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1.
目的探讨直流脉冲电刺激在痛觉功能磁共振成像(fMRI)研究中的应用与价值。方法采用Medtronic全功能肌电图/诱发电位仪对10名健康右利手志愿者分别施加1倍痛阈、2倍痛阈、3倍痛阈三个不同强度的电刺激任务,同期采用GE1.5T超导型磁共振扫描系统进行全脑fMRI扫描,应用功能性神经图像分析(AFNI)软件包对原始数据进行后处理以获得脑功能图像。结果10名受试者的痛阈测定结果为1.17~2.12mA,平均痛阈强度为1.75mA。实验中所有受试者均顺利完成了各刺激任务,无受试者中途退出实验,数据处理后获得较为理想的脑功能激活图。结论电刺激对于诱发痛觉的强度、频率等各项参数能够达到精确量化,是一种较为理想的刺激方式,在痛觉的fMRI研究中具有重要的价值。  相似文献   

2.
目的 应用血氧水平依赖功能磁共振成像(BOLD-fMRI)技术,分析正常成人痛觉相关皮层中枢的分布及量化特征.方法 选取10名正常成人志愿者,测定其痛阈并给予利手和非利手腕部2倍痛阈的电刺激,同时进行脑功能BOLD-fMRI扫描,应用SPM5进行后处理获得脑功能图像和数据,对脑激活区进行定位并测定其体积、强度.结果 刺激利手时激活对侧Brodmann Area(BA)3、1、2区7例,BA40区5例,BA5、7区3例,BA9、10、11区3例,BA6、8区2例,激活同侧BA5、7区2例,BA9、10、11区2例,BA6、8区3例;刺激非利手时激活对侧BA3、1、2区7例,BA40区6例,BA5、7区3例,BA9、10、11区2例,BA6、8区1例,激活同侧BA5、7区3例,BA9、10、11区1例,BA6、8区2例.3例在刺激两侧时BA3、1、2区和BA5、7区均没有激活,刺激利手时激活对侧BA40区2例、BA6区2例、前额叶皮质1例,刺激非利手时激活对侧BA40区2例、BA6区1例、前额叶皮质1例.结论 痛觉刺激可同时激活一般躯体感觉中枢、缘上回、辅助运动区、边缘系统等相关的皮层中枢,从而引发情绪、认知和内脏系统以及躲避反应等一系列相关活动.  相似文献   

3.
目的探讨耳甲迷走神经刺激术的脑通路,为耳迷走神经刺激调制孤束核-边缘叶脑网络假说提供证据。材料与方法随机录用16名健康志愿者,参加经皮电刺激右耳甲部迷走神经分布区(t VNS),以同侧上耳舟部刺激为对照,记录刺激的耳部感觉,观察全脑6 min扫描的Bold-f MRI信号变化,分析脑功能激活特点,应用SPM8处理f MRI数据。结果两组电流、感觉频率及强度未见明显区别。经皮电刺激耳甲部t VNS正常人激发了左侧孤束核及边缘叶脑区广泛而较强的负激活效应,局限性激活位于体感区及岛叶等,而对照部产生了右侧三叉神经核等脑干核团负激活及脑部体感区明显的激活现象。结论经皮电刺激迷走神经产生了孤束核-边缘叶脑网络的调制效应,为经皮电刺激耳甲部迷走神经治疗抑郁症等脑中枢机制打下基础。  相似文献   

4.
目的:利用功能性核磁共振(f MRI)观察功能性电刺激(FES)对脑功能的影响,探讨FES在皮层下脑卒中患者中枢神经系统康复中的作用机制。方法:纳入5例皮层下脑卒中患者,同时收集5例同期同年龄的健康者作为对照者。用FES仪刺激健康对照组左侧与皮层下脑卒中患侧的腕背伸和拇外展肌群,产生腕背伸和拇外展动作,刺激同时进行全脑的f MRI检查,获取脑功能图像。用SPM2软件进行图像分析,得到接受运动任务时2组脑区的激活图谱,比较2组感觉运动区(SMC)的激活强度和范围,计算SMC的单侧化指数(LI),并探讨其与上肢功能恢复的相关性。结果:健康对照组FES主要激活了对侧脑区的SMC,对侧运动前区(PMC)、顶下小叶(IPL)、扣带回运动区(CMA)、小脑(CRB)等运动相关区域也有不同程度激活;皮层下脑卒中组出现更多同侧脑区激活,包括同侧SMC、IPL等。2组双侧脑SMC激活范围及强度差异无统计学意义,但皮层下脑卒中组显示出同侧SMC激活增强的趋势,且LI值与Fugl-Meyer上肢评分呈正相关趋势(P0.05)。结论:FES通过感觉输入和被动运动两种方式激活感觉及运动相关的脑区,这可能是FES改善皮层下脑卒中患者肢体功能的机制之一。  相似文献   

