磁共振成像和弥散张量成像评价缺血性脑卒中患者皮质运动功能激活状态及皮质脊髓束异常与肌力的关系

目的：应用磁共振成像和弥散张量成像观察缺血性脑卒中急性期患者皮质运动功能及皮质脊髓束的异常，评估皮质脊髓束受损与肌力的关系。 方法：实验于2005-08／2005-12在解放军南京军区福州总医院完成。对9例缺血性脑卒中急性期患者和9例健康志愿者进行磁共振成像及弥散张量成像检查。缺血性脑卒中诊断符合中国现行脑血管病诊断标准，临床表现以偏瘫为主，所有患者均知情同意。①磁共振成像应用组块设计，以被动对指运动作为刺激任务，静息状态作为基线任务。设备采用GE1．5T磁共振成像系统，所有数据进行离线后处理，应用SPM2软件处理磁共振成像图像，观察皮质运动功能激活状态。②弥散张量成像采用dTV．Ⅱ软件进行处理，显示各向异性图及彩色各向异性方向图，并重建患者的双侧皮质脊髓束三维纤维图。③应用Brunnstorm标准判断脑卒中患者患手肌力。 结果：9例患者和9例健康志愿者的数据值均进入结果分析。①磁共振成像表现结果：7例脑卒中患者患手运动时，对侧半球的感觉运动皮质可见微弱激活，而在同侧后顶叶皮质见到明显激活。3例患者可见小脑激活状态。2例出现患手运动时，双侧感觉运动皮质激活，且同侧激活区域大于对侧。健手运动时，激活对侧感觉运动皮质及后顶叶皮质及对侧辅助运动区，同侧未见明显激活区。②弥散张量成像表现结果：9例脑梗死患者梗死区各向异性值均较对侧降低，两侧具有显著性意义（t=4．570，P〈0．001）。梗死区各向异性值与对侧肌力有明显相关性（rs=0．888，P〈0．05）。③皮质脊髓束表现结果：双侧皮质脊髓束重建，健侧解剖形态与正常人大致相吻合，自中央前回下行至内囊并延续至脑桥和延髓，每条连续形态一致性良好。患侧皮质脊髓束因受梗死区不同程度的累及，表现为连续性中断及解剖结构形态一致性的丧失。皮质脊髓束损伤程度与患手肌力明显相关（rs=0.888，P〈0．05）。 结论：①脑卒中患者患手运动时磁共振成像表现与正常人不同，提示存在脑功能代偿与重组。②皮质脊髓束损伤程度与肌力相关，可用于判断康复治疗的预后。     

三维纤维束示踪成像评价急性脑梗死患者皮质脊髓束损伤的意义

目的∶观察缺血性脑卒中急性期患者皮质脊髓束的状况,分析运动功能与皮质脊髓束受损情况的关系。方法∶采用GE1.5T磁共振成像系统,对2005-02/12解放军南京军区福州总医院就诊的15例缺血性脑卒中急性期患者进行磁共振弥散张量成像检查,用dTV.Ⅱ软件进行处理,显示部分各向异性图及彩色部分各向异性方向图;并采用种子方法重建双侧皮质脊髓束的三维纤维束成像图,观察纤维束的移位、连续性及破坏情况;同时采用Brunnstorm标准判断脑梗死患者患手肌力,应用Spearmen相关分析分析皮质脊髓束损伤程度与患手肌力的相关性。以15例健康志愿者为对照组进行比较。结果:30例受试者均进入结果分析。①脑卒中患者梗死白质区部分各向异性值显著低于健侧,两侧相比差异有显著性意义(t=4.570,P<0.001)。②对照组双侧皮质脊髓束重建,自中央前回下行至内囊并延续至脑桥和延髓,每条连续形态一致性良好。脑梗死患者健侧皮质脊髓束形态与对照组一致,连续性好;患侧皮质脊髓束因受梗死区不同程度的累及,表现为连续性中断及解剖结构形态一致性的丧失。表现为1级(皮质脊髓束完整)2例;2级(皮质脊髓束完整,但受压推移)5例;3级(皮质脊髓束中断)8例。③皮质脊髓束损伤程度与患手肌力明显相关(rs=0.888,P<0.05)。结论:①急性脑梗死患者患侧皮质脊髓束不同程度受损,且损伤程度与肌力相关,提示可用于判断康复治疗的预后。②三维纤维束示踪成像图可以更立体直观的显示锥体束状况。     

