应用磁源性影像对健康青年人大脑听觉皮层功能区定位的初步研究

目的探讨磁源性影像在大脑听觉皮层功能区定位的应用价值。方法应用全头型306通道生物磁仪，对30例健康青年人(20～32岁)男16例，女14例进行了大脑听皮层诱发磁场的测试，5例观察了0．5、1、2、4、8kHz纯音诱发的脑磁反应波M100，另25例均测试了2kHz纯音诱发的脑磁反应波M100，并将脑磁图的电生理资料与磁共振成像的解剖结构资料叠加，获得大脑听觉皮层磁源性影像，以确定M100在大脑初级听觉皮层的位置。结果30例受试者均可诱发出M100，且重复性好，其位置均位于大脑的颞横回；不同频率的纯音诱发的M100在大脑颞横回有其各自的定位和分布；初级听觉皮层在两侧大脑半球的位置相对而言左侧靠后，右侧靠前，两侧明显不对称。M100潜伏期在左侧和右侧大脑半球对侧声刺激均较同侧声刺激为短，但M100等电流偶极的位置与刺激声的侧别无关。结论由脑磁图的M100所获得的磁源性影像，具有良好的时间和空间分辨率，可对大脑初级听皮层功能区进行精确定位，将在耳科学的临床和基础研究中具有广阔的应用前景。     

听神经病大脑听觉皮层功能区脑磁图初步观察

目的应用脑磁图探讨听神经病患者大脑听觉皮层功能区的病变情况。方法应用全头型306通道生物磁仪，对10例（20耳）听神经病患者和15例（30耳）正常对照组进行大脑听觉皮层诱发磁场的测试，观察了左右耳分别给予0．5、1、2、4、6、8kHz纯音刺激诱发的双侧大脑半球听觉皮层磁反应波M100，将其脑磁图的电生理资料与磁共振成像的解剖结构资料叠加，获得听神经病患者大脑听觉皮层的磁源性影像。结果15例正常对照组除16耳8kHz未诱发出M100外，其他各频率双耳均可诱发出M100，而听神经病患者在0．5、1、2、4、6kHz20耳（40侧）大脑听觉皮层磁反应波M100引出率分别为27．5％（11／40）、22．5％（9／40）、7．5％（3／40）、5％（2／40）、5％（2／40）；8kHz均未引出反应。与正常对照组相比较其潜伏期明显延长，波幅明显降低（P〈0．01）。在初级听皮层1kHz纯音刺激诱发的M100位置听神经病患者较正常对照组更靠大脑半球的外侧。结论听神经病是一种临床表现主要为听力学异常的，包括耳蜗后第Ⅷ颅神经耳蜗支和听觉传导通路直至大脑听觉皮层在内的听觉系统疾患。脑磁图可作为其是否适合配带助听器和电子耳蜗植入治疗的参考。     

感音神经性聋患者听觉皮层BOLD-fMRI研究

目的利用血氧水平依赖的功能磁共振成像（blood oxygenation level dependent functional magnetic resonance imaging,BOLD—fMRI）技术观察感音神经性聋患者纯音刺激时大脑听觉皮层激活情况,探讨感音神经性聋的中枢客观检查方法。方法对22例单侧中重度感音神经性聋患者（耳聋组）和15例健康志愿者（对照组）行听觉刺激BOLD-fMRI检查,比较两组纯音刺激时听觉皮层激活的体积和信号强度。结果对照组纯音刺激单耳时,对侧听觉皮层激活体积和信号强度明显大于同侧（P〈0．01）,表现为对侧半球传导优势;耳聋组刺激健侧时健侧听觉皮层激活体积和信号强度大于患侧,但差异无统计学意义（P〉0．05）。结论感音神经性聋患者纯音刺激健耳时对侧听觉半球传导优势消失,其听觉皮层可能发生了结构重塑。     