5.
目的:探讨健康人群自主吞咽时脑激活区域(尤其是小脑和脑干激活区)的分布及特点。方法:通过block设计的血氧水平依赖性功能磁共振成像技术(BOLD-fMRI),观察健康受试者自主吞咽时的全脑激活的分布情况,用软件SPM5处理脑功能磁共振的影像资料。结果:主要激活区为双侧中央前回、左侧补充运动区、内侧及旁扣带回、左侧前额叶(眶部额上回、眶部额中回)、颞上回、颞横回、丘脑及壳核,且脑干、小脑半球小叶及小脑蚓都显示有激活。结论:中央前回、补充运动区、扣带回、前额叶(包括眶额回和三角部)、丘脑、壳核、小脑半球及小脑蚓是吞咽的相关脑区,而脑干由于受到fMRI分辨率的限制仍需进一步研究。  相似文献   

6.
目的 用功能磁共振成像(fMRI)方法观察补法和泻法针刺足三里穴对大脑作用的中枢机制. 方法 选取32名健康右利手志愿者,对11名受检者用补法电针刺激右侧足三里穴(ST36)、11名用泻法电针刺激ST36、10名电针刺激右侧足三里穴同一水平向外2~3 cm处.同时行全脑fMRI扫描;用SPM2软件进行图像后处理. 结果 电针结束后5 min,泻法组的脑区激活不明显,而补法组平均信号升高的脑区主要有双侧尾状核头部、丘脑、左侧岛叶、扣带回及小脑齿状核.电针结束后20~30 min期间两组脑区的激活最为明显,均激活左侧的丘脑、中央旁小叶、中央前回、颞中回、额中回、岛叶、双侧尾状核头部、小脑半球、前、后扣带回;两组激活区域大致相同,但补法组激活的脑区范围更广、强度更大.针刺假穴组只激活中央旁小叶及小脑半球. 结论 补、泻手法针刺足三里穴均能激活边缘系统、辅助运动区、灰质结构等脑区,而应用补法能更早、更强烈地激活上述脑区.  相似文献   

7.
目的 利用血氧水平依赖性功能性磁共振成像(BOLD-fMRI)技术,探讨共济失调患者在主动与被动复杂对指运动模式下关键脑功能区激活体积和强度的变化.方法 选取共济失调患者16例作为病例组,另选10名健康志愿者作为正常组.入选者均进行主动与被动复杂对指运动,在这两种运动模式下进行BOLD-fMRl检查,记录相应脑运动功能区的激活体积和强度并进行定量分析.采用共济失调量表(ICARS)对共济失调患者的共济运动进行评分.结果 病例组患手主动运动时,同侧辅助运动区(SMA)激活体积大于正常组同侧手的测定结果,激活强度也高于正常组;同侧小脑的激活体积和激活强度则小于正常组,小脑激活区的出现率也低于正常组.病例组患手主动运动时,同侧小脑激活区的体积、激活强度与共济失调量表评分无相关性.结论 共济失调患者患侧小脑功能下降,而同侧SMA可以发挥代偿作用,临床共济失调量表的评分尚不能准确反映小脑功能情况.  相似文献   

8.
目的 利用血氧水平依赖性功能性磁共振成像(BOLD-fMRI)技术,探讨共济失调患者在主动与被动复杂对指运动模式下关键脑功能区激活体积和强度的变化.方法 选取共济失调患者16例作为病例组,另选10名健康志愿者作为正常组.入选者均进行主动与被动复杂对指运动,在这两种运动模式下进行BOLD-fMRl检查,记录相应脑运动功能区的激活体积和强度并进行定量分析.采用共济失调量表(ICARS)对共济失调患者的共济运动进行评分.结果 病例组患手主动运动时,同侧辅助运动区(SMA)激活体积大于正常组同侧手的测定结果,激活强度也高于正常组;同侧小脑的激活体积和激活强度则小于正常组,小脑激活区的出现率也低于正常组.病例组患手主动运动时,同侧小脑激活区的体积、激活强度与共济失调量表评分无相关性.结论 共济失调患者患侧小脑功能下降,而同侧SMA可以发挥代偿作用,临床共济失调量表的评分尚不能准确反映小脑功能情况.  相似文献   

