甘油对实验性内淋巴积水前庭功能和形态的影响

制作内淋巴积水的动物模型，观察甘油对前庭的影响。４０只健康豚鼠随机分成实验和对照组各２０只。用眼震电图仪描记对照组、实验组用甘油前和口服甘油后１２０ｍｉｎ时的前庭摆动民生眼震，实验动物进行内耳形态学观察。     

甘油对实验性内淋巴积水前庭功能和形态的影响

自Klockhoff和lindblom[1]报道用甘油试验诊断梅尼埃病以来，人们就甘油对内耳的作用进行了大量的研究。但有关甘油对实验性内淋巴积水的影响的报道很少”[2－6]，且这些研究主要集中在观察甘油对实验性内淋巴积水耳蜗功能和形态的影响，而有关甘油对实验性内淋巴积水前庭功能和形态的影响罕见报道。本研究是在制作豚鼠一例内淋巴积水动物模型的基础上，观察甘油对内淋巴积水前庭功能的影响，同时进行内耳形态学观察。1材料和方法健康豚鼠40只（空军总医院动物室提供），体重300～450g，雌雄兼有，耳廓反射灵敏，随机分为对照组和实验组，…     

咽鼓管阻塞对实验性内淋巴积水前庭功能和形态的影响

目的观察咽鼓管阻塞对实验性内淋巴积水前庭功能和形态的影响。方法用眼震电图（ＥＮＧ）描记１５只健康豚鼠的前庭摆动性眼震，然后将其随机分成３组（各组ｎ＝５）。Ａ组（咽鼓管阻塞组）：阻塞右咽鼓管后；Ｂ组（内淋巴积水组）制作右内淋巴积水模型３周后；Ｃ组（内淋巴积水＋咽鼓管阻塞组）：对制作右内淋巴积水模型３周的动物阻塞右咽鼓管后，进行低压舱试验。各组动物低压舱试验的速率均为（１０／１００）ｍ／ｓ（上升／下降），在低压舱试验前后分别复查ＥＮＧ，最后观察鼓膜并处死动物进行内耳形态学观察。结果Ｃ组动物低压舱试验后ＥＮＧ示右向眼震数明显减少，与手术前和术后低压舱试验前相比，具有显著性差异，Ｐ均＜０．０５。形态学显示右鼓膜弥漫充血、右内淋巴积水、右外半规管壶腹嵴毛细胞损伤。结论内淋巴积水复合咽鼓管阻塞可加重前庭功能和形态的损害。     

豚鼠单侧内淋巴囊破坏后诱导前庭失代偿特点

目的观察豚鼠单侧内淋巴囊破坏后前庭功能损伤、中枢代偿及代偿的稳定性等特点。方法将30只健康豚鼠随机等分为对照组和实验组,用正弦角加速度试验评估前庭功能。硫喷妥钠腹腔注射诱导前庭失代偿,观察注射后静态姿势、紧张性眼位移及自发性眼震,同步记录眼震电图。结果①内淋巴囊破坏后第8周正弦摆动性前庭眼震的慢相速度有明显失对称。②硫喷妥钠可诱导前庭失代偿现象,损伤越重,代偿愈不稳定,越易诱发失代偿。以紧张性眼位移最常见,自发性眼震最少。③病理切片示内淋巴囊破坏后第8周蜗管有明显积水。结论内淋巴囊破坏后可引起前庭功能损害,由于中枢代偿而不表现出明显的前庭功能紊乱症状,但这种代偿是不稳定的。     