正常听力国人听觉皮层频率分布的功能MRI研究

目的 利用血氧水平依赖功能磁共振成像(BOLD-fMRI)研究正常听力国人的听皮质频率响应分布的特点.方法 对25例健康受试者采用事件相关Sparse设计、正弦调幅音任务下的回波平面成像技术(echo-planar imaging,EPI)进行fMRI数据采集,实验刺激声分别为0.5、2、4 kHz纯音经8 Hz正弦调幅,双耳同时间断给声,给声持续时间9 s,扫描3 s,随机插入静音序列.利用SPM2软件进行数据分析,观察左右大脑听觉皮层频率响应分布特点.结果 25例受试者中9例由于EPI采集时头动超过最大限度而删除数据,余16例受试者均表现为初级听觉皮层激活,其中2例左侧、3例右侧、4例双侧初级听觉皮层激活的部位表现出高频偏内、低频偏外的频率响应分布特点,另7例双侧初级听觉皮层无明显的排列规律.结论 正常听力国人初级听觉皮层的频率响应分布表现出高频偏内、低频偏外的特点.     

耳鸣患者听觉皮质BOLD-fMRI研究

目的 利用血氧水平依赖（blood oxygenation leve ldependent,BOLD）功能磁共振成像（functional magnetic resonance imaging）（BOLD—fMRI）技术观察耳呜患者纯音刺激时大脑皮质区激活情况,探讨耳呜的客观检查方法。方法对7例长期耳呜患者行BOLD—fMRI检查,观察其大脑皮质区激活信号,15例健康人作为对照组。结果15例健康志愿者纯音刺激时颞叶区均出现激活,颞上回激活率最高。刺激单耳时对侧听觉皮质激活体积和信号强度明显大于同侧（P〈0．01）,表现为对侧半球传导优势。耳鸣组纯音刺激时大脑皮质激活解剖部位、激活体积和信号强度无明显规律。结论长期耳呜患者可能存在听觉皮质的异常神经活动。     

感音神经性聋人和正常人纯音刺激脑功能区BOLD-fMRI研究

目的利用血氧水平依赖效应功能磁共振成像(blood oxygenationlevel dependent-functional magnetic resonancei maging,BOLD-fMRI)观察正常人和感音神经性聋人在纯音刺激时脑听觉中枢的兴奋情况,比较两组间的差异.方法正常人和聋人受试者各30名.功能成像采用组块设计.声音刺激用1000Hz纯音,强度(sound pressure level,SPL)140dB,持续时间500ms,刺激间隔500ms,刺激施加频率1Hz.结果正常人接受纯音刺激激活脑区有:两侧颞横回、颞平面前极、颞平面、外侧裂周围的中央前回、中央后回、颞上回(除颞横回、颞平面前极、颞平面以外的部分)、缘上回、额下回、以及两侧枕叶和小脑半球.聋人纯音激活脑区与正常人相似.对正常人和聋人各脑区的激活强度行t检验,表现为正常人激活强度显著高于聋人的脑区有:两侧颞横回、颞平面前极及额下回,左侧颞上回,右侧颞平面;表现聋人激活强度显著高于正常人的脑区有:两侧枕叶、中央后回、中央前回.结论正常人和感音性聋人接受适当纯音刺激都可激活听觉中枢.在相同刺激条件下聋人听觉中枢激活程度较正常人低.人脑以网络模式处理听觉信息,不同感觉中枢间存在固有的联系,聋人的听觉中枢有重组现象发生.     

