三半规管阻塞与迷路切除术后前庭功能动态变化

目的：比较豚鼠三半规管阻塞与迷路切除术后前庭功能代偿的异同。材料与方法：将15只健康豚鼠分为2组，其中8只豚鼠行右侧三半规管阻塞术（triple semicircular canal occlusion,TCO)，7只豚鼠行右侧迷路切除术（labyruinthectomy,LE)，于术后一个月内观察豚鼠行为学及眼震电图（ENG）的动态变化，结果：发现术后第1天两组均出现自发性眼震，正弦摆动刺激术侧时未引出衣发性眼震，头向右侧偏斜并沿地面垂直轴向术侧旋转；LE组却出现番滚现象，术后第3，5，10，15，30天正弦摆动眼震试验，两组豚鼠术侧眼震均随时间的推移逐渐恢复，TCO组于15天左右向眼震基本恢复对称，而LE组至术后30天仅摆动幅度120，150度，180度左右向眼震基本对称，摆动幅度为60度，90度双向眼震反应差异仍有显著意义（P＜0．05），。另外，LE组有3只豚鼠仍存在头偏，结论：TCO组要比LE组动物恢复快，建立代偿和失平衡时间短。     

豚鼠迷路切除后前庭代偿的动态观察

对１０只健康豚鼠进行单侧迷路切除术，其中７只术后９周行健侧迷路切除。一侧迷路切除后豚鼠出现向健侧的自发眼震及向术侧偏头、翻滚、旋转等现象，除偏头外，反应于１～３天内逐渐消失，术后３～５天，０．０８３Ｈｚ正弦摆动，幅度９０°，眼震优势偏向向健侧。第二侧迷路切除后，又出现向第一次手术侧的自发眼震，向第二次手术侧翻滚、旋转，１～２天内眼震、翻滚及旋转迅速消失。由此对前庭代偿机理进行了讨论。     

应用微波技术行后半规管阻塞术的实验研究

目的 :探讨应用微波技术行后半规管阻塞术的可行性。方法 :应用微波技术对 2 0只豚鼠行后半规管阻塞术 ,观察术前、术后豚鼠眼震电图 (ENG) ,听性脑干反应 (ABR)及形态学的变化。结果 :术后第 1天豚鼠正弦摆动刺激时术侧眼震反应减弱 ;术后第 3天双侧眼震恢复对称 ;术后 30 d冰水实验结果显示两耳能引出对称性眼震 ;术后 ABR阈值无明显改变 ;术后 6 0 d病理切片证实后半规管完全阻塞而耳蜗 Corti器和壶腹嵴正常。结论 :应用微波技术行后半规管阻塞术是对后半规管阻塞术的一种有意义的改进方法。     

豚鼠阻尼旋转摆动试验

用２０只健康豚鼠进行阻尼旋转摆动试验（简称摆动试验），以Ｌ和Ｒ分别代表左、右向眼震，计算左、右向眼震的对称比。然后将其随机分成庆大霉素组和膜迷路积水组各１０只，观察每日肌注庆大霉素（２５０ｍｇ／ｋｇ）３ｄ后和右内淋巴囊和淋巴管阻塞３０天后摆动试验的眼震变化。结果显示：①健康豚鼠摆动试验的左右向眼震对称比正常值为＜８．２５％；②庆大霉素组向左和向右摆动的眼震数均减少（Ｐ＜０．０１）；③膜迷路积水组向右摆动的眼震数明显减少（Ｐ＜Ｏ．０１），其中６只豚鼠的对称比＞８．２５％。内耳形态学观察，庆大霉素组部分毛细胞受损，膜迷路积水组球囊明显积水，证明动物造模成功。结论认为，阻尼旋转摆动试验是一种重要的评价豚鼠前庭功能的试验方法。     

