Brain regional homogeneity and function connectivity in attenuated psychosis syndrome —based on a resting state fMRI study

Background

By combining regional homogeneity (ReHo) and functional connectivity (FC) analyses, this study aimed to explore brain functional alterations in Attenuated Psychosis Syndrome (APS), which could provide complementary information for the neurophysiological indicators for schizophrenia (SZ) associated brain dysfunction.

Methods

Twenty-one APS subjects and twenty healthy controls were enrolled in the data acquisition of demographics and clinical characteristics as well as structural and resting-state functional magnetic resonance imaging (rs-fMRI). ReHo analysis was conducted to determine the peak coordinate of the abnormal regional brain activity. Then, identified brain regions were considered as seed regions and were used to calculate FC between reginal brain voxels and whole brain voxels. Finally, potential correlations between imaging indices and clinical data were also explored.

Results

Four APS and two HC subjects were excluded because the largest dynamic translation or rotation had exceeded 2?mm / 2°. Compared with healthy controls (HCs), APS subjects exhibited higher ReHo values in the right middle temporal gyrus (MTG) and lower ReHo values in the left middle frontal gyrus (MFG), left superior frontal gyrus (SFG), left postcentral gyrus (PoCG), and left superior frontal gyrus, medial (SFGmed). Considered these areas as seed regions, the APS subjects showed abnormal enhancement in functional brain connections, predominantly in the frontal and temporal lobes.

Conclusions

We concluded that the APS subjects had spatially regional dysfunction and remoted synchronous dysfunction in the frontal and temporal lobes of the brain, and changes in ReHo and FC patterns may reveal the mechanism of brain dysfunctions and may serve as an imaging biomarker for the diagnosis and evaluation of SZ.

     

基于核磁共振成像技术的甲状腺功能减退伴焦虑患者的脑功能区研究

目的 探讨甲状腺功能减退伴焦虑患者脑功能区核磁共振成像(Magnetic resonance imaging,MRI)表现。方法 选取本院2018年5月-2019年8月收治的甲状腺功能减退伴焦虑患者30例为观察组,并选取同期体检健康者30例为对照组; 收集2组研究对象的一般资料,并对脑功能区进行功能磁共振成像(Functional magnetic resonance imaging,fMRI)扫描,采用局部一致性(Regional homogeneity,ReHo)值找出基础状态下自发异常脑功能活动区,Speaeman分析异常脑功能区与甲状腺激素水平、神经精神症状的相关性。结果 fMRI扫描显示甲状腺功能减退患者右海马旁回、左侧颞下回、左右前扣带回脑功能区的ReHo值明显高于对照组(0.81±0.02 vs. 0.78±0.04、0.73±0.07 vs. 0.69±0.05、0.89±0.12 vs.0.84±0.09、0.87±0.11 vs. 0.83±0.07)(P<0.05),左侧内额上回ReHo值明显低于对照组(0.77±0.13 vs. 0.72±0.11)(P<0.05); 不同焦虑程度的右海马旁回、左侧颞下回、左前扣带回、右前扣带回、左侧内侧额上回5个异常脑功能区ReHo值相近(P>0.05); 左、右前扣带回ReHo值与游离甲状腺素(Free thyroxine,FT4)水平显著相关(r=-0.398,P=0.023; r=-0.424,P=0.031); 左、右前扣带回ReHo值与焦虑等级显著相关(r=0.425,P=0.533; r=0.027,P=0.017)。结论 海马旁回、颞下回、前扣带回、内侧额上回4个脑功能区可能参与甲状腺功能减退患者引发焦虑症状的脑部生理机制,甲状腺功能减退患者焦虑症状的脑神经反常活动与前扣带回自发异常活动密切相关,可为甲状腺功能减退伴焦虑患者的临床诊疗提供新思路。     

Regional Homogeneity Brain Alterations in Schizophrenia: An Activation Likelihood Estimation Meta-Analysis

