Increased Cerebellar Functional Connectivity With the Default-Mode Network in Unaffected Siblings of Schizophrenia Patients at Rest

The default-mode network (DMN) is vital in the neurobiology of schizophrenia, and the cerebellum participates in the high-order cognitive network such as the DMN. However, the specific contribution of the cerebellum to the DMN abnormalities remains unclear in unaffected siblings of schizophrenia patients. Forty-six unaffected siblings of schizophrenia patients and 46 healthy controls were recruited for a resting-state scan. The images were analyzed using the functional connectivity (FC) method. The siblings showed significantly increased FCs between the left Crus I and the left superior medial prefrontal cortex (MPFC), as well as between the lobule IX and the bilateral MPFC (orbital part) and right superior MPFC compared with the controls. No significantly decreased FC was observed in the siblings relative to the controls. The analyses were replicated in 49 first-episode, drug-naive patients with schizophrenia, and the results showed that the siblings and the patients shared increased FCs between the left Crus I and the left superior MPFC, as well as between the lobule IX and the left MPFC (orbital part) compared with the controls. These findings suggest that increased cerebellar-DMN connectivities emerge earlier than illness onset, which highlight the contribution of the cerebellum to the DMN alterations in unaffected siblings. The shared increased cerebellar-DMN connectivities between the patients and the siblings may be used as candidate endophenotypes for schizophrenia.Key words: unaffected siblings of schizophrenia patients, schizophrenia, cerebellum, functional connectivity, default-mode network     

Morphological and functional abnormalities of salience network in the early-stage of paranoid schizophrenia

A salience network (SN), mainly composed of the anterior insula (AI) and anterior cingulate cortex (ACC), has been suggested to play an important role in salience attribution which has been proposed as central to the pathology of paranoid schizophrenia. The role of this SN in the pathophysiology of paranoid schizophrenia, however, still remains unclear. In the present study, voxel-based morphometry and resting-state functional connectivity analyses were combined to identify morphological and functional abnormalities in the proposed SN in the early-stage of paranoid schizophrenia (ESPS). Voxel-based morphometry and resting-state functional connectivity analyses were applied to 90 ESPS patients and 90 age- and sex-matched healthy controls (HC). Correlation analyses were performed to examine the relationships between various clinical variables and both gray matter morphology and functional connectivity within the SN in ESPS. Compared to the HC group, the ESPS group showed significantly reduced gray matter volume (GMV) in both bilateral AI and ACC. Moreover, significantly reduced functional connectivity within the SN sub-networks was identified in the ESPS group. These convergent morphological and functional deficits in SN were significantly associated with hallucinations. Additionally, illness duration correlated with reduced GMV in the left AI in ESPS. In conclusion, these findings provide convergent evidence for the morphological and functional abnormalities of the SN in ESPS. Moreover, the association of illness duration with the reduced GMV in the left AI suggests that the SN and the AI, in particular, may manifest progressive morphological changes that are especially important in the emergence of ESPS.     

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。     

Volumetric white matter abnormalities in first-episode schizophrenia: a longitudinal, tensor-based morphometry study

OBJECTIVE: While schizophrenia has long been considered a disorder of brain connectivity, few studies have investigated white matter abnormalities in patients with first-episode schizophrenia, and even fewer studies have investigated whether there is progressive white matter pathology in the disease. METHOD: The authors obtained a T1-weighted structural magnetic resonance imaging (MRI) scan on 41 patients with first-episode schizophrenia. These first-episode schizophrenia patients were analyzed relative to 47 age- and sex-matched healthy comparison subjects who also underwent an MRI scan. Of the baseline participants, 25 first-episode schizophrenia patients and 26 comparison subjects returned 2 to 3 years later for a follow-up scan. To identify regional volumetric white matter differences between the two groups at baseline, voxel-based morphometry in statistical parametric mapping-2 (SPM2) was used, while tensor-based morphometry was used to identify the longitudinal changes over the follow-up interval. RESULTS: The first-episode schizophrenia patients exhibited volumetric deficits in the white matter of the frontal and temporal lobes at baseline, as well as volumetric increases in the white matter of the frontoparietal junction bilaterally. Furthermore, these first-episode schizophrenia patients lost considerably more white matter over the follow-up interval relative to comparison subjects in the middle and inferior temporal cortex bilaterally. CONCLUSIONS: These results indicate that patients with schizophrenia exhibit white matter abnormalities at the time of their first presentation of psychotic symptoms to mental health services and that these abnormalities degenerate further over the initial years of illness. Given the role that white matter plays in neural communication, the authors suggest that these white matter abnormalities may be a cause of the dysfunctional neural connectivity that has been proposed to underlie the symptoms of schizophrenia.     