后半规管阻塞前后豚鼠前庭及耳蜗功能的动态变化

目的 探讨机械性后半规管阻塞前后豚鼠前庭和耳蜗功能的动态变化。方法 采用２０只豚鼠建立单侧后半规管阻塞的动物模型,观察手术前后眼震电图,听性脑干反应,耳声发射等变化。结果 术后第１天,第３天豚鼠正弦摆动刺激术侧眼震反应,明显减术,术后第５天起双侧眼震恢复正常。术后早期ＡＢＲ阈值一度升高,第５天达高峰,ＡＢＲ阈值平均升高４．５ｄＢ。ＤＰＯＡＥ反应幅度无明显改变。结论 后半规管阻塞能选择性地消除后半规     

金纳多对一侧迷路切除豚鼠旋转后眼震的代偿

目的：观察豚鼠一侧迷路切除（unilateral labyrinthectomy,UL)后旋转后眼震的自然恢复及金纳多对（ginaton)其恢复的影响。方法：切除豚鼠左侧迷路，以其自然恢复和金纳多给药两种结果，观察旋转后眼震在不同时间恢复的差别。结果：金纳多能明显促进一侧迷路切除后旋转后眼震恢复正常并能改善两则的前庭的均衡性。一侧迷路切除后旋转后眼震频率明显下降，单纯手术组（UL组）术后眼震频率90天才恢复正常；手术＋金纳金组（UL＋G组）21天眼震频率与正常已无显著差别。两侧优势偏向（directional preponderance,DP)比较显示，UL组7－50天结果异常，而UL＋G组自第7天起DP都在正常范围，参照旋转后眼震频率恢复情况，两侧均衡性的恢复比眼震频率恢复快。结论金纳多能够促进动态症状的代偿，且两侧均衡性的恢复比眼震频率恢复复快。     

豚鼠阻尼旋转摆动试验

用２０只健康豚鼠进行阻尼旋转摆动试验（简称摆动试验）以Ｌ和Ｒ分别代表左、右向眼震，计算左、右向眼震的对称比。然后将其随机分成庆大霉素组和膜迷路积水级各１０只，观察每日肌大霉素（２５０ｍｇ／ｋｇ）３ｄ后和右内淋巴囊和淋巴管阻塞３０天后摆试验的眼震变化。结果显示：（１）健康豚鼠摆动试验的左向眼震对称比正常值为＜８．２５％；（２）庆大霉素组向左和向右摆动的眼震数均减少（Ｐ＜０．０１）；（３）膜迷路积水组     

三个半规管阻塞动物模型的建立

目的　旨在建立豚鼠单侧三个半规管阻塞的动物模型。方法　利用 2 0只豚鼠行单侧三个半规管阻塞 ,观察手术前后眼震电图、听性脑干反应 (auditorybrainstemresponses,ABR)、畸变产物耳声发射 (distortionproductotoacousticemissions,DPOAE)及形态学的变化 ,非手术耳作为对照。结果　豚鼠术后 1d出现自发性眼震 ,正弦摆动刺激单侧眼震反应消失 ,侧别与术侧一致 ,术后 30d左相与右相眼震反应对称。术前微量冰水灌注 ,两耳均能引出眼震 ,术后 30d做冰水实验结果为术耳未能引出眼震 ,非术耳出现正常的眼震反应。术后ABR阈值有轻度升高 ,DPOAE反应幅度无明显改变。 8只动物病理切片证实三个半规管完全阻塞而耳蜗Corti器和壶腹嵴结构正常。结论　表明三个半规管阻塞动物模型成功 ,提示三个半规管阻塞术可望成为治疗难治性外周性眩晕的安全有效、操作相对容易的手术方法。     

氨基苷类药物对内淋巴积水豚鼠前庭及耳蜗功能的影响

目的探讨氨基甙类药物对内淋巴积水豚鼠前庭及耳蜗功能的影响。方法8只内淋巴积水模型豚鼠全身应用链霉素,观察给药前后豚鼠行为学、眼震电图(ENG),听性脑干反应(ABR),畸变产物耳声发射(DPOAE)及形态学变化。结果给药后未出现头偏斜、走路不稳等前庭功能紊乱的行为征象,连续给药第10天、停药后第7天摆动幅度90°,停药后第21天,摆动幅度为90°、120°时积水侧眼震反应降低的幅度明显大于对照耳(     

