铁缺乏对大鼠畸变产物耳声发射的影响

目的 观察铁缺乏大鼠畸变产物耳声发射（DPOAE）的一般特征及幅值变化,探讨铁缺乏对DPOAE的影响机制。方法 18只大鼠随机分为正常对照及实验组,缺铁饮食饲养法制备动物模型,实验及动物处死前检测DPOAE,并进行耳蜗肌动蛋白免疫组化检测,分析DPOAE变化及可能机制。结果 铁缺乏组大鼠20个测试耳中,12耳2．0kHz以上频率点的DPOAE幅值略有降低,耳蜗免疫组化检测显示其外毛细胞的肌动蛋白免疫组化无明显变化;另8耳2．0kHz以上频率点的幅值下降明显,尤以2．0kHz处为,相应的耳蜗免疫组化染色显示外毛细胞肌动蛋白免疫反应活性明显降低。结论 铁缺乏可影响DPOAE幅值,其机制可能与耳蜗听毛细胞肌动蛋白免疫反应活性降低及组织缺氧有关。     

畸变产物耳声发射用于新生儿听力筛查的影响因素分析

目的 探讨畸变产物耳声发射(DPOAE)用于新生儿听力筛查的影响因素。方法 采用GSI-70全自动便携式耳声发射仪进行新生儿听力筛查，在筛查同时，自制问卷表，对新生儿的出生史，母亲妊娠史，家族史，父母社会阶层等35个因素进行调查，调查结果运用SPSS统计软件进行统计分析。结果 住院期间82．8％的(3242／3944)新生儿通过筛查，通过率右耳高于左耳，女婴高于男婴，单胎高于多胎，足月儿高于早产儿，正常及高出生体重儿高于低出生体重儿，阴道助产高于自然产、剖宫产，P值均小于0．05。多因素logistic回归分析，出生体重、性别、胎数与初筛结果相关。42天复筛，96．4％(3167／3284)通过筛查，影响初筛结果的因素对复筛无影响。结论 新生儿的性别、分娩方式、胎数、孕周、出生体重对应用DPOAE进行的新生儿听力筛查的初筛结果有显著影响。     

The influence of epidural anesthesia on the hearing system after normal labor

Abstract

Objective: The purpose of our study was to evaluate the influence of epidural anesthesia on the hearing system in women undergoing normal labor. Design: We examined two groups of patients: women with epidural anesthesia underwent four tests of distortion product otoacoustic emissions(DPOAEs): on admission, and fifteen minutes, one hour, and three hours after the last epidural bolus of local anesthetic. Auditory brainstem response (ABR) tests were performed on admission, and one hour, and three hours after the last epidural bolus. Women who gave birth without epidural anesthesia underwent DPOAEs tests on admission, during a uterine contraction, during active delivery, and three hours after labor. ABR tests were performed on admission, during a uterine contraction, and three hours after labor Study sample: twenty patients participated in the study. Twelve gave birth with epidural anesthesia and eight without anesthesia. Results: No significant changes in DPOAEs and ABR recordings were found between the two groups. Conclusions: Epidural anesthesia does not impair the sensory or the neural elements of the hearing system and therefore does not influence hearing.

Sumario

Objetivo: El propósito de este studio fue evaluar la influencia de la anestesia epidural en el sistema auditivo de mujeres en trabajo de parto normal. Diseño: examinamos dos grupos de pacientes: uno de mujeres con anestesia epidural, realizaron cuatro pruebas con emisiones otoacústicas por productos de distorsión (DPOAE): al ingreso y a los 15 minutos, una hora y tres horas después del último bolo de anestesia local epidural. También se obtuvieron Respuestas Auditivas de Tallo Cerebral (ABR) al ingreso y una y tres horas después del último bolo epidural. Al grupo de mujeres que dieron a luz sin anestesia epidural se les practicaron pruebas de DPOAE al ingreso, durante una contracción uterina durante el parto activo y tres horas después del mismo. También se hicieron pruebas de ABR al ingreso, durante una contracción uterina y tres horas después del parto. Muestra de estudio: veinte pacientes participaron en el estudio. Doce dieron a luz con anestesia epidural y ocho sin anestesia. Resultados: No se encontraron cambios significativos en los registros de las DPOAE y de las ABR entre los dos grupos. Conclusiones: La anestesia epidural no afecta los elementos sensoriales y neurales del sistema auditivo y consecuentemente, no influencia la audición     