Regional deficits in brain volume in schizophrenia: a meta-analysis of voxel-based morphometry studies

OBJECTIVE: Voxel-based morphometry is a method for detecting group differences in the density or volume of brain matter. The authors reviewed the literature on use of voxel-based morphometry in schizophrenia imaging research to examine the capabilities of this method for clearly identifying specific structural differences in patients with schizophrenia, compared with healthy subjects. The authors looked for consistently reported results of relative deficits in gray and white matter in schizophrenia and evaluated voxel-based morphometry methods in order to propose a future strategy for using voxel-based morphometry in schizophrenia research. METHOD: The authors reviewed all voxel-based morphometry studies of schizophrenia that were published to May 2004 (15 studies). The studies included a total of 390 patients with a diagnosis of schizophrenia and 364 healthy volunteers. RESULTS: Gray and white matter deficits in patients with schizophrenia, relative to healthy comparison subjects, were reported in a total of 50 brain regions. Deficits were reported in two of the 50 regions in more than 50% of the studies and in nine of the 50 regions in one study only. The most consistent findings were of relative deficits in the left superior temporal gyrus and the left medial temporal lobe. Use of a smaller smoothing kernel (4-8 mm) led to detection of a greater number of regions implicated in schizophrenia. CONCLUSIONS: This review implicates the left superior temporal gyrus and the left medial temporal lobe as key regions of structural difference in patients with schizophrenia, compared to healthy subjects. The diversity of regions reported in voxel-based morphometry studies is in part related to the choice of variables in the automated process, such as smoothing kernel size and linear versus affine transformation, as well as to differences in patient groups. Voxel-based morphometry can be used as an exploratory whole-brain approach to identify abnormal brain regions in schizophrenia, which should then be validated by using region-of-interest analyses.     

海洛因成瘾者扣带前回结构与功能连接的MRI研究

目的 利用基于体素的形态学分析(voxel-based morphometry,VBM)和静息态fMRI探讨扣带前回结构和功能连接的改变,分析扣带前回在海洛因成瘾中的作用.方法 15例海洛因成瘾者和15例正常人分别作为成瘾组和正常对照组,均接受3D结构像和静息态fMRI检查,使用VBM比较2组受试者大脑的结构差异;以扣...     

Functional disintegration in paranoid schizophrenia using resting-state fMRI

Functional disintegration has been observed in schizophrenia during task performance. We sought to investigate functional disintegration during rest because an intrinsic functional brain organization, including both "task-negative" (i.e., "default mode") and "task-positive" networks, has been suggested to play an important role in integrating ongoing information processing. Additionally, the brain regions that are involved in the intrinsic organization are believed to be abnormal in schizophrenia. Patients with paranoid schizophrenia (N=18) and healthy volunteers (N=18) underwent a resting-state fMRI scan. Functional connectivity analysis was used to identify the connectivity between each pair of brain regions within this intrinsic organization, and differences were examined in patients versus healthy volunteers. Compared to healthy volunteers, patients showed significant differences in connectivity within networks and between networks, most notably in the connectivities associated with the bilateral dorsal medial prefrontal cortex, the lateral parietal region, the inferior temporal gyrus of the "task-negative" network and with the right dorsolateral prefrontal cortex and the right dorsal premotor cortex of the "task-positive" network. These results suggested that the interregional functional connectivities in the intrinsic organization are altered in patients with paranoid schizophrenia. These abnormalities could be the source of abnormalities in the coordination of and competition between information processing activities in the resting brain of paranoid patients.     