三维纤维束示踪成像评价急性脑梗死患者皮质脊髓束损伤的意义

目的：观察缺血性脑卒中急性期患者皮质脊髓束的状况，分析运动功能与皮质脊髓束受损情况的关系。方法：采用GE1．5T磁共振成像系统，对2005—02／12解放军南京军区福州总医院就诊的15例缺血性脑卒中急性期患者进行磁共振弥散张量成像检查，用dTV．Ⅱ软件进行处理，显示部分各向异性图及彩色部分各向异性方向图；并采用种子方法重建双侧皮质脊髓束的三维纤维束成像图，观察纤维束的移位、连续性及破坏情况；同时采用Brunnstorm标准判断脑梗死患者患手肌力，应用Spearmen相关分析分析皮质脊髓束损伤程度与患手肌力的相关性。以15例健康志愿者为对照组进行比较。结果：30例受试者均进入结果分析。①脑卒中患者梗死白质区部分各向异性值显著低于健侧，两侧相比差异有显著性意义（t=4．570，P〈0．001）。②对照组双侧皮质脊髓束重建，自中央前回下行至内囊并延续至脑桥和延髓，每条连续形态一致性良好。脑梗死患者健侧皮质脊髓束形态与对照组一致，连续性好；患侧皮质脊髓束因受梗死区不同程度的累及，表现为连续性中断及解剖结构形态一致性的丧失。表现为1级（皮质脊髓束完整）2例；2级（皮质脊髓束完整，但受压推移）5例；3级（皮质脊髓束中断）8例。③皮质脊髓束损伤程度与患手肌力明显相关（ta=0．888。P〈0．05）。结论：①急性脑梗死患者患侧皮质脊髓束不同程度受损，且损伤程度与肌力相关，提示可用于判断康复治疗的预后。②三维纤维束示踪成像图可以更立体直观的显示锥体束状况。     

被动单指运动的脑激活模式:正常被试者与脑卒中患者的比较

目的:探讨被动单指运动任务在脑卒中急性期功能磁共振成像研究中的应用。方法:应用被动单指运动任务,对2004年6月大庆油田总医院住院的1名急性单侧皮质下梗死患者和1名正常右利手被试进行功能性磁共振成像研究。分析比较正常被试与脑卒中患者被动单指运动的脑激活模式及其异同。结果:正常人被动单指运动激活对侧感觉运动皮质和辅助运动区。脑卒中患者健手运动功能性磁共振成像结果基本同正常人,脑卒中急性期患者患手被动单指运动,依赖双侧感觉运动皮质,运动前区,辅助运动区和同侧后顶叶皮质等脑区的协同参与。结论:正常人双手被动运动和脑卒中患者健手被动运动的脑激活模式与主动运动相似,但患手被动运动则不一样。被动运动为脑卒中急性期运动恢复的功能性磁共振成像研究提供了简便易行的方法。     

被动单指运动的脑激活模式：正常被试者与脑卒中患者的比较

目的：探讨被动单指运动任务在脑卒中急性期功能磁共振成像研究中的应用，方法：应用被动单指运动任务，对2004年6月大庆油田总医院住院的1名急性单侧皮质下梗死患者和1名正常右利手被试进行功能性磁共振成像研究。分析比较正常被试与脑卒中患者被动单指运动的脑激活模式及其异同。结果：正常人被动单指运动激活对侧感觉运动皮质和辅助运动区。脑卒中患者健手运动功能性磁共振成像结果基本同正常人，脑卒中急性期患者患手被动单指运动，依赖双侧感觉运动皮质．运动前区，辅助运动区和同侧后顶叶皮质等脑区的协同参与。结论：正常人双手被动运动和脑卒中患者健手被动运动的脑激活模式与主动运动相似，但患手被动运动则不一样，被动运动为脑卒中急性期运动恢复的功能性磁共振成像研究提供了简便易行的方法。     

