特发全面性癫痫基底节丘脑皮层环路的多模态MRI研究进展

特发性全面性癫痫是一组非局灶性发病且没有明确病因的癫痫综合征。其发病原因至今不明,之前有研究推测丘脑皮质环路起着重要作用,目前通过MRI新技术的研究,发现了基底节-丘脑-皮质环路可能影响癫痫发作的产生和传播。常规MRI未能发现异常改变,而扩散张量成像、基于体素的形态测量学分析及静息态功能MRI的多模态MR新技术可从结构、体积及功能三方面发现该环路的异常改变,就其最新研究进展予以综述。     

静息态脑功能磁共振成像的研究进展

静息态脑功能磁共振成像(rfMRI)是基于静息态下血氧水平依赖检测功能相关脑区低频波动信号,用于静息态网络的研究,rfMRI比任务相关fMRI更简单易行,一致性更高。本文将综述rfMRI的网络基础、特点及研究方法。     

注意缺陷多动障碍儿童静息态的脑功能磁共振成像研究

目的 探讨注意缺陷多动障碍(ADHD)儿童静息态脑功能磁共振成像的特点.方法 对15名正常学龄期儿童(对照组)和14例ADHD儿童(ADHD组)进行静息态功能磁共振成像(fMRI)扫描,采用局部一致性(ReHo)作为测最指标.结果 ADHD组在双侧顶下小叶(Z=3.73,Z=3.34)、双侧楔叶(Z=3.42,Z=3.86)、左侧额中回(Z=3.24)、左侧颢中同(Z=3.24)、左侧楔前叶(Z=3.45)及右侧岛叶(Z=3.09)、右侧小脑(Z=3.42)等区域的ReHo值低于对照组,而双侧额下回(Z=3.19,Z=2.93)的ReHo值高于对照组.结论与对照组比较,静息态下ADHD患者与执行控制功能、注意认知功能及默认网络功能等相关区域存在异常.     

How default is the default mode of brain function? Further evidence from intrinsic BOLD signal fluctuations

The default mode of brain function hypothesis and the presence of spontaneous intrinsic low-frequency signal fluctuations during rest have recently attracted attention in the neuroscience community. In this study we asked two questions: First, is it possible to attenuate intrinsic activity in the self-referential, default mode of brain function by directing the brains resources to a goal-oriented and attention-demanding task? Second, what effect does a sustained attention-demanding overt task performance have on the two intrinsically active networks in the brain, those being the task-negative, default-mode and the anticorrelated, task-positive network? We used functional magnetic resonance imaging to monitor spontaneous intrinsic activity during rest and sustained performance of a sequential two-back working memory task. We compared intrinsic activity during rest and the two-back task to the signal increases and decreases observed in an epoch-related version of the working memory task. Our results show that spontaneous intrinsic activity in the default-mode network is not extinguished but rather attenuated during performance of the working memory task. Moreover, we show that the intrinsic activity in the task-positive network is reorganized in response to the working memory task. The results presented here complements earlier work that have shown that task-induced signal deactivations in the default-mode regions is modulated by cognitive load to also show that intrinsic, spontaneous signal fluctuations in the default-mode regions persist and reorganize in response to changes in external work load.     

抑郁症患者静息状态的功能磁共振成像研究

目的 了解在静息状态下抑郁症患者脑区的局部一致性特点.方法 采用功能磁共振成像(fMRI)技术,检测静息状态下27例抑郁症患者(患者组)和性别、年龄、受教育程度均与患者相匹配的27名正常人(对照组)的脑功能活动,并对两组进行比较.利用局部一致性方法 分析fMRI数据,用SPM2软件进行配对t检验(P＜0.005).结果 与对照组相比,患者组双侧额中回、右额下回、右颞上回、左前扣带回、右后扣带回、右岛叶、双侧豆状核、双侧屏状核、左尾状核局部一致性显著增高(P＜0.005,未校正,体素值＞10);未显示脑区有明显的局部一致性减低.结论 抑郁症患者神经环路脑区局部在静息状态下具有很高的一致性,其局部一致性的增高可能参与了抑郁症的代偿机制.     