Altered resting-state functional connectivity of the cerebellum in schizophrenia

Structural and functional abnormalities of the cerebellum in schizophrenia have been reported. Most previous studies investigating resting-state functional connectivity (rsFC) have relied on a priori restrictions on seed regions or specific networks, which may bias observations. In this study, we aimed to elicit the connectivity alterations of the cerebellum in schizophrenia in a hypothesis-free approach. Ninety-five schizophrenia patients and 93 sex- and age-matched healthy controls underwent resting-state functional magnetic resonance imaging (fMRI). A voxel-wise data-driven method, resting-state functional connectivity density (rsFCD), was used to investigate cerebellar connectivity changes in schizophrenia patients. Regions with altered rsFCD were chosen as seeds to perform seed-based resting-state functional connectivity (rsFC) analyses. We found that schizophrenia patients exhibited decreased rsFCD in the right hemispheric VI; moreover, this cerebellar region showed increased rsFC with the prefrontal cortex and subcortical nuclei and decreased rsFC with the visual cortex and sensorimotor cortex. In addition, some rsFC changes were associated with positive symptoms. These findings suggest that abnormalities of the cerebellar hub and cerebellar-subcortical-cortical loop may be the underlying mechanisms of schizophrenia.     

Effects of antipsychotics on prepulse inhibition of the startle response in drug-na?ve schizophrenic patients.

BACKGROUND: Disturbances in sensorimotor gating measured by prepulse inhibition of the startle response (PPI) have frequently been reported in medicated and unmedicated schizophrenia spectrum patients and in their relatives, suggesting that the deficit represents a stable vulnerability marker for schizophrenia. Clinical data on the effects of antipsychotics on PPI disturbances are scarce, but from preclinical studies, antipsychotics have been shown to influence PPI. To differentiate pathogenetic mechanisms from drug related effects, longitudinal clinical studies on the effect of antipsychotic treatment on PPI in drug-naive first-episode schizophrenic patients are needed. METHODS: First-episode schizophrenic patients never previously medicated with antipsychotics were examined at inclusion and after 3 months of treatment with the atypical antipsychotic compound, risperidone, or the typical drug, zuclopenthixol. Healthy controls were used as a comparison group. RESULTS: The results confirm deficits in PPI in drug-naive first-episode patients. No effect of antipsychotic treatment on PPI dysfunction was observed in any of the treatment groups. CONCLUSIONS: The data are the first to show the possible effect of treatment with antipsychotic drugs on PPI disturbances in a longitudinal study of drug-naive schizophrenic patients. The data do not support any influence of treatment with antipsychotic drugs on sensorimotor gating deficits. Instead, the results point to the impairment in PPI as a stable vulnerability indicator.     

Prefrontal dysconnectivity links to working memory deficit in first-episode schizophrenia

Working memory (WM) deficit is a core feature of schizophrenia and is characterized by abnormal functional integration in the prefrontal cortex, including the dorsolateral prefrontal cortex (dLPFC), dorsal anterior cingulate cortex (dACC), and ventrolateral prefrontal cortex (vLPFC). However, the specific mechanism by which the abnormal neuronal circuits that involve these brain regions contribute to this deficit is still unclear. Therefore, this study focused on these regions and sought to answer which abnormal causal relationships in these regions can be linked to impaired WM in schizophrenia. We used spectral dynamic causal modeling to estimate directed (effective) connectivity between these regions based on resting-state functional magnetic resonance imaging data from healthy control (HC) subjects and patients with first-episode schizophrenia (FES). By comparing these effective connections in the controls and patients, we found that the effective connectivity from the dACC to the dLPFC and from the right dLPFC to the left vLPFC was weaker in the FES group than in the HC group. Furthermore, these effective connections displayed a positive correlation with WM performance in the HCs. However, in the FES patients, the effective connectivity from the dACC to the dLPFC was not correlated with WM performance, and the effective connectivity from the right dLPFC to the left vLPFC was negatively correlated with WM performance. These results could be explained by an aberrant top-down mechanism of WM processing and provide new evidence for the dysconnectivity hypothesis of schizophrenia.     