飞行变压性眩晕动物模型的建立

目的建立变压性眩晕的动物模型，观察前庭功能和前庭终器形态学的变化。方法20只健康豚鼠描记前庭功能后随机分成4组，每组各5只动物。A组行右鼓膜造孔，B组行左咽鼓管阻塞，C组行右鼓膜造孔并左咽鼓管阻塞，D组为对照组。实验组动物建模后和对照组动物置于低压舱内，反复升降3次，观察动物躯体反应和自发性眼震，出舱后即刻复查前庭功能，最后行前庭终器的形态学观察。结果①在低压舱上升时，实验组动物均出现了前庭躯体异常反应；15只动物中有12只（A组3只，B组4只，C组5只）出现了快相向左的水平性眼震，持续数十余秒到数分钟；出舱后即刻复查前庭功能，A组正弦摆动实验4只动物左右向眼震不对称比大于正常，B组和C组正弦摆动实验和旋转急停实验5只动物不对称比均大于正常。②光镜和透射电镜显示实验组动物前庭终器毛细胞胞浆及线粒体空泡样变，扫描电镜示毛细胞纤毛局限性倒伏、缺失（C组最明显，B组于A组和C组之间）。结论双侧中耳不平衡压力及中耳相对高压，引起了前庭功能变化和前庭终器的形态学改变。本设计可作为深入研究变压性眩晕的动物模型。     

诱生型一氧化氮合成酶在豚鼠内淋巴积水耳蜗的表达

观察诱生型一氧化氮合成酶（iNOS）在豚鼠内淋巴积水耳蜗的表达。将20只豚鼠随机分为正常对照组和实验组，破坏实验组豚鼠内淋巴囊以造成内淋巴积水模型。采用免疫组织化学的方法检测iNOS在内淋巴积水耳蜗的表达。结果显示，iNOS在内淋巴积水耳蜗的表达阳性，且以血管纹和螺旋神经节细胞的表达较强。提示一氧化氮参与了内淋巴积水的病理生理过程。     

基于三维液体衰减反转恢复序列静脉增强内耳膜迷路图像的定量评估方法评价内淋巴积水的对比研究

目的比较基于内耳三维快速液体衰减反转恢复序列(3D-FLAIR)静脉增强内耳膜迷路图像的3种定量评估方法对内淋巴积水的诊断价值。方法回顾性收集2017年10月至2019年4月就诊于首都医科大学附属北京同仁医院单侧耳源性眩晕患者86例。入组患者均采取单倍剂量静脉增强, 延迟8 h采集内耳3D-FLAIR图像。采用3种评价方法, 分别为计算前庭内淋巴间隙面积与整个前庭内、外淋巴间隙总面积的比值、椭圆囊与球囊面积的比值和前庭内淋巴间隙体积与整个前庭内、外淋巴间隙总体积的比值。采用配对t检验比较患侧与健侧耳前庭内淋巴/总淋巴面积比、球囊/椭圆囊面积比、前庭内淋巴/总淋巴体积比的差异。以临床诊断为金标准, 采用受试者操作特征(ROC)曲线分析3种评估方法诊断内淋巴积水的效能。结果本组86例患者中临床确诊内淋巴积水65例。患侧耳与健侧耳前庭内淋巴/总淋巴面积比、球囊/椭圆囊面积比、前庭内淋巴/总淋巴体积比的差异均有统计学意义(t=9.93、7.22、8.20, P均<0.001)。ROC曲线显示前庭内淋巴/总淋巴面积比、球囊/椭圆囊面积比、前庭内淋巴及总淋巴体积比诊断内淋巴积水的曲线下面积分...     

甘油对实验性豚鼠膜迷路积水的影响

眩晕是飞行人员常见的症状,美尼尔氏病是眩晕的主要原因之一。甘油试验是诊断美尼尔氏病的客观依据之一。为了更深入地探讨美尼尔氏病的发病机制和甘油对膜迷路积水的影响,为飞行人员眩晕的诊断和鉴别诊断提供形态学和电生理学依据,我们用豚鼠进行了实验性观察。 虽然甘油用于膜迷路积水的诊断已有报道,但临床主要以患者口服甘油前后的听功能变化来判断其对膜迷路的影响,动物实验主要是观察甘油对正常豚鼠膜迷路的作用,我们观察了甘油对实验性豚鼠膜迷路积水的影响。现将我们做的电生理记录和形态学观察报告如下。     