轻度阿尔茨海默病患者静息态脑默认活动网络的fMRI研究

目的 采用静息态功能磁共振(fMRI)技术,探讨轻度阿尔茨海默病(AD)患者的脑默认活动网络(DMN)是否存在异常及其可能的神经机制. 方法 以复旦大学附属华山医院和同济大学附属同济医院神经内科门诊自2009年1月至2010年6月收治的24名轻度AD患者和同期上海社区中整群抽样选择的25名正常老年人为研究对象,对其进行简易智能状态(MMSE)、Mattis痴呆评定量表(DRS)检查和静息态脑功能成像.利用低频振幅(ALFF)算法对全脑静息态数据进行对比分析,观察AD患者相对于正常老年人ALFF有显著差异的区域. 结果 行为学结果显示:轻度AD患者相对对照组成员记忆功能存在明显损害.静息态fMRI结果显示:与对照组比较,AD患者中与记忆密切相关的后扣带回、前额叶中内侧腹侧、前额叶中内侧背侧等脑区ALFF明显减弱. 结论 AD患者静息态脑DMN中与记忆密切相关的脑区节点活动强度减弱,DMN异常在其早期记忆损害的病理机制中起着非常重要的作用.     

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.     

Beta-amyloid-induced increase in the resting intracellular calcium concentration gives support to tell Alzheimer lymphocytes from control ones

Senile plaques containing beta-amyloid peptide (betaAP) comprise the major neuropathological lesions in Alzheimer's disease (AD). In line with ongoing studies investigating alterations of various biochemical processes of cells of peripheral tissues, the authors demonstrate differences in resting intracellular free calcium levels of lymphocytes harvested from sporadic Alzheimer patients and from age-matched controls. Resting intracellular calcium concentration was measured in Fura-2AM-loaded human lymphocytes by dual wavelength spectrofluorimetry. Resting calcium level appeared to be higher in Alzheimer cells when compared to control lymphocytes. After incubating cells in 10(-7)M of beta-amyloid, the resting calcium concentration of the control cells elevated, while that of Alzheimer lymphocytes did not differ considerably.     

尘肺患者心肺功能运动试验与静态肺功能相关性和一致性分析

目的探讨静态肺功能与心肺功能运动试验指标间的相互关系,为心肺功能运动试验应用于尘肺伤残评定提供客观依据。方法调查对象219人,其中I期煤工尘肺患者64例,正常对照155名,所有对象进行心肺功能运动试验和静态肺功能测定;测定结果进行相关分析、一致性分析和多元回归分析。结果尘肺患者单项静态肺功能指标中,控制年龄、身高和体重后,仅用力肺活量(FVC)指标与最大摄氧量(VO2max)有相关性(r=0.285),静态肺功能6项指标对VO2max变化的贡献率为25.6%。VO2max与静态肺功能各指标间判定肺损伤的一致性为0.065～0.255,而VE/VCO2AT和VE/VCO2max与静态肺功能各指标间判定肺损伤的一致性为0.158～0.329。结论运动试验与静态肺功能判定肺损伤相关性、一致程度和关联程度较低,在相同程度肺损伤评定上有较大差异。静态肺功能不能准确评定体力能力的大小和丢失程度。     

Pathophysiologic basis for growth failure in children with ichthyosis: an evaluation of cutaneous ultrastructure, epidermal permeability barrier function, and energy expenditure

OBJECTIVE: Because an impaired epidermal permeability barrier is present in many of the ichthyoses, we examined the contribution of barrier failure to caloric requirements in children with ichthyosis and growth failure. STUDY DESIGN: Transepidermal water loss (TEWL) and ultrastructural parameters of the permeability barrier were evaluated in 10 hospitalized children with ichthyosis and growth failure. Nutritional intake, resting energy expenditure, and calories lost as heat of evaporation were determined. RESULTS: Mean basal TEWL rates were markedly elevated in all study patients in comparison to the expected upper limit of normal (39.6+/-20.6 vs 8.7 mL/m(2) per hour). The severity of abnormalities in the ultrastructure of permeability barrier-related structures, assessed semiquantitatively, correlated significantly to mean basal TEWL rates (P <.001). Total body daily TEWL was elevated (746 +/- 468 vs 209 mL/d), resulting in a caloric drain of 433 +/- 272 kcal/d (21 +/- 9.8 kcal/kg per day) through heat of evaporation. Nutrient intake exceeded requirements in all, but resting energy expenditure exceeded predicted in 5 of 6 patients and correlated significantly with mean basal TEWL rates (P <.005). CONCLUSIONS: A defective permeability barrier in children with ichthyosis can result in ample chronic losses of water and calories to impair growth.