Prefrontal Brain Network Connectivity Indicates Degree of Both Schizophrenia Risk and Cognitive Dysfunction

Objective:

Cognitive dysfunction is a core feature of schizophrenia, and persons at risk for schizophrenia may show subtle deficits in attention and working memory. In this study, we investigated the relationship between integrity of functional brain networks and performance in attention and working memory tasks as well as schizophrenia risk.

Methods:

A total of 235 adults representing 3 levels of risk (102 outpatients with schizophrenia, 70 unaffected first-degree relatives of persons with schizophrenia, and 63 unrelated healthy controls [HCs]) completed resting-state functional magnetic resonance imaging and a battery of attention and working memory tasks (Brief Test of Attention, Hopkins Verbal Learning Test, and Brief Visuospatial Memory Test) on the same day. Functional networks were defined based on coupling with seeds in the dorsal anterior cingulate cortex, dorsolateral prefrontal cortex (DLPFC), medial prefrontal cortex (MPFC), and primary visual cortex. Networks were then dissected into regional clusters of connectivity that were used to generate individual interaction matrices representing functional connectivity within each network.

Results:

Both patients with schizophrenia and their first-degree relatives showed cognitive dysfunction compared with HCs. First canonicals indicated an inverse relationship between cognitive performance and connectivity within the DLPFC and MPFC networks. Multivariate analysis of variance revealed multivariate main effects of higher schizophrenia risk status on increased connectivity within the DLPFC and MPFC networks.

Conclusions:

These data suggest that excessive connectivity within brain networks coupled to the DLPFC and MPFC, respectively, accompany cognitive deficits in persons at risk for schizophrenia. This might reflect compensatory reactions in neural systems required for cognitive processing of attention and working memory tasks to brain changes associated with schizophrenia.Key words: resting state, fMRI, default-mode network, attention, working memory     

静息状态功能磁共振成像观察轻度阿尔茨海默病后扣带回功能连通性的变化

目的 利用静息状态功能磁共振成像(fMRI)研究阿尔茨海默病(AD)早期后扣带回相关的静息脑网络连通性是如何变化的.方法 运用fMRI研究了16例轻度AD患者和16名健康对照者在静息状态后扣带回的功能连通性.与后扣带回有功能连通性的脑区是通过检测低频波动信号的时程相关性获得的.应用通用的SPM2图像统计软件计算组间和组内连通性差异,激活区阈值设置:P<0.01(校正),像素范围>5.利用SPM2软件随机效应分析t检验(经校正P<0.01,t=2.47,像素范围>5),比较患者组和对照组连通性激活的脑区.结果 与后扣带回有功能连通性减弱的脑区包括前额叶中线区、楔前叶、双侧视皮质、双侧颞下回、左侧海马、右侧丘脑、右侧额叶背外侧区;偏左侧化的连通性增高的脑区包括前额叶中线区、左侧颞下回、左侧基底节区、双侧额叶背外侧区及左侧中央前区.结论 与后扣带回相关的静息状态脑网络连通性减低与AD早期情节记忆损害和高级视觉功能损害有关系,轻度AD保留着功能连接的重塑性以便维持脑功能.静息fMRI是一种探索AD脑功能机制的适宜方法.     

Widespread functional disconnectivity in schizophrenia with resting-state functional magnetic resonance imaging

Using resting-state functional magnetic resonance imaging, we examined the functional connectivity throughout the entire brain in schizophrenia. The abnormalities in functional connectivity were identified by comparing the correlation coefficients of each pair of 116 brain regions between 15 patients and 15 controls. Then, the global distribution of the abnormal functional connectivities was examined. Experimental results indicated, in general, a decreased functional connectivity in schizophrenia during rest, and such abnormalities were widely distributed throughout the entire brain rather than restricted to a few specific brain regions. The results provide a quantitative support for the hypothesis that schizophrenia may arise from the disrupted functional integration of widespread brain areas.     

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.     