脑卒中后皮质脊髓束与上肢运动功能关系的弥散张量成像研究

目的应用弥散张量成像(DTI)观察脑卒中患者基底节区皮质脊髓束损伤情况及其与上肢运动功能的关系。方法2013年1月~2015年7月住院脑卒中患者18例接受DTI,并采用简式Fugl-Meyer评定和金子翼上肢功能评定进行评分,比较病灶侧与健侧基底节区皮质脊髓束部分各向异性(FA),对病灶侧FA与上肢运动功能评分进行相关性分析。结果患侧FA显著小于健侧(t=-21.09,P0.001)。患侧FA与Fugl-Meyer评分正相关(r=0.570,P0.05),与金子翼上肢功能评分正相关(r=0.509,P0.05)。结论脑卒中后基底节区皮质脊髓束受损,损伤程度与上肢运动功能相关。     

弥散张量成像在脑卒中患者运动功能预后评估中的研究进展

弥散张量成像可表征水分子扩散过程的取向特性,能有效观察和追踪脑白质纤维束。脑卒中患者各向异性分数下降表明纤维结构完整性受损,显著下降提示可能出现华勒变性;各向异性分数升高与运动功能恢复程度有关;患健侧各向异性分数比更适合成为脑卒中患者运动功能恢复预测指标。纤维束成像显示的皮质脊髓束变化,也可作为脑卒中患者运动功能结局的预测指标。     

磁共振弥散张量成像在脑卒中后皮质脊髓束损伤与运动功能的相关性研究

目的:应用磁共振弥散张量成像(MR-diffusion tensor imaging,DTI)探讨脑卒中后皮质脊髓束(corticospinal tract,CST)损伤与运动功能的相关性。方法:29例脑卒中后偏瘫患者,分为脑出血组15例,脑梗死组14例,病变部位为内囊基底核区,且累及皮质脊髓束,发病后30—60d采用1.5T核磁共振仪进行弥散张量成像扫描,依次从大脑脚、内囊后肢、放射冠区、初级皮质运动区4个层面,测量病变同侧皮质脊髓束和病变对侧相应脑组织的部分各向异性值(FA),计算得出FA比值(r FA)及FA不对称性(FAasy),同时采用简化Fugl-Meyer运动功能量表(The Fugl-Meyer motor assessment,FMA)对偏瘫肢体运动功能评分。结果:病灶侧4个层面CST的FA值均较对侧相应脑组织降低。脑出血组:大脑脚、内囊后肢、放射冠区3个层面的FA值、r FA和FAasy均与FMA评分之间存在相关性,且放射冠层面有显著相关性;而初级皮质运动区层面的FA值、r FA和FAasy与FMA评分之间无明显相关性。脑梗死组:大脑脚、内囊后肢、放射冠区、初级皮质运动区4个层面的FA值、r FA和FAasy均与FMA评分之间存在相关性,且放射冠层面有显著相关性。结论:DTI可用于评估脑卒中后皮质脊髓束损伤及运动功能障碍,以放射冠层面皮质脊髓束的DTI参数最有意义。     

磁共振弥散张量成像在急性腔隙性脑梗死预后评估中的价值

目的 探讨磁共振弥散张量成像（DTI）在急性腔隙性脑梗死患者预后评估中的临床价值及相关性。 方法 急性腔隙性脑梗死患者40例,在MRI常规检查的同时加做DTI检查,得到各向异性分数伪彩图并测量分析梗死灶各向异性分数值,重建双侧皮质脊髓束,以梗死灶在双侧皮质脊髓束的空间位置分为纤维束外、纤维束旁、纤维束内3组;每次磁共振检查之前进行Fugl-Meyer运动功能评分评定,最后分析梗死灶位置与运动功能评分之间的关系。 结果 康复治疗前后病灶与皮质脊髓束越空间关系越密切的,运动功能评分增加的百分数越低,呈负相关（P<0.01）。 结论 通过DTI在急性腔隙性脑梗死灶与双侧皮质脊髓束的空间位置关系的水分子扩散各向异性分值及扩散张量纤维束成像分级,可以较准确、直观地显示皮质脊髓束的损伤程度,为脑梗死患者临床治疗及预后提供明确的依据。       