儿童有无平台短纯音诱发听性脑干反应研究

目的 比较有平台与无平台短纯音诱发的儿童听性脑干反应(Auditory Brain Stem Response,ABR)反应阈之间的相关性,选择更优化的频率特异性ABR刺激信号.方法 应用SmartEP听觉诱发电位仪(美国IHS公司)记录0～4岁儿童短声、有平台及无平台短纯音诱发ABR各频率反应阈,共26例(17男/9女)41耳.结果 0.5 kHz、1 kHz、2 kHz、4 kHz有平台短纯音ABR反应阈与无平台短纯音ABR反应阈的线性相关系数分别为0.949、0.968、0.979、0.936,前者比后者反应阈分别高(5.0±7.6)、(9.4±5.8)、(8.2±5.2)、(7.6±10.3)dB,差异有统计学意义(t值分别为3.397、8.060、7.915、3.682,P值均<0.01).极重度听力损失耳有平台短纯音各频率ABR反应阈值引出率均高于无平台短纯音.结论 本实验室应用SmartEP听觉诱发电位仪评估儿童听力时.总体上,在测试非极重度听力损失患儿时,无平台短纯音诱发ABR优于有平台短纯音;但本仪器后者可提供更高强度的声刺激,以用于极重度听力损失耳.     

纯音刺激前后正常人听皮层代谢变化~1HMRS研究

目的利用质子磁共振波谱(protonmagnetic resonance spectroscopy,1H-MRS)技术研究纯音刺激前后正常人大脑听皮层代谢变化。方法 10例健康受试者双侧听皮层在纯音刺激前后接受两次多体素磁共振波谱检查。刺激声为声强90dB、频率1000Hz的正弦波纯音脉冲,左耳给声。观察双侧听皮层N-乙酰天门冬氨酸(N-aceytlaspartate,NAA)、肌酸(creatine,Cr)、胆碱(choline,Cho)、谷氨酰胺和谷氨酸(glutamate/glutamine,Glx)等代谢物的波峰变化并进行半定量分析。结果左耳纯音刺激后双侧听皮层NAA/(Cho+Cr)、Glx/(Cho+Cr)比值均增高,Cho/Cr比值降低,NAA/(Cho+Cr)、Glx/(Cho+Cr)、Cho/Cr刺激前后差异在右侧听皮层均具有统计学意义(P<0.05),但在左侧听皮层差异无统计学意义(P>0.05)。结论 1HMRS可无创性检测听皮层中与能量代谢及神经递质有关的化合物,纯音刺激单耳时,正常人对侧听皮层代谢变化明显大于同侧,表现为对侧半球传导优势。     

短纯音及切迹噪声掩蔽的短纯音ABR用于儿童听力评估的研究

目的研究儿童短纯音（tone burst）及同侧切迹噪声（notched noise）掩蔽短纯音诱发的ABR反应阈,与短声诱发的听性脑干反应（click-evoked auditory brainstem response,c-ABR）以及40Hz听觉事件相关电位（40Hz Auditory Event Related Potentials,40Hz AERP）反应阈的关系,以评价这些测试方法在儿童听力评估中的应用价值。方法应用SmartEP听觉诱发电位仪在29例（53耳）儿童（男18例,女11例,年龄2月-8岁）中测试短声ABR、短纯音ABR、两种不同强度切迹噪声掩蔽短纯音诱发的ABR（分别定义为c-ABR、tb-ABR、amtb-ABR和bmtb-ABR）及40Hz AERP。结果（1）fb-ABR、amtb-ABR、bmtb-ABR在2kHz、4kHz两个频率的反应阈与c-ABR的反应阈接近,反应阈之间有较好的相关性;（2）tb-ABR、amtb-ABR、bmtb-ABR的反应阈与40Hz AERP的反应阈在0.5、1、2、4kHz各个频率均接近并有较好的相关性。结论使用短纯音及同侧切迹噪声掩蔽短纯音诱发的ABR的反应阈预测儿童的纯音行为听阈是可行的。     