Altered resting-state functional connectivity and anatomical connectivity of hippocampus in schizophrenia

Hippocampus has been implicated in participating in the pathophysiology of schizophrenia. However, the functional and anatomical connectivities between hippocampus and other regions are rarely concurrently investigated in schizophrenia. In the present study, both functional magnetic resonance imaging (fMRI) during rest and diffusion tensor imaging (DTI) were performed on 17 patients with paranoid schizophrenia and 14 healthy subjects. Resting-state functional connectivities of the bilateral hippocampi were separately analyzed by selecting the anterior hippocampus as region of interest. The fornix body was reconstructed by diffusion tensor tractography, and the integrity of this tract was evaluated using fractional anisotropy (FA). In patients with schizophrenia, the bilateral hippocampi showed reduced functional connectivities to some regions which have been reported to be involved in episodic memory, such as posterior cingulate cortex, extrastriate cortex, medial prefrontal cortex, and parahippocampus gyrus. We speculated that these reduced connectivity may reflect the disconnectivity within a neural network related to the anterior hippocampus in schizophrenia. Meanwhile the mean FA of the fornix body was significantly reduced in patients, indicating the damage in the hippocampal anatomical connectivity in schizophrenia. The concurrence of the functional disconnectivity and damaged anatomical connectivity between the hippocampus and other regions in schizophrenia suggest that the functional–anatomical relationship need to be further investigated.     

首发未服药精神分裂症患者脑弥散张量成像的基于体素分析

目的分析首发未服药精神分裂症患者脑白质完整性的变化。 方法对40例首发未服药精神分裂症患者和68例健康对照者进行脑弥散张量磁共振成像检查,以DTI-studio软件和统计参数图(SPM)软件对所得图像进行预处理,得到的各向异性分数(FA)图像在SPM软件中进行两样本t检验,获得两组患者FA值差异统计参数图。 结果在P值小于0.001（未校正）水平下,首发未服药精神分裂症患者右侧杏仁核区(MNI：24,2,-14,cluster=347 voxels)、双侧前扣带区(MNI:6,42,2,cluster=586 voxels)、右侧前额叶眶上回区域(MNI：20,18,-10,cluster= 166 voxels)白质FA值较健康对照者下降,且未发现前者有脑区白质FA值较后者增高。 结论精神分裂症患者皮层一边缘系统环路存在结构连接障碍,这可能是精神分裂症的神经机制。     

Altered functional brain networks in amnestic mild cognitive impairment: a resting-state fMRI study

Amnestic mild cognitive impairment MCI (aMCI) has a high progression to Alzheimer’s disease (AD). Recently, resting-state functional MRI (RS-fMRI) has been increasingly utilized in studying the pathogenesis of aMCI, especially in resting-state networks (RSNs). In the current study, we aimed to explore abnormal RSNs related to memory deficits in aMCI patients compared to the aged-matched healthy control group using RS-fMRI techniques. Firstly, we used ALFF (amplitude of low-frequency fluctuation) method to define the regions of interest (ROIs) which exhibited significant changes in aMCI compared with the control group. Then, we divided these ROIs into different networks in line with prior studies. The aim of this study is to explore the functional connectivity between these ROIs within networks and also to investigate the connectivity between networks. Comparing aMCI to the control group, our results showed that 1) the hippocampus (HIPP) had decreased FC with the medial prefrontal cortex (mPFC) and inferior parietal lobe (IPL), and the mPFC showed increased connectivity to IPL in the default mode network; 2) the thalamus showed decreased FC with the putamen and HIPP, and the HIPP showed increased connectivity to the putamen in the limbic system; 3) the supplementary motor area had decreased FC with the middle temporal gyrus and increased FC with the superior parietal lobe in the sensorimotor network; 4) increased connectivity between the lingual gyrus and middle occipital gyrus in the visual network; and 5) the DMN has reduced inter-network connectivities with the SMN and VN. These findings indicated that functional brain networks involved in cognition such as episodic memory, sensorimotor and visual cognition in aMCI were altered, and provided a new sight in understanding the important subtype of aMCI.     