9.
研究摩擦刺激足三里等下肢穴位对小脑的激活与去激活效应。共10例健康右利手受试者接受功能性磁共振成像(fMRI)研究,采用3.0 T Siemens Magnetom Trio磁共振成像系统采集全脑功能像。穴位选取右侧足三里、阴陵泉、丰隆和三阴交穴,刺激采用组块设计模式,刺激期操作者使用海绵用力摩擦受试者穴位区,频率约为2 Hz。以SPM5和SUIT软件包分析数据,识别相对于基线水平,刺激不同穴位在小脑引发的激活和去激活效应信号,并计算小脑28个分区中激活和去激活信号的均值。 结果不同穴位对于小脑半球各分区的影响方式均不相同,但各穴位激活效应均值最大值所在分区均为小脑蚓部Crus I区;除三阴交外,各穴位的去激活效应最大值所在分区均为小脑蚓部VI区。在小脑半球20个分区中,各穴位刺激引起的左右两侧激活效应的变化趋势基本一致,但多数区域右侧的均值高于左侧。刺激足三里等下肢穴位对小脑的调节效应既存在共性,也存在特异性。这一结果有助于针刺治疗中穴位的选择。  相似文献   

10.
穴位TENS对正常年轻人热痛阈特异性抑制作用的研究   总被引:5,自引:2,他引:3  
目的:探讨经皮神经电刺激疗法(TENS)对人体实验性热痛阈及实验性振动阀的影响,从而阐明TENS作用机理。方法:20名正常人,年龄在20-39岁,随机分为TENS组和空白刺激组,每位受试者左手合谷穴和大鱼际区接受30min,TENS(200us,100Hz,2-3倍感觉阈)或空白刺激,分别采用Medoc TSA 2001和Medoc VSA-300对受试者左手鱼际区的热痛阈和振动阈进行测定,并分析在TENS或空白刺激前的30,20,10min及刺激后0,10,20,30,40,50min记录热痛阈和振动阈,采用逐步回归分析法对结果进行分析。结果:本研究显示与空白刺激相比,30min的TENS治疗后即刻,即0min(P=0.002)和20min(P=0.004)热痛阈显著增高,增高值分别为0.81℃和1.54℃。而同一治疗方案在同一人群中对振动阈无改变。结论:TENS作用于针灸穴位具有镇痛的特异性,而对其他感觉如振动觉无改变。换言之,TENS可能通过激活粗纤维传导,抑制细胞传导的痛觉,从而达到镇痛的作用。  相似文献   

11.
Objective: To identify patterns of nonfatal and fatal penetrating trauma among children and adults in New Mexico using ED and medical examiner data.
Methods: The authors retrospectively sampled in 5-year intervals all victims of penetrating trauma who presented to either the state Level-1 trauma center or the state medical examiner from a 16-year period (1978–1993). Rates of nonfatal and fatal firearm and stabbing injury were compared for children and adults.
Results: Rates of nonfatal injury were similar (firearm, 34.3 per 100,000 person-years; stabbing, 35.1). However, rates of fatal injury were significantly different (firearm, 21.9; stabbing, 2.7; relative risk: 8.2; 95% confidence interval: 5.4, 12.5). From 1978 to 1993, nonfatal injury rates increased for children (p = 0.0043) and adults (p < 0.0001), while fatal penetrating injury remained constant. The increase in nonfatal injury in children resulted from increased firearm injury rates. In adults, both stabbing and firearm nonfatal injury rates increased.
Conclusions: Nonfatal injury data suggest that nonfatal violence has increased; fatal injury data suggest that violent death rates have remained constant. Injury patterns vary by age, mechanism of trauma, and data source. These results suggest that ED and medical examiner data differ and that both are needed to guide injury prevention programs.  相似文献   

12.
Three supplementary perspectives are presented arguing that interprofessional collaboration is both necessary and desirable. Nonetheless, there are often too many serious intra-professional barriers and obstacles to interprofessional collaboration to make it successful. Some of these barriers, it is argued and illustrated, are found in the multiple ways in which professional identity is tacitly acquired and embodied in the practitioners' habitual, everyday practice. The paper then explores ways in which reflection, especially Second order reflection, can help to elucidate and overcome these obstacles, as well as increasing professional adaptability and competence.  相似文献   

13.
This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.  相似文献   

14.
ABSTRACT

The Cochrane Library of Systematic Reviews is published quarterly as a DVD and monthly online. The January 2011 issue (first quarterly DVD for 2011) contains 4515 complete reviews, 1985 protocols for reviews in production, and 13,521 one-page summaries of systematic reviews published in the general medical literature. In addition, there are citations of 641,000 randomized controlled trials, and 14,018 cited papers in the Cochrane methodology register. The health technology assessment database contains over 9300 citations. One hundred and seven new reviews have been published in the last 3 months, of which five have potential relevance for practitioners in pain and palliative medicine.  相似文献   