DPOAE level mapping for detecting noise-induced cochlear damage from short-duration music exposures

Distortion product otoacoustic emission (DPOAE) level mapping provides a comprehensive picture of cochlear responses over a range of DP frequencies and f₂/f₁ ratios. We hypothesized that individuals exposed to high-level sound would show changes detectable by DPOAE mapping, but not apparent on a standard DP-gram. Thirteen normal hearing subjects were studied before and after attending music concerts. Pure-tone audiometry (500-8,000 Hz), DP-grams (0.3-10 kHz) at 1.22 ratio, and DPOAE level maps were collected prior to, as soon as possible after, and the day after the concerts. All maps covered the range of 2,000-6,000 Hz in DP frequency and from 1.3 to -1.3 in ratio using equi-level primary tone stimuli. Changes in the pure-tone audiogram were significant (P ≤ 0.01) immediately after the concert at 1,000 Hz, 4,000 Hz, and 6,000 Hz. The DP-gram showed significant differences only at f₂ = 4,066 (P = 0.01) and f₂ = 4,348 (P = 0.04). The postconcert changes were readily apparent both visually and statistically (P ≤ 0.01) on the mean DP level maps, and remained statistically significantly different from baseline the day after noise exposure although no significant changes from baseline were seen on the DP-gram or audiogram the day after exposure. Although both the DP-gram and audiogram showed recovery by the next day, the average DPOAE level maps remained significantly different from baseline. The mapping data showed changes in the cochlea that were not detected from the DP-gram obtained at a single ratio. DPOAE level mapping provides comprehensive information on subtle cochlear responses, which may offer advantages for studying and tracking noise-induced hearing loss (NIHL).     

雌激素对大鼠噪声性听力损伤的保护作用研究

目的探讨雌激素对大鼠噪声性听力损失的影响。方法 SD大鼠20只随机分为去势组与对照组,各10只。对两组大鼠进行听性脑干诱发电位(ABR)和畸变产物耳声发射(DPOAE)检测后,去势组行卵巢切除术,对照组行假手术。术后正常饲养3周后所有大鼠同时在隔声室中用强度为115d B SPL(C)的白噪声造模,噪声暴露2周后进行同样听力测试,比较两组在噪声暴露后的听力情况。结果噪声暴露后去势组与对照组大鼠均出现听力下降;对照组在噪声暴露后Click、2、4、6、8k Hz ABR阈值分别为(15.63±1.51)d B n HL、(9.38±1.93)d B n HL、(10.63±2.04)d B n HL、(7.19±1.94)d B n HL、(4.69±1.55)d B n HL,去势组噪声暴露后相应频率阈值分别为(51.50±3.93)d B n HL、(54.75±4.33)d B n HL、(57.25±3.71)d B n HL、(55.50±4.23)d B n HL、(51.75±3.83)d B n HL,两组各频率相比差异均有统计学意义(P0.05),噪声暴露后对照组ABR阈值小于去势组;两组在噪声暴露前后Click ABR阈上20、40、60d B SL潜伏期未出现明显变化(P0.05);对照组在噪声暴露后2、4、6、8k Hz DPOAE信噪比分别为(12.14±3.07)d B、(22.65±7.92)d B、(20.17±12.05)d B、(13.55±11.51)d B(P0.05),去势组在噪声暴露后相应频率信噪比分别为(1.18±6.53)d B、(2.22±5.46)d B、(2.61±3.38)d B、(3.12±3.67)d B,两组各频率相比差异均有统计学意义(P0.05),噪声暴露后对照组DPOAE信噪比大于去势组(P0.05)。结论雌激素对大鼠噪声性听力损伤具有保护作用,主要影响区域在耳蜗。     

Auto-inflammatory challenge of the endolymphatic sac – Cochlear damage measured by distortion product oto-acoustic emissions