三个半规管阻塞动物模型的建立

目的 旨在建立豚鼠单侧三个半规管阻塞的动物模型。方法 利用２０只豚鼠行单侧三个半规管阻塞,观察手术前后眼震电图、听性脑干反应（ａｕｄｉｔｏｒｙ ｂｒａｉｎｓｔｅｍ ｒｅｓｐｏｎｓｅｓ,ＡＢＲ）、畸变产物耳声发射（ｄｉｓｔｏｒｔｉｏｎ ｐｒｏｄｕｃｔ ｏｔｏａｃｏｕｓｔｉｃ ｅｍｉｓｓｉｏｎ,ＤＰＯＡＥ）及形态学的变化,非手术耳作对照。结果 豚鼠术后１ｄ出现自发性眼震,正弦摆动刺激单侧眼震反应消失,     

Results of trapezoid rotation test in guinea pigs with unilateral endolymphatic hydrops

Obliteration of the right endolymphatic sac was performed by Kimura's method in 57 guinea pigs with normal hearing and vestibular function. However, 43 animals exhibited postoperative cerebellopontile disturbance and labyrinthitis detected by gait test, ABR test and histological examination. The remaining 14 guinea pigs were evaluated periodically by the trapezoid rotation test. Two weeks after the operation, 11 of these 14 guinea pigs exhibited prolonged right beating nystagmus based on the labyrinthine preponderance of impaired side (Lpi). In addition, endolymphatic hydrops was histological detected in the labyrinth on the operation side. A positive relation was observed between the degree of endolymphatic hydrops and the degree of Lpi. Lpi at 4 weeks after the operation was markedly lower than that at 2 weeks (P = 0.05). Therefore, the degree of Lpi was thought to be influenced by the rate of hydrops development. These results corresponded with the clinical findings that the degree of Lpi increases prior to vertiginous episodes in Meniere's patients.     

Vestibular responses of normal and hydropic ears of the guinea pig to middle ear pressure application

The pressure in the middle ears of normal and hydropic guinea pig ears was increased, and nystagmographic recordings were compared. Two-month unilateral hydropic guinea pigs and normal control guinea pigs underwent pressure treatments in which pressure was introduced into the middle ear. Significantly lower pressure was needed to elicit nystagmus in hydropic ears (mean 1.00 psi or 70.3 cm H2O) compared with normal control ears (mean 1.27 psi or 89.3 cm H2O). All of the normal control guinea pigs showed fast phase nystagmus toward the pressure-applied side, while hydropic guinea pigs showed nystagmus toward the normal ear. The duration of nystagmus was slightly longer in hydropic animals than in normal control animals. The slow phase velocity was slightly higher in the hydropic guinea pigs. Histologic examination revealed that the vestibular sensory cells remained normal and that changes in the organ of Corti were similar between the hydropic ears with and without pressure treatment at equal survival times.     

Outcomes of uvulopalatopharyngoplasty with harmonic scalpel after failure of continuous positive airway pressure in sleep apnea syndrome

The subjective visual horizontal (SVH) was measured by means of a small rotatable luminous line in darkness in the upright body position and at 10, 20 and 30° of body tilt to the right and left prior to, and during a follow-up period after, stapedotomy in 12 patients with otosclerosis. In the acute stage after surgery, SVH in the upright body position was significantly tilted away from the operated side. In addition, the perception of roll tilt towards the operated side (K_op) was significantly increased after stapedotomy, while the perception of roll tilt towards the healthy side (K_he) showed a slight but not significant reduction. After exclusion of two outliers, a statistically significant correlation was found between changes in K_op and in K_he. The slope of the regression line was 1.8 : 1, probably corresponding to a preference of the utricle for ipsilateral as opposed to contralateral head tilt. In four patients there was a weak (&;lt;1°/s) spontaneous nystagmus, not systematically related to the side of surgery, while in most cases there were no nystagmus or subjective vertigo symptoms. These specific changes in the subjective horizontal show that the otolithic effects on perception can be dissociated from canal effects. Further, the results are opposite to those for patients with unilateral loss of vestibular function. The tilt of SVH after stapedotomy indicates an increase in resting activity of utricular afferents. In addition, based on recent theories on otolith function, we suggest that an increased activity in saccular afferents is of major importance for the changes in roll-tilt perception because of its interaction with the utricle on the central nervous level.     