15.
目的 探讨手转胎头术失败的原因与分娩结局.方法 选择2008年1月至2010年12月于我院住院分娩的持续性枕横位、枕后位产妇198例,根据行手转胎头术后结果分为成功组126例、失败组72例.比较两组分娩结局,对比分析失败原因.结果 失败组胎儿体质量≥3500 g的发生率[76.4%(55/72)]明显高于成功组[31.7%(40/126)],差异有统计学意义(x2=30.177,P=0.001)、失败组宫缩乏力发生率[58.3%(42/72)]高于成功组[38.1% (48/126)],差异有统计学意义(x2=7.569,P=0.006)、失败组骨盆临界或轻度狭窄发生率[38.9% (28/72)]高于成功组[23.8%(30/126)],差异有统计学意义(x2 =5.030,P=0.002)、失败组手转胎头时机不当(宫口开大<6 cm、胎头位于坐骨棘上及宫口开大8~10 cm、胎头位于坐骨棘下≥2 cm)发生率[61.1%(44/72)]高于成功组[38.9%(49/126)],差异有统计学意义(x2=9.084,P=0.003).失败组母儿并发症(产后出血、产褥病率、胎儿窘迫、新生儿窒息)发生率高于成功组(x2 =9.586,P=0.002、x2=9.334,P=0.002、x2=5.910,P=0.015、x2=5.240,P=0.022)、失败组剖宫产发生率[72.2%(52/72)]明显高于成功组[34.1 %(43/126),x2=26.641,P=0.001)].结论 手转胎头术能使难产变顺产,降低剖宫产率,减少母儿并发症,但须积极预防、处理导致手转胎头术失败的原因,对矫正失败后继续矫正及试产应慎重.  相似文献   

16.
The Department of Veterans Affairs (VA) in the USA operates a network of 172 medical centres which all utilize a hospital information system (HIS) which has been developed and is currently maintained by the VA. During the past several years, an image management and communication module has been developed, installed and clinically utilized at the Washington DC and Maryland VA Medical Centres. This image management and communication system, referred to as the decentralized hospital computer program (DHCP) imaging system, is fully integrated with a commercial picture archiving and communication system (PACS). The system is utilized to capture, archive, and display all images generated within the hospital including radiology, nuclear medicine, pathology, endoscopy, bronchoscopy, and dermatology, intraoperative photographs, ECG data, and a limited number of paper documents. The ultimate goal of the project is to have all patient text and image data available at any clinical workstation to any authorized user anywhere within the network of medical centres. Clinical requirements for an imaging workstation include ease of use, rapid and reliable access to the complete set of patient information, and images which are of acceptable quality to meet the requirements of the user and the subspecialty. Patient confidentiality and data security must be safeguarded at all times. Integration of the images with the remainder of the patient's database was found to be critical to the success of the project. The experience at the Washington and Maryland facilities suggests that an imaging system that is successfully integrated with a hospital information system can provide substantial clinical and economic benefits both within and among medical centres. Clinical acceptance and utilization of the system has been excellent, particularly in diagnostic radiology where DHCP Imaging has been interfaced to a commercial PAC system. Based upon this initial experience, the VA has begun to deploy the system throughout its large network of medical centres.  相似文献   

17.
18.
目的 探讨俯卧位通气对高海拔地区肺复张术(RM)治疗无效急性呼吸窘迫综合征(ARDS)患者的治疗作用.方法 从海拔2260m的地区医院筛选RM治疗无效的41例ARDS患者[平均氧合指数( PaO2/FiO2)较RM前升高<20%视为RM无效],依不同病因分为肺内源性ARDS组(ARDSp组)和肺外源性ARDS组(ARDSexp组),每组再按信封法随机分为俯卧位组和仰卧位组,即ARDSp俯卧位组(11例)、ARDSp仰卧位组(9例)、ARDSexp俯卧位组(10例)、ARDSexp仰卧位组(11例).在通气前及通气1、2、3、4h监测动脉血氧分压( PaO2)、PaO2/FiO2、静态顺应性(Cst)、气道阻力(Raw)的变化.结果 通气lh时,ARDSexp俯卧位组PaO2/FiO2( mm Hg,l mm Hg=0.133 kPa)即较通气前显著升高(157.4±40.6比129.3±48.7,P<0.05),并随通气时间延长呈持续增高趋势,4h达峰值(219.1 ±41.1);且ARDSexp俯卧位组通气3h内PaO2/FiO2较其他3组显著增高,另3组间则差异无统计学意义.ARDSp俯卧位组、ARDSexp俯卧位组通气4h时PaO2/FiO2均较相应仰卧位组显著增高(208.8±39.7比127.4±47.1,219.1±41.1比124.9±50.8,均P<0.05).4组通气前后Cst无显著改变,各组间差异也无统计学意义.ARDSp俯卧位组通气4h时Raw(cmH2O·L-1·s-1)较通气前显著降低(6.8±1.7比10.7±1.8,P<0.05),且明显低于其他3组;其他3组各时间点Raw组内及组间比较差异均无统计学意义.结论 俯卧位通气作为ARDS机械通气重要策略之一,可以改善RM无效高原ARDS患者的氧合,为抢救患者赢得宝贵的时间.  相似文献   