ObjectiveResting state functional magnetic resonance imaging (rsfMRI) provides a lot of evidence for local abnormal brain activity in schizophrenia, but the results are not consistent. Our aim is to find out the consistent abnormal brain regions of the patients with schizophrenia by using regional homogeneity (ReHo), and indirectly understand the degree of brain damage of the patients with drug-naive first episode schizophrenia (Dn-FES) and chronic schizophrenia. MethodsWe performed the experiment by activation likelihood estimation (ALE) software to analysis the differences between people with schizophrenia group (all schizophrenia group and chronic schizophrenia group) and healthy controls. ResultsThirteen functional imaging studies were included in quantitative meta-analysis. All schizophrenia group showed decreased ReHo in bilateral precentral gyrus (PreCG) and left middle occipital gyrus (MOG), and increased ReHo in bilateral superior frontal gyrus (SFG) and right insula. Chronic schizophrenia group showed decreased ReHo in bilateral MOG, right fusiform gyrus, left PreCG, left cerebellum, right precuneus, left medial frontal gyrus and left anterior cingulate cortex (ACC). No significant increased brain areas were found in patients with chronic schizophrenia. ConclusionOur findings suggest that patients with chronic schizophrenia have more extensive brain damage than FES, which may contribute to our understanding of the progressive pathophysiology of schizophrenia.     

Graph-theory based degree centrality combined with machine learning algorithms can predict response to treatment with antiepileptic medications in children with epilepsy

Background and purposeThe purpose of the current study is to detect changes of graph-theory-based degree centrality (DC) and their relationship with the clinical treatment effects of anti-epileptic drugs (AEDs) for patients with childhood absence epilepsy (CAE) using resting-state functional MRI (RS-fMRI).MethodsRS-fMRI data from 35 CAE patients were collected and compared with findings from 35 age and gender matched healthy controls (HCs). The patients were treated with AEDs for 46.03 weeks before undergoing a second RS-fMRI scan.ResultsCAE children at baseline showed increased DC in thalamus, postcentral and precentral and reduced DC in medial frontal cortex, superior frontal cortex, middle temporal cortex, angular and precuneus. However, those abnormalities showed a clear renormalization after AEDs treatments. We then explored the viability of graph-theory-based degree centrality to accurately classify effectiveness to AEDs. Support Vector Machine analysis using leave-one-out cross-validation achieved a correct classification rate of 84.22% [sensitivity 78.76%, specificity 89.65%, and area under the receiver operating characteristic curve (AUC) 0.96] for differentiating effective subjects from ineffective subjects. Brain areas that contributed most to the classification model were mainly located within the right thalamus, bilateral middle temporal gyrus, right medial frontal gyrus, right inferior frontal gyrus, left precuneus, bilateral angular right precentral and left postcentral. Furthermore, the DC change within the bilateral angular are positively correlated with the symptom improvements after AEDs treatment.ConclusionThese findings suggest that graph-theory-based measures, such as DC, combined with machine-learning algorithms, can provide crucial insights into pathophysiological mechanisms and the effectiveness of AEDs.     

以妄想为主的男性精神分裂症患者脑局部一致性的功能磁共振研究

目的：探讨男性偏执型精神分裂症患者在静息状态下是否存在脑功能活动异常及其区域。方法：采用病例一对照研究方法,对20例以妄想为主的男性精神分裂症患者（患者组）和20名性别、年龄、受教育程度相匹配的正常对照者（正常对照组）进行功能磁共振成像（fMRI）扫描,分析静息状态下各脑区的局部一致性（regionalhomogeneity,ReHo）的差异。结果：设P〈0．05、体素范围（k值）≥85,与正常对照组比较,患者组双侧额上回、双侧颞中回、左额中回、左中央前回、左小脑脚和右扣带回局部一致性（ReHo值）减低,右颞上回和左颞下回ReHo值增高,而左梭状回ReHo值既有增高也有减低。结论：以妄想为主的男性精神分裂症患者在静息状态下可能存在广泛分布的脑区功能异常。     

