identified in nonhuman primate tract‐tracing data. In our PeaCoG (“ pea k co nnectivity on a g radient”) approach we use information about the location of strongest FC on empirical frontostriatal connectivity gradients. We have recently described a basic PeaCoG version with conventional FC, and now developed a dynamic PeaCoG approach with sliding‐window FC. In resting state data of n = 66 AUD participants and n = 40 healthy controls we continue here the analyses that we began with the basic version. Our former result of an AUD‐associated ventral shift in right orbitofrontal cortex PeaCoG is consistently detected in the dynamic approach. Temporospatial variability of dynamic PeaCoG in the left dorsolateral prefrontal cortex is reduced in AUD and associated with self‐efficacy to abstain and days of abstinence. Our method has the potential to provide insight into the dynamics of frontostriatal circuits, which has so far been relatively unexplored, and into their role in mental disorders and normal cognition.