氟桂利嗪,倍他司汀对膜迷路积水豚鼠蜗内电位及Ca^2＋浓度的影响

４５只豚鼠随机分为３组，造成膜迷路积水的模型，对照组右耳作空白对照，两用药组的豚鼠分别于造模后第１天口服大剂量氟桂利嗪（１０ｍｇ／ｋｇ，１／日）及倍他司汀（１０ｍｇ／ｍｇ，２／日）３０天，发现在造模３０天后，实验对照组听性脑干反应（ＡＢＲ）阈值增高，向术侧摆动试验眼震（ＳＰＶＮ）频数下降，蜗内电位（ＥＰ）下降，内淋巴Ｃａ＾２＋浓度增高，ＥＴ和Ｃａ＾２＋呈负相关，氟桂利嗪和倍他司汀均能显著抑制前庭性     

晕复静对豚鼠诱发性运动病的作用

目的探讨中成药晕复静对豚鼠诱发性运动病的作用。方法将１５只健康豚鼠分成三组：Ａ组（ｎ＝５）肌注庆大霉素（２５０ｍｇｋｇ－１ｄ－１）３天；Ｂ组（ｎ＝５）口服抗眩晕中药晕复静１片后１ｈ；Ｃ组（ｎ＝５）给动物口服安慰剂１片，１ｈ后进行正弦摆动下的眼震电图（ＥＮＧ）记录和加速度旋转过程中胃电图（ＥＧＧ）记录，与平静状态下和用药前的记录相比较，并用电镜进行内耳形态学观察。结果①旋转加速度刺激使ＥＧＧ振幅明显增加。②当前庭性眼震明显减弱，前庭终器部分受损时，加速度刺激不能诱发豚鼠的ＥＧＧ变化。③晕复静能降低前庭摆动性眼震和旋转加速度刺激引起的ＥＧＧ振幅变化。结论旋转加速度可做为豚鼠运动病的诱发方式。ＥＧＧ振幅的改变可做为豚鼠运动病模型的客观评判指标。晕复静确能有效地抑制豚鼠诱发性运动病的前庭眼反射和前庭植物神经反射。     

High-resolution MR imaging of the inner ear: findings in Menière's disease.

Symptoms in Menière's disease are characterized by hydrops of the endolymphatic system with recurrent rupture of the membranous labyrinth. The primary cause of the increased endolymphatic volume appears to be an imbalance between secretion and resorption of the endolymph which may be due to an obstruction of the membranous endolymphatic duct and sac, located in the vestibular aqueduct. The membranous endolymphatic duct and sac are not expected to be visualized using conventional tomography and high-resolution computed tomography (HR-CT), whereas, these are identified with high resolution MRI (HR-MRI). By HR-MRI, we proposed to demonstrate morphological alternation in 12 patients with Menière's disease, this group was compared with a group of 20 healthy subjects. The degree of visualization on HR-MRI of the membranous endolymphatic duct and sac running through the vestibular aqueduct in the bony canal was assessed. There was a distinct decrease in visualization of the membranous endolymphatic duct and sac in the Menière's group. The results confirm the value of the HR-MRI technique to identify an anatomical abnormality, which is directly correlated with the lesion in cases of unilateral Menière's disease.     

MR imaging of the cochlear modiolus: area measurement in healthy subjects and in patients with a large endolymphatic duct and sac

PURPOSE: To evaluate the cochlear modiolus with thin-section magnetic resonance (MR) imaging in healthy subjects and patients with a large endolymphatic duct and sac, and to assess whether the cochlea is normal or abnormal in patients with a large endolymphatic duct and sac. MATERIALS AND METHODS: MR images were obtained in 10 ears in five volunteers (group 1), 40 ears in 20 patients with bilateral sensory hearing loss (group 2), three ears in two patients with Mondini malformation (group 3), and 12 ears in seven patients with a large endolymphatic duct and sac (group 4). RESULTS: In groups 1 and 2, all modiolar areas were larger than 4.0 mm2. In group 3, each modiolus was smaller than 2.0 mm2. In group 4, modiolar areas were smaller than 2.0 mm2 in eight ears and were larger than 4.0 mm2 in four ears. CONCLUSION: Findings in this study confirm that a large endolymphatic duct and sac is frequently associated with modiolar deficiency, but the modiolar area is normal in some cases. This result does not support the recently proposed hypothesis that hearing loss with a large endolymphatic duct and sac is caused by the transmission of subarachnoid pressure forces into the labyrinth through a deficient modiolus.     