不同亚型轻度认知障碍患者静息态脑功能局部一致性研究

目的探讨遗忘型和非遗忘型轻度认知障碍(mild cognition impairment,MCI)患者局部自发脑活动特点。方法纳入遗忘型MCI(amnesicMCI,aMCI)患者25例,非遗忘型MCI(non-amnesticMCI,naMCI)患者21例和正常对照(normal control,NC)15名进行静息态功能磁共振扫描,通过计算每个给定体素与其最邻近26个体素时间序列的相似性获得全脑局部一致性(regional homogeneity,ReHo)图,比较三组被试全脑ReHo差异。结果 aMCI组右侧额叶ReHo值低于NC组,左侧颞中回和左侧小脑ReHo值高于NC组(P0.05,Alphasim校正);naMCI组前扣带回和右侧额中回ReHo值低于NC组,右侧海马旁回、右侧颞中回和右侧楔前叶ReHo值高于NC组(P0.05,Alphasim校正);aMCI左侧前额叶和左侧颞中回ReHo值高于naMCI组,右侧小脑ReHo值低于naMCI组(P0.05,Alphasim校正)。结论 aMCI和naMCI患者左侧前额叶、左侧颞中回及右侧小脑自发脑功能活动存在差异,这为区别aMCI和naMCI两者脑功能活动特点提供了初步影像学依据。     

Dysfunctional beliefs and attitudes about sleep are associated with regional homogeneity of left inferior occipital gyrus in primary insomnia patients: A preliminary resting state functional magnetic resonance imaging study

BackgroundThe neural mechanisms of sleep beliefs and attitudes in primary insomnia (PI) patients at resting state remain unclear. The aim of this study was to investigate the features of regional homogeneity (ReHo) in PI using resting-state functional magnetic resonance imaging (rsfMRI).MethodsThirty-two PI patients and 34 normal controls (NC) underwent rsfMRI using a 3 T scanner at Tongde Hospital of Zhejiang Province. Participants were assessed with the Dysfunctional Beliefs and Attitudes about Sleep scale (DBAS-16) and Pittsburgh Sleep Quality Index (PSQI). Statistical analyses were performed to determine the regions in which ReHo differed between the two groups. Correlation analyses were performed between the ReHo index of each of these regions and DBAS-16 in PI patients.ResultsPI patients showed increased ReHo values in the right superior frontal gyrus, and decreased ReHo values in the left cerebellar gyrus, left inferior occipital gyrus (IOG) and left amygdala compared with those of NC. ReHo values in the left IOG were negatively correlated with total DBAS-16 scores, and scores for “consequences of insomnia” and“worry/helplessness about sleep”in PI patients.ConclusionsThese results suggest that ReHo alterations in the left IOG may play an important role in the dysfunctional beliefs and attitudes about sleep in PI.     

Effects of obstructive sleep apnoea severity on neurocognitive and brain white matter alterations in children according to sex: a tract-based spatial statistics study

ObjectivesTo investigate alterations in neurocognitive, attention, paediatric sleep questionnaire (PSQ) scores and whole brain white matter (WM) integrity between children with mild and severe obstructive sleep apnoea (OSA) according to sex and whether these changes are associated with OSA severity.MethodsFifty-seven children (36 males and 21 females) diagnosed with OSA were recruited for this study. Children of both sexes were divided into mild (male-MG, female-MG) and severe (male-SG, female-SG) groups according to OSA severity. Polysomnography (PSG), neurocognitive, attention and PSQ tests were compared between groups by one-way samples analysis of variance (ANOVA) F test. Diffusion tensor imaging (DTI) was scanned using a 3T GE MRI scanner and analysed by Tract-based Spatial Statistics (TBSS). Spearman correlation was calculated between DTI Eigenvalues and clinical characteristics.ResultsCompared to mild OSA patients, severe OSA patients presented greater severity of obstructive apnoea hypopnea index (OAHI), neurocognition, PSQ and attention tests in both male and female patients. Brain WM integrity in the male-SG, compared to the male-MG, demonstrated significantly reduced fractional anisotropy (FA) values in the right middle frontal gyrus and the right frontal sub-gyral regions and increased axial diffusivity (AD) values in the right inferior frontal gyrus, left parietal angular gyrus and sub-gyral regions, while no differences were found between the female-MG and female-SG. Alterations in male-SG brain regions were observably correlated with severity in male OSA patients.ConclusionsThe integrity of WM, which regulates autonomic, cognitive, and attention functions, is impaired in male, but not female, children with severe OSA.     