脑缺血性卒中患者运动功能康复的功能性磁共振成像研究

目的利用功能性磁共振成像（fMRI）技术研究急性期缺血性脑卒中患者（以下简称急性期患者）运动相关皮质的激活情况，并探讨脑卒中后脑功能重组特点及其与肢体运动功能恢复的关系。方法采用GEI．5T双梯度16通道磁共振成像系统，对9例急性期患者和9例健康志愿者行Bold—fMRI检查。fMRI检查以被动对指运动（以下简称运动）为刺激任务，所有数据采用SPM2软件包进行离线后处理。比较健康志愿者与急性期患者fMRI结果的异同点，计算脑激活区体积和单侧化指数（LI），考察急性期患者患手运动LI值与患手运动功能的关系。结果健康志愿者单手运动激活对侧感觉运动皮质（SMC）、双侧辅助运动区（SMA）。急性期患者患手运动时同侧半球脑激话增多，健手运动的fMRI结果与健康志愿者基本一致。LI值也进一步确定，急性期患者患手运动时同侧半球脑激活增多。统计学分析表明，急性期患者患手运动的LI值与患手运动功能呈正相关。结论fMRI检查能客观地反映急性期患者运动相关皮质改变，提示存在脑功能代偿与重组。急性期患者患手运动LI值与患手运动功能呈正相关，提示fMRI是研究缺血性脑卒中后肢体运动功能康复与脑功能重组之间关系的一种有效工具。     

Repeatability of the intensity dependence of cortical auditory evoked potentials in the assessment of cortical information processing

Data on repeatability and optimal settings are needed when studying the influence of drugs on the intensity dependence of auditory evoked cortical potentials (IDAP). IDAP was recorded at intervals of 1, 2, and 24 h at two centers in 22 healthy volunteers. Settings were modified to compare fixed versus randomly varied stimulus repetition rate, as well as 30 Hz and 100 Hz low pass filters. Repeatability was assessed for different intervals and different settings. Group means did not differ between centers, the 2-h or 24-h retest, or when using different settings. We observed an order effect for the 1 h retest. Fixed repetition rate and the 30 Hz filter improved repeatability with still high intraindividual variability. IDAP group means can be compared between centers for retest intervals of 2 h and 24 h and different settings. Variability is too large to compare individuals.     

Brain segmentation and the generation of cortical surfaces.

This paper describes methods for white matter segmentation in brain images and the generation of cortical surfaces from the segmentations. We have developed a system that allows a user to start with a brain volume, obtained by modalities such as MRI or cryosection, and constructs a complete digital representation of the cortical surface. The methodology consists of three basic components: local parametric modeling and Bayesian segmentation; surface generation and local quadratic coordinate fitting; and surface editing. Segmentations are computed by parametrically fitting known density functions to the histogram of the image using the expectation maximization algorithm [DLR77]. The parametric fits are obtained locally rather than globally over the whole volume to overcome local variations in gray levels. To represent the boundary of the gray and white matter we use triangulated meshes generated using isosurface generation algorithms [GH95]. A complete system of local parametric quadratic charts [JWM+95] is superimposed on the triangulated graph to facilitate smoothing and geodesic curve tracking. Algorithms for surface editing include extraction of the largest closed surface. Results for several macaque brains are presented comparing automated and hand surface generation.     

肾上腺皮质腺瘤、腺癌48例临床病理分析

目的　探讨肾上腺皮质腺瘤 (ACA)、皮质腺癌 (ACC)的临床病理特征和诊断要点。方法　对 4 6例ACA、2例ACC的临床病理学资料进行分析 ,18例ACA、2例ACC做免疫组化检测。结果　ACA 4 6例 ,其中功能性ACA 34例 ,无功能性ACA 12例。腺瘤为有包膜的孤立性肿块 ,平均重量 9 12g ,包膜外肾上腺组织受压萎缩 ;肿瘤由透明细胞和致密细胞不同比例构成 ,瘤细胞形态较一致 ,核分裂罕见 ,可见散在巨形细胞 ,核不规则深染或怪异核。免疫组化 :18例ACA中 5例PCNA( ) ,见于致密嗜酸性细胞占肿瘤 6 0 %以上者 ,p5 3均 (- )。 2例ACC重量均 >10 0g,肿瘤与周围组织粘连 ,瘤细胞嗜酸性 ,高度异型 ,核分裂 >5个 5 0HPF ,瘤细胞浸润包膜及周围组织 ;PCNA( ) ,p5 3( )。结论　功能性ACA的组织结构和细胞特征在预测内分泌综合征时不完全可靠 ,需要结合临床内分泌检测 ;ACA仅靠形态学难以判断良恶性 ,需随访 ;伴有肾上腺生殖器综合征者、PCNA阳性者应重点随访。肿瘤的大小、重量、核分裂象及PCNA、p5 3检测对肾上腺皮质肿瘤的良恶性鉴别有重要的参考价值 ;但包膜、血管的浸润和转移才是区分良恶性的确切指标     