MRI of enlarged endolymphatic sacs in the large vestibular aqueduct syndrome

We studied ten inner ears of five patients with a bilateral large vestibular aqueduct syndrome, using CT and MRI. Although the large vestibular aqueduct varied in size, a markedly dilated endolymphatic sac extending to the sigmoid sinus was demonstrated bilaterally on MRI in all patients. The cause of hearing loss in this syndrome is unclear. However, it is suggested that reflux of the protein-rich, hyperosmolar endolymph from the enlarged endolymphatic sac (EES) into the cochlea through a widely patent endolymphatic duct may damage the neuroepithelium. CT density and spin-echo MRI signal intensity of the endolymph in EES were markedly higher than those of CSF in eight inner ears of four patients. Increased density and high signal may indicate protein-rich, hyperosmolar endolymph. In some patients with sensorineural hearing loss and EES, the vestibular aqueduct may not appear dilated on CT. MRI is therefore necessary for correct diagnosis of this syndrome, which should more correctly be termed “large endolymphatic duct and sac syndrome”. Prominent EES may predict poor prognosis in this syndrome. Received: 28 March 1997 Accepted: 18 July 1997     

大前庭导水管综合征内淋巴囊和前庭导水管MRI信号特征及其临床意义

目的 探讨大前庭导水管综合征患者内淋巴囊和前庭导水管MRI信号特征及其与听力损失的关系.方法 搜集大前庭导水管综合征31例共62只内耳的MRI和听力资料.MRI表现分4型:I型的内淋巴囊及前庭导水管裂隙范围内均为低信号区,无高信号区;Ⅱ～Ⅳ型除低信号区外,还可见高信号区;Ⅱ型的高信号区局限于前庭导水管裂隙内;Ⅲ型的高信号区自前庭导水管裂隙向后超出岩骨后缘,但其下界在后半规管下脚平面以上,在平面以下者为Ⅳ型.为避免肉眼观察误差,测量内淋巴囊高信号区、低信号区和前庭的信号强度,并与同层脑脊液信号强度比较.采用配对t检验分析内淋巴囊高信号区与低信号区、前庭之间信号强度的差异,纠正卡方检验,用Spearman分析判断内淋巴囊MRI分型与听力损失程度的相关性.结果 31例共62耳中Ⅰ型10耳(听力下降为中度1耳,重度4耳,极重度5耳);Ⅱ型17耳(听力下降为中度1耳,重度5耳,极重度11耳);Ⅲ型23耳(听力下降为中度3耳,重度5耳,极重度15耳);Ⅳ型12耳(听力下降为轻度1耳,中度1耳,重度3耳,极重度7耳).高信号区与同层脑脊液信号强度的比值为0.95 ±0.12,低信号区为0.49±0.10,前庭为0.99±0.08,高、低信号区分界清楚,信号比值为2.02±0.06.高、低信号区间信号强度差异有统计学意义(t=- 24.966,P＜0.05),高信号区与前庭的信号差异无统计学意义(t=-24.966,P＞0.05).不同MRI分型对应的听力损失差异无统计学意义(似然比值为5.02,P＞0.05),高、低信号区强度比值与听力损失无相关性(r=0.135,P=0.297).结论 大前庭导水管综合征不只是内淋巴囊扩大,也可以伴有外淋巴液疝入前庭导水管骨性裂隙中;内淋巴囊MRI信号特征与听力损失程度之间未见相关.     

Overlapping thin-section fast spin-echo MR of the large vestibular aqueduct syndrome.

