MR磁化传递对比成像观察新生儿轻度窒息

目的观察MR磁化传递对比(MTC)成像在轻度窒息新生儿中的应用价值。方法对15例轻度窒息新生儿(Apgar评分10分,病例组)及25名正常新生儿(对照组)采集脑常规T1WI、3D-T1WI和T1WI-MTC,计算脑磁化率(MTR),配准于标准新生儿脑模板后行统计分析。采用3dRegAna对病例组MTR与Apgar评分进行回归分析。结果相比对照组,病例组右颞极、左颞下回、左额上回、右缘上回、右眶额皮质、左额中叶、右额中回及左上额叶MTR显著降低;右梭状回、右顶叶下回、右枕中回、右颞中回、右颞下回、右颞上极、右楔叶、右角回、右舌回及右颞上回MTR显著增加。回归分析显示,病例组左中央后回、右颞下叶(前)、右额中回、右颞上极、左眶额皮质及右颞下叶(后)MTR与Apgar评分呈正相关,右壳核、右眶额皮质、左杏仁核、右颞下回、左舌回、右舌回、左颞中回、左枕中回、延髓及右梭状回呈负相关。组间MTR差异有统计学意义、且病例组MTR与Apgar评分呈正相关脑区为右额中叶、右颞极,呈负相关脑区则为右舌叶及右梭状回。结论 MR MTC成像能检出轻度窒息新生儿缺血缺氧脑区;缺血缺氧主要导致新生儿右侧脑损害。     

静息态fMRI评估急性酒精暴露对恒河猴脑功能的影响

目的采用静息态fMRI基于分数低频振荡幅度(fALFF)方法评估急性酒精暴露后恒河猴脑功能改变。方法分别对7只健康雄性恒河猴于静脉注射酒精前及注射后10、28、46min进行BOLD fMRI序列及3D结构像扫描,采用fALFF算法获得并比较4个时间点fALFF差异的脑区。结果 4个时间点fALFF总体差异显著的脑区为右侧中央后回、右侧岛叶、右侧小脑、左侧海马旁回、双侧额下回、小脑蚓部、右枕叶、楔前叶、左侧缘上回(P均0.05);静脉注射酒精后fALFF值减低的脑区为双侧额上回、右侧额下回、右侧梭状回、右侧角回、双侧颞上回、右枕叶、左侧外侧沟、左侧中央后回、左侧楔状叶、左侧丘脑、左侧岛叶、前扣带回(P均0.05);静脉注射酒精后fALFF值增高的脑区为右侧额下回、右侧颞中回(P均0.05)。结论酒精暴露急性期脑代谢活动发生显著变化,主要涉及默认网络、奖赏及情绪加工系统、视听皮层等。     

前庭功能的静息态脑功能磁共振成像

目的探讨基于局部一致性(ReHo)、低频振幅(ALFF)和低频振幅分数(fALFF)的静息态脑fMRI技术对于前庭冰水刺激诱导后脑内前庭功能相关区域的BOLD信号变化。方法纳入20名正常志愿者,在10s内将15ml 0℃冰水注入受试者右侧外耳道,采用平面回波序列和32通道头线圈采集受试者的BOLD静息态脑功能成像数据,采用MatLab 7.1和SPM 8进行数据预处理,预处理后的数据采用REST 1.4软件计算获得ReHo、ALFF和fALFF图像。结果ReHo、ALFF和fALFF图像均出现多个脑区激活增加或减低,其中3个参数值增加即激活脑区主要包括岛叶皮层、颞上回、顶下小叶、脑干、海马旁回、小脑半球等,减低即负激活脑区主要包括额上回、额中回、额下回、颞中回、枕下回、楔前叶等。结论人类存在广泛的涉及前庭信息处理的脑皮层及皮层下网络区域,静息态脑功能成像ReHo、ALFF、fALFF分析方法具有较好的一致性,具备定位前庭功能区的潜在能力。     

青少年肌阵挛性癫痫患者镜像同伦功能连接的初步研究

目的采用镜像同伦连接(VMHC)技术观察青少年肌阵挛性癫痫(JME)患者静息态功能连接的异常改变,以及连接强度与认知间的相关性。方法收集JME患者21例(JME组)及与之匹配的健康志愿者21名(对照组)进行静息态BOLD MR检查。图像数据采用DPABI中DPASFA软件进行预处理,之后采用REST软件进行VMHC分析,提取两组间有差异脑区,并将其与蒙特利尔认知评估量表(MoCa)评分进行相关性分析。结果与对照组比较,JME组的双侧尾状核、丘脑、额中回、额下回及枕中回VMHC值增加(Alphasim校正,P0.01);JME组的双侧尾状核VMHC值与MoCa评分呈正相关(r=0.43,P=0.015)。结论 JME患者静息态下基底核—丘脑—皮层环路中多个脑区间功能连接异常,且双侧尾状核异常可能与认知障碍有关。     