Inflammation is associated with decreased functional connectivity of insula in unmedicated bipolar disorder

BackgroundSystemic inflammation and immune dysregulation have been considered as risk factors in the pathophysiology of mood disorders including bipolar disorder (BD). Previous neuroimaging studies have demonstrated metabolic, structural and functional abnormalities in the insula in BD, proposed that the insula played an important role in BD. We herein aimed to explore neural mechanisms underlying inflammation-induced in the insular subregions functional connectivity (FC) in patients with BD.MethodsBrain resting-state functional magnetic resonance imaging (rs-fMRI) data were acquired from 41 patients with unmedicated BD II (current episode depressed), 68 healthy controls (HCs). Three pairs of insular seed regions were selected: the bilateral anterior insula (AI), the bilateral middle insula (MI) and the bilateral posterior insula (PI), and calculated the whole-brain FC for each subregion. Additionally, the serum levels of pro-inflammatory cytokines in patients and HCs, including IL-6 and TNF-α, were detected. Then the partial correlation coefficients between the abnormal insular subregions FC values and pro-inflammatory cytokines levels in patients with BD II depression were calculated.ResultsThe BD II depression group exhibited decreased FC between the right PI and the left postcentral gyrus, and increased FC between the left AI and the bilateral insula (extended to the right putamen) when compared with the HC group. Moreover, the patients with BD II depression showed higher IL-6 and TNF-α levels than HCs, and IL-6 level was negatively correlated with FC of the right PI to the left postcentral gyrus.ConclusionsOur results demonstrated that abnormal FC between the bilateral insula, and between the insula and sensorimotor areas in BD. Moreover, disrupted FC between the insula and sensorimotor areas was associated with elevated pro-inflammatory cytokine levels of IL-6 in BD.     

首发精神分裂症患者静息态脑局部一致性功能性磁共振研究

目的:应用功能性磁共振(f MRI)技术,探讨首发精神分裂症患者静息状态下脑局部一致性(Re Ho)功能变化的特征。方法:对首发未用药精神分裂患者(急性期组)及性别、年龄、受教育年限匹配的经抗精神病药治疗后症状缓解的首发精神分裂症患者(缓解组)各17例,分别进行f MRI扫描,利用Re Ho的方法分析数据,比较两组间Re Ho变化。结果:与急性期组相比,缓解期组表现出右侧颞上回、舌回/梭状回、左侧和右侧额下回、左侧和右侧中央后回、小脑等脑区局部一致性异常,均有统计学意义(P均0.05)。结论:缓解期组较急性期组相比,多个脑区有相应的局部一致性异常,这种脑功能特征的变化,可能与抗精神病药改善症状有关,且可能反映精神分裂症生物内表型的变化。     

Altered cerebral activity associated with topiramate and its withdrawal in patients with epilepsy with language impairment: An fMRI study using the verb generation task

