听神经病对前庭功能的影响

听神经病是一种以双耳中度低频感音神经耳聋为临床症状,但ABR反应严重异常、耳声发射正常的病症。其相关的前庭功能检测的报道与关注在学术界仍较少,本文旨对听神经病所伴有的前庭功能异常进行文献回顾,从前庭生理学及与其相关的前庭功能检测手段进行总结和概述。期望为听神经病患者的诊治与前庭功能评估提供参考。     

听神经病伴发前庭下神经损害

OBJECTIVE: To investigate if auditory neuropathy have inferior vestibular nerve (IVN) lesion and to explore the relation between AN and the IVN lesion by vestibular evoked myogenic potentials (VEMPs). METHODS: VEMPs were observed in 13 patients with auditory neuropathy. And the relation among the duration, hearing threshold of lower frequency and speech discrimination score with VEMPs were observed. RESULTS: Fifty-four percent patients in auditory neuropathy had abnormal VEMPs. They took the form of lower amplitude and no response. The statistical analysis showed that the abnormality of VEMPs had no correlation with lower frequency hearing loss, the duration and speech discrimination score. CONCLUSIONS: The IVN dysfunction may coexist with auditory neuropathy, having lesion in the IVN. However, there was no significant relation between the severity of AN and VEMPs, which meant that AN and inferior vestibular neuropathy had their independence to some extent.     

听神经病与前庭上、下神经损害的关系

目的观察听神经病(auditory neuropathy,AN)患者伴发前庭上、下神经损害的特点,分析其与AN的关系。方法检测70例AN患者的眼震电图(electronystagmography,ENG)及前庭诱发肌源性电位(vestibular evoked myo-genic potential,VEMP),观察VEMP波形、潜伏期及振幅,并与对照组比较,分析前庭神经受损与AN患者听力损害程度、年龄及病程的关系。结果70例(139耳)AN患者中VEMP引出38耳(27.3%),未引出101耳(72.7%),ENG冷热试验半规管功能正常106耳(76.3%),异常33耳(23.7%),两种检测结果差异有显著统计学意义(P<0.01)。VEMP引出的38耳中,左、右耳的潜伏期均值P13为24.54±5.388及25.17±6.068ms,N23为31.38±5.766及32.02±6.058ms,对照组P13为17.04±1.781及17.49±2.291ms;N23为25.05±2.864及25.81±3.273ms,两组差异有显著统计学意义(P<0.01);左、右耳的振幅均值为60.16±34.732及43.83±31.288μV,对照组为147.16±50.026及135.66±54.737μV,两组差异有显著统计学意义(P<0.01)。AN患者VEMP是否引出与听力损害程度有相关性(P<0.05),与年龄及病程无相关性(P>0.05)。AN患者ENG的半规管功能是否正常与病程有相关性(P<0.05),与听力损害程度及年龄无相关性(P>0.05)。结论AN患者伴发前庭下神经损害的几率远大于前庭上神经,表现为VEMP波形未引出或潜伏期延长、振幅低;VEMP是否引出与听力损害程度有相关性,ENG的半规管功能异常与病程有相关性,提示AN患者听神经病变极易累及前庭下神经及其终器球囊;VEMP与ENG联合应用可对AN伴发前庭神经病变的范围作出较全面可靠的评估,应作为AN诊断常规检查项目之一。     

前庭试验组合在听神经病患者前庭功能评估中的应用

目的 本研究旨在探究是否可以通过使用多种前庭检测项目的组合来确定听神经病(AN)患者前庭受累情况.方法 本研究收集了30名听神经病患者(AN研究组)和30名健康受试者(对照组).30名AN患者均接受了颈肌前庭诱发肌源性电位(cVEMP)和眼肌前庭诱发肌源性电位(oVEMP)测试;30名中的20名患者接受了双温试验(CT...     