健康成人膀胱储尿功能的大脑静息态功能网络连接研究

目的:研究采用静息态功能磁共振(rs-fMRI)成像技术分析健康成人膀胱储尿功能的大脑功能网络连接。方法:2014年10月~2016年10月筛选健康受试者44例,其中男19例,女25例,年龄22~50岁,均为右利手。分别在膀胱空虚状态和膀胱充盈状态进行2次rs-fMRI扫描。扫描后通过rs-fMRI分析软件Matlab、SPM8、DPABI等进行处理分析。选取左侧前额叶(X=-39,Y=45,Z=-12);右侧前额叶(X=3,Y=49,Z=40);左侧前扣带回(X=-7,Y=-30,Z=-6);右侧前扣带回(X=9,Y=42,Z=-6);左侧颞叶(X=-33,Y=-51,Z=6);左侧颞上回(X=-57,Y=-18,Z=9)6个种子点,进行全脑功能连接。结果:6个种子的全脑功能连接区域:左侧前额叶,激活区域为双侧岛叶,右侧额下回;抑制区域为左侧海马旁回,左侧枕叶,左侧前额叶。右侧前额叶,抑制区域为左侧岛叶。左侧颞叶,抑制区域为右侧眶额叶。左侧颞上回,激活区域为左侧前额叶,右侧距状回;抑制区域为右侧小脑。左侧颞叶,激活区域为海马旁回;抑制区域为右侧额下回,右侧旁中央小叶。左侧颞上回,激活区域为左侧前额叶,左侧额中回,左侧中央颞叶;抑制区域为右侧岛叶,左侧小脑,左侧颞上回。结论:通过功能连接(functional connectivity,FC)分析发现大脑控尿区域不是某一区域单独完成的,而是广泛的、存在着功能相关性的多个区域共同协调完成的。     

正常(牙合)者下颌运动的肌电活动研究

目的研究正常(牙合)者在姿势位及下颌不同运动中,双侧颞肌前束(TA),后束(TP),嚼肌(MM),二腹肌前腹(DA)的肌电活动情况.方法采用美国BioEMG Ⅱ八道表面肌电仪和瑞士Kistler双极表面电极,同步记录30例正常牙合者上述诸肌的肌电变化.结果①姿势位:TA,TP,MM,DA均有轻微的肌电活动,其中TP的活动比较明显,起主要作用;②正中牙合位最大紧咬:TA,TP,MM均有强烈的肌电活动,其肌电压值达到最高峰,TA肌电活动最大,其次为MM,再次为TP;③前伸运动:MM,DA的肌电活动大于TA,TP;④后退运动:DA肌电活动最明显,其次为TP; ⑤左右侧方运动:肌电活动主要表现在同侧TA和TP,对侧MM和左右侧DA.结论 TA是重要的升颌肌;TP是维持姿势位、下颌后退和侧方运动的主要肌肉;MM为下颌紧咬产生咬(牙合)力,以及下颌前伸的主要肌肉;DA参加下颌的各种运动,起调节作用.     

正常者下颌运动的肌电活动研究

目的研究正常者在姿势位及下颌不同运动中,双侧颞肌前束(TA),后束(TP),嚼肌(MM),二腹肌前腹(DA)的肌电活动情况。方法采用美国BioEMGⅡ八道表面肌电仪和瑞士Kistler双极表面电极,同步记录30例正常者上述诸肌的肌电变化。结果①姿势位:TA,TP,MM,DA均有轻微的肌电活动,其中TP的活动比较明显,起主要作用;②正中位最大紧咬:TA,TP,MM均有强烈的肌电活动,其肌电压值达到最高峰,TA肌电活动最大,其次为MM,再次为TP;③前伸运动:MM,DA的肌电活动大于TA,TP;④后退运动:DA肌电活动最明显,其次为TP;⑤左右侧方运动:肌电活动主要表现在同侧TA和TP,对侧MM和左右侧DA。结论TA是重要的升颌肌;TP是维持姿势位、下颌后退和侧方运动的主要肌肉;MM为下颌紧咬产生咬力,以及下颌前伸的主要肌肉;DA参加下颌的各种运动,起调节作用。     