ObjectiveTopiramate (TPM) is well recognized for its negative effects on language in healthy volunteers and patients with epilepsy. The aim of this study was to investigate the brain activation and deactivation patterns in TPM-treated patients with epilepsy with language impairment and their dynamic alteration during TPM withdrawal using functional magnetic resonance imaging (fMRI) with the verb generation task (VGT).MethodsTwelve patients with epilepsy experiencing subjective language disfluency after TPM add-on treatment (TPM-on) and thirty sex- and age-matched healthy controls (HCs) were recruited. All subjects received a battery of neuropsychological tests and an fMRI scan with the VGT. Withdrawal of TPM was attempted in all patients. Only six patients reached complete withdrawal without seizure relapses (TPM-off), and these patients underwent a reassessment of neuropsychological and neuroimaging tests.ResultThe neuropsychological tests demonstrated objective language impairments in TPM-on patients. Compared with the HCs, the bilateral medial prefrontal cortex and the posterior midline and lateral parts of the default mode network (DMN) (including the bilateral posterior cingulate cortex (PCC), the right medial prefrontal cortex, the right angular gyrus, the right inferior temporal gyrus, and the bilateral supramarginal gyrus) in TPM-on patients failed to deactivate during the VGT. Their task-induced activation patterns were largely similar to those of the HCs. After TPM withdrawal, partial improvement of both task-induced deactivation of the DMN (the left parahippocampal gyrus and the bilateral PCC) and task-related activation of the language network (the right middle frontal gyrus and the left superior occipital gyrus) was identified along with partial improvement of neuropsychological tests.ConclusionTask-induced deactivation is a more sensitive neuroimaging biomarker for the impaired language performance in patients administered TPM than task-induced activation. Disruption and reorganization of the balance between the DMN and the cortical language networks are found along with reversible TPM-related language impairment. These results may suggest an underlying brain mechanism by which TPM affects cognitive function.     

首次发病且未用药的成年早发和晚发抑郁症患者脑功能连接差异研究

目的比较成年早发抑郁症(EOD)和成年晚发抑郁症(LOD)患者默认网络(DMN)内部功能连接的差异,探究不同发病年龄的抑郁症患者是否有不同的发病机制。方法选取在昆明医科大学第一附属医院精神科门诊或住院的EOD患者(n=58)和LOD患者(n=62)为研究对象,同期招募年轻健康对照组(n=60)和年老健康对照组(n=52)。对受试者进行静息态功能磁共振扫描,选择左侧楔前叶为种子点,计算该种子点与全脑的功能连接,并比较各组间该种子点的功能连接差异。结果四组之间功能连接具有差异的脑区涉及双侧额叶、颞叶、基底节、枕叶、顶叶及小脑等脑区。EOD组左侧楔前叶与左侧小脑Crus1区、左侧小脑IX区、左侧颞中回、右侧楔前叶、右侧前扣带回、右侧额中回、右侧角回、右侧脑岛、右侧内侧额上回、右侧颞中回的功能连接均高于年轻健康对照组(Z=3. 752 4～5. 867 8,P均0. 05);而左侧楔前叶与左侧额中回、左侧中央旁小叶、右侧缘上回、右侧额上回、右侧颞下回、右侧中央后回、右侧中央前回、右侧枕上回的功能连接均低于年轻健康对照组(Z=-5. 007 6～-3. 797 7,P均0. 05)。LOD组左侧楔前叶与左侧小脑Crus2区、左侧尾状核、左侧颞下回、左侧小脑Crus1区、左侧角回、左侧额中回、右侧额中回、右侧角回、右侧眶额部额中回的功能连接均高于年老健康对照组(Z=4. 122 8～6. 579 4,P均0. 05);与左侧海马旁回、左侧额上回、右侧枕中回、右侧中央前回、右侧内侧额上回、右侧锯状回、右侧颞下回、右侧中央旁小叶、右侧梭状回、右侧后扣带回的功能连接均低于年老健康对照组(Z=-5. 884 0～-3. 617 2,P均0. 05)。EOD组左侧楔前叶与左侧锯状回、左侧小脑IV-VI区、左侧小脑Crus2区的功能连接比LOD组高(Z=4. 087 7、3. 937 4、3. 672 1,P均0. 05);EOD组左侧楔前叶与右侧额中回、右侧眶额部额下回、右侧额上回的功能连接比LOD组低(Z=-4. 274 8、-3. 956 8、-4. 724 3、-3. 663 2,P均0. 05)。结论 DMN内部功能连接增高及额顶网络功能连接降低可能与EOD的发病机制相关,而DMN前部功能连接增高和后部功能连接降低可能与LOD的发病机制相关,不同发病年龄的成年抑郁症患者可能有不同的发病机制。     

Two types of mental fatigue affect spontaneous oscillatory brain activities in different ways

Background

Fatigue has a multi-factorial nature. We examined the effects of two types of mental fatigue on spontaneous oscillatory brain activity using magnetoencephalography (MEG).