听神经病的听功能状态分析

目的 :探讨听神经病的听功能状态及病损部位。方法 :分析 6 5例听神经病患者的临床资料、纯音测听、声导抗测试、听性脑干反应 (ABR)、4 0Hz听觉相关电位及OAE检查结果。结果 :听神经病的低频听力损失源于蜗后的传入、传出神经及听性脑干受损 ,表现为声反射、传出抑制、ABR异常及诱发性OAE与纯音听阈不呈平行关系 ,与之相对应 ,低频区的外毛细胞处于失抑制的超常活动状态 ,表现为低频区SOAE增强、TEOAE反应幅值及DPOAE幅值升高 ;听神经病的高频听力损失源于耳蜗的外毛细胞损害 ,表现为高频区DPOAE幅值与纯音听阈呈一致性下降 ;听神经病的中频听力损失最轻或接近正常 ,表现为 2kHz附近的纯音听阈和DPOAE幅值均接近于正常。结论 :听神经病的传入、传出系统及耳蜗水平均有不同程度的功能障碍 ,其病损部位主要在耳蜗传入、传出神经 ,向上可侵及脑干 ,向下可侵及耳蜗     

听神经病

目的介绍一种特殊的感音神经性听力疾患-听神经病,探讨其临床特征及听力学特点.方法报道5例听神经病患者,2例为成人;3例为儿童.记录患者的临床资料,并对患者进行纯音测听、脑干电反应测听、耳声发射、耳蜗电图及语言辨别率等听力学检查.结果5例均主诉听力下降,听力学检查纯音听阈为轻、中度感音神经性聋,与纯音测听不相符的语言辨别率明显下降,不能引出脑干诱发电位(ABR),耳蜗电图基本正常,畸变产物耳声发射(DPOAE)基本正常.提示外毛细胞功能正常,病变可能在听神经.结论听神经病是一种主诉听力下降,纯音听阈为轻、中度感音神经性聋,不能引出脑干诱发电位(ABR),畸变产物耳声发射正常的听力疾患,临床上应与其他感音神经性聋区别.     

以听神经病为始发的多发性硬化2例

听神经病由Starr等于1996年命名以来,引起了国内外耳科学者们的极大关注。在他报道的10例成人中,8例在听力损失若干年后,出现了不同程度外周神经病的表现。我院也曾收治2例一家系亲姐妹,分别以听功能损害1～2年半后出现多发性硬化。现报告如下。     

听神经病实验动物模型

听神经病的临床听力学特征主要表现在具有正常的耳蜗感受器电位和异常的听性脑干反应波形以及对语言的理解障碍,其病理学改变部位被确定是在周边听觉系统,主要表现在内毛细胞缺损、听神经末梢破坏、听神经纤维脱髓鞘病变、螺旋神经节细胞缺损,或上述一个或几个部位同时发生病变。本文介绍了模拟听神经病的各种实验动物模型,其中包括模拟单纯内毛细胞缺损的Slc19a2基因缺陷小鼠和Ggt1基因缺陷小鼠实验模型;模拟单纯Ⅰ型传入神经末梢损害的谷氨酸盐实验模型;模拟单纯脱髓鞘病变的甘油实验模型;模拟Ⅰ型螺旋神经节及其神经纤维损害的乌苯酐实验模型和免疫性疾病损害模型;模拟单纯神经纤维脱髓鞘病变的胆红素实验模型和髓鞘缺陷仓鼠模型;模拟单纯听神经近端脱髓鞘病变的阿霉素模型和压力夹伤听神经实验模型;以及模拟整个周边听觉系统全程病变的卡铂南美栗鼠实验模型。这些实验模型可以分别用于模拟听神经病的一种或几种临床表现及病变特征的实验研究。     