听力损害时脑皮层的正电子发射断层成像

目的 探讨听力损失对脑葡萄糖代谢活动的影响。方法 对12例有听力损失但无耳鸣患者进行正电子发射断层成像(PET)研究,其中2例双耳全聋,10例双耳中度聋。分别在静息(视听封闭)和声刺激(2kHz短纯音130dBSPL)条件下进行PET成像。与13例听力正常者在静息条件下和4例听力正常者在声刺激条件下的PET作对照。PET示踪剂为~(18)F标记的去氧葡萄糖(~(18)F-FDG)。用专门统计分析软件(SPM)以及感兴趣区技术(ROI)进行统计分析。结果 2例全聋患者的听皮层葡萄糖代谢活动显著低于正常人(P<0.001),而视皮层及体感皮层的代谢活动显著高于正常人(P<0.001)。另10例听力下降患者的听皮层代谢活动低于正常人(P<0.05),声刺激后听皮层兴奋区域显著大于正常人(P<0.001)。提示听力下降引起听皮层神经元葡萄糖代谢活动的相应下降,但与听力下降相邻频率的声刺激却引起相应听皮层的代谢活动的显著增加,而且兴奋区域扩大。表明听皮层发生了功能重组。全聋患者的结果提示,视觉功能显著增强了,这是系统间功能重组的重要证据。结论 PET作为新型脑功能成像仪器,为研究听觉与脑功能提供了新方法,为听系功能重组和中枢神经系统的可塑性提供了有力证据。     

Comparative study on the morphology and the composition of the otoliths in the teleosts

Conclusion. Saccular otoliths of teleosts were mostly larger than utricular otoliths, which might relate to the three-dimensional movement. The large and heavy otolith may be better suited in saccules of the bottom and reef fishes. The quantities of iron in lagenar otoliths were found to be lower than those of birds. The function of the fish lagena remains to be elucidated by further studies. Objective. To evaluate the morphological characteristics and the chemical composition of the otoliths in fishes as related to behaviour and habitat. Materials and methods. We studied the morphology of the otoliths of 18 genera of fishes (81 samples) divided into 3 groups: saltwater fish (13 genera), freshwater fish except for the carp family (3 genera) and carp family fish (2 genera). The otoliths and the living environments were compared. The chemical composition was analysed using a synchrotron X-ray fluorescence analyser. Results. Bottom fishes generally have larger saccular otoliths, and migrating fishes have smaller saccular otoliths. In comparing the bottom/reef fishes and the migrating fishes in salt water, the former tended to have larger saccular otoliths. In saltwater bottom fishes the tendency was found that the thinner the head, the larger was the saccular otolith. We found significant quantities of iron, zinc and manganese in the lagenar otoliths.     

Observations on the stria vascularis of the guinea pig cochlea and the changes resulting from the administration of the diuretic furosemide

An electron microscope examination of the stria vascularis of guinea pigs and the structural changes occurring after administration of furosemide has been made. The use of ruthenium-red, which stains cell coats, has shown that the stria is impermeable to the passive diffusion of material from both the endolymph and the spiral ligament. The first changes after administration of furosemide are observed 4 hours after injection; small spaces develop between the cells. After 5–6 hours the spaces have enlarged but the tight junctions between marginal cells remain intact. The intermediate cells show signs of atrophy. In severely affected animals the intermediate cells have so shrunk that the spaces are very large and the marginal cells clearly resolved. These latter cells show no structural damage. In this severely affected tissue it is seen that the blood vessels are entirely surrounded by marginal cell extensions. It is suggested that the intermediate cells may have a regulatory function. The damage appears to be recoverable, since 6 hours after injection the spaces have decreased in size although some signs of intermediate cell atrophy are still apparent.     

胃镜联合食管镜取出胃内异物1例

患者,男,49岁,因＂反复中上腹疼痛6年＂于2012年6月12日就诊于我院消化内科。患者有反复胃痛、胃部不适症状,长期按胃病治疗效果不佳。既往有吸毒史、丙型肝炎病史。6年前患者毒瘾发作时曾吞入牙刷,在当地医院复查未发现异物,未进一步诊治。     

On the High Frequency Transfer of Mechanical Stimuli from the Surface of the Head to the Macular Neuroepithelium of the Mouse