利用静息态功能磁共振探究颈动脉狭窄患者的认知障碍研究

目的采用静息态功能磁共振成像探讨无症状严重颈动脉狭窄患者产生认知障碍的机制。方法对2016年1月至2018年06月南京大学医学院附属鼓楼医院血管外科收治的21例无症状严重颈动脉狭窄患者和招募的21名健康人为对照组行认知量表评估和静息态磁共振检查,前瞻性分析两组人群的认知水平与影像数据的差异。结果患者组简易精神状态量表(MMSE)和蒙特利尔认知评估量表(MoCA)评分明显低于对照组,差异具有统计学意义(P0.001)。与对照组相比,患者组在右脑内侧额上回处低频振幅(ALFF)水平增加,在舌回处ALFF减少;在左侧额下回低频振幅比率较对照组增加;在颞上回局部一致性(ReHo)值较对照组增加,在右侧枕下回ReHo减少。患者组在右背外侧额上回与后扣带皮层的相关性显著低于对照组。影像学差异和认知评分之间没有显着相关性(P0.05)。结论无症状严重颈动脉狭窄存在不同程度的认知障碍,右内侧额上回、左侧额下回、颞上回、右背外侧额上回在与颈动脉狭窄相关的认知障碍的发生中可能起着重要的作用。     

腋神经中三角肌功能束组在四边孔平面分布的显微解剖及组织学研究

目的观察研究腋神经中支配三角肌的功能束(组)于四边孔平面在神经干中的分布规律及组织学特征。方法根据自然分束逆行显微解剖分离12具(24侧)福尔马林灌注固定成人尸体标本(左右各半)的腋神经,于四边孔平面观察记录三角肌功能束组在神经干中的分布情况并测量其直径;另取新鲜冷冻尸体上肢标本6具(左右各半),对腋神经束组于四边孔平面断面取材,组织横断面切片,分别行乙酰胆碱酯酶染色(Karnovsky-Roots法)及Loyez髓鞘染色,观察断面纤维束性质及行纤维计数。结果腋神经在四边孔平面可分为两大束组,支配三角肌的腋神经前支组成的束组走行于神经干外侧,截面积为(2.449±1.327)mm2,占神经干面积的55.4%±9.3%;纤维束性质表现为运动纤维;纤维计数为(2112±631)根,占神经纤维总数的45.6%±1.1%。结论在臂丛神经根性损伤进行神经移位重建肩外展功能时,将移位神经选择性与腋神经外侧束组吻接,会减少纤维散失,提高功能恢复率。     

儿童肾移植术后早期可逆性后部白质脑病综合征1例

可逆性后部白质脑病综合征(posterior reversible encephalopathy syndrome,PRES)最早是由Hinchey等[1]于1996年在合并肾功能不全、高血压或应用免疫抑制剂的患者中,根据临床表现和放射影像学结果阐述的一组包括头痛、瘫痪、意识状态改变、视物模糊、视野缺失和癫痫发作等表现的临床综合征,头部影像学检查提示主要发生在大脑后部顶枕叶的脑白质水肿性病变且具有可逆性。     

Connection patterns distinguish 3 regions of human parietal cortex

Three regions of the macaque inferior parietal lobule and adjacent lateral intraparietal sulcus (IPS) are distinguished by the relative strengths of their connections with the superior colliculus, parahippocampal gyrus, and ventral premotor cortex. It was hypothesized that connectivity information could therefore be used to identify similar areas in the human parietal cortex using diffusion-weighted imaging and probabilistic tractography. Unusually, the subcortical routes of the 3 projections have been reported in the macaque, so it was possible to compare not only the terminations of connections but also their course. The medial IPS had the highest probability of connection with the superior colliculus. The projection pathway resembled that connecting parietal cortex and superior colliculus in the macaque. The posterior angular gyrus and the adjacent superior occipital gyrus had a high probability of connection with the parahippocampal gyrus. The projection pathway resembled the macaque inferior longitudinal fascicle, which connects these areas. The ventral premotor cortex had a high probability of connection with the supramarginal gyrus and anterior IPS. The connection was mediated by the third branch of the superior longitudinal fascicle, which interconnects similar regions in the macaque. Human parietal areas have anatomical connections resembling those of functionally related macaque parietal areas.     