听神经病的临床与听功能特征

目的:探讨听神经病的临床与听功能特征。方法:总结分析54例听神经病患者的临床资料、听力学测试及电生理检查情况。结果:纯音听力图呈上升型70耳,覆盆型25耳,平坦型5耳,下降型4耳;低频、中频及高频平均阈值为(67.63±15.30,43.61±16.28,32.25±14.80)dB HL。声导抗鼓室图全部正常,77耳镫骨肌声反射消失,31耳声反射阈部分增高。听性脑干反应(ABR)全部未引出。畸变产物耳声发射(DPOAE)正常引出,26例行对侧声抑制未受影响。16例言语识别率差,与纯音听阈不成比例。23例颞骨CT或MRI未见异常。10例伴有周围神经病。结论:ABR自波Ⅰ起缺失而DPOAE正常引出,言语分辨力差与纯音听阈不成比例,镫骨肌声反射及OAE交叉抑制异常,纯音听力图多呈上升型以低频损失为主,是听神经病听功能的重要特征。提示病损主要位于耳蜗内听神经纤维。应与一般的感音神经性聋和中枢性聋相鉴别。     

非综合征型听神经病患者前庭上下成分功能障碍定位研究与频率特征

目的 探讨听神经病伴发前庭功能障碍的可能性,并分析其部位和频率特征。 方法 以眼肌前庭诱发肌源性电位(oVEMP)、颈肌前庭诱发肌源性电位(cVEMP)、视频头脉冲试验(vHIT)、头脉冲抑制试验(SHIMP)和冷热试验对20例(40耳)非综合征型听神经病患者进行前庭功能评估,对统计学处理结果进行客观分析。 结果 20例患者(40耳)接受oVEMP和cVEMP测试,oVEMP异常率为85%,cVEMP异常率为95%,差异无统计学意义。11例(22耳)接受vHIT和SHIMP测试,外、上、后半规管vHIT和SHIMP的异常率分别为14%、18%、9%和9%,组间差异无统计学意义。19例患者行冷热试验,异常率为74%。11例接受vHIT和SHIMP测试的患者,冷热试验异常率为82%,显著高于vHIT和SHIMP异常率,差异有统计学意义。 结论 听神经病患者存在前庭功能障碍,前庭上下成分(包括感受器和前庭上下神经)受累概率相当,耳石器和半规管均可受累,各半规管受累概率相当,半规管功能损伤主要累及低频。     

Vestibular function in children with auditory neuropathy spectrum disorder

Objective

Children with auditory neuropathy spectrum disorder (ANSD) account for about 10% of paediatric patients referred for cochlear implantation. Vestibulopathy may be associated with ANSD, and may have implications when formulating management plans in this patient group. We wanted to determine the incidence and predictive factors for vestibulopathy in this patient group to guide vestibular testing in this patient population, and give insight to the aetiology of ANSD.

Methods

We reviewed the outcomes of vestibular function testing in a cohort of paediatric patients with ANSD.

Results

Probable or definite vestibulopathy was seen in 42% of patients who were tested. Vestibulopathy was associated with medical co-morbidities, but was not associated with imaging findings.

Conclusions

Vestibulopathy is relatively prevalent in this patient group, and should be considered when planning the investigation and management of children with ANSD.     

Vestibular nerve functions in children with auditory neuropathy

In disorders affecting the cochlear nerve it is highly probable that the vestibular nerve is involved as well. The caloric test and VEMP (vestibular evoked myogenic potentials) enable a separate evaluation of the inferior and superior vestibular nerve. In the present study we evaluated the inferior and superior vestibular nerves in three children with auditory neuropathy. Electrophysiological tests, VEMP and caloric tests were carried out in these three cases with the preliminary diagnosis of auditory neuropathy. Magnetic resonance imaging was obtained which revealed an intact cochlear nerve in all three patients. The caloric tests were all normal, while in two out of the three cases the VEMP test yielded abnormal results. Since the caloric test may prove abnormal as well, as reported in the literature, it would be valuable to carry out both of the tests in the vestibular evaluation of children with auditory neuropathy, in our opinion.     