Vestibular macular sensors are activated by a shearing motion between the otoconial membrane and underlying receptor epithelium. Shearing motion and sensory activation in response to an externally induced head motion do not occur instantaneously. The mechanically reactive elastic and inertial properties of the intervening tissue introduce temporal constraints on the transfer of the stimulus to sensors. Treating the otoconial sensory apparatus as an overdamped second-order mechanical system, we measured the governing long time constant (Τ_L) for stimulus transfer from the head surface to epithelium. This provided the basis to estimate the corresponding upper cutoff for the frequency response curve for mouse otoconial organs. A velocity step excitation was used as the forcing function. Hypothetically, the onset of the mechanical response to a step excitation follows an exponential rise having the form Vel_shear = U(1-e^−t/TL), where U is the applied shearing velocity step amplitude. The response time of the otoconial apparatus was estimated based on the activation threshold of macular neural responses to step stimuli having durations between 0.1 and 2.0 ms. Twenty adult C57BL/6 J mice were evaluated. Animals were anesthetized. The head was secured to a shaker platform using a non-invasive head clip or implanted skull screws. The shaker was driven to produce a theoretical forcing step velocity excitation at the otoconial organ. Vestibular sensory evoked potentials (VsEPs) were recorded to measure the threshold for macular neural activation. The duration of the applied step motion was reduced systematically from 2 to 0.1 ms and response threshold determined for each duration (nine durations). Hypothetically, the threshold of activation will increase according to the decrease in velocity transfer occurring at shorter step durations. The relationship between neural threshold and stimulus step duration was characterized. Activation threshold increased exponentially as velocity step duration decreased below 1.0 ms. The time constants associated with the exponential curve were Τ_L = 0.50 ms for the head clip coupling and T_L = 0.79 ms for skull screw preparation. These corresponded to upper −3 dB frequency cutoff points of approximately 318 and 201 Hz, respectively. T_L ranged from 224 to 379 across individual animals using the head clip coupling. The findings were consistent with a second-order mass-spring mechanical system. Threshold data were also fitted to underdamped models post hoc. The underdamped fits suggested natural resonance frequencies on the order of 278 to 448 Hz as well as the idea that macular systems in mammals are less damped than generally acknowledged. Although estimated indirectly, it is argued that these time constants reflect largely if not entirely the mechanics of transfer to the sensory apparatus. The estimated governing time constant of 0.50 ms for composite data predicts high frequency cutoffs of at least 318 Hz for the intact otoconial apparatus of the mouse.     

Contact between the tectorial membrane and the cochlear sensory hairs in the human and the monkey

European Archives of Oto-Rhino-Laryngology - The surface structure of the organ of Corti and the overlying tectorial membrane were studied in human and monkey cochleas under a scanning electron...     

膈神经与面神经吻合的解剖学研究

目的:探讨膈神经移位与面神经干吻合的解剖学基础。方法:解剖11具22侧成年尸体头颈部,观察并测量:①膈神经根与面神经总干腮腺区分叉处之间的距离;②膈神经干在颈部可利用长度;③面神经总干腮腺区分叉处游离至水平半规管下缘可利用长度,面神经总干腮腺区分叉处游离至水平半规管下缘较游离至茎乳孔处增加的面神经干可利用长度;④面神经总干腮腺区分叉处至水平半规管下方切断处膈神经干及面神经干神经移位后并列放置重合长度。结果:①膈神经根与面神经总干腮腺区分叉处之间的距离为(7.2±0.9)cm。②膈神经起点至锁骨下静脉上缘平面为(7.2±1.6)cm。③面神经总干腮腺区分叉处至水平半规管下方切断处的长度2.7~3.5 cm,较面神经干自茎乳孔下方切断增加1.0~1.5 cm。④神经移位后重合长度为0.4~1.8 cm。结论:在锁骨下静脉上缘平面切断20侧标本膈神经可与自乳突内切取的面神经干无张力吻合,两侧膈神经不能与自乳突内切取的面神经干无张力吻合。