PURPOSETo evaluate a high-resolution, thin-section fast spin-echo MR imaging technique of the inner ear to identify the large vestibular aqueduct syndrome seen on temporal bone CT scans.METHODSWe retrospectively reviewed the temporal bone CT scans of 21 patients with hearing loss and enlarged bony vestibular aqueducts by CT criteria. High-resolution fast spin-echo MR imaging was then performed on these patients using dual 3-inch phased-array receiver coils fixed in a temporomandibular joint holder and centered over the temporal bones. MR imaging included axial and oblique sagittal fast spin-echo sequences. The diameter of the midvestibular aqueduct on CT scans and the signal at the level of the midaqueduct on MR images were measured on axial sequences, then compared. High-resolution MR imaging with the same protocol was performed in 44 control subjects with normal ears, and similar measurements were taken.RESULTSThe average size of the enlarged bony vestibular aqueduct on CT scans was 3.7 mm, and the average width of the signal from within the enlarged aqueduct on MR images was 3.8 mm. Statistical analysis showed excellent correlation. MR images alone displayed the enlarged extraosseous endolymphatic sac, which accompanies the enlarged aqueduct in this syndrome. Five ears in three patients with enlarged bony vestibular aqueducts on CT scans showed no evidence of an enlarged endolymphatic duct or sac on MR images. An enlarged endolymphatic sac was seen on MR images in one patient with a bony vestibular aqueduct, which had normal measurements on CT scans. MR imaging alone identified a single case of mild cochlear dysplasia (Mondini malformation). In the 88 normal ears studied, the average size of the endolymphatic sac at its midpoint between the common crus and the external aperture measured on MR images was 0.8 mm (range, 0.5 to 1.4 mm). In 25% of the normal ears, no signal was seen from within the vestibular aqueduct.CONCLUSIONThin-section, high-resolution fast spin-echo MR imaging of the inner ear is complementary to CT in studying patients with the large vestibular aqueduct syndrome, as MR imaging better displays the soft tissue and fluid of the membranous labyrinth.     

前庭导水管扩大的CT和MRI的诊断(附14例报告)

目的本文回顾分析了14例前庭导水管扩大患者的CT、MRI资料,并对两种检查方法作了比较.方法14例患者作了高分辨的颞骨颅底横断位扫描,其中6例作了MRI多方位的扫描.具体测量相关数据.结果在CT图像上,在14位患者中12例双侧和2例单侧扩大的前庭导水管外口均大于1.5mm.MRI图像上,5例双侧,1例单侧内淋巴管和内淋巴囊均有扩大,骨外内淋巴囊扩大尤为明显.倾斜矢状位能清晰显示与前庭相连的扩大的内淋巴管.结论CT和MRI都能准确地判定前庭导水管扩大的存在,MRI更为直观、明显.     

MR of the endolymphatic duct and sac: findings in Menière disease.

PURPOSETo compare the visibility of the endolymphatic duct and sac on high-resolution MR images with the symptoms and clinical course in patients with Menière disease.METHODSTwenty-two patients with unilateral Menière disease were sorted into two groups on the basis of the clinical stage of their disease at the time of imaging. Group 1 included patients in the acute phase, who presented with vertigo. Group 2 comprised patients in the nonacute phase of the disease, who were studied 9 days or more after an episode of vertigo.RESULTSDuring acute attacks, the endolymphatic duct and sac were not adequately visible in the affected ear but were visible in the unaffected ear. During remission, the endolymphatic duct and sac were not observed in clinically advanced patients, but they were seen in patients in the early and intermediate stages.CONCLUSIONHigh-resolution MR imaging can be used to evaluate the endolymphatic duct and sac: visible abnormalities and lack of a visible endolymphatic duct and sac correlate with the clinical course of Menière disease.     

Communication between cochlear perilymph and cerebrospinal fluid through the cochlear modiolus visualized after intratympanic administration of Gd-DTPA