Audiovestibular neuropathy in an immunocompetent man with cryptococcal meningitis

IntroductionCryptococcus spp. is a fungus responsible for 600,000 deaths per year worldwide, mainly in immunosuppressed subjects. However, 20% of cases occur in immunocompetent subjects. Neuropathic disorders involving the auditory nerve have been reported, but vestibular disorders have never been described in detail. We report the case of an immunocompetent man, who presented audiovestibular disorders leading to a diagnosis of cryptococcal meningitis.Case reportA 39-year-old man was referred for balance disorders and right sensorineural hearing loss. He presented right vestibulo-saccular impairment and bilateral absence of auditory brainstem responses. Brain MRI was suggestive of cryptococcal meningitis. A cystic lesion in the right flocculus compressed the vestibulocochlear nerve. During monthly follow-up, pure tone audiometry gradually improved and speech audiometry in silence returned to normal. Partial resynchronization of the auditory afferent pathways was observed only on the contralateral side to vestibulocochlear nerve compression, while complete recovery of saccular function was observed.DiscussionCryptococcal meningitis in immunocompetent subjects may be accompanied by lesions of the auditory and vestibular afferent pathways. Recovery of hearing and balance was observed in response to medical treatment and early vestibular rehabilitation.     

听神经病并发的前庭及肢体神经损害

目的 :观察听神经病患者前庭神经和四肢末梢周围神经的受累情况 ,加深对听神经病的总体认识。方法 :对2 8例青少年听神经病患者行前庭功能和神经传导速度检查并分析其结果。结果 :2 8例听神经病中 ,有 2 2例外周前庭功能受损 (78.5 7% ) ,11例肢体末梢神经受损 (39.2 9% )。冷热试验诱发性眼震反应分下列三种类型 :1双侧正常 6例 (占2 1.43% ) ;2双侧减弱 2 0例 (占 71.43% ) ;3单侧减弱 2例 (占 7.4% )。神经传导速度检查结果分四种类型 :1运动、感觉均正常 17例 (占 6 0 .71% ) ;2运动、感觉均异常 4例 (占 14.2 9% ) ;3单独运动异常 4例 (占 14.2 9% ) ;4单独感觉异常 3例 (占 10 .71% )。结论 :影响听神经的病理过程也可以影响其它颅内或颅外的周围神经 (如前庭神经和肢体神经 ) ,听神经病既可以单发也可以并发多种周围神经病。     

Effect of age at cochlear implantation on auditory and speech development of children with auditory neuropathy spectrum disorder

Objective

To evaluate the auditory and speech abilities in children with auditory neuropathy spectrum disorder (ANSD) after cochlear implantation (CI) and determine the role of age at implantation.

Methods

Ten children participated in this retrospective case series study. All children had evidence of ANSD. All subjects had no cochlear nerve deficiency on magnetic resonance imaging and had used the cochlear implants for a period of 12–84 months. We divided our children into two groups: children who underwent implantation before 24 months of age and children who underwent implantation after 24 months of age. Their auditory and speech abilities were evaluated using the following: behavioral audiometry, the Categories of Auditory Performance (CAP), the Meaningful Auditory Integration Scale (MAIS), the Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS), the Standard-Chinese version of the Monosyllabic Lexical Neighborhood Test (LNT), the Multisyllabic Lexical Neighborhood Test (MLNT), the Speech Intelligibility Rating (SIR) and the Meaningful Use of Speech Scale (MUSS).

Results

All children showed progress in their auditory and language abilities. The 4-frequency average hearing level (HL) (500 Hz, 1000 Hz, 2000 Hz and 4000 Hz) of aided hearing thresholds ranged from 17.5 to 57.5 dB HL. All children developed time-related auditory perception and speech skills. Scores of children with ANSD who received cochlear implants before 24 months tended to be better than those of children who received cochlear implants after 24 months. Seven children completed the Mandarin Lexical Neighborhood Test. Approximately half of the children showed improved open-set speech recognition.

Conclusion

Cochlear implantation is helpful for children with ANSD and may be a good optional treatment for many ANSD children. In addition, children with ANSD fitted with cochlear implants before 24 months tended to acquire auditory and speech skills better than children fitted with cochlear implants after 24 months.     