Functional relevance of interindividual differences in temporal lobe callosal pathways: a DTI tractography study

The midsagittal corpus callosum is topographically organized, that is, with regard to their cortical origin several subtracts can be distinguished within the corpus callosum that belong to specific functional brain networks. Recent diffusion tensor tractography studies have also revealed remarkable interindividual differences in the size and exact localization of these tracts. To examine the functional relevance of interindividual variability in callosal tracts, 17 right-handed male participants underwent structural and diffusion tensor magnetic resonance imaging. Probabilistic tractography was carried out to identify the callosal subregions that interconnect left and right temporal lobe auditory processing areas, and the midsagittal size of this tract was seen as indicator of the (anatomical) strength of this connection. Auditory information transfer was assessed applying an auditory speech perception task with dichotic presentations of consonant-vowel syllables (e.g., /ba-ga/). The frequency of correct left ear reports in this task served as a functional measure of interhemispheric transfer. Statistical analysis showed that a stronger anatomical connection between the superior temporal lobe areas supports a better information transfer. This specific structure-function association in the auditory modality supports the general notion that interindividual differences in callosal topography possess functional relevance.     

Evidence of basal temporo-occipital cortex involvement in stereoscopic vision in humans: a study with subdural electrode recordings

Stereoscopic vision is based on small differences in both retinal images known as retinal disparities. We investigated the cortical responses to retinal disparities in a patient suffering from occipital epilepsy by recording evoked potentials to random dot stereograms (RDS) from subdural electrodes placed in the parieto-occipito-temporal junction, medial surface of the occipital lobe (pericalcarine cortex) and basal surface of the occipital and temporal lobes (fusiform gyrus). Clear responses to disparity present in RDS were found in the fusiform cortex. We observed that the fusiform responses discriminate the onset from the offset of the stimulus, correlation from uncorrelation, and they show a longer latency than responses found in the pericalcarine cortex. Our findings indicate that the fusiform area is involved in the processing of the stereoscopic information and shows responses that suggest a high level of stereoscopic processing.     

The neural basis of visual skill learning: an fMRI study of mirror reading

The learning of perceptual skills is thought to rely upon multiple regions in the cerebral cortex, but imaging studies have not yet provided evidence about the changes in neural activity that accompany visual skill learning. Functional magnetic resonance imaging (fMRI) was used to examine changes in activation of posterior brain regions associated with the acquisition of mirror-reading skill for novel and practiced stimuli. Multiple regions in the occipital lobe, inferior temporal cortex, superior parietal cortex and cerebellum were involved in the reading of mirror-reversed compared to normally oriented text. For novel stimuli, skilled mirror-reading was associated with decreased activation in the right superior parietal cortex and posterior occipital regions and increased activation in the left inferior temporal lobe. These results suggest that learning to read mirror- reversed text involves a progression from visuospatial transformation to direct recognition of transformed letters. Reading practiced, relative to unpracticed, stimuli was associated with decreased activation in occipital visual cortices, inferior temporal cortex and superior parietal cortex and increased activation in occipito-parietal and lateral temporal regions. By examining skill learning and item- specific repetition priming in the same task, this study demonstrates that both of these forms of learning exhibit shifts in the set of neural structures that contribute to performance.      

DTI tractography of the human brain's language pathways

Diffusion Tensor Imaging (DTI) tractography has been used to detect leftward asymmetries in the arcuate fasciculus, a pathway that links temporal and inferior frontal language cortices. In this study, we more specifically define this asymmetry with respect to both anatomy and function. Twenty right-handed male subjects were scanned with DTI, and the arcuate fasciculus was reconstructed using deterministic tractography. The arcuate was divided into 2 segments with different hypothesized functions, one terminating in the posterior superior temporal gyrus (STG) and another terminating in the middle temporal gyrus (MTG). Tractography results were compared with peak activation coordinates from prior functional neuroimaging studies of phonology, lexical-semantic processing, and prosodic processing to assign putative functions to these pathways. STG terminations were strongly left lateralized and overlapped with phonological activations in the left but not the right hemisphere, suggesting that only the left hemisphere phonological cortex is directly connected with the frontal lobe via the arcuate fasciculus. MTG terminations were also strongly left lateralized, overlapping with left lateralized lexical-semantic activations. Smaller right hemisphere MTG terminations overlapped with right lateralized prosodic activations. We combine our findings with a recent model of brain language processing to explain 6 aphasia syndromes.     

White matter fiber dissection of the optic radiations of the temporal lobe and implications for surgical approaches to the temporal horn