Methods

Participants were randomly assigned to two groups in a single-blinded, crossover fashion to perform two types of mental fatigue-inducing experiments. Each experiment consisted of a 30-min fatigue-inducing 0- or 2-back test session and two evaluation sessions performed just before and after the fatigue-inducing mental task session.

Results

After the 0-back test, decreased alpha power was indicated in the right angular gyrus and increased levels in the left middle and superior temporal gyrus, left postcentral gyrus, right superior frontal gyrus, left inferior frontal gyrus, and right medial frontal gyrus. After the 2-back test, decreased alpha power was indicated in the right middle and superior frontal gyrus and increased levels in the left inferior parietal and superior parietal lobules, right parahippocampal gyrus, right uncus, left postcentral gyrus, left middle frontal gyrus, and right inferior frontal gyrus. For beta power, increased power following the 0-back test was indicated in the left middle temporal gyrus, left superior frontal gyrus, left cingulate gyrus, and left precentral gyrus. After the 2-back test, decreased power was suggested in the left superior frontal gyrus and increased levels in the left middle temporal gyrus and left inferior parietal lobule. Some of these brain regions might be associated with task performance during the fatigue-inducing trials.

Conclusions

Two types of mental fatigue may produce different alterations of the spontaneous oscillatory MEG activities. Our findings would provide new perspectives on the neural mechanisms underlying mental fatigue.     

Analysis of Altered Baseline Brain Activity in Drug-Naive Adult Patients with Social Anxiety Disorder Using Resting-State Functional MRI

Objective

We hypothesize that the amplitude of low-frequency fluctuations (ALFF) is involved in the altered regional baseline brain function in social anxiety disorder (SAD). The aim of the study was to analyze the altered baseline brain activity in drug-naive adult patients with SAD.

Methods

We investigated spontaneous and baseline brain activities by obtaining the resting-state functional magnetic resonance imaging data of 20 drug-naïve adult SAD patients and 19 healthy controls. Voxels were used to analyze the ALFF values using one- and two-sample t-tests. A post-hoc correlation of clinical symptoms was also performed.

Results

Our findings show decreased ALFF in the bilateral insula, left medial superior frontal gyrus, left precuneus, left middle temporal gyrus, right middle temporal pole, and left fusiform gyrus of the SAD group. The SAD patients exhibited significantly increased ALFF in the right inferior temporal gyrus, right middle temporal gyrus, bilateral middle occipital gyrus, orbital superior frontal gyrus, right fusiform gyrus, right medial superior frontal gyrus, and left parahippocampal gyrus. Moreover, the Liebowitz Social Anxiety Scale results for the SAD patients were positively correlated with the mean Z values of the right middle occipital and right inferior occipital but showed a negative correlation with the mean Z values of the right superior temporal gyrus and right medial superior frontal gyrus.

Conclusion

These results of the altered regional baseline brain function in SAD suggest that the regions with abnormal spontaneous activities are involved in the underlying pathophysiology of SAD patients.     

Executive functions in obsessive–compulsive disorder: An activation likelihood estimate meta-analysis of fMRI studies

Objectives: To identify activation changes assessed in functional magnetic resonance imaging (fMRI) studies of obsessive–compulsive disorder (OCD) through Activation Likelihood Estimate meta-analysis. Methods: We included 28 peer-reviewed standard stereotactic space studies assessing adult OCD patients (OCDpts) vs. healthy controls (HCs) with fMRI during executive task performance. Results: In within-group analyses, HCs showed task-related activations in bilateral inferior frontal gyri, right middle frontal gyrus, right inferior parietal lobule, right claustrum, bilateral cingulate gyri, and left caudate body. OCDpts showed task-related left-sided activations in the superior, medial, and inferior frontal gyri, and thalamus, and bilateral activations in the middle frontal gyri, inferior parietal lobule, and insular cortices. Subtraction analysis showed increased left middle frontal gyrus activation in OCDpts. In between-groups analyses, OCDpts hypoactivated the right caudate body, left putamen, left ACC, and right medial and middle frontal gyri. Right caudate hypoactivation persisted also after applying Family‐wise error algorithms. Conclusions: This meta-analysis confirms that during executive functioning OCDpts show a functional deficit of the right caudate body, which could represent a major neural functional correlate of their illness.     