Electrocochleography in auditory neuropathy

Auditory neuropathy (AN) is a disorder characterized by the absence or the severe impairment of the auditory brainstem responses (ABRs) together with the preservation of otoacoustic emissions and/or cochlear microphonic (CM). We recorded transtympanic electrocochleography (ECohG) evoked by 0.1 ms clicks in one young adult and in four children having distortion product otoacoustic emissions and absent ABRs. In all but one patient CM and summating potential (SP) were present with normal threshold, and their amplitudes appeared comparable to or higher than the values obtained from subjects with normal hearing. The compound action potential (CAP) was absent in two patients while in one subject CM and SP were followed by a highly desynchronized neural activity. A broad CAP was found in two children and the threshold appeared clearly elevated in one of them, while it showed only a mild elevation in the other. No correlation was found between CAP and behavioral thresholds. These results suggest that ECohG can be useful in AN diagnoses since it is the only reliable tool in evaluating the auditory peripheral function in the presence of a desynchronized ABR.     

听神经病/听觉失同步化患者的交替短声诱发耳蜗电图

目的 分析听神经病/听觉失同步化(auditory neuropathy/auditory desynchronization.AN/AD)患者交替短声诱发的耳蜗电图特征,探索耳蜗电图在确定听神经病,听觉失同步化病变部位时的应用价值.方法 AN/AD组患者14人,共28耳,所有患者听性脑干反应(ABR)波形缺失或严重分化异常,耳声发射正常:听力正常对照组28人,共35耳.对两组受试者行耳蜗电图(ECochG)检查,使用交替极性短声作为刺激信号.观测AN/AD组和对照组ECochG的波形,并对比:(1)CAP-N1(复合动作电位N1波)的峰潜伏期;(2)-SP(总和电位)和CAP绝对幅度;(3)-SP和CAP幅度比值;(4)CAP反应周值.结果 对照组全部引出分化良好的CAP和-SP.AN/AD组ECochG波形可分为四种类型:(1)可同时引出-SP、CAP,占60.7%;(2)仅有-SP引出,未见CAP引出,占10.7%;(3)仅有CAP引出,占3.6%;(4)-SP、CAP均未引出,占25%.AN/AD组与对照组的CAP潜伏期(P=0.052)无统计学差异;ANIAD组的CAP绝对幅度低于对照组(P<0.001),-SP(P=0.045)绝对幅度、-SP/CAP幅度比(P<0.001)和阈值(P<0.001)高于对照组.结论 在ABR引不出或分化较差时,耳蜗电图是一种比较可靠的评估外周听觉神经功能的方法,在AN/AD的诊断中能够发挥重要作用.     

Incidence of auditory neuropathy among the deaf school students

OBJECTIVE: We aimed to determine the incidence of auditory neuropathy (AN) among the deaf school students that have severe hearing loss. METHOD: All students having severe hearing loss constituting a total of 75 at Deafness school in Afyon Province of Turkey were enrolled in the study. The etiological factors about the hearing loss were determined by performing an individual file survey and by interviewing the teachers and parents. First, all the children were subjected to an otolaryngologic examination. Then, auditory brainstem response (ABR) and transient evoked otoacoustic emissions (TEOAE) tests were done to all students enrolled in the study. RESULTS: The ages of the children were between 6 and 17 (mean age 11.9) and 32 (42.9%) of them were girls and 43 (57.1%) were boys. Three cases (4%) were diagnosed as AN in our study, however, no risk factors were determined in two of them. A history of hearing loss following a vaccination was found in only one patient. CONCLUSION: Our data show that the incidence of AN in the children with severe hearing loss is not negligible. Therefore, our results suggest that automatic ABR should be also used with OAE as a routine application in the neonatal screening programmes, since the solely use of OAE in the neonatal screening programmes may result in the delay of the diagnosis of the children with AN.