OBJECT: The aim of this anatomical study was to define more fully the three-dimensional (3D) relationships between the optic radiations and the temporal horn and superficial anatomy of the temporal lobe by using the Klingler white matter fiber dissection technique. These findings were correlated with established surgical trajectories to the temporal horn. Such surgical trajectories have implications for amygdalohippocampectomy and other procedures that involve entering the temporal horn for the resection of tumors or vascular lesions. METHODS: Ten human cadaveric hemispheres were prepared with several cycles of freezing and thawing by using a modification of the method described by Klingler. Wooden spatulas were used to strip away the deeper layers of white matter progressively in a lateromedial direction, and various association, projection, and commissural fibers were demonstrated. As the dissection progressed, photographs of each progressive layer were obtained. Special attention was given to the optic radiation and to the sagittal stratum of which the optic radiation is a part. The trajectories of fibers in the optic radiation were specifically studied in relation to the lateral, medial, superior, and inferior walls of the temporal horn as well as to the superficial anatomy of the temporal lobe. In three of the hemispheres coronal sections were made so that the relationship between the optic radiation and the temporal horn could be studied more fully. In all 10 hemispheres that were dissected the following observations were made. 1) The optic radiation covered the entire lateral aspect of the temporal horn as it extends to the occipital horn. 2) The anterior tip of the temporal horn was covered by the anterior optic radiation along its lateral half. 3) The entire medial wall of the temporal horn was free from optic radiation fibers, except at the level at which these fibers arise from the lateral geniculate body to ascend over the roof of the temporal horn. 4) The superior wall of the temporal horn was covered by optic radiation fibers. 5) The entire inferior wall of the temporal horn was free from optic radiation fibers anterior to the level of the lateral geniculate body. CONCLUSIONS: Fiber dissections of the temporal lobe and horn demonstrated the complex 3D relationships between the optic radiations and the temporal horn and superficial anatomy of the temporal lobe. Based on the results of this study, the authors define two anatomical surgical trajectories to the temporal horn that would avoid the optic radiations. The first of these involves a transsylvian anterior medial approach and the second a pure inferior trajectory through a fusiform gyrus. Lateral approaches to the temporal horn through the superior and middle gyri, based on the authors' findings, would traverse the optic radiations.     

Diffusion tensor tractography of the temporal stem on the inferior limiting sulcus

OBJECT: The aim of this study was to use diffusion tensor tractography (DTT) to define the 3D relationships of the uncinate fasciculus, anterior commissure, inferior occipitofrontal fasciculus, inferior thalamic peduncle, and optic radiation and to determine the positioning landmarks of these white matter tracts. METHODS: The anatomy was studied in 10 adult human brain specimens. Brain DTT was performed in 10 healthy volunteers. Diffusion tensor tractography images of the white matter tracts in the temporal stem were obtained using the simple single region of interest (ROI) and multi-ROIs based on the anatomical knowledge. RESULTS: The posteroinferior insular point is the anterior extremity of intersection of the Heschl gyrus and the inferior limiting sulcus. On the inferior limiting sulcus, this point is the posterior limit of the optic radiation, and the temporal stem begins at the limen insulae and ends at the posteroinferior insular point. The distance from the limen insulae to the tip of the temporal horn is just one third the length of the temporal stem. The uncinate fasciculus comprises the core of the anterior temporal stem, behind which the anterior commissure and the inferior thalamic peduncle are located, and they occupy the anterior third of the temporal stem. The inferior occipitofrontal fasciculus passes through the entire temporal stem. The most anterior extent of the Meyer loop is located between the anterior tip of the temporal horn and the limen insulae. Most of the optic radiation crosses the postmedian two thirds of the temporal stem. CONCLUSIONS: On the inferior limiting sulcus, the posteroinferior insular point is a reliable landmark of the posterior limit of the optic radiations. The limen insulae, anterior tip of the temporal horn, and posteroinferior insular point may be used to localize the white matter fibers of the temporal stem in analyzing magnetic resonance imaging or during surgery.     

Microsurgical anatomy of the superficial veins of the cerebrum

The microsurgical anatomy of the superficial cortical veins was examined in 20 cerebral hemispheres. The superficial cortical veins are divided into three groups based on whether they drain the lateral, medial, or inferior surface of the hemisphere. The veins on the three surfaces are further subdivided on the basis of the lobe and cortical area that they drain. The superficial cerebral veins collect into four groups of bridging veins: a superior sagittal group, which drains into the superior sagittal sinus; a sphenoidal group, which drains into the sphenoparietal and cavernous sinuses on the inner surface of the sphenoid bone; a tentorial group, which converges on the sinuses in the tentorium; and a falcine group, which empties into the inferior sagittal or straight sinus or their tributaries. The superior sagittal group drains the superior part of the medial and lateral surfaces of the frontal, parietal, and occipital lobes and the anterior part of the basal surface of the frontal lobe. The sphenoidal group drains the parts of the frontal, temporal, and parietal lobes adjoining the sylvian fissure. The tentorial group drains the lateral surface of the temporal lobe and the basal surface of the temporal and occipital lobes. The falcine group drains an area that includes the cingulate and parahippocampal gyri and approximates the cortical parts of the limbic lobe of the brain. The relationship of these veins to the venous lacunae was also examined.