Altered intrinsic brain activity and memory performance improvement in patients with end-stage renal disease during a single dialysis session

Memory deficits are considered to have a great influence on self-management, dietary restriction and therapeutic regimen for end-stage renal disease (ESRD) patients with dialysis treatment. This study was aim to investigate the spontaneous brain activity and its relationship with memory performance in ESRD patients before dialysis (T1) and after 24 h (T2) during a single dialysis session. 23 ESRD patients and 25 matched healthy controls (HCs) were scanned using functional magnetic resonance imaging (fMRI) at T1, and all patients were also scanned at T2. Amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) methods were used to evaluate the spontaneous brain activity between two groups. The Auditory Verbal Learning Test-Huashan version (AVLT-H) was performed to assess memory function. Compared with HCs, ESRD group showed a significant decreases in the immediate recall total score (IR-S), short-term delayed recall score (SR-S), and long-term delayed recall score (LR-S) at T1. IR-S, SR-S, LR-S and recognition score (REC-S) were significantly increased at T2. Compared with HCs at T1, ESRD patients showed that the lower mean ALFF (mALFF) values were mainly located in dorsolateral prefrontal cortex (DLPFC), medial frontal gyrus, and precuneus. Higher ReHo in the bilateral inferior temporal gyrus and left hippocampus and lower ReHo in the right precentral gyrus, anterior cingulate cortex were found at T1 too. The mALFF values of the DLPFC and precuneus were significantly increased during a dialysis session, while no significantly difference of ReHo region was found. Furthermore, the increased mALFF values of the DLPFC were significantly positively correlated with the improvement in the IR-S. Our results indicated that increased regional spontaneous activity of the DLPFC may reflect memory performance improvement after a single dialysis treatment, which may provide insight into the effect of hemodialysis on spontaneous brain function during a single dialysis session.     

抑郁症首次发病患者静息态脑功能局部一致性的研究

目的 利用功能磁共振(fMRI)和局部一致性(regional homogeneity,ReHo)探讨抑郁症首次发病(以下简称首发)患者在静息态脑功能是否存在异常及异常部位.方法 对34例符合美国精神疾病诊断与统计手册第4版诊断标准的首发抑郁症患者(抑郁症组)和34名性别、年龄、文化程度匹配的健康志愿者(对照组)进行静息态fMRI扫描.结果 抑郁症组静息态脑血氧水平依赖信号的ReHo高于对照组的脑区有左侧额叶眶回、顶下小叶、颞上回,右侧额内侧回、顶下小叶、小脑后叶;低于对照组的脑区有左颞下回、右颞上同和胼胝体、双侧后扣带回(P＜0.005,K≥10).结论首发抑郁症患者在静息态存在多个腩区功能活动的异常,并可能和抑郁症的病理机制有关.     

A resting-state functional magnetic resonance imaging study on the first-degree relatives of persons with schizophrenia

In this study, resting state fMRI images and BOLD signals were recorded from 13 first-degree relatives of schizophrenic patients and 13 healthy controls. The data were analyzed with the ReHo approach after realignment, registration, and normalization in statistical parametric mapping 2 (SPM2). A two-sample t-test was used to analyze the ReHo differences between first-degree relatives and healthy controls in a voxel by voxel manner. A combined threshold of p < 0.005 and number of voxels >5 was designated as statistically significant. To evaluate cognitive deficits in first-degree relatives, attention/vigilance and verbal/visual memory were measured. Significant impairments in attention were observed in first-degree relatives compared to healthy controls. Significant abnormalities in ReHo were observed in resting brain in first-degree relatives. Decreased ReHo was found to be distributed over the bilateral middle frontal, middle temporal, cingulate gyrus and cerebellar tonsil; the left inferior frontal gyrus, inferior parietal lobule and dorsolateral prefrontal cortex; the right superior frontal gyrus and dorsolateral prefrontal cortex. Increased ReHo was found to be distributed in the right precuneus and superior temporal gyrus. These changes in ReHo suggest abnormality in the resting state brain function of first-degree relatives of schizophrenic patients and may be early signs for the development of schizophrenia.     