Purpose  Intratympanic injection of gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) has been reported as a procedure to visualize endolymphatic hydrops of Meniere’s disease. We frequently noted that cerebrospinal fluid (CSF) in the internal auditory canal (IAC) was also enhanced after this procedure. The purpose of this study was to evaluate how frequently this occurs and to investigate the specific features of patients who lack this communication. Materials and methods  A total of 25 patients with clinically suspected endolymphatic hydrops underwent the procedure. After 24 h, three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) and 3D constructive interference in steady state (3D-CISS) were performed. The presence of contrast enhancement in the CSF space of the fundus of the IAC was evaluated. Results  The contrast ratio between CSF of the IAC fundus and cerebellar white matter on the injected side was 1.49 ± 0.65, and that of the noninjected side was 0.32 ± 0.16 (P < 0.01). Enhancement of the CSF space in the IAC fundus was seen in all but two subjects: one had enlarged endolymphatic duct and sac syndrome (EEDS), and the other had cochlear nerve agenesis. In these two patients, the cochlear modiolus seemed to be normal. Conclusion  Intratympanic Gd-DTPA administration can reveal permeability of the modiolus and might facilitate evaluation of functional abnormalities of the modiolus not detected by conventional imaging tests.     

Large vestibular aqueduct syndrome with high CT density and high MR signal intensity.

We report a case of large vestibular aqueduct syndrome with a markedly dilated endolymphatic sac bilaterally. The density and signal intensity of the extraosseous portion of the sac were higher than those of cerebrospinal fluid on CT and MR studies. The findings may represent protein-rich and hyperosmolar fluid within the endolymphatic sac.     

Detection and Grading of Endolymphatic Hydrops in Menière Disease Using MR Imaging

BACKGROUND AND PURPOSE:Endolymphatic hydrops has been recognized as the underlying pathophysiology of Menière disease. We used 3T MR imaging to detect and grade endolymphatic hydrops in patients with Menière disease and to correlate MR imaging findings with the clinical severity.MATERIALS AND METHODS:MR images of the inner ear acquired by a 3D inversion recovery sequence 4 hours after intravenous contrast administration were retrospectively analyzed by 2 neuroradiologists blinded to the clinical presentation. Endolymphatic hydrops was classified as none, grade I, or grade II. Interobserver agreement was analyzed, and the presence of endolymphatic hydrops was correlated with the clinical diagnosis and the clinical Menière disease score.RESULTS:Of 53 patients, we identified endolymphatic hydrops in 90% on the clinically affected and in 22% on the clinically silent side. Interobserver agreement on detection and grading of endolymphatic hydrops was 0.97 for cochlear and 0.94 for vestibular hydrops. The average MR imaging grade of endolymphatic hydrops was 1.27 ± 0.66 for 55 clinically affected and 0.65 ± 0.58 for 10 clinically normal ears. The correlation between the presence of endolymphatic hydrops and Menière disease was 0.67. Endolymphatic hydrops was detected in 73% of ears with the clinical diagnosis of possible, 100% of probable, and 95% of definite Menière disease.CONCLUSIONS:MR imaging supports endolymphatic hydrops as a pathophysiologic hallmark of Menière disease. High interobserver agreement on the detection and grading of endolymphatic hydrops and the correlation of MR imaging findings with the clinical score recommend MR imaging as a reliable in vivo technique in patients with Menière disease. The significance of MR imaging detection of endolymphatic hydrops in an additional 22% of asymptomatic ears requires further study.

According to the 1985 American Academy of Otolaryngology-Head and Neck Surgery Committee on Hearing and Equilibrium guidelines, Menière disease (MD) is defined by ≥2 definitive spontaneous episodes of vertigo 20 minutes or longer, audiometrically documented hearing loss on at least 1 occasion, and tinnitus or aural fullness.¹ In 1995, a clinical diagnostic scale was added with the categories possible, probable, definite, and certain,² with “certain” defined as definite disease plus histopathologic confirmation. It is universally agreed that the pathogenesis of MD consists of endolymphatic hydrops (EH), but a simple cause-effect relation between EH and clinical symptoms is not present. Moreover, EH appears to be an end point of different etiologies such as trauma,² viral infection and autoimmune processes,³ electrolyte imbalance,⁴ and cellular channelopathies.⁵ Histopathology has provided evidence that not every individual with EH presents with symptoms of MD^6–8 and not every individual with the clinical diagnosis of MD has EH.^9–12 Only recently has MR imaging enabled depiction of EH,¹³ opening a window for in vivo confirmation of EH. The purpose of our study was to assess the degree of EH in 53 patients with MD and to correlate the MR imaging findings obtained by a specific protocol with the certitude of clinical diagnosis.