Conclusion: Twenty-five rats were challenged by an immunologic attack of the endolymphatic sac. After 6 months, distortion product oto-acoustic emissions (DPOAE) revealed a dysfunction of the outer hair cells and immunological active cells were observed in the endolymphatic sac. This information could contribute to the understanding of Ménière’s disease. Objectives: This study investigated if an autoimmune challenge of the endolymphatic sac could affect DPOAE output measurements in rats. Also, a potential autoimmune cell infiltration of the endolymphatic sac was investigated. Methods: Eighteen Lewis rats were immunized with a crude endolymphatic sac extract in complete Freund’s adjuvant. Seven control animals were injected with Freund’s adjuvant in saline. Cochlear damage was estimated by DPOAE dynamics 3 weeks and 6 months after the immunization. Infiltrative cells in the endolymphatic sac were investigated with transmission electron microscopy. Results: The hearing assessment 6 months after immunization revealed a reduction of the DPOAE, on the full range of frequencies (2–63 kHz) in an average of the mean, of 2 dB ± 1.1 in the immunized group compared to the controls (p < 0.05). The same test showed a 2.5 dB decrease from 2 to 5 kHz (p < 0.01). Immunological active cells were observed in the endolymphatic sac in most of the immunized rats.     

Neurophysiology of hearing in patients with mucopolysaccharidosis type IV

Background

Hearing impairment is a common problem in patients with mucopolysaccharidosis IV (MPS IV) throughout their life. Many of the adult patients with MPS IV exhibit permanent or severe hearing loss. However, there has been no systematic review of detailed audiological test results in MPS IV.

畸变产物耳声发射对2968例新生儿听力筛查的临床分析

目的探讨畸变产物耳声发射(DPOAE)与听性脑干反应(ABR)联合应用用于新生儿听力筛查的可行性。方法应用Bio-logic自动耳声发射仪对2968例新生儿进行听力筛查,经3次筛查不合格的新生儿应用GSI诱发电位仪进行检查,并随机抽样60例120耳新生儿连续进行1~5d跟踪筛查。结果2968例新生儿有2852例分别于出生的1~5d及5d~1个月(提前出院而延筛),经1~3次DPOAE筛查通过,通过率为96.09%。116例未通过,经ABR检测有5例不合格,假阳性率为3.74%。出生在第2天、第3天通过率相差显著(P<0.01),第3天以后通过率之间差别无统计学意义(P>0.05)。结论DPOAE测试具有方便、快速、无创、客观等优点,筛查时间以生后第3天及3d以后为宜。但其只能反映耳蜗功能,不能用来诊断听神经或中枢听觉通路病损,同时由于假阳性率较高,对未通过DPOAE筛查者不能立即作出听力损伤的结论。ABR测试为比较可靠的新生儿听力筛查工具,联合DPOAE和ABR听力筛查技术,使其相互补充,能提高新生儿听力筛查的精确性、可靠性。     

DPOAE在新生儿听力筛查结果分析中的意义

目的根据诱发性畸变产物耳声发射法(DPOAE)听力筛查初筛“通过”情况,确定合理的“筛查通过标准”及DPOAE的应用价值。方法用DPOAE仪测试出生后2～4天的新生儿。结果正常足月新生儿听力初筛的通过率为84.8%,早产儿为71.4%;轻、中度窒息儿通过率为57.1%。结论此“筛查通过标准”设定合理。应加强早产儿,轻、中度窒息儿等高危儿的听力筛查及随访,以便及早确诊,进行早期干预。     

母系遗传性聋家系的纯音测听及畸变产物耳声发射测试的相关分析

目的：探讨母系遗传非综合征性聋的听力学特征及畸变产物耳声发射测试对其听改变早期诊断的优越性。方法：对六个母系遗传家系成员共102人进行纯音测听、DPOAE评估其听力，比较纯音测听与DPOAE检测耳蜗早期病变的灵敏性。结果：纯音测听为感音神经性聋的38例中，PTA≥45d B HL的18例，DPOAE反应缺失；PTA＜45dB HL的20例，DPOAE高频或高、中频振幅下降或缺失；纯音测听正常者中4例DPOAE显示高频或高中频振幅下降。结论：母系遗传非综合征性聋的听力损害为双侧、对称性、进行性感音神经性聋，早期表现高频损害，DPOAE可在纯音听阈改变之前，发现早期耳蜗轻微的病理变化，对早期诊断及遗传咨询有较大指导意义。