Structural MRI investigation in schizophrenia with optimised voxel-based morphometry--a pilot study

The quantitative and structural MRI methods have an emergent role in the fields of psychiatric disorders. In our paper we present voxel-based morphometry, which is the most frequently used structural MRI method. We compared eight patients with schizophrenia and eight, age-matched healthy subjects to detect focal tissue differences in gray and white matter, and cerebrospinal fluids between the two groups. As with earlier studies, patients with schizophrenia showed decreased gray matter tissue density in frontotemporal and insular regions bilaterally. Moreover, the left-sided parietal operculum and the calcarina showed focal decrease in tissue density. Density decrease in the frontotemporal and insular white matter was detected bilaterally, which was similar to gray matter changes. The left sided precuneus and lingual gyrus were also involved in reduced white matter density. Increased cerebrospinal fluid spaces were detected in the frontal regions and the ventricles. Our results with the optimised voxel-based morphometry are in line with earlier imaging studies and correspond with neuropsychological detectable frontotemporal deficits in schizophrenia.     

首发未用药精神分裂症与精神分裂症患者健康子女静息态脑功能低频振幅研究

目的探讨首发未用药精神分裂症患者和精神分裂症患者健康子女脑功能磁共振低频振幅(amplitude of low frequency fluctuation,ALFF)的共性与差异。方法应用静息态功能磁共振ALFF的方法对年龄30岁的23例首发未用药精神分裂症患者、25名精神分裂症患者健康子女以及29名健康对照进行大脑范围内ALFF值比较。结果与对照组相比,患者组和患者子女组在左侧颞下回后部、左侧海马旁回、左侧海马、右侧中央后回、双侧楔前叶的ALFF值有统计学差异(P0.05),而患者组和患者子女组间在以上脑区的ALFF值无统计学差异(P0.05);与患者子女组和对照组相比,患者组在左侧颞下回前部、左侧颞上极、双侧距状裂周围皮层的ALFF值有统计学差异(P0.05),患者子女组和对照组间在以上脑区的ALFF值无统计学差异(P0.05)。结论首发未用药精神分裂症患者以及精神分裂症患者健康子女都存在脑功能异常;左侧颞下回后部、左侧海马旁回、左侧海马、右侧中央后回、双侧楔前叶可能是与精神分裂症遗传素质性相关的脑区;左侧颞下回前部、左侧颞上极、双侧距状裂周围皮层可能是与疾病状态性相关的脑区。     

Reduced paralimbic system gray matter volume in schizophrenia: Correlations with clinical variables,symptomatology and cognitive function

BackgroundPsychopathy is associated with dysfunction in regions that compose the paralimbic system, such as the orbitofrontal cortex (OFC), insular cortex (IC), temporal pole (TP), parahippocampal gyrus (PHG) and cingulate cortex (CC). However, findings of structural alterations in these regions are inconsistent in schizophrenia, and correlations between paralimbic system measures and symptomatology and cognitive function have not been investigated.Method93 patients with schizophrenia and 99 healthy controls received structural magnetic resonance imaging and clinical and cognitive assessment. We compared gray matter volume (GMV) between the two groups using voxel-based morphometry, and evaluated correlations between abnormal GMVs and clinical variables, symptomatology and cognitive function. The assessment of cognition included measures of processing speed, verbal fluency and memory.ResultsPatients with schizophrenia demonstrated significant GMV decreases in the paralimbic system, including bilateral OFC, IC and TP (p < 0.05, FWE corrected). GMV decreases were also observed in bilateral superior temporal gyri (STG). The GMVs in bilateral OFC, left IC, left TP and bilateral STG were positively correlated with processing speed, and the GMVs in bilateral OFC were positively correlated with memory function in all participants. In our patient group, the GMV deficits were also associated with earlier age of onset, longer duration of illness, greater number of hospitalizations and more severe positive symptoms.ConclusionsGMVs in the paralimbic system were significantly reduced in schizophrenia, and these abnormalities were correlated with clinical variables, symptomatology and cognitive function. These results suggest the paralimbic system plays an important role in the pathophysiology of schizophrenia.