轻度认知功能障碍患者正电子发射计算机体层摄影术和神经心理学测定的初步研究

目的　探讨轻度认知功能障碍患者脑葡萄糖代谢与神经心理学特点及其相互关系。方法　采用正电子发射体层摄影术 (PET)、简易智能状态测定 (MMSE)、韦克斯勒记忆量表测定 (WMS)和总体衰退量表 (GDS)测定 10例轻度认知功能障碍 (MCI)患者和 10名健康志愿者 (HC)。结果 (1)MCI组MMSE[(2 4.6± 2 2 )分 ]、WMS[(6 9.4± 10 .4)分 ]分值低于HC组 [分别为 (2 8.9± 1.1)分和 (93.1± 9.0 )分 ;P〈0 .0 1];(2 )MCI组左侧眶回、右侧颞叶中回和右侧壳核的局部脑葡萄糖代谢率 (rCMRglc)较HC组低 (P〈0 .0 5～ 0 .0 1) ;(3)将年龄、受教育年限、MMSE、WMS与不同脑区用18F标记的脱氧葡萄糖放射性比值进行相关分析显示 ,与年龄呈负相关 (P〈0 .0 5或P〈0 .0 1)的脑区有 :眶回、左侧额上回、左侧额下回、颞叶中回、颞叶下回、左侧顶叶、左侧中央前回、右侧中央后回、左颞叶内侧皮质、左侧海马回、左侧海马旁回、右侧前扣带回、后扣带回、左侧杏仁核等。与文化程度呈正相关 (P〈0 .0 5或P〈0 .0 1)的脑区有 :左侧颞叶下回、中央前回、左侧中央后回等 ;而右侧壳核则呈负相关。与MMSE呈正相关 (P〈0 .0 5或P〈0 .0 1)的脑区有 :额下回、左侧颞叶上回、颞叶中回、颞叶下回、左侧顶叶、左侧中央前回、中央后回、颞叶内侧皮     

Altered intra- and interregional synchronization in the absence of the corpus callosum: a resting-state fMRI study

Agenesis of the corpus callosum (AgCC) can result in subtle to severe cognitive deficits. Individuals with impaired cognition often show abnormalities on resting-state functional magnetic resonance imaging (rs-fMRI). This study used rs-fMRI to investigate changes in regional homogeneity (ReHo) and functional connectivity (FC) among individuals with AgCC. AgCC individuals (n = 10) and age-, sex-, and education-matched healthy control subjects (n = 19) were included in this study. The ReHo values were calculated to represent spontaneous brain activity. The regions which showed altered ReHo were selected as seeds to compare FC with the whole brain between the AgCC group and the healthy control group. Compared with healthy control subjects, the AgCC individuals had increased ReHo in the left anterior cingulate gyrus, left rolandic operculum, and right precuneus and decreased ReHo in the right calcarine, right cingual gyrus and right cuneus gyrus. The right calcarine and the right lingual gyrus in the AgCC exhibited decreased FC with bilateral cuneus, superior occipital gyrus, Rolandic operculum, superior temporal gyrus, posterior central gyrus, and midcingulate gyrus.The right cuneus gyrus in the AgCC individuals exhibited decreased FC with the bilateral calcarine gyrus, left cuneus, and left superior occipital gyrus. Our study revealed several subareas within the visual cortex exhibited remarkable abnormalities of spontaneous brain activity and decreased FC with the higher-order cognitive cortex.The abnormalities of ReHo and FC in AgCC individuals may provide new insights into the neurological pathophysiology.