Evaluation of the effect of dexamethasone in experimentally induced endolymphatic hydrops in guinea pigs

PURPOSE: The aim of this study was to investigate the audiological and histopathologic effects of dexamethasone in the treatment of experimentally induced endolymphatic hydrops. MATERIALS AND METHODS: Thirty mature, male guinea pigs weighing 400 +/- 50 g were operated on to induce experimental endolymphatic hydrops in their right ear. Left ear served as control. Subjects were separated into control and dexamethasone groups, with the latter receiving dexamethasone 5 mg/(kg d) intraperitoneally for 10 days. Electrocochleography and auditory brainstem response were applied to all subjects at preoperation, on the second postoperative day and also on the 15th postoperative day in animals that lived for a long time. The histopathologic examination of the inner ear in all animals was done at the end of the study. RESULTS: The summating potential and the ratio of the summating potential to the action potential measured on the second postoperative day were found to be increased in both groups, but more significantly in the control one. When the left and right ears were compared, significant difference was found in the control group; however, no significant difference was found between the ears in the dexamethasone group. Histopathologic examination revealed varying degrees of hydrops in the control group, but showed only normal findings or minor changes in the dexamethasone group. CONCLUSIONS: Dexamethasone can prevent the audiological and histopathologic findings of experimentally induced endolymphatic hydrops. However, these results must be supported by clinical and experimental studies designed with a large number of subjects.     

Qualitative and quantitative studies in electron microscopy on influence of experimental ischemia of the vertebral arteries on the outer hair cells function in guinea pigs

Histological studies were performed in 20 guinea pigs, both sexes, weighing 250-300 g and divided into two groups: I--control (anaesthetized animals without surgery), II--examined (in anaesthetized animals through an incision of the skin and muscles of the neck), the left or right vertebral artery was exposed and a vascular clip was inserted into the foramen of the transverse process of the 2-nd cervical vertebra. 50 days after this procedure, the guinea pigs were again anaesthetized by intraperitoneal injection of 35% solution of chloral hydrate, then vascular and cochlear perfusion with 3.6% solution of glutaraldehyde was performed. Simultaneously, by means of micropreparation, samples of cochlea were made for electron studies by means of electron microscope (Philips EM 300). In qualitative histopathologic examinations in guinea pigs of II group, the ischemia changes of the outer hair cells were greater in the side of irritation of the vertebral artery than at the opposite side. At the receptor side of these cells, under the membrane, there are multilamellar outgrowths in the shape of cisterns, partly expanded. The relative volume of external compartment of mitochondria in control group is as follows respectively: 0.15 +/- 0.0% at the right side and 0.15 +/- 0.08% at the left side, and in II group, respectively: 0.22 +/- 0.06% at the side of irritation and 0.19 +/- 0.07% at the opposite side. The obtained data in electron microscopy, both qualitative and quantitative pointed at ischemia changes of outer hair cells in guinea pigs after prolonged irritation of periarterial plexus of vertebral artery.     

庆大霉素对豚鼠前庭功能影响的动态研究

为研究庆大霉素破坏前庭感觉上皮所致的生理功能障碍，观察庆大霉素对前庭功能影响的动态变化过程，应用正弦摆动试验和旋转试验进行动态观察。分别对白色和杂色豚鼠按每日125mg／kg体重皮下注射硫酸庆大霉素连续12天。结果示：用药7天豚鼠的前庭功能无明显改变，用药后10天出现明显的前庭功能受损，停药后5天受损程度最明显，停药14天前庭功能稍有恢复，但仍明显低下，直到停药后3个月，未见前庭功能明显改善；且杂色豚鼠前庭功能损害程度较白色豚鼠为轻。此研究为氨基式类抗生索性内耳损伤的防护和治疗提供了实验依据。