Smoking experience modulates the cortical integration of vision and haptics

Human neuroplasticity of multisensory integration has been studied mainly in the context of natural or artificial training situations in healthy subjects. However, regular smokers also offer the opportunity to assess the impact of intensive daily multisensory interactions with smoking-related objects on the neural correlates of crossmodal object processing. The present functional magnetic resonance imaging study revealed that smokers show a comparable visuo-haptic integration pattern for both smoking paraphernalia and control objects in the left lateral occipital complex, a region playing a crucial role in crossmodal object recognition. Moreover, the degree of nicotine dependence correlated positively with the magnitude of visuo-haptic integration in the left lateral occipital complex (LOC) for smoking-associated but not for control objects. In contrast, in the left LOC non-smokers displayed a visuo-haptic integration pattern for control objects, but not for smoking paraphernalia. This suggests that prolonged smoking-related multisensory experiences in smokers facilitate the merging of visual and haptic inputs in the lateral occipital complex for the respective stimuli. Studying clinical populations who engage in compulsive activities may represent an ecologically valid approach to investigating the neuroplasticity of multisensory integration.     

Age-related alterations in the modular organization of structural cortical network by using cortical thickness from MRI

Normal aging is accompanied by various cognitive functional declines. Recent studies have revealed disruptions in the coordination of large-scale functional brain networks such as the default mode network in advanced aging. However, organizational alterations of the structural brain network at the system level in aging are still poorly understood. Here, using cortical thickness, we investigated the modular organization of the cortical structural networks in 102 young and 97 normal aging adults. Brain networks for both cohorts displayed a modular organization overlapping with functional domains such as executive and auditory/language processing. However, compared with the modular organization of young adults, the aging group demonstrated a significantly reduced modularity that might be indicative of reduced functional segregation in the aging brain. More importantly, the aging brain network exhibited reduced intra-/inter-module connectivity in modules corresponding to the executive function and the default mode network of young adults, which might be associated with the decline of cognitive functions in aging. Finally, we observed age-associated alterations in the regional characterization in terms of their intra/inter-module connectivity. Our results indicate that aging is associated with an altered modular organization in the structural brain networks and provide new evidence for disrupted integrity in the large-scale brain networks that underlie cognition.     

Assessing nitrous oxide effect using electroencephalographically-based depth of anesthesia measures cortical state and cortical input

Existing electroencephalography (EEG) based depth of anesthesia monitors cannot reliably track sedative or anesthetic states during n-methyl-d-aspartate (NMDA) receptor antagonist based anesthesia with ketamine or nitrous oxide (N₂O). Here, a physiologically-motivated depth of anesthesia monitoring algorithm based on autoregressive-moving-average (ARMA) modeling and derivative measures of interest, Cortical State (CS) and Cortical Input (CI), is retrospectively applied in an exploratory manner to the NMDA receptor antagonist N₂O, an adjuvant anesthetic gas used in clinical practice. Composite Cortical State (CCS) and Composite Cortical State distance (CCSd), two new modifications of CS, along with CS and CI were evaluated on electroencephalographic (EEG) data of healthy control individuals undergoing N₂O inhalation up to equilibrated peak gas concentrations of 20, 40 or 60% N₂O/O₂. In particular, CCSd has been devised to vary consistently for increasing levels of anesthetic concentration independent of the anesthetic’s microscopic mode of action for both N₂O and propofol. The strongest effects were observed for the 60% peak gas concentration group. For the 50–60% peak gas levels, individuals showed statistically significant reductions in responsiveness compared to rest, and across the group CS and CCS increased by 39 and 42%, respectively, while CCSd was found to decrease by 398%. On the other hand a clear conclusion regarding the changes in CI could not be reached. These results indicate that, contrary to previous depth of anesthesia monitoring measures, the CS, CCS, and especially CCSd measures derived from frontal EEG are potentially useful for differentiating gas concentration and responsiveness levels in people under N₂O. On the other hand, determining the utility of CI in this regard will require larger sample sizes and potentially higher gas concentrations. Future work will assess the sensitivity of CS-based and CI measures to other anesthetics and their utility in a clinical environment.