19.
Ranganath C  Heller AS  Wilding EL 《NeuroImage》2007,35(4):1663-1673
Although substantial evidence suggests that the prefrontal cortex (PFC) implements processes that are critical for accurate episodic memory judgments, the specific roles of different PFC subregions remain unclear. Here, we used event-related functional magnetic resonance imaging to distinguish between prefrontal activity related to operations that (1) influence processing of retrieval cues based on current task demands, or (2) are involved in monitoring the outputs of retrieval. Fourteen participants studied auditory words spoken by a male or female speaker and completed memory tests in which the stimuli were unstudied foil words and studied words spoken by either the same speaker at study, or the alternate speaker. On "general" test trials, participants were to determine whether each word was studied, regardless of the voice of the speaker, whereas on "specific" test trials, participants were to additionally distinguish between studied words that were spoken in the same voice or a different voice at study. Thus, on specific test trials, participants were explicitly required to attend to voice information in order to evaluate each test item. Anterior (right BA 10), dorsolateral prefrontal (right BA 46), and inferior frontal (bilateral BA 47/12) regions were more active during specific than during general trials. Activation in anterior and dorsolateral PFC was enhanced during specific test trials even in response to unstudied items, suggesting that activation in these regions was related to the differential processing of retrieval cues in the two tasks. In contrast, differences between specific and general test trials in inferior frontal regions (bilateral BA 47/12) were seen only for studied items, suggesting a role for these regions in post-retrieval monitoring processes. Results from this study are consistent with the idea that different PFC subregions implement distinct, but complementary processes that collectively support accurate episodic memory judgments.  相似文献   

20.
Myocardial elastography is a novel method for noninvasively assessing regional myocardial function, with the advantages of high spatial and temporal resolution and high signal-to-noise ratio (SNR). In this paper, in-vivo experiments were performed in anesthetized normal and infarcted mice (one day after left anterior descending coronary artery [LAD] ligation) using a high-resolution (30 MHz) ultrasound system (Vevo 770, VisualSonics Inc., Toronto, ON, Canada). Radiofrequency (RF) signals of the left ventricle (LV) in longitudinal (long-axis) view and the associated electrocardiogram (ECG) were simultaneously acquired. Using a retrospective ECG gating technique, 2-D full field-of-view RF frames were acquired at an extremely high frame rate (8 kHz) that resulted in high-quality incremental displacement and strain estimation of the myocardium. The incremental results were further accumulated to obtain the cumulative displacements and strains. Two-dimensional and M-mode displacement images and strain images (elastograms), as well as displacement and strain profiles as a function of time, were compared between normal and infarcted mice. Incremental results clearly depicted cardiac events including LV contraction, LV relaxation and isovolumetric phases in both normal and infarcted mice, and also evidently indicated reduced motion and deformation in the infarcted myocardium. The elastograms indicated that the infarcted regions underwent thinning during systole rather than thickening, as in the normal case. The cumulative elastograms were found to have higher elastographic SNR (SNR(e)) than the incremental elastograms (e.g., 10.6 vs. 4.7 in a normal myocardium, and 6.0 vs. 2.4 in an infarcted myocardium). Finally, preliminary statistical results from nine normal (m = 9) and seven infarcted (n = 7) mice indicated the capability of the cumulative strain in differentiating infracted from normal myocardia. In conclusion, myocardial elastography could provide regional strain information at simultaneously high temporal (>/=0.125 ms) and spatial ( approximately 55 microm) resolution as well as high precision ( approximately 0.05 microm displacement). This technique was thus capable of accurately characterizing normal myocardial function throughout an entire cardiac cycle, at the same high resolution, and detecting and localizing myocardial infarction in vivo.  相似文献   

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